Chapter 39: Upper Extremity

Treatment of the injured upper extremity and the appreciation of the severe disability that could result from poor management was the major driving force in the evolution of upper extremity and hand surgery as independent and distinct specialties.

A primary theme was the recognition that many injuries to the upper extremity are combined injuries and that appropriate treatment could best be delivered by someone trained in management of both bone and soft tissue injuries. Today, the successful approach to the treatment of many upper extremity injuries requires microsurgical skills to deal with soft tissue coverage, nerve repair, and revascularization, in addition to fracture care.

One useful way to classify injuries to the upper extremity relates to the amount of energy involved in their generation. Low-energy forces typically cause simple injuries, while high-energy forces lead to complex injuries involving soft tissue and bones that are often associated with joint, neurologic, or vascular involvement. A classic example is a distal radius fracture that typically occurs in two age groups with different mechanisms related to the transfer of energy. A low-energy distal radius fracture typically occurs in an elderly osteopenic woman where the mechanism was a simple fall on an outstretched hand. This usually results in a simple fracture pattern that may best be treated via closed reduction and splinting. A high-energy distal radius fracture, on the other hand, typically occurs in a young healthy and fit patient resulting from a high-speed motor vehicle crash or fall from a significant height. These injuries are associated with swelling of soft tissue, severely comminuted intra-articular shear-type fractures, and several associated potential complications. At first glimpse both scenarios share the diagnosis of “distal radius fracture” and may even seem similar, but it is extremely important to recognize that these two are very different entities. While the low-energy distal radius fracture is simply treated as noted above, the high-energy counterpart should be closely monitored for swelling that may lead to an “acute carpal tunnel syndrome” with subsequent injury to the median nerve, breakdown of soft tissue, and vascular insufficiency. Furthermore, high-energy distal radius fractures will often require surgical treatment including open reduction and internal fixation to restore articular congruency.

Similarly, soft tissue lacerations can be classified as high or low energy depending on the causative agent. A laceration from a sharp kitchen knife to the forearm is to be distinguished from a laceration to the same region caused by a high-speed electrical saw. While they may initially appear similar on presentation in the emergency department (ED), they are quite different. The former may be irrigated and sutured primarily, while the latter requires careful observation due to the late effects of thermal and kinetic energy causing burns of the skin and soft tissue. Skin breakdown with necrosis of the wound edges is typically seen with high-energy lacerations, and recurrent debridements in the operating room may be needed with more complex plastic reconstruction.

It is useful to gather information regarding the mechanism of injury in the initial evaluation and to classify injuries based on whether they were caused by high or low energy. The exact type of mechanism such as blunt, penetrating, lacerating, shear, or degloving and crushing injuries should be elicited, as each of these will deserve specific attention related to the mechanism. Other important components of the history include time of injury, whether the environment was clean or contaminated, whether the injury was work related, the patient’s occupation, hand dominance, and important activities. Finally, a previous history of an injury to an upper extremity should be elicited and any prior functional limitations should be described. Once the airway, breathing, and circulation are stabilized, the physical examination of the upper extremity should focus primarily on the soft tissue components of artery, nerve, and tendon, before focusing on bony injuries.

Circulation can be assessed by observation of the color of the skin and nail bed, skin temperature, and rate of capillary refill after blanching the skin with light pressure. One useful maneuver is to interpret findings by comparison with an uninjured extremity. This approach is useful in the evaluation of unclear x-ray findings, especially in the growing child, also. Arterial insufficiency produces a pale, cool limb with prolonged (>2 seconds) or absent capillary refill and loss of turgor. Venous insufficiency will result in a purple, congested extremity with faster than normal capillary refill. Evaluation of arterial pulses begins proximally with palpation of the brachial artery followed by the radial and ulnar arteries. A manual Allen’s test should be performed when the injury allows. When clinically indicated, confirmation of a positive manual Allen’s test can be obtained using Doppler ultrasound, pulse oximetry, or angiography.

Sensation and motor function should be tested if there is any question of injury to a peripheral nerve. There are three autonomous zones in the hand. The median nerve zone is the index fingertip, the ulnar nerve zone is the small fingertip, and the radial nerve zone is the dorsal side of the first web space over the first dorsal interosseous muscle. More proximally, standard dermatome maps can be utilized. For sensibility, the most useful screening test is light touch perception that can be elicited by gently scratching or tapping the area of interest with a broken applicator stick. A more precise evaluation of distal innervation density can be accomplished by determining static and moving two-point discrimination at the fingertip. At the pulp, normal static two-point discrimination should be less than 6 mm and moving two-point discrimination less than 3 mm. Occasionally, threshold testing with a Semmes-Weinstein monofilament or vibration sensibility evaluation may be indicated.

Motor testing should begin distal to the level of suspected injury. A systematic evaluation of each muscle based on innervation is the ideal (Tables 39-1 and 39-2). In the trauma setting, recreating the maneuvers of rock, paper, and scissors from the childhood game of “roshambo” demonstrates function of the median, radial, and ulnar nerves, respectively. Integrity of the musculocutaneous, axillary, and suprascapular nerves can be grossly evaluated by asking the patient to grasp a cup and simulate drinking. The examination must be interpreted in light of any other soft tissue or bony injuries that might bias the examination.

The minimal x-ray examination includes the anterior–posterior (AP) or posterior–anterior (PA) and lateral views. When dealing with a long-bone fracture, an important rule is to image the entire bone from the joint above to the joint below the injury. Complete evaluation at any articular level, or within the hand itself, usually requires additional views designed to better visualize specific injuries. These may include fluoroscopic motion views and stress views to help diagnose ligamentous instability. More sophisticated x-ray studies such as arthrography, ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) may be important in future surgical planning, but are rarely indicated in the initial management of injury to an upper extremity. A practical guide to some commonly used x-ray views is suggested in Tables 39-3, 39-4, 39-5, 39-6.

When assessing injuries in the upper extremity, it is important to avoid missing secondary problems as described in Table 39-7.

Compartment Syndrome

Compartment syndrome is mentioned due to the importance of early recognition and the devastating consequences of a missed or delayed diagnosis (Fig. 39-1). While compartment syndrome has been described in the arm, it is much more common in the forearm and hand.¹ The forearm is composed of three distinct compartments including the volar, dorsal, and the mobile wad, while the hand has four dorsal and three volar interosseous compartments. After trauma, if acute swelling of the forearm or hand occurs, then one should be suspicious that a compartment syndrome is present (Fig. 39-2). Clinically, pain out of proportion to the clinical findings and pain on passive tendon stretching are probably the most reliable indications to pursue further diagnostic testing or operative treatment. Prompt diagnosis and treatment must be initiated before irreversible ischemic necrosis and tissue damage ensues. Therefore, late findings such as pallor, pulselessness, paresthesia, or paralysis should not be awaited for since their appearance is associated with irreversible damage. If a compartment syndrome is suspected after application of a cast or splint, it should be immediately split to the underlying skin.

At any time, measurement of a compartment pressure is a particularly valuable aid in diagnosis and may be the most useful tool in the unconscious or noncommunicative patient. Controversy still exists over the compartment pressure at which fasciotomy is deemed necessary. Whitesides et al² recommended fasciotomy when the pressure was measured at 10–30 mm Hg below the diastolic blood pressure. Others in the general trauma and vascular community have recommended that the compartment pressure alone be used as a guide for fasciotomy, but this recommendation has varied from 30 to 50 mm Hg in normotensive individuals. Another practical and safe indication to help guide decision making is when the intracompartmental pressure of the affected limb is higher than in the contralateral normal limb and progressively rises above 30 mm Hg. Regardless of which of the above methods is used, once a clinical suspicion arises, it is better to err on the side of early release to avoid devastating sequelae. Muscle damage begins within 4 hours of ischemia and is irreversible by 6 hours. In addition, nerve damage can put distal intrinsic function at risk and further limit reconstructive options.

“Fight Bite” Injuries of the Head of the Metacarpal Bone

It is important to recognize these injuries as they may lead to an intra-articular infection/septic arthritis of the metacarpophalangeal (MCP) joint. Clenched fist or “fight bite” injuries occur when the patient strikes the mouth of another person.³ This most commonly involves the metacarpal head of the long finger because of its prominence in the clenched position. The initial injury may appear quite innocuous; however, all injuries should be assumed to have penetrated deeper structures and to have entered the underlying joint. X-rays are mandatory for these injuries, not only to look for a fracture but to rule out the presence of a retained tooth fragment, also. Even when seen acutely, these injuries should be explored by a formal arthrotomy in the operating room where cultures are obtained and the joint irrigated. It is preferable to enter the joint by taking down the ulnar sagittal band to decrease the possibility of ulnar luxation or subluxation of the extensor hood. Operative intervention should be followed by intravenous antibiotics targeting Staphylococcus sp. for 24–48 hours (see Chapter 18).

Appropriate wound debridement must first be done before adequate soft tissue coverage can be safely provided.⁴ Irrigation with a pressure of at least 7 psi is mandatory. Earlier studies of complex wounds in the lower extremity have shown a clear advantage for wound closure after debridement within 5 days of the injury with regard to flap survival, most rapid time to bone healing, reduced infection, and lowest number of hospital days.⁵ So-called emergency free flaps have been shown to have a high degree of success for complex upper extremity wounds.⁶ While early wound closure is desirable, it depends on the energy of the initial injury, degree of contamination involved, vital structures exposed, and the general health of the patient, as well as the availability of a surgical team. Excessive delay of wound closure results in prolongation of the inflammatory response to wounding, increases the formation of edema, allows joints to become stiff, increases fibrosis around moving structures, and delays hand therapy. Early wound coverage with a flap aborts the extended inflammatory phase of healing that is encountered in chronic wounds and inhibits contraction of the wound. Well-vascularized axial pattern muscle flaps seem to help combat infection, also.⁷ If wound coverage is done late, after granulation has developed, then the inhibitory effect on wound contraction is lost.⁸

Once the wound satisfies the requirements for closure, the reconstructive ladder is borne in mind, and the simplest option that is best suited to both the general condition of the patient and the local requirements of the wound is then selected.

The reconstructive requirements for the upper extremity are listed as follows:

1. Replace missing tissue type with a similar type, for example, thin and pliable soft tissue coverage is required in the hand and fingers.

2. There may be a subsequent or simultaneous need for secondary reconstruction of bone, tendon, or nerve.

3. Flap reconstruction may need to be sensate.

4. The size of the defect must be considered three dimensionally to provide deep volume fill as well as coverage of surface area.

5. Flap reconstruction may be functional and provide motion.

Skin grafts may be suitable for wounds of large surface area that do not expose important structures. In the hand, a more durable wound coverage such as a full-thickness skin graft or flap may be required to cover exposed important structures and to meet the frequent secondary need for later tenolysis and tendon transfers. Full-thickness skin grafts or flaps result in less wound contraction, probably by their effect on attenuating the life cycle of myofibroblasts.⁹ Axial and random pattern flaps may be helpful in covering large wounds, as well.¹⁰ The former is a single pedicled flap with an anatomically recognized arterial and venous system running along its axis. The groin flap was one of the first such axial pattern flaps that was used for resurfacing of the upper extremity, but suffers from the disadvantage of having to keep the arm dependent until it is cut free from the groin pedicle at a later date. Microvascular free flap reconstruction may be more elegant than a groin flap since the upper extremity can remain elevated and therapy might be initiated sooner. Axial flaps, either free or pedicle flaps, may consist of skin only, fascia and fasciocutaneous tissue (such as radial forearm, lateral arm, temporoparietal), or muscle and musculocutaneous tissue (such as latissimus dorsi, rectus abdominis, and gracilis muscles). The radial forearm flap and posterior interosseous flap may be pedicled on the distal blood supply so that venous flow is actually retrograde. Flaps have many advantages over skin grafts¹⁰ in that they avoid wound contraction, fill dead space, cover important structures (such as exposed vessels, bone, tendons, and nerves), help “clean up” infection, enhance vascularity, and provide specific functions (such as a latissimus muscle transfer to restore biceps function).

Extensor Tendons

The extensor tendon is the end organ of a complex mechanism, which involves input from both the extrinsic and intrinsic muscles of the hand to maintain the balanced finger function that is expected by most individuals. Disruption of any component of this balance such as bone, skin, the musculotendinous system, or neurovascular structures can lead to stiffness and a poor functional outcome.

In the evaluation of injury to an extensor tendon, the hand and distal forearm are divided into eight zones that aid in communication and, to a degree, guide treatment. Zone I injuries involve disruption of the extensor mechanism over the distal interphalangeal (DIP) joint resulting in the classic mallet finger deformity. Closed injury results from forced flexion while the finger is in rigid extension. Rupture of the terminal tendon itself or avulsion of its insertion with a variable sized bony fragment results in an inability to extend the distal phalanx. Lacerations or other open injuries, with combined skin and tendon loss, can result in a similar deformity. A closed acute mallet finger should be treated initially by continuous splinting in extension for 6 weeks.¹¹ The splint should not incorporate the other joints of the finger or hand, and active motion of the proximal interphalangeal (PIP) joint should be encouraged. If resisted extension is present at the end of 6 weeks, the splint can be limited to nighttime use for an additional 6 weeks with close follow-up. Any relapse should be treated with 3 weeks of additional continuous splinting. Care must be taken during this prolonged period of splint use that skin maceration and necrosis do not occur. Occasionally, operative fixation by a variety of pinning methods is required for complete healing or to more appropriately manage subluxation of the DIP joint.

Open mallet fingers can present a treatment challenge. Simple transverse lacerations are best treated by mass suturing with incorporation of the terminal tendon and skin with a series of interrupted, nonabsorbable sutures. Fingers with skin and tendon loss require soft tissue coverage and primary tendon grafting or late reconstruction. Emergency treatment consists of irrigation of the open wound/joint, dressing of the wound, antibiotic coverage, splinting in extension, and arranging urgent follow-up in the next 24 hours for surgical evaluation and treatment.

Zone II injuries occur over the shaft of the middle phalanx and are usually associated with a laceration or open fracture. Lacerations involving less than 50% of the tendon width, and with no extensor lag, can be treated by wound care and splinting in extension for 7–10 days, followed by active range of motion. If more than 50% of the tendon is lacerated, or an extensor lag at the DIP joint exists, then the tendon should be repaired followed by splinting or pinning the DIP in extension for 6–8 weeks in a mallet finger protocol. Open fractures with tendon involvement require fracture and tendon repair and extensive therapy to regain range of motion.

Zone III injuries involve the central slip of the extensor tendon over the PIP joint and initially result in loss of extensor power at this joint. Untreated, this injury results in palmar subluxation of the lateral bands and, within 1–2 weeks, development of the classic boutonniere (or buttonhole) deformity. With this deformity, the finger rests in a position of flexion at the PIP joint and hyperextension at the DIP joint. Physical examination will show weak or absent extension of the PIP joint with this injury. With a closed rupture of the central slip, initial evaluation may be difficult due to pain and swelling at the PIP joint. Extension splinting of the PIP joint with follow-up and reexamination at 7 days is a reasonable course of action in this situation. Splinting must not incorporate either the MCP joint or DIP joint. If, at 1 week, findings support the diagnosis of closed rupture of the central slip, then splinting should continue for 4–6 additional weeks with weekly follow-up. Formal therapy is usually required at the completion of splinting to successfully regain full range of motion. Open injury in zone III requires wound management in the form of irrigation and debridement, formal arthrotomy if indicated, and soft tissue coverage if local tissue has been lost. Tendon repair may be primary or may be managed by transarticular pinning for 4–6 weeks to allow the tendon to heal on its own. Second intention healing of the tendon in this area is possible because of the design of the extensor apparatus that prevents retraction if the PIP joint is held in extension.

Zone IV lies over the proximal phalanx, and injury at this level is often associated with a proximal phalangeal fracture. Many tendon injuries at this level are incomplete, due to the broad nature of the extensor hood. Like zone III injuries, even a complete laceration will not result in proximal migration of the tendon due to the constraints of the sagittal bands that tether the severed end.

Lacerations in zone IV will need to be extended to allow complete exploration and primary repair. Early motion in this zone by an active flexion, passive extension protocol is recommended. When zone IV injuries are associated with proximal phalangeal fractures, a stable repair of the fracture will greatly facilitate initiation of early tendon motion.

Open zone V injuries are commonly associated with the “fight bite” wound, and treatment is addressed in the section “Infections in the Hand.” Closed tendon injuries in this zone are less common and usually involve the radial sagittal band, which results in subluxation or luxation of the extensor digitorum communis (EDC) tendon into the ulnar gutter. Splinting may be with the wrist neutral, the MCP joints in extension and the PIP and DIP joints free,¹² or a recently described finger-based sagittal band bridge splint.¹³ If splinting for 6–8 weeks fails, or the injury is seen late, then operative recentralization should be performed.

Zone VI injuries can occur distal or proximal to the juncturae tendini, the tendinous connections between the EDC tendons. Diagnosis and treatment of these injuries are difficult and beyond the spectrum of this chapter, since the finger will still extend at the MP joints via the transmission of the adjacent tendon action through the juncturae. In these situations, exploration may be the only means of diagnosis, short of imaging techniques such as ultrasound or MRI. Proximal retraction of the lacerated tendon will occur. In these instances, exploration in the operating room is probably preferable to exploration in the ED.

Open injuries in zone VI can be associated with extensive loss of soft tissue. Repair of such injuries often requires complex soft tissue coverage with immediate or delayed tendon reconstruction or transfer.

Zone VII injuries to the extensor tendons occur at the level of the wrist retinaculum, where the tendons are divided into six compartments. In this zone, retraction of the tendon ends always occurs, making formal operative exploration imperative. Repair needs to be meticulous to avoid adhesions to the overlying retinaculum that often needs to be expanded by z-plasty during closure. Failure to appropriately repair the retinaculum will result in bowstringing of the extensor tendons at the level of the wrist. An associated injury to the dorsal sensory branches of the radial and ulnar nerves can occur with these injuries and requires a high level of suspicion to prompt exploration and microneural repair. Ignoring these associated nerve injuries can lead to loss of sensation over a portion of the dorsum of the hand and chronic neuropathic pain.

Zone VIII represents the musculotendinous junctions of the extensors. Injury at this level is always associated with penetrating trauma or massive injury to soft tissue, often with an associated open forearm fracture. Initial evaluation of penetrating trauma, usually by glass or knives, may show a relatively small wound that belies the damage that has been caused internally. Even with what appears to be normal extension on examination, significant damage can be found with surgical exploration.¹⁴ Repair of the musculotendinous junction itself is difficult because muscle does not hold sutures well. Large figure of eight sutures are required to restore continuity, and repair should be followed by 4–6 weeks of splinting with the wrist in 20° of extension and the MCP joints in 20° of flexion. If the injury is distal to the posterior interosseous nerve, good restoration of function is possible. Injury to the posterior interosseous nerve requires a thorough exploration and repair by an experienced microneural surgeon to maximize functional recovery. Even with meticulous repair of the nerve, a tendon transfer may be required at a later date. In order to salvage a functionally threatened extremity, a massive combined injury in zone VIII requires application of the principles discussed in the section “Compound, Complex, and Mangled Upper Extremities.”

Thumb Extensor Injury

The thumb represents a unique structure in many contexts including its extensor anatomy. Because the thumb has only two phalanges, the zones are slightly different and often referred to as T I–V. T I and T II are over the only interphalangeal joint of the thumb and the proximal phalanx, respectively. Injuries in these areas can result in a mallet deformity similar to zone I injuries in the fingers. Treatment principles in these thumb zones remain the same as previously described for zone I of the fingers.

T III is over the MCP joint of the thumb and, unlike the fingers, two tendons are vulnerable to injury at this level. The extensor pollicis brevis (EPB) inserts here in the radial aspect of the base of the proximal phalanx, while the extensor pollicis longus (EPL) passes ulnarly and inserts on the distal phalanx. Injury to the EPB at this level can be isolated or associated with injury to the dorsal capsule and radial collateral ligament. Examination of patients with injury at this level should include a thorough evaluation of the stability of the MCP joint and, at surgical exploration, all potentially injured structures should be evaluated and repaired. After surgical repair, both the thumb and wrist should be immobilized.

In T IV, the EPL and EPB tend to become more oval, making them amenable to both core and epitendinous sutures. These two tendons remain closely associated at this level, and, with isolated injury of one tendon, retraction may be prevented by the remaining intact tendon; however, one should be prepared for more proximal exploration, particularly with injury to the EPL.

T V injuries may involve the EPL, EPB, and/or abductor pollicis longus. In addition, injury to branches of the superficial radial nerve is often present at this level. Failure to repair the superficial radial nerve branches can result in not only sensory loss in its distribution but also a syndrome of chronic neuropathic pain.

Flexor Tendons and “Spaghetti Wrist”

Because of its complexity, the treatment of an injury to a flexor tendon is a major component of the history of the development of hand surgery.¹⁵ Today, despite many advances in the surgical treatment of an injury to a flexor tendon and rehabilitation, the care of these injuries remains a significant challenge. Because of the proximity of neurovascular structures at all levels along the course of the flexor tendons in the forearm, wrist, and hand, combined injury of these soft tissue structures is common and adds to the complexity of care.

Examination of the flexor tendons of the fingers and thumb is based on the anatomical relationship of the flexors to specific joint function. In the fingers, both the DIP and PIP joints can be flexed by the flexor digitorum profundus (FDP), a muscle that has its radial component (index and long fingers) innervated by the anterior interosseous (median) nerve and its ulnar component (ring and small fingers) innervated by the ulnar nerve. In contrast, the flexor digitorum superficialis (FDS), which flexes the PIP joint alone, is innervated only by the anterior interosseous (median) nerve. Specific simple maneuvers, however, can be performed to separate FDP and FDS function during examination of the hand. The thumb is flexed predominantly by the flexor pollicis longus, which is innervated by the anterior interosseous nerve and is solely responsible for flexion of the IP joint.

Flexor tendon repair, in general, consists of both core and epitendinous sutures. A number of core stitches have been described and, while all have been shown to be effective when applied correctly, the addition of preformed loop sutures offers several advantages in repair and should be considered for use.¹⁶ These sutures allow easier placement of an increased number of strands, which proportionally increases the strength of the repair allowing earlier and more aggressive therapy.¹⁷

As with injuries to extensor tendons, various zones (I–V) have been defined for injuries to flexor tendons. This classification helps in communication when describing an injury and in determining appropriate treatment and rehabilitation. Zone I injuries involve the insertion of the FDP or FPL into the distal phalanx of the finger or thumb. If the distal stump is less than 1 cm, then suture repair will not be sufficient and the FDP should be advanced and reinserted into the bone. FDP avulsions at this level, often called jersey fingers, occur as three patterns of decreasing severity.¹⁸ Type I avulsions are the most severe and the most easily missed because of lack of x-ray evidence of injury. In this instance, the tendon pulls off the bone and ruptures the vincula within the finger. This allows complete retraction of the proximal tendon into the palm. Early recognition and treatment of this injury is necessary to avoid the need for two-stage tendon reconstruction. Repair can be accomplished early by a pullout button or suture anchor with equal outcome.¹⁹ In type II avulsions, the tendon is held at the level of the vincula, which does not rupture. With a type III avulsion, a large bony fragment is associated with the distal FDP, which causes the tendon to be retained at the level of the distal A-4 pulley. Repair in this instance is often possible by reinsertion using a pullout stitch or fixation of the bony fragment with a Kirschner wire or screw.

Zone II has historically been referred to as “no man’s land” because of the difficulty of rehabilitation with this level of injury.¹⁵ This zone is defined by the presence of the adjacent FDS and FDP within the flexor sheath. Skillful repair with preservation of the pulley system during this repair may require passage of the proximally retrieved end with a small catheter that has been passed from the distal site of the injury. Even when all principles are adhered to, secondary tenolysis may be required due to the development of peritendinous adhesions. Early motion protocols are needed for functional restoration.

Zone III injuries are in the palm between the distal extent of the carpal tunnel and the proximal border of the A-1 pulley. Because this zone is not constrained by the fibro-osseous canal, the prognosis for recovery is markedly improved over an injury in zone II.

Zone IV (within the carpal tunnel) and zone V injuries (distal to the musculotendinous junction) have a high probability of associated injuries to a major vessel and/or nerve. Preoperative examination should include a thorough evaluation of the motor and sensory status of the patient with appropriate documentation. Hemorrhage in these situations can be quite dramatic, but can usually be controlled by direct pressure. Blind clamping or use of a tourniquet is discouraged and is usually unnecessary. Only rarely, with laceration of both the ulnar and radial arteries is the hand truly threatened by ischemia. Collateral circulation through the interosseous arteries will maintain adequate distal perfusion if not obstructed by application of a proximal tourniquet.

Spaghetti Wrist

On the volar side of the wrist there are 16 structures, including 12 tendons, 2 nerves, and 2 arteries in close proximity to the skin. This leaves these structures vulnerable to trauma when the integument is violated. Because of the appearance when the wrist at this level is lacerated resulting in exposure of numerous white string appearing structures, the term “spaghetti wrist” has frequently been applied. Other colloquialisms include “full house wrist” and “suicide wrist.”

Even when this injury is complete, with involvement of both the radial and ulnar arteries, only rarely is circulation to the hand compromised because of the abundant collateral circulation via the anterior and posterior interosseous arteries and dorsal branches from the ulnar and radial arteries. While blood loss may be dramatic, initial hemostasis can often be achieved by direct pressure or brief use of a tourniquet and closure of the skin. These maneuvers should be followed by application of a splint and compressive dressing. Once this is accomplished, if this was a self-inflicted injury, the patient’s inciting cause can be addressed and at least initial postoperative cooperation assured.

Repair of the “spaghetti wrist” is performed in a sequential manner from deep to superficial. This is undertaken in the operating room with tourniquet control. Following a thorough exploration and cataloging of injured structures, tendon repair is usually followed by microscopic nerve repair, and, finally, repair of the ulnar and radial arteries. At this point the tourniquet is decompressed and final hemostasis is assured prior to closure of the skin. An initial dorsal blocking splint with the wrist neutral and the fingers in the intrinsic plus position is applied. A controlled tendon rehabilitation program is initiated as soon as the patient’s cooperation can be assured.

As with most injuries of the upper extremity, the final determining factor in degree of disability in this injury is successful recovery of the injured nerve.²⁰ Both sensory and motor recoveries are required for an optimal result. Factors that affect outcome even with application of modern microsurgical nerve repair are age (<16 years with a better prognosis than >40 years), nerve repair before 3 months, and whether the ulnar nerve is involved. Sensory recovery is usually equal for both ulnar and median nerve injury and repair; however, the failure to recover critical intrinsic muscle function innervated by the ulnar nerve invariably leads to an unbalanced weak hand with significant long-term disability.

All patients who have injuries to the nail bed must have x-rays, and any underlying distal phalangeal fracture is appropriately reduced to improve alignment and splinted for protection. Internal fixation may occasionally be needed. This is generally performed by placing a longitudinal 0.028-in Kirschner wire. These fractures are technically open, and appropriate antibiotics must be administered.

Dorsal Fingertip Injuries

The least severe of these injuries is the nail bed hematoma. If it is seen early, the hematoma can be decompressed by perforating the nail plate after administration of a digital local anesthetic block.²¹ If the nail plate is split, then the nail should be gently removed to examine the underlying nail bed. Many injuries to a fingertip and/or nail bed can be evaluated and treated in the emergency room by simple placement of digital block anesthesia and use of a Penrose drain at the base of the finger to act as a tourniquet. Suture repair of the nail bed after irrigation and cleansing is performed by using loupe magnification and 6-0 catgut suture. Even in a crushing injury, a stellate injury of the nail bed can often be meticulously repaired.

Once the nail bed has been repaired, the thoroughly cleaned nail can be placed back under the nail fold where it serves as a rigid splint for any underlying distal phalangeal fracture and prevents adhesions from forming between the germinal matrix and the nail fold. These synechiae would lead to a future unsightly “split” nail deformity and pterygium formation. If a portion of the nail bed is missing, the undersurface of the nail plate should be examined as the missing nail bed may often still be adherent to the nail. It can then be gently removed from the nail and replaced as a nail bed graft. If a substantial portion of the sterile nail bed matrix is missing, it cannot be replaced by a split-thickness skin graft since the outgrowing nail would not adhere to the surface provided. Such a missing piece of nail bed is best treated by obtaining a split nail bed graft from the adjacent nail or from a toenail bed. For more severe dorsal fingertip injuries, a reverse cross-finger subcutaneous fascial flap as described by Atasoy²² may provide an excellent bed on which to place either a split-thickness skin graft or a nail bed graft. When the dorsal fingertip injury is more extensive, and there is no hope of reconstructing the nail bed, preservation of digit length can still be achieved by use of the more recently described homodigital retrograde-flow intrinsic finger flap.²³ This retrograde vascular flap is based on the extensive “stepladder”-type collateral arterial circulation between adjacent radial and ulnar digital vascular structures. Some fingertip injuries may be so severe that amputation revision is the most sensible functional solution.

Volar Fingertip Injures

Smaller volar pulp injuries without exposure of bone and of a diameter less than 1 cm in an adult are best treated open with soaks and dressings and will heal with excellent cosmetic and functional results.²¹ Larger soft tissue wounds, but still without exposure of bone, may be more appropriately treated with a split-thickness skin graft. If bone is exposed, either flap coverage is required to maintain the length of the digit or the amputation is revised by trimming back exposed bone to accomplish coverage with soft tissue. Once again, a reverse-flow homodigital island vascular flap may provide good soft tissue coverage or a cross-finger flap should be considered.²¹ The cross-finger flap suffers from the disadvantage of a two-stage procedure and unnecessary flexion of the finger that may potentially lead to a flexion contracture of the PIP joint.²⁴ A large V-Y neurovascular homodigital island flap may be considered, especially when the distal amputation of soft tissue is angulated more dorsally.²³

Retained Amputated Fingertip

If the amputated fingertip is retained and is not too severely crushed, reimplantation may be considered. Reimplantation of avulsed tissue containing a large proportion of thumb pulp should always be considered in view of the functional importance. If the amputated part from the thumb has been too severely crushed, then thumb pulp may be reconstructed with a neurovascular island sensate “kite flap” that is based on the vascular branches of the first dorsal metacarpal artery.²³ Another consideration for reconstruction of the volar pulp of the thumb is a microvascular medial toe pulp transfer.²⁵

For fingertip amputations, a simple revision of the amputation may be an option in spite of the patient bringing in the amputated tip or replantation may be considered. Replacement of the fingertip simply as a composite graft after removing distal bone may at least suffice as a biologic dressing for the healing fingertip even if it were to fail. As there is a high incidence of tissue necrosis with fingertip composite grafts, an alternate solution is to retain the perionychial tissues as a full-thickness graft and to reconstruct the volar pulp support with alternative measures such as one of the local flaps already described.²⁶

These injuries to the hand are relatively uncommon, but the consequences of a misdiagnosis are very serious.²⁷ High-pressure injection guns are found in industrial settings and are used for painting, cleaning, and lubricating. Potential injected materials include paint, paint thinner, oil, grease, water, and plastics. The injection is most frequently at the level of the DIP joint of the nondominant index finger that is directly opposite to the nozzle of the injection gun. High-pressure injection guns generate pressures ranging between 3000 and 12,000 psi. A pressure of 100 psi is sufficient to penetrate the skin. In addition to injection guns, these injuries may result from other sources such as pneumatic hoses and hydraulic lines.

The type of material injected is the most important prognostic factor. Oil-based paints and paint thinners can generate significant inflammation and fibrosis. The injectate will generally enter the tendon sheath and flow down its path into the hand. X-rays are often helpful in determining the extent of dispersion of the injected material. Non-lead-based paints may appear as subcutaneous emphysema, grease may be lucent, and lead-based paints may be seen as radiopaque densities in soft tissue. Antibiotic prophylaxis is started, and incisions are made to decompress the affected part and to enable extensive exploration and debridement of injected material. Wounds are either closed loosely over Penrose drains or left open to be closed in a delayed manner. Despite recognition and treatment, many of these injuries can still ultimately result in surgical amputation of the affected digits.

Frostbite

The management of frostbite consists of restoring core body temperature by rapid rewarming of the frozen extremity in a 44°C water bath. Active hand therapy must be instituted, also. Ibuprofen may be helpful and has been recommended for potential prevention of frostbite injuries prior to cold exposure such as on mountaineering expeditions. Thrombolytic therapy using tissue plasminogen activator (tPA) early in treatment has recently emerged as a modality to save digits and limit the extent of subsequent amputation. It is important to avoid premature amputation, as demarcation and mummification of digits may take as long as 2–3 months. If a disabling vasospastic syndrome persists as a chronic problem following an occult cold injury, digital sympathectomy may be helpful.²⁸

Many follow the therapy protocol described by McCauley et al.²⁹ On completion of rewarming, the protocol is as follows:

1. White blisters are debrided, and topical aloe vera is applied every 6 hours in order to prevent the synthesis of thromboxane.

2. Hemorrhagic blisters are drained but left intact to prevent desiccation of the underlying dermis, and topical aloe vera is applied every 6 hours.

3. The injured part is splinted and elevated in order to minimize edema.

4. Tetanus prophylaxis is given as appropriate.

5. Intravenous narcotics may be utilized.

6. Oral ibuprofen is given in a dose of 400 mg every 12 hours to inhibit the eicosanoid cascade.

7. Penicillin G is administered intravenously in a dose of 500,000 U every 6 hours for 48 hours to potentially decrease streptococcal infection during the edema phase.

8. Daily hand therapy is instituted to provide both active and passive range of joint motion.

   (This protocol was suggested prior to recent research on tPA, and the surgeon may consider adding tPA to this regimen.)

The long interval from initial injury to definitive debridement and reconstruction may subject patients to increased risk of local infection and may cause great psychological stress and inconvenience for the patient. The initial use of radioisotope scans has been helpful in predicting the need for future amputation.³⁰ A triple-phase technetium (Tc-99) bone scan is performed within 48 hours of rewarming for all but the most superficial frostbite injuries. Patients with an absent early blood pool phase on scanning as well as no bone uptake are restudied 72 hours later. If the second scan does not demonstrate significant blood flow, then mummification and amputation are highly likely. Based on these findings the following protocol for deep frostbite injuries using technetium bone scans has been recommended. A triple-phase bone scan is performed at 48 hours and then at 5 days. If there are normal blood and bone pool images, then one proceeds with expectant observation. If there are diminished but visible blood pool images, then continued observation is undertaken with delayed debridement if necessary. If there is little or no flow in either blood or bone pool images, early debridement or amputation is recommended with potential salvage with vascularized tissue.³¹

Chemical Burns

Chemical burns may affect hands and upper extremities in the industrial environment. The most important part of treatment is water lavage that must be started at the scene of the accident and is continued for 1–2 hours for acid burns and even longer for alkali burns. General principles of chemical burns follow those of thermal burns, but there are some specific therapeutic antidotes for chemicals.³²

If massive water lavage is not immediately available, then reducing agents such as hydrochloric acid will only be diluted if small amounts of water are available. Under such circumstances the agent must be neutralized with soap or soda lime. Hydrofluoric acid is a common ingredient in rust removers and degreasers and causes hypocalcemia and hypomagnesemia with a burn greater than 5% of body surface area. Immediate water lavage is required followed by subdermal injection of 10% calcium and gluconate. This can be painful if it is not combined with local or regional anesthesia. More recently, calcium carbonate gel has been used for topical application instead of the injection therapy. In contrast, phenol is not water soluble and requires specific treatment with topical polyethylene glycol (PEG 400) followed by water lavage. Treatment of white phosphorous burns chiefly involves water lavage followed by identification and excision of any remaining phosphorus particles. A 1% copper sulfate irrigation solution helps identify these particles, and this is followed immediately by water lavage to avoid the toxic effects of the copper sulfate. Sterile debridement then follows.

Electrical Injuries

When contact with high voltage occurs, it is usually established by an arc that is a hot, electrically conducting gas. Ten to 20 kV is required to establish an arc of a distance of 1 cm. Arcing also occurs across joint flexion creases such as the elbow. Current flow begins when a complete circuit is made. The hand and upper extremity are the most common body parts affected by electrical injuries since this is often the contact area for electrocution. The arc is intensely hot, usually in the range of 5000–20,000°C.

In the body, current is carried by electrolyte ions in solution. Current density is highest at the contact points and rapid conversion to heat occurs, leading to the deepest burns at the entrance and exit wounds. As the current enters the deeper tissues, it spreads out in proportion with the conductance of the tissues. Injuries result both from the heating and from the direct electric forces acting on larger cells. The latter results in excessive charging of the cell membrane, high transmembrane potentials, and subsequent membrane electroporation.³³ Tissue adjacent to bone appears to be damaged more severely since cortical bone is denser than soft tissue and may thus store the heat generated from the adjacent soft tissue. The heat is returned to the surrounding tissue later. Due to electroporation and deep tissue heating, the damage caused is often nonuniform and difficult to interpret clinically. Electroporated muscle appears viable on gross inspection for hours and, coupled with subsequent damage from tissue reheating, initial diagnosis of the extent of the tissue undergoing necrosis remains problematic.

High-tension electrical injuries are devastating, and a compartment syndrome may result. Not only is there a conversion of electrical energy into heat that causes coagulation necrosis of tissues, but thrombosis of blood vessels may lead to further necrosis of tissue.³⁴ Rhabdomyolysis may lead to myoglobinemia and myoglobinuria and possible renal failure. There may be coexistent problems such as cardiac arrhythmias, spinal fractures due to tetanic muscular contractions, other skeletal injuries, serum electrolyte derangements, and blast trauma. Because peripheral nerves are very sensitive to electrical injury, even minor electrical trauma may cause a temporary dysfunction.

Once the patient has been stabilized, attention is directed toward debridement of clearly necrotic parts, preservation of residual function, and soft tissue coverage of open wounds (especially of exposed vital structures) to prevent infection. Also, forearm and hand fasciotomies may be required early in the treatment of electrical injuries to the upper extremity.³⁵ One might use temporary soft tissue coverage with porcine or artificial skin substitutes, but, once the viability of the remaining tissue has been established, fasciocutaneous flaps or microvascular free flaps will close wounds and salvage the injured extremity.^36,37 Occasionally, survival of the patient and the best functional outcome may mandate an early amputation of the proximal limb.

Postoperative care will include physical therapy and, possibly, fitting of a prosthesis. Successful rehabilitation may require tendon transfers, transferring of innervated muscle, or even toe transfer for missing digits. The upper extremity is involved in about 80% of all electrical injuries, amputation rates range between 40% and 70%, and mortality ranges from 8% to 14%.³⁸

Thermal Burns

Treatment of major burns and resuscitation is outside of the scope of this chapter (see Chapter 48) that will focus only on the management of a burn in the upper extremity. Initial first aid for hand burns requires immediate cooling of the wound by rinsing in cold water for 5–10 minutes. This helps reduce subsequent edema formation, also.²⁹ Capillary refill must be documented to decide upon the need for an escharotomy or fasciotomy. Full-thickness circumferential burns of an upper extremity frequently require an escharotomy.³⁹ Fasciotomy for the interossei and the first web space should be performed in situations of severe edema of the hand.⁴⁰

The hand often assumes the intrinsic minus posture because of swelling. The wrist is drawn into flexion with hyperextension at the MCP joints and flexion at the proximal and distal IP joints resulting in a claw deformity. The thumb adducts toward the palm, and the interphalangeal joint is hyperextended.³⁴ Appropriate early splinting is necessary to overcome this posture in the severely burned hand. Splinting in the intrinsic plus position places the ligaments of the digital joints in maximal stretch and minimizes their shortening. Customized thermoplastic splints are effective and can be adjusted easily.

Local wound care depends on the depth of the burn. Partial-thickness superficial second-degree burns are expected to heal within 7–14 days. Larger blisters may be aspirated or removed by incision and debridement. Moist wound healing is required for the wound to heal spontaneously. The burn wound is cleaned daily, followed by the application of an antibacterial cream. As epithelialization occurs, a bland ointment is helpful to prevent desiccation of the newly formed epithelium.

Deep dermal and full-thickness burns of the hand are best treated by early excision and grafting. A burn wound is uninfected initially and suitable for primary surgical treatment during the first 5 days. Tangential excision is performed down to punctate bleeding. Blood loss can be minimized by use of an upper arm tourniquet. Exsanguination of the arm by simple elevation rather than by wrapping with a rubber bandage will still enable the surgeon to determine the appropriate depth of tangential excision and visualization of punctate bleeding. Residual devitalized tissue must not be left behind as this could be a cause of failure of a skin graft. Resurfacing the wound with a split-thickness skin graft is then immediately performed.⁴¹ Skin grafting is rarely necessary for palmar burns due to its capacity for spontaneous healing from the skin appendages at this site. A full-thickness burn, however, may occasionally lead to exposure of tendons, bones, and joints. In this situation primary coverage of soft tissue by regional flaps or even free flaps may be required. It has been found that fascial flaps are very useful to provide coverage of dorsal hand wounds since cutaneous flaps may be too thick. Suitable fascial flaps include temporoparietal, serratus anterior, or anterolateral thigh.⁴²

After a skin graft is placed, the hand is immobilized for 5 days until healing of the graft has occurred. Passive and active hand therapy is then initiated to reduce stiffness and contractures. Once again, the importance of appropriate postoperative splinting should be emphasized. In the first few months following the burn injury, there is a period of scar hypertrophy. This scar tightness is overcome with range of motion exercises of the joints. An important adjunct to management of the scar is having the patient use a custom-fitted elastic pressure garment that should be initiated as early as 2–3 weeks after skin grafting. Pressure garments may be required for as long as 6 months, while secondary surgical procedures for release of contractures may be required at a later date.

A vascular injury can occur with either closed or open trauma (see Chapter 41). Closed injuries associated with arterial disruption include scapulothoracic dissociation, shoulder dislocation, and elbow fractures and dislocations. A scapulothoracic dissociation represents a complex injury with a high incidence of both vascular disruption and concurrent rupture or avulsion of the brachial plexus. Successful treatment requires prompt diagnosis, preoperative angiography, and reconstruction of the axillary or brachial artery with an interposition graft.⁴³

Despite the frequency of shoulder dislocations or fractures, an associated arterial injury remains a relatively rare complication. Anterior dislocation in the elderly patient is the most common scenario where vascular injury occurs with blunt shoulder trauma. Predisposing atherosclerotic disease with a more tortuous and noncompliant artery may play a role in this injury, and the injury is just as likely to occur during relocation for the same reasons. Because of this, the distal vascular status should be assessed prior to reduction of any anterior dislocation.

Supracondylar fractures in children infrequently involve the brachial artery; however, the extension-type fracture with posterolateral displacement of the distal fragment and wide separation can result in injury to this vessel. The ischemia present after this injury can be caused by direct impingement from the medial spike, secondary to vascular spasm and progressive soft tissue swelling, or thrombosis of the distal brachial artery. When vascular trauma is suspected, a gentle closed manipulation of the fracture and percutaneous pin fixation should be followed by a repeat clinical examination. If distal pulses do not return with reduction, then angiography should be obtained. A surgical release of the artery from entrapment in the fracture or a formal vascular repair may be needed.

An open injury with pulsatile hemorrhage in the upper extremity should be managed initially with pressure alone, whenever feasible. Blind clamping and ligation can lead to devastating injury of closely associated nerves that can result in a successfully revascularized, but worthless limb. With such injuries to nerves multiple procedures may be needed to restore less than satisfactory function. Similarly, use of the tourniquet should be limited to avoid contributing further to ischemic damage from occlusion of collateral flow. Once hemorrhage is controlled, few would argue that prompt surgical repair of a subclavian, axillary, or brachial artery injury is indicated. Less obvious is the treatment of a single-vessel injury in the forearm. Many have argued that, with documentation of adequate collateral flow from the remaining artery, it is more expeditious to ligate the injured vessel. With improvements in microvascular surgery, however, repair of arteries this size has become quite straightforward and the procedure itself adds little time to an exploration of the wrist or forearm where other associated injuries are being addressed.

Treatment of injury to a peripheral nerve represents a major component of upper extremity surgery, and the end result of the care of this injury is often the major determinant of the degree of functional recovery. A nerve injury should be looked for with a high level of suspicion based on the anatomical location of injury to the extremity. Furthermore, serial examinations over the course of the patient’s recovery are warranted. Also, if surgery is planned to deal with other injuries, the opportunity for direct exploration of known at-risk nerves in the zone of injury being addressed should not be missed. This is particularly indicated in the presence of sharp penetrating trauma.

The terms neurapraxia, axonotmesis, and neurotmesis are commonly used to describe different degrees of the continuum of injury to a peripheral nerve, and each term correlates with the potential for recovery. Neurapraxia, the most minor form of injury, represents a conduction block with preservation of anatomical continuity. The neuropraxic injury may be complete or partial and, although recovery will be complete, it may take up to 3 months. Importantly, there is no nerve regeneration involved in this recovery and there is no advancing Tinel’s sign as there is no axonal involvement. It should be remembered that a neuropraxic injury can be associated with a concussive blow or a compressive injury such as a promptly released compartment syndrome or a tourniquet-type injury, as well.

In axonotmesis there is structural damage to the axon while the endoneurium and perineurium remain intact. A Tinel’s sign is present in this form of injury, and it can be followed during recovery as it progresses distally with axonal regrowth. In this injury, there is classic histological Wallerian degeneration distal to the site of axonal disruption. Because the axon sheaths remain essentially undisturbed, complete restoration of the original pattern of innervation is possible.

Neurotmesis represents complete severance of the nerve from traction, rupture, or penetrating trauma. Recovery in this situation is not possible without microsurgical repair.

In large nerves it is possible to have all forms of injury present within the same nerve. This situation can complicate both initial diagnosis and interpretation of recovery as well as delay and complicate surgical intervention.

Surgical interventions with injury to a peripheral nerve include decompression, neurolysis, direct repair, and nerve grafting.⁴⁴ In complex injuries involving multiple nerves or nerve segments, all these techniques may be required. Direct nerve repair may be by epineural or fascicular suturing. While fascicular repair intuitively seems like it would give more precise anatomical alignment, this has never been substantiated and the principle of less is more seems to apply. Minimal foreign material in the form of suture, minimal or no tension, and minimal trauma are required for a successful repair. When a tension-free repair is not possible, a nerve conduit in the form of an autogenous nerve graft or a vein or artificial conduit for a short segment replacement must be utilized to fill the defect and serve as a guide for new axonal growth. A number of sensory nerves can be sacrificed with minimal deficit, but the most common is the sural nerve from the lower leg.

Timing of nerve repairs can be defined as primary when repaired within 1 week of injury, while nerve repairs after this time are considered secondary. Direct end-to-end tensionless suture neurorrhaphy may not always be possible in the case of secondary repair, and one should be prepared for interposition grafting or employment of other techniques to achieve successful reinnervation.

In general, nerve injuries associated with sharp penetrating trauma should be explored early. If the injury is a sharp laceration, immediate direct repair is usually the best option for optimal recovery. When the precise zone of injury to the nerve cannot be determined, as after a traction or crush injury, a delayed repair is indicated so that the zone of injury is more clearly defined. Simple tagging of injured nerves at the time of exploration in itself probably serves no useful purpose since the experienced peripheral nerve surgeon will readily locate the injured nerve proximal and distal to the injury at the time of reexploration. Suture tagging the nerve to a stable adjacent structure, however, may serve to prevent the inevitable retraction and minimize the distance that requires grafting at the time of definitive repair.

An exception to early exploration of penetrating injuries is the gunshot wound. In these injuries the mechanism of injury includes heat and shock wave effects, and expectant management is usually appropriate. A vascular injury where the vessel is enclosed with the nerve in a common sheath, however, may lead to similar injury to both the nerve and vessel. In these situations, it is imperative that continuity of the nerve is verified during repair of the vessel.

Nerve transfer represents another option for dealing with both motor and sensory losses in what potentially would be a nonreconstructable injury.⁴⁴ The theory behind nerve transfer is to convert a high-level nerve injury into a low-level injury. This is accomplished by utilizing redundant or unimportant nerves or fascicles of the donor nerve to innervate critical motor or sensory targets. Initial experience with this concept was in brachial plexus surgery with the now classic intercostal to musculocutaneous nerve transfer to restore elbow flexion. This technique has now been expanded in brachial plexus neurotization to a number of nerve transfers with specific functional targets and more recently to reconstruct a number of other injuries to nerves.

An important example of a nerve transfer outside of the brachial plexus is the transfer of the distal anterior interosseous nerve to the motor branch of the ulnar nerve to restore intrinsic function. This gives a very simple functional alternative to complex tendon transfer and preserves muscle mass within the hand resulting in a more cosmetic outcome.

Brachial Plexus Injury

Brachial plexus injuries most often occur in young active males participating in extreme sporting activities or involved in high-speed motor vehicle crashes. This is a devastating injury that frequently leads not only to physical disability but to psychological distress and socioeconomic hardship also. This injury is initially overlooked with some frequency when the surgical team is caring for the polytrauma patient with more obvious life-threatening injuries. Even when detected, treatment historically has been delayed in hopes of some type of spontaneous functional recovery. This delay is largely unjustified today and is now known to potentially compromise future reconstructive options.

Common terms used to describe injuries to the brachial plexus are root rupture, root avulsion, preganglionic, postganglionic, supraclavicular, and infraclavicular.⁴⁵ Supraclavicular injury refers to injury of the spinal nerves, trunks, or divisions, while infraclavicular injury refers to injury of the cords and their terminal branches. When an injury causes tearing of the rootlets from the spinal cord proximal to the dorsal root ganglion, the injury is classified as preganglionic or a root avulsion. If an injury is distal to the dorsal root ganglion, it is called a postganglionic injury. This type of injury is often associated with rupture of the root.

There are practical implications to determining a lesion to be preganglionic or postganglionic. At this time a preganglionic injury is not amenable to direct surgical repair and, therefore, alternate means of functional restoration must be explored. In contrast, postganglionic injuries can potentially be restored by insertion of an interposition nerve graft. Importantly, there are features in the history and clinical examination that can indicate a preganglionic versus a postganglionic injury. Horner’s syndrome is characterized by ptosis, miosis, anhydrosis of the cheek, and enophthalmos and suggests a preganglionic avulsion of C8 and T1. Winging of the scapula suggests a preganglionic avulsion of C6, as the serratus anterior muscle is supplied by the long thoracic nerve that arises predominantly from the anterior division of C6 close to the intervertebral foramen. Inability to move the scapula medially indicates rhomboid muscle dysfunction and is indicative of a C5 avulsion with compromise of the dorsal scapular nerve. This motion can be evaluated by asking the patient to attempt to bring the elbows together behind the back with the hands resting on the hips.

Postganglionic injury occurs at points of tethering of the plexus to surrounding structures. Erb’s point where the suprascapular nerve comes off the upper trunk is a common and historic site of postganglionic injury. Rupture of C5 commonly occurs from the previously described fascial attachments from the transverse process. As they are particularly strong at this segment, this anatomical feature may help preserve C5 for grafting when other roots have been injured by avulsion. The suprascapular nerve is also confined at the suprascapular notch and can be injured with upward displacement of the scapula during trauma. Injury to a clavicle can result in injury to the brachial plexus at the level of the divisions where they are relatively immobile. The axillary nerve is tethered both at its point of takeoff from the posterior cord and as it passes through the quadrangular space and is vulnerable to injury at both these points.

Advances in ancillary diagnostic tests have paved the way for early surgical intervention. When used appropriately, the combination of electrodiagnostic studies, CT myelography, and, occasionally, MRI can, when coupled with clinical findings, determine that significant recovery is not possible without surgical intervention.

Nerve conduction studies (NCS) and electromyography (EMG) are the primary electrodiagnostic studies that can aid in the evaluation of a patient with a brachial plexus injury.⁴⁶ With a nerve injury other than neuropraxia at 48–72 hours following injury, the axons distal to the lesion begin to undergo Wallerian degeneration and lose the ability to conduct. Unfortunately, it may take as long as 4–6 weeks after injury before fibrillation potentials that indicate muscle denervation are detected by EMG. NCS can be utilized to help differentiate between preganglionic and postganglionic injuries by evaluating the sensory nerve action potential (SNAP). This is possible because of the previously described location of the dorsal root ganglion outside the spinal cord proper. With a root avulsion the electrical circuit involved in SNAP recordings remains intact, whereas the ganglion circuit is disrupted with rupture distal to the dorsal root. This information can be extremely valuable both preoperatively and intraoperatively when trying to determine whether a root remains accessible for grafting. In practice, electrodiagnostic studies should be initially performed at 4–6 weeks post-injury.

Both CT and MRI have a place in the evaluation of brachial plexus pathology^45,47; however, CT myelography remains the “gold standard” for demonstration of root avulsion in the setting of a traumatic brachial plexus injury. MRI, while being the preferred modality for compressive lesions or other nontraumatic brachial plexopathies, still suffers from too much motion artifact generated by pulsations of the cerebrospinal fluid. Therefore, it does not consistently demonstrate root avulsion and aid in surgical planning. Early CT myelography timed to coincide with the initial electrodiagnostic studies can allow for surgery within 2–3 months of injury, if not sooner. If these initial studies at 4–6 weeks are consistent with an in-continuity injury, then follow-up electrodiagnostic testing should be performed 6 weeks later to evaluate for evidence of reinnervation. This second study is still within the 3-month time frame for early aggressive intervention if indicated.

While still a devastating injury, advances in the last 20 years have significantly improved the prognosis for some degree of functional recovery with trauma to the brachial plexus. Surgical options include neurolysis, nerve grafting, and neurotization.

Neurolysis is the surgical technique of freeing intact nerves from scar tissue. With trauma to the brachial plexus, this technique is rarely a definitive treatment. More often neurolysis is an incidental technique that occurs during reconstruction of the plexus by nerve grafting or neurotization.

Prior to undertaking nerve grafting or brachial plexus neurotization, prioritization is essential. It is generally agreed that elbow flexion is the most important function to restore followed by active shoulder control and scapular stabilization. Triceps control through restoration of radial nerve function may be achievable, also. Restoration of useful median and ulnar nerve function by nerve surgery alone, however, is probably not a realistic goal.

Nerve grafting requires a suitable lead-in nerve source. C5 and C6 may serve this purpose even when a global brachial plexus injury is present. Grafting from these sources is targeted toward the above-listed priorities via the suprascapular nerve and posterior division of the upper trunk to allow for control of the shoulder. When only minimal suitable lead-in nerves are present, further supplementation via nerve transfer will be required for elbow flexion. The classic transfer for this additional function is the aforementioned intercostal nerve transfer directly to the musculocutaneous nerve.

While the above approach has led to significant functional recoveries, it now needs to be weighed against more modern options. These include nerve grafting in conjunction with more aggressive nerve transfers utilizing the terminal branches of the spinal accessory and phrenic nerves. This can be performed in conjunction with functional free muscle transfers with one or two gracilis muscles revascularized and reinnervated via microsurgical techniques.⁴⁸ These aggressive techniques have led to successful restoration of simple grasp, a previously unheard of functional restoration.

While the focus of this review has been closed injuries, penetrating trauma accounts for 10–20% of injuries to the brachial plexus. These injuries are often infraclavicular and cause a more selective loss of function. Sharp, penetrating injuries are often associated with a vascular injury that should be addressed with extreme care to avoid injury to the adjacent nerves. The plexus should then be explored by a surgeon with expertise in peripheral nerve injuries.

Gunshot wounds present a more difficult dilemma.⁴⁹ In the instance of a vascular injury requiring surgical exploration, the plexus must also be explored and any injuries identified. Acute repair is probably not indicated since the zone of injury to the nerve will be poorly defined, and this could cause an inadequate resection and failed grafting. Exploration at 6 weeks post-injury is recommended since nerve transection has been confirmed and there is no hope of spontaneous recovery. Gunshots without an associated vascular injury may be managed expectantly with serial examinations and sequential electrodiagnostic examinations at 6 and 12 weeks post-injury. If no recovery is detected at 12 weeks, then exploration is probably indicated.

Infection is a common occurrence in the hand with most organisms introduced by direct inoculation via puncture, laceration, open fractures, or bites (see Chapter 18). The apparent vulnerability of the hand to infection is probably related to the multiple anatomical closed spaces present. Untreated infection in these spaces can lead to severe damage and ultimately diminished or lost function. A careful history is important to determine not only possible accidental trauma but also other predisposing factors such as an immunocompromised state or intradermal or intravenous injection of illicit drugs.

Despite a variety of initiating causes, the infection itself is usually caused by common gram-positive flora to the skin and mouth such as Staphylococcus sp. and Streptococcus sp. Exceptions to this occur in patients with diabetes mellitus or those who are intravenous drug users where gram-negative organisms are frequently encountered.⁵⁰

Physical examination will often reveal erythema, warmth, tenderness, and swelling, as well as restricted function. Lymphangitic spread may be observed proximal to the site of infection. Careful palpation should detect areas of fluctuance that would require surgical drainage as opposed to monitored antibiotic treatment alone.

The most common infections of the hand are paronychias and felons. Paronychias, or nail fold infections, occur when bacteria gain entrance through a break in the seal between the nail and fold. Nail biting and excessive manicuring may predispose to this infection. If cellulitis is present, soaks and antibiotic therapy targeting Staphylococcus species may lead to resolution of the infection. Once fluctuance is noted under the nail fold, surgical drainage is indicated. A simple approach to drainage is to sharply elevate the nail fold from the nail plate in the region of the fluctuance. If any dissection of purulence is noted under the nail at this time, then the involved portion of the nail plate or the entire nail plate should be avulsed to allow complete drainage.

A felon is an abscess of the fingertip pulp that is confined by many fibrous vertical septa that secure the relationship between the bony tuft and overlying skin. When undrained, this infection will ultimately liquefy the pulp fat and lead to malformation of the tip of the finger. Surgical drainage is always indicated once an abscess has developed, and a number of incisions have been advocated. A straight midaxial incision on the nonopposition side of the finger is preferred unless the abscess points volarly. In this instance, a straight longitudinal midline volar incision is acceptable.

Suppurative flexor tenosynovitis represents an infection of the flexor tendon sheath, another confined space of the hand. This condition is usually diagnosed clinically and has the characteristic signs of partially flexed resting posture of the finger, pain with passive extension, fusiform swelling of the entire finger, and volar tenderness along the course of the flexor sheath. Delayed treatment of this condition can lead to scarring of the tendon or necrosis and, in the small finger and thumb, development of a horseshoe abscess because of the anatomical communication through the radial and ulnar bursa.

Treatment with antibiotics alone is rarely successful for these infections unless initiated early after the onset of symptoms. Furthermore, it is difficult to advocate medical management because of the severe sequelae associated with a delay in definitive care. Early surgical intervention with open or closed irrigation of the sheath remains the “gold standard.”⁵¹

Interdigital infection of the web space (collar button abscess) and infections of the palmar space represent two additional infections of closed spaces that mandate prompt surgical intervention. The term “collar button abscess” refers to the hourglass shape of the abscess that occurs in a web space infection and its resemblance to the collar button used in dress shirts in the 1900s. Inspection of the hand in this instance will usually show an associated fissured callus at the involved web space and the two adjacent fingers in abduction. Physical examination will reveal tenderness and palpable swelling both dorsally and volarly. Because of this, dorsal and volar drainage is required through separate incisions that do not carry across the web space.

The palm has three distinct anatomical spaces, all of which may become infected. These are the thenar space, midpalmar space, and hypothenar space. Of these, the thenar and midpalmar spaces are most frequently affected by a suppurative process. Patients with these infections almost always have a history of penetrating trauma with or without retention of a foreign body. On inspection, the hand will be swollen and erythematous volarly and will be exquisitely tender to palpation. If doubt exists as to the presence of an abscess versus cellulitis, aspiration or an ultrasound examination may be performed. As with suppurative flexor tenosynovitis, the severe sequelae of a delay in treatment means that a negative aspirate should not rule out the need for surgical exploration. As in all infections, routine x-rays should be obtained to rule out the presence of radiopaque material prior to exploration.

Bite wounds from dogs and cats often serve as the source of bacteria responsible for the above-described closed space infection.⁵² Whether prophylactic antibiotics can prevent this infection when initiated early has been the subject of a great deal of research. It would appear that there are good prospective data to support the routine use of prophylactic antibiotics in human bite wounds. While retrospective data support antibiotic use in dog and cat bites, no similar prospective data exist.⁵³

Sternoclavicular Dislocation

Sternoclavicular dislocation is a rare, high-energy injury. The clavicle typically dislocates in an anterior direction, but posterior dislocations do occur and are more commonly associated with damage to surrounding structures in the neck and chest. Careful assessment of the patient is warranted, with particular attention paid to these structures. Plain x-rays are often difficult to interpret, but the injury and direction of displacement are generally identifiable on some views or on a CT. If performed early and with general anesthesia, closed reduction is usually successful, but residual subluxation may persist when an anterior displacement has occurred. Correction of posteriorly displaced injuries may require a towel clamp or similar instrument to obtain reduction. It is important that a thoracic surgeon is available at the time of reduction to assess and address any injury to the associated structures. Later referral to a peripheral nerve surgeon may also be required.⁵⁴

Scapulothoracic Dissociation

Scapulothoracic dissociation is a rare but functionally devastating and potentially life-threatening injury that represents a closed amputation of the upper extremity. This should be suspected when the scapula appears laterally displaced on a nonrotated anterior–posterior (AP) chest x-ray (Fig. 39-3). Other clinical signs suggestive of scapulothoracic dissociation include massive shoulder and arm swelling, reduced or absent pulses, diffuse weakness or paralysis, cold and blue mottled arm, and a positive Horner’s syndrome. CT or MRI findings may confirm the diagnosis and identify damage to the surrounding soft tissues, as well. An unusual intrathoracic variant can occur, in which the inferior angle of the scapula penetrates an intercostal space and becomes lodged within the chest. This musculoskeletal injury is often accompanied by injury to the subclavian artery and brachial plexus. Emergent surgical treatment may be required to revascularize the upper extremity. Simultaneous exploration of the plexus after the vascular repair is strongly recommended to accurately access the degree of neurologic injury. If vascular exploration is not done, MRI is used to assess the degree of brachial plexus injury. If a global injury to the brachial plexus is detected at this initial exploration, consideration should be given to primary amputation, as the chance of meaningful neurologic recovery is minimal.^55,56

Acromioclavicular Dislocation

A “shoulder separation” is a common diagnosis, especially among athletes. Injury to the acromioclavicular (AC) joint typically occurs due to a fall onto the acromion. Stability of the AC joint is dependent on both the AC and coracoclavicular (CC) ligaments. The severity and classification of the injury is based on which of these structures is injured and to what degree (Table 39-8). X-rays are often normal in mild injuries and, although they may confirm the diagnosis, stress x-rays are rarely indicated.

Some still consider type III injuries a relative indication for surgical treatment, but most orthopaedic surgeons recommend initial nonoperative treatment for all type I–III injuries.^57,58 This typically consists of yearly range of motion, analgesics, and sling support for a few days to a few weeks with expected regaining of full range of motion by 6 weeks and return to normal activity by 12 weeks. Successful early rehabilitation is possible, especially in injuries of lesser severity. Types IV–VI are much less common, but generally require surgical reduction and ligamentous repair or reconstruction using a variety of surgical techniques. AC joint injuries may also contribute to the late development of an arthrosis and impingement necessitating excision of the distal clavicle.

Glenohumeral Dislocation

The glenohumeral joint is among the most commonly dislocated joints with a reported incidence of 2% in the general population and as high as 7% in athletes. Dislocation can occur with high- or low-energy injuries and may be anterior (95%), posterior (4%), or inferior (0.5%) in direction. In approximately 1% of these patients, there may be an associated fracture. In anterior dislocations the extremity is typically adducted, and there is often a visible or palpable deformity of the anterior chest. Posterior dislocations present with a less obvious gross deformity, and careful examination will show an inability to externally rotate the humerus and posterior prominence of the humeral head. It is important not to miss luxatio erecta, an inferiorly dislocated shoulder locked in abduction. Inferior dislocations such as this are often associated with neurovascular injury, injury to the rotator cuff, labral tears, and/or greater tuberosity fractures.⁵⁹

A common pattern of injury is a dislocation of the shoulder that occurs with an associated fracture of the greater tuberosity of the humerus. This should be reevaluated after closed reduction and, if there is proximal migration of the fragment (>0.5 cm), surgical treatment may be indicated.

Compression fractures, termed Hill–Sachs lesions, may occur in which the anterior glenoid impacts the posterior humeral head and can contribute to recurrent instability,⁶⁰ as can displaced fractures of the glenoid rim.⁶¹ Patients aged 40 years and over are at increased risk for an associated rotator cuff tear that may require repair, also.⁶² Considering the range of injuries described above, it is impossible to detect all lesions simply using two-dimensional plain x-rays. When such associated injuries are suspected on x-rays or by physical examination, it is recommended that three-dimensional (3D) imaging (MRI or CT) be performed to better evaluate the nature of the injury.

The patient with a shoulder dislocation is often in severe pain. A detailed physical examination should be performed before reduction as associated neurovascular injuries are relatively common. The neurovascular exam is repeated after the reduction of the dislocation, as well. An injury to the brachial artery should be explored and repaired. The most common neurologic injury is a traction neurapraxia of the axillary nerve, and these typically recover fully without surgical treatment if early reduction is performed. More serious neurologic injuries may occur, including complete disruption of the brachial plexus.

A missed or unreduced shoulder dislocation can be functionally devastating. Late treatment often requires open reduction and additional bony and soft tissue procedures to attain stability. If the duration of dislocation exceeds 6 months or if there is extensive damage to the joint, a glenohumeral arthroplasty may be indicated. Delayed treatment seldom results in the return of full function, highlighting the importance of accurate early diagnosis and treatment.⁶³

X-ray evaluation of a suspected shoulder dislocation should include AP and Bloom–Obata modified axillary views. The Velpeau axillary view, which includes the glenoid fossa and the humeral head, is of particular importance in evaluating the traumatized shoulder. AP x-rays of the shoulder may appear grossly normal despite dislocation of the glenohumeral joint, especially if the direction of the dislocation is posterior. Anterior or posterior displacement of the humeral head relative to the glenoid is readily apparent in the Velpeau axillary view (Fig. 39-4).⁶⁴ A CT or MRI is indicated if a more complicated injury is suspected.

Urgent reduction of a glenohumeral dislocation is the preferred treatment. Many closed reduction techniques have been described, but most dislocations can be successfully reduced in the ED by manipulation with or without sedation. In general, maneuvers involve either traction on the humerus or manipulation of the scapula.⁶⁵ Of the many named methods described for reduction, all have similar reported success rates of 70–95%. Failure to achieve reduction in the ED is an indication for general anesthesia and possible open reduction in the operating room.

After successful closed reduction, most shoulder dislocations can be successfully managed by a period of immobilization and early rehabilitation. The ideal duration and position of immobilization continue to be debated, but adequate results are typically achieved with a simple sling and early, gentle pendulum exercises. Surgical indications include missed or recurrent dislocations, dislocations with associated injuries, and young, high-demand patients.

Trauma to the Elbow

The elbow is frequently injured by falls from a standing height, especially in the elderly population. High-energy injuries are more common in younger patients and are typically sustained in falls from a height, sport injuries, or vehicular trauma. It is important to remember that the elbow is not a single joint, but actually a complex set of articulations including the ulnohumeral, radiocapitellar, and proximal radioulnar joints. Preservation of an arc of motion from 30° short of terminal extension to 130° of flexion and at least 50° of pronation and 50° of supination is sufficient to allow patients to perform most routine tasks. In patients with a more severe post-traumatic contracture or limitation of motion due to heterotopic ossification that does not respond to nonoperative treatment, eventual closed manipulation or even open capsulectomy of the elbow may be necessary.

Because of the relatively thin soft tissue envelope about the elbow, open fractures are common, and any open wound should be scrutinized with this in mind. Care should be taken to identify associated injuries, which may include trauma to the median, ulnar, and radial nerves, as well as to the brachial artery.

X-rays of the severely traumatized elbow with displaced fragments or segments may be difficult to interpret due to nonanatomical overlap of the injured parts. Therefore, a CT scan, particularly with 3D reconstructions, can be helpful in determining the size and location of small articular fragments and is valuable for preoperative planning.

Once the extent of the injury is established, an effort should be made to provisionally reduce any dislocation or displacement as anatomically as possible. Distal neurovascular status should be carefully reassessed after any manipulation or reduction. Repeat x-rays should be carefully evaluated to ensure that reduction is concentric and there are no fractures that were not identified in the original films. Definitive treatment should progress based on the pattern of injury.

Elbow injuries present particular challenges to the surgeon charged with their repair and reconstruction due to the complex motion and stability that are normally present. Small articular or periarticular fractures can contribute to subtle, but significant, subluxation. If this is not recognized and corrected early, the resulting chronic instability may be functionally devastating. Further complicating treatment of elbow injuries is the tendency of this joint to become stiff and develop a post-traumatic contracture, especially if it is immobilized for any length of time. For these reasons, the goal of treatment in most cases is to achieve enough stability to allow early range of motion and prevent stiffness. The challenges of reaching this goal have led to an ongoing expansion of techniques and implants designed to address particular injuries. Despite this, most patients who sustain severe elbow trauma continue to have some permanent limitation of motion.

Dislocation and Fracture–Dislocation of the Elbow

Of all dislocated joints, the elbow is second in frequency only to the shoulder. Dislocation of the elbow typically refers to dislocation of the humerus from both the radius and ulna (Fig. 39-5) and can be classified by the direction of displacement of the forearm segment. Posterior and lateral or posterior–lateral dislocations occur most frequently. Much less common are anterior, medial, and especially high-energy divergent dislocations in which the proximal radioulnar joint is also dislocated and the radius and ulna displaced laterally and medially, respectively. Simple dislocations of the elbow result in injuries of the medial and lateral collateral ligament complexes without bony injury (see Fig. 39-5). Complex dislocations are those associated with fractures about the elbow. Isolated dislocations of the radial head occur also, especially in children. If this injury is suspected in an adult, care should be taken to ensure that it is not a part of a Monteggia fracture–dislocation (dislocation of the radial head in association with a proximal ulna fracture).

Prior to reduction, a careful examination is necessary to rule out an associated injury to the brachial artery, or the median, radial, and, most commonly, ulnar nerve. Urgent closed reduction is then recommended. Unless the joint has remained dislocated for some time, gentle traction on the distal segment and countertraction on the humerus under heavy sedation is usually successful. In thin individuals, it may be possible to pull distally on the subcutaneous olecranon that is palpable posteriorly. Any medial or lateral malalignment is corrected before flexion completes the reduction. Forced maneuvers against resistance and extreme hyperextension should be avoided, and general anesthesia and/or open reduction may be required. Difficulty obtaining a stable closed reduction should increase suspicion that a complex dislocation or other associated injuries are present. Once closed reduction is completed, the elbow should be passively flexed and extended to determine if there is a tendency to redislocate. The position at which this occurs should be noted and a reevaluation of the neurovascular status should be performed. Simple dislocations are usually relatively stable following reduction and after immobilization in 90° of flexion for 7–10 days. Early range of motion activities may then be safely initiated to minimize long-term stiffness.⁶⁶ X-rays should be repeated after reduction and carefully scrutinized to confirm a concentric reduction and identify any associated fractures that may not have been visible with the joint displaced. Simple dislocations rarely require surgical treatment.

Any complex dislocation of the elbow should be definitively addressed within a few days or as soon as the patient’s overall condition allows. The longer the elbow remains in a dislocated or subluxated position, the more difficult it may be to achieve eventual stability. Complex dislocations are prone to dislocate if definitive treatment is delayed. In most patients, immobilization of the elbow in flexion and pronation imparts some stability. Patients immobilized in this way should be carefully monitored as this position may contribute to vascular compromise of the upper extremity as edema increases.⁶⁷

Elbow dislocations that are associated with fractures generally require surgical treatment. A notoriously unstable injury is an elbow dislocation with associated fractures of the radial head and coronoid process of the ulna. This pattern has been termed the “terrible triad of the elbow.” Surgical treatment is required to restore stability to the elbow. Whenever possible this should include repair or reconstruction of the radial head, coronoid, and, if necessary, the collateral ligaments. In severe injuries dynamic external fixation or even transarticular pin fixation may be required.⁶⁸

Carpal Dislocations

Compared with other types of injuries to the wrist, carpal dislocations are relatively infrequent in occurrence.⁶⁹ Because these injuries are usually associated with high-energy trauma, they may have devastating effects on future function of the wrist. Early diagnosis and aggressive treatment is indicated, but simple closed reduction rarely results in long-term stability of the wrist.

Based on anatomical patterns of injury, these may be classified as perilunar, radiocarpal, midcarpal, axial, and isolated carpal dislocations. The most frequent traumatic carpal dislocations are perilunar dislocations and fracture–dislocations (Fig. 39-6). Radiocarpal and axial pattern dislocations are much less common, but still more frequent than isolated dislocations of the carpal bones. A pure midcarpal dislocation without an associated fracture is an extremely rare event.

Perilunar dislocations represent part of a staged pattern of injury centered around the lunate. These can be purely ligamentous injuries, often referred to as lesser arc injuries, or they can be associated with fracture of a carpal bone and are known as greater arc injuries. These injuries are usually caused by motor vehicle crashes, a fall from a height, or sports.⁷⁰

While these injuries often appear as a dramatic deformity of the wrist, the examiner should still perform a complete physical examination to rule out other more life-threatening injuries. Once this is accomplished, a focused examination of the upper extremity should include a documented neurologic examination because of the frequency of compromise of the median nerve with these dislocations. Posteroanterior and lateral x-ray views of the wrist should be obtained (see Fig. 39-6). The lateral projection is particularly helpful to evaluate the relationship between the lunate, capitate, and distal radius. With a perilunate dislocation the lunate will retain its relationship with the radius, but the capitate will be displaced either palmarly or dorsally from the lunate. On a PA view the carpus will appear crowded due to overlap of the proximal and distal carpal rows.

Greater arc injuries will appear similar to lesser arc injuries on an x-ray of the wrist but will include one or more fractures of the carpal bones and/or fractures of the radioulnar styloids. The most common type is the transscaphoid perilunate fracture–dislocation. It is important not to miss the much less frequent transscaphoid/transcapitate fracture–dislocation often referred to as the scaphocapitate fracture syndrome.

Treatment should be initiated as soon as the patient is able to be safely sedated or anesthetized. Closed reduction in the ED with splinting or application of a bivalved cast may be an appropriate short-term solution to decompress the median nerve and restore a semblance of normal anatomical alignment. This cannot be considered definitive long-term treatment since residual instability and misalignment should always be considered to be present.

Operative treatment consisting of open reduction through a palmar and dorsal approach for ligamentous repair and anatomical realignment followed by pin stabilization should be considered emergently or relatively urgently. When associated fractures are present, these should be stabilized with screw fixation.⁷⁰ Even with ideal treatment, some loss of wrist motion should be anticipated.

Metacarpophalangeal Dislocations

Dislocations of the finger MCP joints are relatively rare because of the stout ligamentous support and the associated flexor and extensor tendons. As would be expected, the index and small fingers are much more vulnerable to this type of injury than the central two fingers. Most dislocations occur dorsally, are associated with a hyperextension injury, and may be classified as simple or complex.⁷¹

Simple MCP joint dislocations are, in reality, subluxations. They differ anatomically from complex or complete dislocations, in that the volar plate is draped over and not entrapped above the metacarpal head. In a simple dislocation the proximal phalanx is locked in 60–80° of hyperextension. A key point in treatment of these injuries is to avoid hyperextension or traction during attempts at reduction, which could result in conversion of this injury to a complex dislocation. The correct reduction maneuver for incomplete dislocations is flexion of the wrist to relax the flexor tendons and application of simple distal- and volar-directed pressure to the dorsal base of the proximal phalanx. This maneuver slides the proximal phalanx and its attached volar plate over the metacarpal head into the reduced position.

In contrast, patients with complex dislocations present with the finger held in only slight extension and an inability to flex.⁷² Palpation of the palm will demonstrate a bony prominence corresponding to the metacarpal head. X-rays will show a widened joint space, and a sesamoid bone will often be present within the joint confirming entrapment of the volar plate.

Surgical reduction of a complex dislocation can be performed through a volar or a dorsal approach. Limitations of the dorsal approach are the assumption that the volar plate is the only blocking structure; however, this approach allows access for any associated fracture fixation and is applicable in most instances. In the event that reduction cannot be obtained by longitudinally splitting the volar plate through a dorsal approach, a volar incision should be added.

Most dislocations of the thumb MCP joint are dorsal and may be simple or complex. Like finger MCP dislocations, the mechanism is hyperextension with rupture of the volar plate proximally, distally, or through the sesamoids. Most dorsal dislocations are reducible, but entrapment of the flexor pollicis longus tendon, usually over the ulnar side of the metacarpal head, may create a noose in conjunction with the radially located intrinsic muscles. X-rays demonstrating entrapment of the sesamoid within the joint usually are consistent with a complex irreducible dislocation, whereas a fracture of the sesamoids usually predicts successful closed reduction.

Closed management of these injuries should avoid longitudinal traction or hyperextension, which could convert a simple dislocation to a complex, irreducible dislocation. Instead, gentle pressure should be applied to the base of the proximal phalanx to push it over the head of the metacarpal. Failed attempts at reduction should be followed by operative intervention through a dorsal approach to split the volar plate longitudinally and remove other interposed tissue, thereby allowing reduction.

Once any MCP dislocation is reduced, integrity of the collateral ligaments should be tested. If there is no injury to the collateral ligaments, the finger or thumb should be immobilized in flexion no longer than 14 days, at which point an active range of motion protocol should be initiated with a dorsal blocking splint.

Interphalangeal Joint Dislocations

Dislocation of the PIP joint may occur in dorsal, volar, or lateral directions with reference to the position of the middle phalanx. Of these possibilities, dorsal dislocation is the most common and is usually associated with hyperextension of the PIP joint, often during ball sports.⁷³

Dorsal dislocation may be a purely soft tissue injury or a fracture–dislocation. A greater axial force increases the likelihood that the volar lip of the middle phalanx will be sheared off. Reduction of a dorsal dislocation is by longitudinal traction under a local digital block. After reduction, x-rays should be obtained to ensure a concentric reduction, and the integrity of the collateral ligaments confirmed by a passive lateral stress test in both full extension and 30° of flexion. If the joint is stable, early motion should be encouraged by simple “buddy taping.” When instability exists, the point of dislocation is determined and the finger is flexed 10° further and an extension block splint is applied. Each week the block is decreased by 10° until full extension is achieved.

Volar PIP dislocations exist in two forms and are much less common than dorsal dislocations. In the first type the central slip is disrupted by a straight volar dislocation of the PIP joint. These injuries can be treated by closed reduction with longitudinal traction and splinting of the PIP joint in extension for 6 weeks with the DIP joint free to flex and extend. The second type of dislocation is a volar rotary subluxation as a result of forces applied in a semiflexed position. This results in a split between the central tendon and the lateral band with buttonholing of the condyle through this split. Closed reduction of this type of dislocation can be difficult, but can be attempted by flexion of the MCP and PIP joints with gentle manipulation of the middle phalanx. Failure to promptly achieve reduction should be followed by open reduction rather than repeated attempts at closed reduction. If the central slip is intact following reduction, early motion with buddy tape support should be utilized; however, if the central slip is disrupted, then 6 weeks of PIP extension splinting is required as in any rupture of the central slip.

Lateral dislocations result from rupture of the volar plate and one collateral ligament. This results in asymmetric swelling of the joint with tenderness on the side of the ruptured collateral ligament. Closed reduction is usually easily accomplished by traction and manipulation. This is followed by 2 weeks of static splinting in extension followed by buddy tape protected motion.

DIP dislocations are most often dorsal or lateral. In many patients these are open injuries because of the tightness of the soft tissue envelope at this level of the finger. Closed injuries can be reduced by longitudinal traction, while open dislocations require appropriate antibiotics and irrigation of the joint followed by reduction. Occasionally, an irreducible dislocation may result from interposition of the proximal volar plate or the flexor tendon. Splinting should be in slight flexion for 1 week followed by intermittent protected motion for an additional 1–2 weeks.

Fracture of the Clavicle

Fractures of the clavicle are among the most common injuries in the upper extremity. While they generally heal without major functional limitation, they can be associated with serious neurovascular injuries. Patients generally present after a fall, particularly from a bicycle, or motor vehicle crash with pain and reluctance to move the shoulder. Inspection and palpation will usually identify the location of the fracture. Most fractures can be identified on standard AP radiographs of the shoulder, but additional apical oblique views may assist in characterizing the injury.

Fractures of the clavicle are classified by the location of the fracture in the medial, middle, or distal third of the bone. Approximately 80% of clavicular fractures occur in the middle third and most of these are amenable to closed management. Fractures of the medial third are rare, but can usually be treated symptomatically if they are not associated with other injuries. Fractures of the distal third of the clavicle may be accompanied by injury to the CC ligament complex and are at particular risk for nonunion. Fractures of the middle third of the clavicle have in the past been treated nonoperatively; however, recent well designed studies have demonstrated an up to 15% nonunion rate⁷⁴ as well as significant improvement in functional outcome with operative fixation.^75,76

Sling immobilization is adequate nonoperative treatment for most isolated fractures of the clavicle. Two to 3 weeks are sufficient for a patient’s symptoms to diminish so that he or she can tolerate pendulum exercises. After 6 weeks, the sling can be gradually discontinued and gentle activities resumed. Heavy activities are avoided for 8 weeks or until union is achieved. Because of the clavicle’s subcutaneous location, fracture callus is often palpable and may even be visible. Malunion of the clavicle can result in a functional deficit, particularly if there is angulation or shortening due to comminution.⁷⁷ Malunited fragments or hypertrophic callus may occasionally compress neurovascular structures requiring surgical treatment, also. In most patients, however, the concern is only cosmetic and slight misalignment does not interfere with daily activities.

Surgical treatment of fractures is generally reserved for displaced fractures of the lateral (distal third) clavicle, fractures of the middle third with more than 2 cm of shortening, comminution, open fractures, fractures causing skin compromise (by tenting skin over the edge of the fracture), symptomatic nonunions, or fractures with an associated neurovascular injury. Surgical stabilization of the clavicle may also be indicated in patients with a floating shoulder or other complex injuries to the shoulder girdle as this may improve overall stability of the upper extremity. Surgical treatment of a fracture of the clavicle can be performed with plate and screw fixation or with intramedullary implants.

Fractures of the Scapula

As fractures of the scapula result from high-energy trauma,⁷⁸ patients with these fractures should be closely evaluated with a high index of suspicion for other serious and life-threatening problems. These would include injury to the chest, cervical spine, or neurovascular structures. Initial evaluation of the patient should include a careful assessment of the neurologic and vascular status of the ipsilateral upper extremity. Scapular fractures can occur in the absence of an obvious shoulder deformity and may first be recognized on a routine chest x-ray. True AP, scapular Y, and axillary lateral views of the shoulder should always be obtained, and CT scans, particularly with 3D reconstructions, are often required to fully evaluate the injury.⁷⁹ The majority of scapular fractures occur in the scapular body, while 25% of scapular fractures involve the glenoid neck and 10% are intra-articular. Scapular body fractures are generally treated nonoperatively. Open reduction and internal fixation is considered for displaced intra-articular and glenoid neck fractures. Intra-articular displacement of more than 5 mm or a glenopolar angle of less than 20° are potential indications for surgery, as well as loss of more than 25% of the glenoid surface or more than 2 cm medialization of the glenohumeral joint.⁸⁰

Fractures of the Proximal Humerus

These are relatively common fractures and occur most often as the result of falls or a motor vehicle crash. The incidence increases with age, and the cause is typically a low-energy injury in the elderly patient.

Peripheral nerve injuries are common, especially involving the axillary nerve. Vascular injuries are also a concern, especially in an elderly patient who has calcification in vessel walls. It is important to note that a vascular injury may be present even if a radial pulse is palpable due to the presence of multiple collateral vessels around the shoulder. Shoulder dislocations and rotator cuff tears commonly occur in association with proximal humeral fractures, as well.

X-rays studies using the Grashy view and the lateral scapular Y view are diagnostic. For fractures treated operatively, a CT scan is usually performed for preoperative planning.

Nondisplaced or minimally displaced fractures are treated nonoperatively. Nonoperative management includes a shoulder sling for 2 weeks. Displacement is judged according to the Neer 4-part system classification where a fragment (or part) is considered displaced if it is rotated more than 45° or displaced more than 1 cm. Displaced fractures are generally treated operatively, with the exceptions of valgus impacted fractures and fractures in elderly low-demand patients. Surgical options include closed reduction and percutaneous pining, open reduction and internal fixation (most commonly with locked plating constructs), proximal humerus nailing, hemiarthroplasty and reverse total shoulder arthroplasty.

Fractures of the Shaft of the Humerus

Fractures of the shaft of the humerus have an incidence and mechanism of injury similar to that of proximal humeral fractures. The unstable brachium is of significant discomfort to the patient who typically presents supporting the injured arm with the uninjured extremity. Instability and crepitus at the fracture site are often readily apparent clinically, while standard AP and lateral x-rays are diagnostic.

Because of the risk of an associated neurovascular injury, a carefully performed and documented assessment of the patient’s status should be completed immediately on presentation and repeated after any treatment. The radial nerve is at highest risk of injury with a fracture in the distal third of the shaft, where it is closely associated with the bone in the spiral groove (Fig. 39-7).

Nonoperative treatment is effective for most uncomplicated fractures of the shaft of the humerus. As true cast immobilization of the brachium is impractical due to the inherent difficulty of immobilizing the shoulder, a coaptation splint can provide a more practical alternative. Gentle traction usually results in adequate reduction of even significantly displaced injuries. For this reason, some have advocated the use of a hanging arm cast for a brief period, especially early in the course of treatment. This consists of a long arm cast, which hangs from a loop around the patient’s neck. The weight of the cast maintains longitudinal traction on the fracture fragments and helps to ensure adequate alignment. This does improve patient comfort, but requires an upright posture to be effective. The use of a fracture functional brace after a period of 7–10 days (acute fracture healing phase) has many benefits. It is usually effective in maintaining an adequate reduction and allows active motion of the elbow. The effectiveness of the functional brace depends on active muscle forces and daily brace tightening as the soft tissue swelling resolves. Therefore, functional bracing does not work well with the noncompliant patient. Many patients prefer to sleep in a reclining chair for the first few weeks because this allows the longitudinal traction provided by gravity to be effective in controlling the fracture even when they are somewhat recumbent. Union rates of over 95% have been reported with this device.⁸¹

Surgical treatment for fractures of the shaft of the humerus is indicated for open injuries, associated vascular injuries, comatose patients, fractures of the ipsilateral arm and forearm, or when there is failure to maintain acceptable reduction in a brace, which is less than 20° of anterior angulation, less than 30° of varus/valgus angulation, or less than 3 cm of shortening. In patients with multiple injuries, fixation of the humerus simplifies their care, improves pain control, and allows early mobilization. Surgical treatment is considered in patients who are intolerant of the extreme activity modifications closed treatment requires and in obese patients in whom it is a particular challenge to maintain an acceptable reduction. Operative fixation of the humerus classically involves compression plate and screw fixation, but intramedullary nailing is becoming more common and results are comparable.⁸² When intramedullary nailing is performed with limited exposure of the fracture site, there may be a lower risk of iatrogenic injury to the radial nerve; however, the union rate is slightly lower compared to plating of the humerus. Immediate weight bearing is usually allowed after surgery.

Injuries to the radial nerve occur in 12% of humeral fractures.⁸³ Most nerve injuries associated with closed fractures of the humerus are neurapraxias, and at least 90% will resolve with expectant management. During recovery, patients benefit from splinting of the wrist and digits to improve function. Failure to improve (clinically or by EMG) over 3–4 months is an indication for surgical exploration of the nerve. Early surgical exploration is recommended in patients with open injuries where the risk of nerve transection is increased, as well.

Fractures of the Distal Humerus

The Orthopaedic Trauma Association system for classification of supracondylar and intracondylar humeral fractures includes the following: type A, which are extra-articular; type B, which are partial articular injuries of either the medial or lateral column; and type C, complete articular injuries in which both columns of the distal humerus are fractured from the shaft and from each other. The elbow is usually grossly unstable. Isolated fractures of the medial or lateral epicondyle occur, also. Although they are typically of lesser severity, they may require surgical treatment if significantly displaced.

Rarely is nonoperative treatment indicated for a supracondylar fracture of the humerus. Occasionally, a brief period of immobilization followed by early rehabilitation may be sufficient for a patient with very limited functional expectations due to preexisting health problems. A preferred alternative to this technique in elderly patients with highly comminuted intra-articular fractures or existing degenerative or rheumatoid arthrosis, is total elbow arthroplasty.⁸⁴ In the vast majority of distal humerus fractures, open reduction and internal fixation is indicated. Surgical treatment is technically demanding, especially if there is significant fragmentation of the joint surface.⁸⁵ The surgical approach to intra-articular injuries often requires an osteotomy of the olecranon. The ideal biomechanical construct continues to be debated, but most agree that plating of both the medial and lateral columns is usually indicated.⁸⁶ The goal of surgical treatment is to obtain sufficient stability to allow early motion of the elbow while the fracture proceeds to union. Even when this goal is achieved, a permanent loss of some elbow motion is common.

Supracondylar humeral fractures in children aged 5–7 years are common injuries. Almost all supracondylar humeral fractures in this age group are extra-articular with posterior displacement of the distal fragment. These extension type fractures are classified as type I injuries—nondisplaced or minimally displaced, type II injuries—displaced with an intact posterior cortex, and type III injuries—completely displaced fractures with disruption of the posterior cortex. Children may demonstrate only edema and pain in mild injuries or obvious hyperextension deformity in more severe cases. Most nondisplaced or minimally displaced injuries may be managed with casting for approximately 4 weeks, while surgical treatment is indicated in displaced injuries. In most cases, closed reduction and pinning of the fracture site is sufficient to obtain and maintain reduction. Pins are typically inserted from lateral to medial in order to avoid injury to the ulnar nerve and are spread across the fracture site. Because late stiffness is much less common in children, management typically consists of closed reduction and pinning followed by approximately 4 weeks of immobilization. If satisfactory closed reduction cannot be obtained, it may be due to interposed tissues such as the brachialis muscle or neurovascular structures. Open exploration and reduction are indicated in these patients and an effort should be made to operate during the first 12 hours.^87,88

Associated injuries to the median nerve or its anterior interosseous branch often recover with expectant management. Injuries to the brachial artery are reported with some frequency, also. Because there is generally adequate collateral circulation, vascular reconstruction may not be required emergently if the extremity remains well perfused. The flexion of the elbow often required to maintain reduction of the fracture may further compromise blood flow, and patients should be carefully monitored for any signs of worsening vascular status or a compartment syndrome.⁸⁹

Fractures of the Capitellum

Isolated fractures of the capitellum are relatively rare, are due to low-energy trauma, and are more common in women. Unless there is displacement, this injury may be easily missed on AP and lateral x-rays of the elbow. CT may be helpful if plain x-rays do not fully demonstrate the injury. There are four types of fractures as follows: type I fractures are a complete fracture of the entire capitellum from the remainder of the articular surface, type II injuries involve only a thin wafer of cartilage and subchondral bone, type III injuries are comminuted fractures of the capitellum, and type IV fractures are coronal shear injuries in which the capitellum as well as a significant portion of the anterior trochlea is fractured. Unless fragments are nondisplaced, open reduction and internal fixation is recommended when possible.⁹⁰ In types II and III, the fragments are often so small that stable internal fixation is not possible. In these patients, excision of the fragments may be a reasonable alternative.

Fractures of the Olecranon/Coronoid Process of the Ulna

Injuries through the olecranon are frequent. Fractures with less than 1–2 mm of articular displacement may be treated nonoperatively with a 1- to 2-week period of splinting, followed by gentle early range of motion activities. Frequent x-ray follow-up is important to ensure that there is no increase in displacement. Most olecranon fractures have sufficient displacement to warrant operative treatment. The most common methods are tension band wiring and plate and screw fixation. Both may be effective in transverse or oblique injuries, but comminuted injuries require plate and screw constructs to prevent compression of the trochlear notch. Sufficient stability can usually be obtained to allow early motion, and a satisfactory outcome is likely. In elderly patients with extensively comminuted injuries, excision of up to half of the olecranon with advancement of the triceps muscle may be considered.

Fractures of the coronoid process of the ulna represent the loss of the major anterior skeletal buttress preventing posterior subluxation of the elbow. Type I fractures are avulsions of the tip of the coronoid, type II fractures involve less than 50% of the coronoid process, and type III fractures involve more than 50% of the coronoid. These injuries are typically seen in association with a posterior dislocation of the elbow, and the elbow should be carefully examined for stability even if it appears well reduced. If not associated with significant instability, an avulsion fracture of the tip can be treated nonoperatively, similar to a simple elbow dislocation. Consideration should be given to fixation of some type II and all type III injuries and is required if there is instability of the elbow.⁹¹ Posteriorly placed screw, suture, or wire fixation into or around the coronoid is often sufficient, but a more medial approach with an anterior buttress plate may be required to prevent displacement in the presence of an anteromedial coronoid fracture. If small coronoid fragments are not amenable to rigid fixation, they may be excised with repair of the anterior capsule.

Comminuted fractures of the olecranon that are accompanied by displacement of the coronoid process should be managed carefully. Even with anatomical fixation and union of the olecranon, the elbow may become unstable if the coronoid remains displaced. Stabilization of the coronoid process can be technically difficult, as access to the coronoid is extremely limited after fixation of the olecranon. Through a posterior approach, the proximal, fractured portion of the olecranon is retracted with the triceps muscle and the remainder of the ulna is subluxated dorsally, allowing access to the anterior portion of the joint. The coronoid process is reduced under direct visualization and stabilized as described above. Transolecranon fracture–dislocation of the elbow occurs when the distal humerus is driven distally through the proximal ulna. Displaced coronoid fragments are common in this injury pattern.⁹²

Fractures of the Head of the Radius

Fractures of the head of the radius are common injuries and may occur in association with a dislocation of the elbow. The fractures are classified as follows: type I fractures are nondisplaced, type II fractures have single displaced fragments, type III fractures have comminuted injuries, and type IV are fractures of the head of the radius associated with a dislocation of the elbow. Patients may report relatively mild trauma, and physical findings may be subtle. Injuries to neurovascular structures are uncommon with this fracture. Standard x-rays are usually sufficient to make the diagnosis with occasional need for a radial head view. Once fracture is identified, the elbow should be carefully evaluated for stability and range of motion.

It is important to examine the wrist and forearm to identify any associated injuries to the distal radioulnar joint or interosseous membrane. If pain prevents motion, the intra-articular hematoma should be evacuated and lidocaine injected into the joint. A mechanical block to motion in the anesthetized joint is an indication for surgical treatment.

Type I and II injuries with less than 2 mm of displacement may be managed nonoperatively with early motion and follow-up to ensure that there is no interval displacement. Displaced type II injuries of the head and neck are typically treated with open reduction and internal fixation. It is important that implants do not interfere with the proximal radioulnar joint. The safe zone for implants in the head of the radius is the area between lines extended proximally from the radial styloid and Lister’s tubercle, both of which are palpable at the wrist.⁹³ Headless screws may also be of value when fixation is necessary outside this safe zone.

Type III injuries are usually not amenable to open reduction and internal fixation, and excision of the head of the radius may be considered in some patients. This should not be performed if there is an associated dislocation of the elbow, coronoid fracture, valgus instability of the elbow, or longitudinal instability of the forearm, which would indicate an injury to the interosseous ligament. A fracture of the head of the radius with an associated injury to the interosseous membrane is termed an Essex-Lopresti fracture–dislocation.⁹⁴ Clues to its presence include wrist pain, displacement at the distal radioulnar joint, and/or proximal migration of the radius evident on x-ray. If signs of instability in any plane are present, every attempt should be made to preserve the head of the radius or perform an arthroplasty with a metallic implant.

The Floating Elbow

The floating elbow occurs when there are ipsilateral fractures of the humerus and bones in the forearm. This injury is the result of high-energy trauma and is often associated with injuries to neurovascular structures. The elbow segment is unsupported proximally and distally, and both injuries need to be stabilized. The prognosis for return of full function in these injuries is guarded, especially if the fractures are periarticular.⁹⁵

Fractures of the Shaft of the Ulna

Isolated fractures of the shaft of the ulna, commonly referred to as “nightstick fractures,” are usually amenable to a short period of long arm casting. This is followed by functional bracing when there is less than 10–15° angulation and at least 50% contact area between fragments. Displaced fractures are usually treated with compression plating or, in the distal third, fixed-angle locking plates. Intramedullary nailing in adults has limited application, but may be indicated with some segmental fractures, those associated with severe loss of soft tissue, or in patients with polytrauma. External fixation is really only indicated as a bridge to more definitive fixation.

Special circumstances in the management of ulnar fractures involve those associated with distal radial fractures, isolated fractures of the head of the ulna, and Monteggia fractures.

Fracture of the distal ulna associated with distal radial fracture may or may not require fixation; however, when the integrity of the distal radioulnar joint (DRUJ) is compromised, consideration should be given to fixation.⁹⁶ Restoration can be by fixation of an ulnar styloid base or plating of the head of the ulna, usually with a small condylar blade plate or a small locking plate. Addressing the ulnar component of these fractures in this manner can often greatly facilitate initiation of early motion.

Fractures of the Shaft of the Radius

Isolated radial shaft fractures are relatively rare and are typically treated with compression plating. A Galeazzi fracture–dislocation should always be ruled out. Galeazzi fracture–dislocation is a complex traumatic disruption of the distal radioulnar joint (DRUJ) that is associated with an unstable fracture of the radius.⁹⁷ In these fractures, the injury to the DRUJ can be a pure ligamentous disruption or associated with a fracture of the ulnar styloid. Most commonly, the site of fracture is the junction of the middle and distal thirds of the radius. This injury can be associated with a low-energy fall from a standing height or associated with a high-energy mechanism, such as a fall from a height or a motor vehicle crash. This fracture has also been referred to as a “reverse Monteggia fracture” or “the fracture of necessity” since, in adults, operative intervention is almost always required for a good outcome.

X-ray evaluation of these fractures demonstrates a short appearing radius relative to the ulna because of the pull of the pronator quadratus muscle (Fig. 39-8). On the PA view there will often appear to be an increase in space between the distal radius and ulna where they articulate.

Definitive treatment is by operative fixation of the fracture of the shaft of the radius, usually through a volar approach. This is followed by an intraoperative examination of the DRUJ for instability, predominantly in supination. The intraoperative examination is the definitive test that determines a need to address the DRUJ, not the x-rays.⁹⁸ Treatment of the unstable DRUJ is by fixation of the radius to the ulna in supination using two Kirschner wires, with or without direct repair of the ligamentous component or fracture of the styloid. This is followed by 6 weeks of above-elbow casting.

Fractures of the Radius and Ulna

The forearm long-bone complex should be considered as a single joint, requiring anatomic reduction of both bones in order to restore full range of motion and function. Simultaneous fractures of the radius and ulna are relatively common injuries. Associated neurovascular injuries do occur, and a compartment syndrome may develop. AP and lateral x-rays that include both the elbow and wrist should be obtained. Fractures are classified based on their location as proximal, middle, or distal third, with or without comminution. While closed management is usually acceptable in children, open reduction with fixation using a compression plate has become the accepted standard of care for these fractures in adults.⁹⁹ Fixation of both bones should not be attempted through a single incision in order to reduce the risk of synostosis. Early mobilization after surgery is recommended.

Fractures of the Distal Radius

Fractures of the distal radius are the most common long-bone fracture of the upper extremity.¹⁰⁰ Two primary age groups are involved with varying mechanisms. High-energy comminuted intra-articular fractures occur primarily in young patients, while low-energy extra-articular fractures occur predominantly in elderly patients.

During physical examination a careful assessment of median nerve function should be performed to rule out an acute carpal tunnel syndrome that is an indication for urgent surgical release. The goals of surgical repair are for anatomical restoration of radial length, radial inclination, and volar tilt and, ultimately, restoration of function of the wrist.

The three anatomical goals are based on the normal anatomy of the distal radius. This includes 21° of inclination, 12° of volar tilt, and length defined by baseline relationship to the ulna, which can be determined in most instances from the uninjured wrist. The ability to restore and maintain these relationships, as well as to restore articular congruity, is the prime determinant of the need for operative intervention.¹⁰¹ Because of the dorsal comminution that usually exists with the apex volar malformation that usually accompanies these fractures, maintenance of what appears to be a good reduction in the ED requires continued vigilance and early operative intervention if loss of reduction occurs.

While no consensus exists for treatment of fractures of the distal radius, the recent addition of fixed-angle locking plates and fragment-specific fixation have led to more aggressive early range of motion in both intra- and extra-articular fractures, including highly comminuted fractures. In the elderly low-demand patient population, which comprises a large proportion of these patients, there seems to be no added value to operative fixation over nonoperative fixation.¹⁰² These patients can be managed by a volar splint that allows full finger motion for six weeks, followed by full range of motion exercises and gradual return to full weight bearing.

Fractures of the Scaphoid

Fractures of the scaphoid account for over half of all isolated fracture of the carpal bones. The true incidence of injury to this bone, however, may be higher. This is because many fractures are not appreciated until later when they convert to a symptomatic nonunion, and many remain asymptomatic throughout life.¹⁰³

Fractures of the scaphoid usually result from a fall onto an outstretched hand with the wrist extended and the forearm pronated. Fractures most commonly occur at the waist (75%), followed by the proximal pole (20%), and, least often, at the distal pole or tuberosity (5%). Location of the fracture is an important factor in prognosis for healing because of the blood supply of the scaphoid. As an intra-articular bone, the scaphoid receives its blood supply through ligamentous attachments, with the primary entry at the distal pole. This leaves the proximal pole with a consistently poor blood supply, which makes these fractures susceptible to nonunion or avascular necrosis. Other factors playing a role in the development of nonunion and malunion are stability of the fracture pattern and displacement.

The diagnosis of a fracture of the scaphoid is first suggested by the mechanism of injury associated with the onset of wrist pain and/or swelling. Examination may show tenderness on palpation within the anatomical snuff box and over the scaphoid tubercle. Pain may also be elicited by pronation and ulnar deviation or by applying an axial load to the first metacarpal (scaphoid compression test); however, no maneuver is specific for injury to the scaphoid and appropriate x-rays are critical.¹⁰⁴

Routine x-rays should include a posteroanterior, lateral, and oblique view in 45° of pronation and a posteroanterior view in slight ulnar deviation (“scaphoid view”). Even with a thorough examination and appropriate x-rays, a nondisplaced fracture may be missed. An appropriate course of action in the presence of negative x-rays, but positive clinical signs, would be an immediate MRI or application of a thumb spica cast with more definitive tests scheduled in 72 hours.¹⁰⁵

The concept of an immediate MRI is based on its sensitivity to detection of early fracture-associated edema of the marrow. In addition, numerous studies have now demonstrated a cost benefit to this approach versus the classic approach of repeat x-rays, followed by more definitive studies if these remain negative.^106,107 In centers that cannot perform the test expeditiously, a bone scan or a scheduled MRI in 72 hours is better than repeat x-rays over the course of several weeks.

Surgical treatment is indicated for all displaced fractures of the scaphoid. An aggressive approach is supported by data reporting a 50–92% nonunion rate with displaced scaphoid fractures and development of degenerative joint disease with as little as 1 mm of displacement. An open approach through a dorsal or volar incision, followed by placement of a screw, is the most common means of treating these fractures. Percutaneous placement of a screw, with or without arthroscopically guided reduction, is becoming increasing popular as a minimally invasive option (Fig. 39-9).^108,109

Other Fractures of Carpal Bones

Of the remaining seven bones in the carpus, the triquetrum is the next most frequently injured bone.¹¹⁰ Dorsal avulsion fractures are the most common form, and, while painful, surgical intervention is rarely indicated except to excise a persistently painful fragment. Body fractures and volar avulsion fractures may occur and may be difficult to detect by plain x-rays, also. Both CT and MRI have been used to diagnose or more clearly delineate these fractures and, occasionally, fractures of the body will require fixation. In most instances, 6 weeks of immobilization in a short arm cast will resolve the pain associated with these fractures even though radiographic union may not occur.

The pisiform is rarely fractured and, when this occurs, it is usually the result of a direct blow to the hypothenar eminence. Palpation of the pisiform elicits pain, and carpal tunnel and/or supinated oblique x-rays are required to adequately image this bone. CT may be indicated in the presence of persistent pain and negative plain films. A thorough evaluation of the integrity of the ulnar nerve is required when dealing with injuries to the pisiform because of its close proximity.¹¹¹ This is particularly important if surgical intervention is being considered. Initial treatment with immobilization is recommended. Of interest, a persistently painful fractured pisiform can be excised as definitive treatment, with no significant sequelae.

Fractures of the trapezium are usually associated with a fracture of the first metacarpal or distal radius. These fractures may involve the body, margin of the metacarpal articular surface, or volar ridge. Volar ridge fractures may be associated with injury to the median nerve, and a thorough examination of both motor and sensory components of this nerve should be documented. X-ray diagnosis of any of these injuries requires a variety of special views including a hyperpronated “Roberts” view, a Bett’s view, and a carpal tunnel view, and CT may be required to further delineate a fracture of the ridge. Except for displaced body fractures, the initial treatment of trapezium fractures should consist of a 6-week period of immobilization. If, at the end of this time, persistent palmar pain is associated with a fracture of the volar ridge, then the fracture fragment should be excised. Displaced fractures of the body can usually be stabilized by lag screw fixation.¹¹²

Fractures of the trapezoid are exceedingly rare.¹¹³ Injury to this protected bone is often associated with a high-energy fracture–dislocation involving the index metacarpal bone. X-ray diagnosis of this injury is usually straightforward; however, an isolated injury or injury associated with a spontaneous reduction may require a CT scan to confirm diagnosis. Treatment of nondisplaced isolated fractures is by 6 weeks of immobilization. Displaced fractures or those associated with carpometacarpal (CMC) dislocations require internal fixation or, occasionally, formal CMC arthrodesis with bone grafting to achieve stability and pain relief.

Capitate fractures may be isolated, associated with a scaphoid fracture (“scaphocapitate syndrome”), or associated with another carpal injury. Isolated fractures are often nondisplaced and occur at the waist; however, similar to proximal pole fractures of the scaphoid, the proximal pole of the capitate is dependent on a distal blood supply and prone to avascular necrosis.¹¹⁴ Without treatment, symptomatic nonunion is a common occurrence and can lead to the need for midcarpal fusion if ignored. Both open reduction and percutaneous methods of primary fixation have been described.

Scaphocapitate syndrome is caused by a direct blow to the dorsum of the hand while flexed or a fall onto an extended wrist and results in malrotation of the proximal capitate fragment.¹¹⁵ Following closed reduction of the associated dislocation of the wrist, careful evaluation of the capitate is necessary to detect persistent malrotation. Open reduction with fixation of both the capitate and scaphoid bones is required to restore the normal relationships within the wrist and, hopefully, prevent avascular necrosis of the capitate.

Fractures of the hamate may involve the body, articular surfaces, and/or the hook/hamulus.¹¹⁶ Clinically, pain and tenderness on the ulnar aspect of the hand is present and is often associated with swelling. Injury to both the ulnar and median nerves may be associated with hook fractures, and a thorough examination of motor and sensory function should be documented. Standard x-rays may be inadequate to image the injury. A carpal tunnel view and an oblique view with the hand in 45° of supination and the wrist in radial deviation should be performed. CT may be required if symptoms persist in the presence of negative plain x-rays.¹¹⁷

Isolated fractures of the body are rarely displaced and are usually amenable to a period of immobilization. Those associated with high-energy injuries, such as CMC fracture–dislocations, require internal fixation.¹¹⁸

Fractures of the hamulus of the hamate (“hook fractures”) may be difficult to diagnose without CT, and this should be performed early when this fracture is clinically suspected. A delay in treatment of this fracture can result in rupture of the adjacent flexor tendon from attritional wear over the fracture site.¹¹⁹ Untreated, this fracture can cause chronic pain with many of the activities of daily living. Treatment is by excision of the hook, or open reduction and screw fixation. Neither method has been shown to have an advantage over the other.¹²⁰

Fractures of the lunate are rare when one excludes those associated with idiopathic avascular necrosis or Kienbock’s disease. Accurate imaging to rule out predisposing avascular necrosis usually requires a CT and/or MRI in addition to plain x-rays. Acute fractures may involve the volar or dorsal lips or occur as transverse or sagittal fractures.¹¹⁰ Sagittal fractures and fractures of the dorsal lip are usually stable because of ligamentous support and require only a 6- to 8-week period of immobilization. Fractures of the volar lip and transverse fractures have a tendency to displace and require open reduction and internal fixation.

Fractures of the Metacarpal Bones and Phalanges

These are the most common fractures of the upper extremity. Metacarpal fractures may involve the base, shaft, neck, or head, and may be articular or nonarticular.¹²¹ In addition, when the fracture is at the base, it may be associated with a dislocation. The second and third CMC joints are relatively immobile and are injured less frequently than the more mobile fourth and fifth CMC joints. Thus, the most common metacarpal base fracture involves the small finger metacarpal and is almost always associated with a dislocation. This injury is inherently unstable because of the pull of the extensor carpi ulnaris, and closed reduction and cast immobilization as definitive treatment is usually doomed to failure. Therefore, initial splinting should be followed by scheduled outpatient closed reduction and pinning. When this is performed, care must be taken during the approach to avoid injuring the dorsal sensory branch of the ulnar nerve or entrapping it in the fixation.

More complex injuries can result in the fourth metacarpal bone being dislocated with the fifth metacarpal bone or disruption of the entire finger ray. Both these injuries represent high-energy disruptions of the ligamentous support of these joints, and open reduction and internal fixation are usually necessary. In addition, concomitant injury to the ulnar nerve in these severe disruptions can lead to significant long-term morbidity.

Many fractures of the metacarpal shaft present as stable, nondisplaced fractures. These can be managed by placement into a clam-digger cast or thermoplast splint until the fracture is clinically nontender. At this point, despite x-ray evidence of a fracture line, the hand can be mobilized. In particular, isolated fractures of the third and fourth metacarpal bones are amenable to this type of management because of continued support by the stout transverse metacarpal ligament. Fractures of the metacarpal bones proximal to the index and small fingers will more often develop some degree of malformation often expressed by crossing over of the fingers with flexion “scissoring.” Therefore, these fractures should be treated by operative intervention. Modalities available include open reduction and internal fixation, closed reduction and percutaneous pinning with Kirschner wires, or closed reduction and intramedullary nailing.¹²²

Multiple metacarpal fractures lead to an inherently unstable hand, and operative intervention is always indicated. These injuries will require not only fracture fixation but repair of associated injuries to tendons and soft tissue also. Principles of treatment of this type of injury are covered in the section “Compound, Complex, and Mangled Upper Extremities.” A fracture of the neck is the most common fracture of a metacarpal and usually occurs in the fourth or fifth bone. Acceptable closed reduction of these fractures depends on the digit involved, with fracture angulation of 50–70° tolerable in the fifth finger and only 10–20° in the index finger.^123,124 Fractures of the neck of the fifth metacarpal bone are referred to as “Boxer’s fractures” and are almost always associated with a clenched fist striking a solid object. The result is an apex dorsal angulated fracture with volar comminution. This comminution is the reason that most acute reductions fail, with rapid relapse in a splint or cast to the post-injury state. Because of this, it has been recommended that the patient should initially be splinted in the intrinsic plus position. A reduction is then performed at 7–10 days when the fracture has begun to consolidate. Whether the hand is then splinted in extension to presumably enhance a “ligamentotaxis” effect and counteract the tendency to relapse into an apex dorsal deformity or splinted or casted in the classic “cobra” cast position makes little or no difference to long-term outcome. Four weeks should be the maximum period of immobilization after treatment of such a fracture.

Fractures of the head of the metacarpal bone are usually intra-articular and are often associated with a clenched fist or “fight bite” injury. Closed fractures with significant intra-articular displacement should undergo open reduction and screw fixation. When significant comminution is present, fixation is probably not possible. Either acute replacement of the joint should be performed or the fracture should be allowed to heal. If significant morbidity develops, then replacement of the joint should occur at a later time.

A fracture of the shaft of the first metacarpal bone requires less accurate reduction because of the mobility of the CMC joint; however, articular fractures of the base in the form of Bennett’s and Rolando fractures (see Fig. 39-9) do not have this latitude. Bennett’s fracture is essentially a fracture–dislocation of the CMC joint. Axial loading results in the strong palmar oblique ligament retaining a fragment of bone while the metacarpal bone is dislocated radially and proximally by the pull of the abductor pollicis longus muscle. Post-traumatic arthritis frequently follows a Bennett’s-type fracture, and operative intervention is recommended. Either closed reduction and percutaneous pinning or open reduction and internal fixation is acceptable and both have similar outcomes.¹²⁵

The Rolando fracture is T- or Y-shaped fracture of the base of the first metacarpal bone and includes both the volar lip fracture seen in Bennett’s fracture and a large dorsal fragment (Fig. 39-10). These fractures are extremely difficult to manage and frequently lead to post-traumatic arthritis regardless of which technique is used for management. Surgical options include multiple K-wires, tension band wires, plates and screws, and external fixation.¹²⁵

Phalangeal fractures are common in all age groups.¹⁰⁰ The examination needs to differentiate between a fracture, rupture of the collateral ligament, rupture of the volar plate, and avulsion of a tendon, all of which may have similar signs on cursory inspection. At a minimum, PA, oblique, and lateral x-rays should be obtained.

Nondisplaced, stable proximal and middle phalangeal fractures can be effectively managed by either buddy taping or immobilization in a splint. Many proximal and middle phalangeal fractures, however, have articular involvement or have significant malformation because of the effect of the flexor tendons and/or extensor apparatus. Closed reduction to align displaced fractures can be performed by a combination of axial traction and reversal of the deformity. Even what initially appears to be a nondisplaced articular fracture has the potential to displace. Therefore, if nonoperative management is selected as the primary treatment, then close follow-up and frequent x-rays are necessary to avoid missing displacement.

Operative treatment of articular fractures entails closed reduction with placement of a percutaneous screw or Kirschner wire. More ridged fixation allows early initiation of range of motion. Pilon-type injuries require some type of traction fixation to allow motion with maintenance of articular congruity.¹²⁶ Even with this type of approach, secondary arthroplasty procedures may be required.

Transverse, spiral, oblique, and comminuted fractures of a phalangeal shaft may occur. The apex of a proximal phalangeal fracture angulates in a volar direction due to the strong pull of the interosseous muscles. Deformation of middle phalangeal fractures depends on the location of the fracture in the shaft with relation to the insertion of the superficialis tendon. An apex volar deformation results when the fracture is distal to the insertion of the superficialis tendon, while an apex dorsal deformation results from fractures proximal to the superficialis insertion. A variety of methods have been employed to overcome these distracting forces. These include static casting in the intrinsic plus position for a proximal phalangeal fracture, with early mobilization at 4 weeks with buddy tape support to the adjacent finger. Traction has also been utilized, with force exerted through the skin, pulp, nail plate, or skeleton. Difficulties with this technique include the awkwardness of the device, joint stiffness, and skin problems. Operative techniques include external fixation, percutaneous pinning, and open reduction and internal fixation with plates, screw, or interosseous wires. Of these techniques, percutaneous pin fixation seems to have the least long-term morbidity (Table 39-9).

As opposed to other extremity injuries, a mangled extremity typically involves a combination of severe injury to artery, bone, soft tissue, skin, and tendons. Such injuries require immediate multidisciplinary surgical treatment (Fig. 39-11). In general, prioritization is typically given to lifesaving efforts as well stated in the phrase “life before limb reconstruction.”

Damage control surgery is used in order to save the patient’s life as well as to allow for limb salvage when possible. Therefore, temporary vascular shunting,¹²⁷ temporary external fixation of the bones, and soft tissue flaps are the cornerstones of initial treatment. Damage control procedures (external fixation, fasciotomies) minimize time spent in the operating room.

Furthermore, “damage control resuscitation” (see Chapters 12 and 13) has also been shown to provide a means to aid limb salvage. Fox et al¹²⁸ showed that the use of fresh warm blood, plasma, and recombinant factor VIIa before operation normalized physiologic parameters and allowed for more prolonged procedures, such as revascularization, without an increase in morbidity or graft failure. This is true for patients with a Mangled Extremity Scoring System (MESS) of 6–8 as their degree of shock is not as profound. Patients with a higher MESS should be considered for primary amputation.

New technologies to aid in reconstruction include the use of negative pressure wound therapy, broader-spectrum antibiotics, bone morphogenetic proteins, dermal substitutes, bone grafting substitutes, nerve grafting substitutes, easier options for distraction osteogenesis, and shock wave therapy. While enabling better reconstructive options, none of those new technologies have changed the difficult initial decision making when treating these patients. An attempt at limb salvage, which may involve multiple operations, is not without consequences, and there can be a risk of death.¹²⁹

A valid and reliable scoring system that would help predict which extremity can be successfully reconstructed and which should be amputated would be useful. Orthopaedic surgeons along with vascular, plastic, and general trauma surgeons have used several scoring systems to help guide the decision to amputate after severe lower limb trauma. The most commonly used scoring systems have been developed and designed to change a subjective clinical impression to an objective assessment.^{130,131,132,133,134} Unfortunately, the validation of these scoring systems is debatable at best. Due to the high-energy mechanism and the diversity of associated systemic injuries, most authors conclude that there are many exceptions to the rules of commonly used scoring systems. Efforts at validating these scores in subsequent studies in the civilian setting have shown low sensitivity.^135,136 Furthermore, most scoring systems were developed for mangled lower extremities and their application to the upper extremity is limited. All would agree that the hypotensive patient with prolonged limb ischemia requiring reconstruction is an absolute indication for amputation, especially in an environment with limited recourses.^134,135,136

Upper extremities differ from lower extremities when related to the approach to mangled extremity treatment for a number of reasons. Recent advances in the function and fitting of lower limb prostheses enable a relatively rapid return to good function. This is not true for the upper extremity whose function is more complex and critical and where such an injury is less likely to affect the survival of the patient. Therefore, most authors agree that reconstructive efforts are the rule when dealing with a complex injury in an upper extremity.

Replantation is the reattachment of a part that has been completely amputated. Revascularization requires reconstruction of vessels in a limb in which some soft tissue (skin, tendon, nerve) is intact.¹³⁷ Minor replantation is reattachment at the wrist, hand, or digit level, whereas major replantation is that performed proximal to the wrist.¹³⁷ In major replantations, ischemic time is crucial to muscle viability and functional outcome. The resulting myonecrosis and myoglobinemia and infection from ischemic muscle in major replantations may threaten the patient’s life as well as limb.

Traumatic amputations may be classified into three types as follows:

1. Guillotine sharp amputation with minimal soft tissue damage.

2. Crush amputations where there is adjacent local crushing injury.

3. Avulsion amputations in which tendon, nerve, vessels, and soft tissue structures are all injured at different levels. This occurs with the so-called ring avulsion injury. Such amputations are the most unfavorable for replantation.

While viability of the replantation is important, the most important measure of success is the useful function that can be achieved. Thus, replantation has both absolute and relative contraindications. Contraindications include a significant concomitant life-threatening injury, a severe chronic illness, or extensive injuries to the affected limb or amputated part. The following are important considerations¹³⁸:

1. A warm ischemia time of 12 hours for an amputated digit is a relative contraindication. Prompt cooling of the amputated part to 4–10°C alters the ischemic factor. Ischemia time is even more crucial for replants above the proximal forearm, and these should not be considered after more than 6–10 hours of warm ischemia time.

2. Good candidates for replantation are patients with amputations of the thumb or multiple digits or through the palm, wrist, and individual fingers distal to the insertion of the tendon of the flexor digitorum sublimis (superficialis). Single digit injuries in zone II, other than the thumb, are generally not reattached because of unfavorable functional outcomes. Such a replantation may be considered in a young child, or, perhaps, driven by potential occupational demands.

3. Important considerations are not only sex, occupation, and age, but the mental health of the patient also. Unfortunately, the mental stability of the patient is frequently difficult to assess in the limited time available for preoperative evaluation in the emergency room.

Amputation should not be considered an outmoded operation and is necessary when replantation is not indicated.¹³⁸ Should replantation be a consideration, the amputated part is placed in a clean and dry plastic bag that is sealed and placed on top of ice in a Styrofoam container. This keeps the part sufficiently cool without freezing.¹³⁷

In the operating room, one team can initiate exploration of the amputated parts for suitability of nerves and vessels even before the arrival of the patient. Shortening of the bones allows for skin to be debrided back to where it is free of contusion and where a direct tension-free closure can be achieved. This technique may reduce the need for vein and nerve grafting, also. A thumb bone, however, should not be shortened to less than 10 mm. The order of formal repairs is usually bone, tendons, arteries, nerves, and, finally, veins.¹³⁷

For major replantations, reestablishing arterial circulation as rapidly as possible is crucial to limit ischemia time.¹³⁷ An intraluminal vascular shunt may be placed between the arterial ends. Intermittent clamping of the shunt may, however, be necessary to restrict blood loss during the replantation. In the more proximal upper extremity, bone shortening can be aggressive to allow for primary neurovascular repairs and primary closure of the skin.

Postoperative dressings consist of strips of nonadherent gauze mesh, loose fluff gauze, and a plaster splint, and elevation minimizes edema and venous congestion. The patient’s room must be kept warm, and smoking is absolutely forbidden. In addition to antibiotics and analgesics, one aspirin tablet a day is advised because of its effect on platelet aggregation. Close postoperative monitoring for color, pulp turgor, and digital temperature is mandatory.