Chapter 42: Hand Surgery

Both in industry and in the home, the hand is the most commonly injured part of the body. Disorders of the hand rarely jeopardize life but can significantly affect the ability to function.

The prime functions of the hand are feeling (sensibility) and grasping. Sensibility is most important on the radial sides of the index, middle, and ring fingers and on the opposing ulnar side of the thumb, where one must feel and be able to pinch, pick up, and hold objects. The skin on the ulnar side of the small finger and its metacarpal, upon which the hand usually rests, must register the sensations of contact and pain to avoid burns and other trauma.

Mobility is critical for grasping. The upper extremity is a cantilevered system extending from the shoulder to the fingertips. It must be adaptable to varying rates and kinds of movements. Stability of proximal joints is essential for good skeletal control distally.

The specialization of the thumb has allowed humans to have superior aptitudes for defense, work, and dexterity. The thumb has exquisite sensibility and is a highly mobile structure with well-developed adductor and thenar (pronating) musculature. It is the most important digit of the hand, and every effort must be made to preserve its function.

The position of function of the upper extremity favors reaching the mouth and perineum and achieves a comfortable, forceful, and unfatiguing grip and pinch. The elbow is held at or near a right angle, the forearm neutral between pronation and supination, and the wrist extended 30 degrees with the fingers flexed to almost meet the opposed (pronated) tip of the thumb (Figure 42–1A). This is the desired position of the extremity if stiffness is likely to occur, and it should be maintained when joints are immobilized by splinting, arthrodesis, or tenodesis.

Opposite to the position of function is the position of rest, in which the flexed wrist extends the digits, making grip and pinch awkward, uncomfortable, weak, and fatiguing (Figure 42–1B). The forearm is usually pronated, and the elbow may be extended. This habitus is assumed, without intention, after injury, paralysis, or the onset of a painful stimulus. For that reason, it is also called the position of the injury. Immobility in this position jeopardizes function.

All references to the forearm and hand should be made to the radial and ulnar sides (not lateral and medial) and to the volar (or palmar) and dorsal surfaces. The digits are identified as the thumb, index finger, middle finger, ring finger, and small finger.

The skin is an elastic outer sleeve and glove of the arm and hand. Sacrifice of its surface area or elasticity by debridement and fibrosis can severely diminish the range of motion and constrict circulation. In the adult hand, the dorsal skin stretches about 4 cm in the longitudinal and in the transverse planes when the palm is flattened and spread. The long finger can have as much as 48 cm² of skin cover, and the whole hand (exclusive of digits) has 210 cm².

Fascia anchors the palmar skin to bone to make pinch and grip stable; the midlateral fibers of the Cleland and Grayson ligaments keep the skin sleeve from twisting around the digit (Figure 42–2). In the form of sheaths and pulleys, fascia holds tendons in the concavity of arched joints to convey mechanical efficiency and power. The fascial sleeve of the forearm, hand, and digits must sometimes be released along with skin to prevent or relieve congestion (eg, compartment syndrome). Any fascial compartment of the hand provides a space for infection or an avenue for its dissemination.

Each finger has three joints, the distal interphalangeal joint (DIP), the proximal interphalangeal joint (PIP), and the metacarpophalangeal joint (MCP). The thumb contains the IP, the MCP, and the carpometacarpal joint (CMC). The wrist is the “key joint” of the hand, governing motion of the digits, and may need to be included in the immobilization required for a major finger or hand problem. The position of the wrist governs the efficiency of extrinsic muscle contraction. The wrist is composed of a proximal and distal row of carpal bones. The proximal row contains the scaphoid, lunate, triquetrum, and pisiform, while the distal row contains the trapezium, trapezoid, capitate, and hamate. The stability of the digital joints and their planes of motion are governed by the length of the ligaments and the anatomy of their articulating surfaces. The longitudinal and transverse arches of the hand (Figure 42–3) are architectural prerequisites to gripping, pinching, and cupping, and are maintained by the active contraction and passive tone of intact muscles. The arches create the position of function. When the arches are collapsed, the hand assumes the position of injury. Loss of these arches is most often initiated by edema. They may be preserved by splinting in the position of function, elevation without constriction, and early restoration of active joint motion.

Each MCP and PIP joint has a distally anchored volar plate (Figure 42–4) in addition to collateral ligaments stabilizing the joint on either side (Figure 42–5). The thickened lateral portions of the volar plate form the checkrein ligaments, which prevent IP hyperextension.

The extrinsic flexor tendons are contained in fibrous sheaths to prevent bowstringing and preserve mechanical efficiency as the digits flex into the palm. Pulleys (hypertrophied sections of the sheath) resist the points of greatest tendency to bowstring. The retinacular pulley system contains five annular bands and three cruciform bands. Sheaths are inelastic and relatively avascular. Therefore, they crowd and congest any swollen, inflamed, or injured tendons and curtail glide by friction, constriction, and the generation of inelastic adhesions. The A-2 and A-4 pulleys must be maintained to prevent tendon bowstringing. These are located over the proximal and middle phalanges, respectively. The A-1, A-3, and A-5 pulleys are located over the MCP, PIP, and DIP joints, respectively. Five flexor tendon zones have been described. Zone II, or “no man’s land,” is the zone from the middle of the palm to just beyond the PIP joint, wherein the superficialis and profundus tendons lay ensheathed together and where recovery of glide is difficult after wounding (Figure 42–6).

Across the wrist, the dense volar transverse carpal ligament closes the bony carpal canal (carpal tunnel) through which passes all eight finger flexors as well as the flexor pollicis longus and median nerve (Figure 42–6). The ulnar bursa is the continuation of the synovium around the long flexors of the small finger through the carpal tunnel, encompassing the other finger flexors which interrupted their separated bursa at the midpalm level. The radial bursa is the synovium around the flexor pollicis longus contained through the carpal tunnel. These two bursas may intercommunicate. Parona space is the tissue plane over the pronator quadratus in the distal forearm deep to the radial and ulnar bursas.

The extensor tendons are ensheathed in six individual compartments at the wrist beneath the extensor retinaculum (Figures 42–7 and 42–8), which predisposes to adhesions. Its role as a pulley is not as vital.

The nerves of greatest importance to hand function are the musculocutaneous, radial, ulnar, and median nerves. The importance of the musculocutaneous and radial nerves combined is forearm supination and of the radial nerve alone is innervation of the extensor muscles. The ulnar nerve innervates 15 of the 20 intrinsic muscles. The median nerve provides sensation to the thumb, index finger, middle finger, and the radial aspect of the ring finger; through its motor innervation, it maintains most of the long flexors, the pronators of the forearm, and the thenar muscles. Figure 42–9 shows the sensory distribution of the ulnar, radial, and median nerves.

The presenting complaint must be assessed in complete detail with regard to its mechanisms of onset, evolution, aggravating factors, and relieving factors. Age, sex, hand dominance, occupation, preexisting hand problems, and relevant matters pertaining to the patient’s general health must also be noted.

The examination should follow an orderly routine. Observe the neck, shoulders, both upper extremities, and the action and strength of all muscle groups, and be certain that all parts can pass painlessly and coordinately through a normal range of motion, starting with the head and neck and working down to the fingertips. Compare both upper extremities and keep detailed notes, diagrams, and measurements. Having the patient reach for the ceiling and simultaneously open and close both fists and then spread and adduct the fingers and, finally, oppose the thumbs sequentially to each fingertip will immediately demonstrate any abnormalities.

Observe habitus, wasting, hypertrophy, deformities, skin changes, skin temperature, scars, and signs of pain (including when the patient attempts to bear weight on the palms). Feel the wrist pulses and the sweat of the finger pads, and test reflexes and the sensibility of the median, ulnar, and radial nerves.

Serial x-rays and laboratory studies may clarify a problem with an indolent evolution (eg, Kienböck avascular necrosis of the lunate, causing unexplained wrist pain). Contralateral and multiple-view x-rays in different planes are often helpful. In addition, computed tomography (CT) scans, magnetic resonance imaging (MRI), bone scans, or all of these may aid in diagnosis. This is especially true in patients who have persistent bone and joint pain or limited motion or in patients who have not attained adult growth. In the case of wrist problems, arthrograms and arthroscopy may be of diagnostic value. MRI can be quite helpful in the diagnosis of subtle carpal bone problems.

The diagnosis is often made by noting the response to therapy. This is particularly true in the case of local corticosteroids injected at the site of noninfectious inflammatory conditions (eg, carpal tunnel syndrome, trigger finger).

A bloodless field (eg, by tourniquet ischemia) is essential for accurate evaluation, dissection, and management of tissues of the hand. This is achieved by elevating or exsanguinating the extremity and then inflating a padded blood pressure cuff around the arm to 100 mm Hg above systolic pressure. This is readily tolerated by the unanesthetized arm for 30 minutes and by the anesthetized arm for 2 hours.

Incisions (Figure 42–10) must be either zigzagged across lines of tension (eg, must never cross perpendicularly to a flexion crease), termed Brunner incisions, or run longitudinally in “neutral” zones (eg, connecting the lateral limits of the flexion and extension creases of the digits), and whenever possible, must be designed so that a healthy skin-fat flap is raised over the zone of repair of a tendon, nerve, or artery.

Proper evaluation and treatment of an acute injury often requires extension of the wound. Normal structures can then be identified and traced into the zone of injury, where blood and devitalized tissue can make their identification difficult or impossible.

Constriction and tension by dressings must be avoided. The dressing should be applied evenly to the skin without wrinkles. The wound should be covered with a single layer of fine-mesh gauze followed by a moist spongy medium (fluffs, Rest-On, Kling, or Kerlix). Moisture facilitates the drainage of blood into the dressing, which should be applied with gentle pressure to restrict dead space.

Splinting and immediate elevation are paramount in controlling swelling and pain postoperatively. In general, plaster (fast-setting) or fiberglass is preferred because of its adaptability to specific requirements. More often than not, the wrist requires immobilization along with any other part of the hand (Figures 42–11 and 42–12).

It must be appreciated that effective immobilization of a finger most often requires concomitant immobilization of one or more adjacent fingers, usually in the position of function. Straight splints such as tongue blades involve a hazard of digital stiffness and distortion and should not be used across the MCP joint.

Persistence of pain signifies inadequate immobilization and, if throbbing is present, congestion. Congestion must be promptly relieved by elevation and sectioning of the cast and dressing and, if necessary, the skin and fascia.

Major congenital hand anomalies are not rare, with approximately 1 in 700 live births affected. When minor deformities are included, approximately 3% of all births are affected. Camptodactyly (bent finger), polydactyly (more than five fingers), and syndactyly (two or more fingers are joined together) are the most common malformations. Newborns with hand anomalies should be carefully examined for other malformations because multisystem syndromes can be present in 5% of patients (eg, vertebral, anal atresia, cardiac, trachea, esophageal, renal, and limb [VACTERL] syndrome with radial head dysphasia).

Anomalies may be inherited, caused by environmental factors (drugs, viral infections, irradiation, alcohol), or idiopathic. Major genetic or major environmental causes are infrequently found, suggesting that the cause of most defects is multifactorial.

In order to simplify an extremely complex clinical problem, the American Society for Surgery of the Hand (ASSH) and all major international hand societies have adopted a single classification system that divides anomalies into six main categories: failures of formation (absent digits, phocomelia [seal limb]), failures of differentiation (syndactyly), duplication (polydactyly), undergrowth (brachydactyly), overgrowth (macrodactyly), and constriction ring syndrome (focal necrosis, intrauterine amputation). There is considerable overlap in the categories, as might be expected.

Ideally, surgery is performed early in the first 2 years of life, but timing is individually tailored to the problem.

Movement of the muscles of the hand and arm are transmitted into finger and wrist motion by the tendons. The tendons are strong, compact units that glide within their individual compartments. Disruption of the tendon by trauma or loss of tendon gliding by inflammation hinders tendon excursion and therefore limits active motion of the joints. Passive motion of the joint is still possible with an isolated tendon problem and distinguishes tendon disorders from joint disorders when both active and passive motions are limited.

Tendon disruption can result from any penetrating injury and can be diagnosed by physical examination. A tendon injury should be suspected when the patient is unable to actively move a joint. Certain tendon lacerations, such as an isolated flexor digitorum superficialis disruption, may be masked because the profunda tendon can still move the entire finger. Blocking of profunda function by blocking flexion in the neighboring fingers (the profunda tendons are joined in the palm) reveals the injury to the superficialis when the injured PIP joint cannot be flexed.

The state of the wound and the complexity of the injury are the principal issues the hand surgeon must weigh in choosing between a primary or secondary tenorrhaphy. Clean wounds generally favor primary tenorrhaphy. Primary tenorrhaphy is defined as one that is done within 24-72 hours after injury. When wounds are unstable, contaminated, or complicated by fracture or ischemia, formal tenorrhaphy may have to be delayed for weeks or months until the tendon bed is more favorable to healing and glide. However, interim tacking of the tendons—together, to tendon sheaths, or to bone—to maintain the fiber length of a muscle may be done as a preliminary procedure.

Preoperative treatment of fresh lacerations consists of wound closure, immobilization, and prophylactic antibiotics. Such cases can be deferred for definitive primary repair for 24 hours or more. The timing of delayed secondary procedures depends on the resolution of wound edema and fibrous callus (ie, how soft and pliable it is). After 6-8 weeks, tendons that retract over 2.5 cm may defy full excursion because muscle elasticity has been lost or because the tendon is recoiled and congealed in scar.

Tenorrhaphy must be done without surface trauma along the tendon or its bed. The repair is made end to end or by weaving one tendon with the other, using a 3-0 or 4-0 braided synthetic polyester material, Prolene or nylon sutures. A flexor tendon graft is anchored distally to bone (Figure 42–13). Tenodesis will occur if the surface of the tendon and the surface where adherence is desired are roughened. The position of immobilization should relieve tension on the tendon juncture. The duration of immobilization after tenorrhaphy is generally no more than 3-4 weeks. Controlled early, passive or active mobilization after tenorrhaphy may be initiated as early as 1 week to minimize excessive tendon scarring. This requires a very cooperative patient and close supervision by the hand therapist to avoid rupture of the repaired tendon.

Adhesions invariably form wherever tendons are even slightly inflamed or injured and can severely limit tendon function. Even so, adhesions are necessary for a tendon to reestablish continuity. With continuous active and passive movement over months, tendon glide can be increased with maturation and molding of the collagen in the adhesions. If the adhesions remain thick and tendon excursion is limited, surgical release of the tendon adhesions (tenolysis) needs to be performed. Successful surgery requires the release of all adhesions limiting tendon glide without rupturing the tendon repair. Movement of the tendon as soon as possible after surgery (within 24-48 hours) under the guidance of the hand therapist is critical to avoid recurrence of adhesions.

The access to tenolysis should be through an incision offering effective exposure and placed where the immediate active and passive joint motion that must follow will not jeopardize healing of the wound by undue stretching or direct pressure. Performing a concomitant procedure requiring immobilization such as a neurorrhaphy should be avoided. The patient must understand that joint mobilization after tendon surgery is a time-consuming process, often taking many weeks or months to achieve maximum recovery.

Mallet finger (“baseball” or “drop” finger) (Figure 42–14) is due to disruption of the extensor tendon to the distal phalanx. A distal joint that can be passively but not actively extended is diagnostic. The injury most commonly results from sudden forceful flexion of the digit when it is held in rigid extension. Either the extensor is partially or completely ruptured or the dorsal lip of the bone is avulsed. Less frequently, the injury is due to direct trauma such as a laceration. An x-ray should be taken to determine the presence and extent of any fracture.

Treatment requires 6-8 weeks of continuous splinting in full distal joint extension (not hyperextension) with or without 40 degrees of PIP joint flexion. Patient education and compliance are essential for good results. Joint fixation internally with a percutaneous Kirschner wire or externally with padded aluminum, plastic, or plaster splints are equally effective. A lacerated tendon should be repaired. When a significantly displaced fracture fragment represents one-third or more of the surface of the joint, it should be reduced by wiring or pinning. If there is sufficient articular surface disruption, one may consider joint fusion.

Swan-neck deformity (Figure 42–14) is a frequent complication of mallet finger, but it may also be the result of disparity of pull between the extrinsic flexors and extensor hood with or without attenuation of the DIP joint extensor. It is seen in congenitally hypermobile joints, spastic, and rheumatoid states, and following resection of the superficialis tendon. The dorsal hood acts to extend the distal joint but is held back by its insertion at the base of the middle phalanx, which it therefore hyperextends. This in turn increases the tension on the profundus, which hyperflexes the DIP joint. If the mallet deformity is 25 degrees or less and there is some active distal joint extension, it may be treated by undermining and elevating the extensor hood at the PIP joint and severing its insertion on the base of the middle phalanx. Otherwise, the deformity may be corrected by tethering PIP joint extension with one slip of the flexor digitorum superficialis threaded through the flexor pulley of the proximal phalanx with the PIP joint flexed 20 degrees.

The boutonnière, or “buttonhole,” deformity (Figure 42–15) appears as the opposite of the swan-neck deformity: hyperextension of the DIP joint and flexion of the PIP joint. There is attenuation or separation of the dorsal hood, so that the middle extensor tendon becomes ineffective and the lateral extensor tendons shift volar to the PIP joint axis and the joint buckles dorsally. The entire extrinsic-intrinsic force on the hood passes onto the lateral extensor tendons, which flex the PIP joint and hyperextend the DIP joint. This deformity may develop suddenly or, more often, insidiously after closed blunt or open trauma over the dorsum of the PIP joint.

To avoid this complication, sutured extensor tendon lacerations and severe contusions over the PIP joint should always have the PIP joint alone splinted in extension for 3-4 weeks. Established deformities can be treated by such immobilization but more often require operative correction.

STENOSING TENOSYNOVITIS

In stenosing tenosynovitis, there is a disproportion between the clearance inside a tendon pulley or tunnel and the diameter of the tendon or tendons that must glide through it. Any pulley or tunnel may be implicated. The more common sites are as follows:

1. The proximal digital (A1) pulleys in the distal palm, causing trigger finger or thumb. There is local tenderness of the pulley; pain, which may be referred to the PIP joint; and (usually but not always) locking of the digit in flexion with a painful “pop” as it goes into extension (ie, as the bulge in the tendon or tendons passes through the tight pulley).

2. The pulley over the radial styloid housing the abductor pollicis longus and extensor pollicis brevis (first extensor compartment), causing de Quervain tenosynovitis. Local tenderness and pain occur if these tendons are actively stretched (eg, Finkelstein test). The Finkelstein test is performed by having the patient bend the thumb into the palm and grasp with the fingers. The wrist is then bent ulnarly, and the first extensor compartment palpated. Pain in this area suggests de Quervain tenosynovitis.

Relief of the symptoms can be achieved by local injections of triamcinolone mixed with lidocaine. Immediate surgery is justified if the constriction is so tight that the tendon is locked. Surgical section of the constricting tendon sheath is also indicated if symptoms persist or recur. When releasing the flexor tendon, care is taken not to resect more than the section of sheath restricting the tendon or else the tendon will pull away from the finger like a bowstring and weaken the grip.

Injuries to the bones and joints of the hand are the most common skeletal injuries treated by physicians. Recognition of the injury, appropriate diagnostic tests, and timely treatment are essential for minimizing the complications of these injuries. Some patients may neglect obvious fractures and dislocations in hope of spontaneous recovery. More subtle injuries to the wrist are more often neglected by the patient and sometimes even missed by physicians until further damage is done. The use of the fluoroscope, found in many offices, greatly enhances the surgeon’s ability to diagnose fractures. The machine allows real-time assessment of the bones as part of the physical examination. A common late sequela of skeletal injury at the articular surfaces is osteoarthritis, which is difficult to treat. Patients with symptoms related to the hand or wrist but without a discernible cause should be referred early to a hand specialist.

METACARPALS & PHALANGES

Fractures

Fractures of the metacarpal and phalangeal bones such as distal phalanx tuft of the fingers caught in closing doors and metacarpal shaft fractures of the ulnar side of the hand (boxer’s fractures) create an obvious deformity and are easy to diagnose. Adequate x-rays of the specific site of the fracture with anteroposterior, lateral, and oblique views are essential for developing a treatment plan.

Fractures of the shaft can usually be treated with closed reduction and a cast or splint holding the hand in the position of function (Figure 42–1) for 3-4 weeks. Residual angulation of a metacarpal shaft fracture of up to 30 degrees in the fifth finger and 20 degrees in the fourth finger is functionally well tolerated, although a dorsal bump may be aesthetically unpleasant. However, even a small rotational misalignment of the fracture at the metacarpal bone results in scissoring of the fingers in flexion and causes severe dysfunction.

When fractures do not remain reduced, fixation with Kirschner pins placed through the skin is required. Placement of more than one pin is usually needed to keep the fracture reduced. The pins are removed after the fracture is healed. Displaced and comminuted fractures may require opening of the fracture site and reduction under direct visualization. Pins, lag screws, and small, low-profile metal plates and screws are used to maintain reduction. Metal plates provide strong support to the fracture site and allow earlier mobilization of the hand. However, plates are more invasive and occasionally interfere with tendon function due to excessive scar formation postoperatively.

Fractures through an articular surface need to be carefully evaluated. Nondisplaced fractures can be treated by casting. Displaced fractures require open reduction and accurate pin or lag screw fixation because discrepancies of the articular surface will eventually result in degenerative arthritis.

Fractures of the distal phalanx from crush injuries require attention to the disrupted nail bed. The nail is removed to decompress the painful subungual hematoma and provide irrigation of the open fracture and careful reapproximation of the nail matrix. Large disruptions in the nail matrix may result in deformity of the regenerating nail. The nail is replaced under the nail fold (eponychium) as a splint. A protective splint is placed over the finger to hold the distal fragment in extension.

An intra-articular fracture of the base of the thumb metacarpal bone with subluxation (displacement) of the metacarpal leaving a volar pyramidal shaped fragment attached to the trapezium is called a Bennett fracture. The anterior oblique ligament, responsible for stability of the thumb base, is left attached to the pyramidal fragment. The remainder of the thumb metacarpal is unstable and limits use of the thumb. The fracture must be reduced and stabilized with Kirschner pins, plate, or lag screws. Accurate reduction of the articular surface is crucial in reducing complications. Even despite adequate treatment, most patients eventually develop arthritis.

Dislocations

Dislocations are most common in the PIP joint. Injuries are classified according to the position of the distal digit as hyperextension, dorsal displacement, or volar displacement. The type of dislocation determines which structures, such as the volar plate, collateral ligaments, and extensor tendon, are likely to be disrupted.

The MCP and CMC joints are better protected by surrounding soft tissue but can still be dislocated. The MCP joint of the thumb is most frequently injured by forced abduction. The ulnar collateral ligament is torn, as occurs with forced use of a ski pole or as historically described in gamekeepers when twisting the neck of birds (“gamekeeper’s thumb”). Of the CMC joints, the fifth is most commonly injured. A fracture analogous to a Bennett fracture (reverse Bennett fracture) can occur. Examination to determine injury to the deep motor branch of the ulnar nerve in this area should be done.

Radiographs are occasionally useful for diagnosis, but the physical examination is most important. Since pain often limits the extent of the examination, regional anesthesia with a wrist or finger block allows a more detailed examination. Partial tears of ligaments without dislocation or instability are treated by splints. Dislocations can usually be reduced, and the need for surgical therapy is determined by the stability of the joint after reduction. Stable reductions are treated with early mobilization to decrease stiffness.

Fracture dislocations usually require surgical repair. Instability after reduction can be treated by repair of the torn collateral ligament or volar plate. Severe dislocations of the PIP and MCP joints can result in interposition of disrupted soft tissue in the joint, making closed reduction impossible. The joint must be opened and the trapped soft tissue removed and repaired to correct the dislocation. A complete disruption of the ulnar collateral ligament in a gamekeeper’s thumb injury can result in interposition of the adductor aponeurosis between the torn ends of the ulnar collateral ligament. The ends of the ligament must be reduced and repaired under direct vision.

WRIST & FOREARM INJURIES

Fractures

Fractures in the wrist and forearm usually result from falls on the outstretched hand. The distal radius is most commonly fractured. Many classification systems and eponyms have been used based on the extent and displacement of the fracture and involvement of the articular surface. The hyperextended wrist also exposes the scaphoid bone to injury in a fall. Since the scaphoid is crucial to wrist motion, displacement of the fracture is poorly tolerated. In addition, the blood supply enters the distal part of the bone and makes ischemic necrosis of the proximal fragment a problem.

Diagnosis of distal radius fractures is not difficult, but scaphoid fractures can easily be missed. Special radiographic views of the wrist or CT or MRI scans may be needed in difficult cases. If the clinical picture is suspicious but the radiographs are inconclusive, the wrist should be immobilized. Repeat radiographs in 7-10 days may demonstrate the fracture. Untreated scaphoid fractures lead to debilitating arthritis and collapse of the wrist.

Distal radius fractures are treated by reduction and immobilization. As with other fractures, articular irregularities and unstable fractures need to be treated by open reduction and internal fixation. Use of bone grafting and external fixation devices to initially treat the fracture has been advocated. Scaphoid fractures require careful and prolonged immobilization. Displaced fractures or nonhealing fractures require operative treatment with screw compression, bone grafts, and/or scaphoid replacement.

Dislocations & Sprains

Dislocations and ligamentous injuries of the wrist are the most difficult hand injuries to diagnose and treat. Wrist injuries often present as a painful wrist after minor trauma. Routine radiographs are often normal, and physical findings can be unimpressive. Still, these injuries can lead to chronic problems. Special stress radiographs, fluoroscopy, and physical maneuvers (scaphoid shift test) help delineate the injury.

The scaphoid lunate ligament is most often injured. Instability of the joint is best treated by repair or reconstruction of the ligament. Injury of the ligaments of the radiocarpal-radioulnar joint is likewise difficult to determine. Surgical treatment involves repair of the disrupted ligament.

NERVE DISORDERS

Nerve disorders of the hands are conveniently organized into compression neuropathies, injuries of peripheral nerves, and various problems located more proximal to the upper extremities (spinal cord or central nervous system). For nerve dysfunction due to strokes, cerebral palsy, and spinal cord injury, readers are referred to more specific textbooks on hand surgery.

Compression Neuropathies

Compression of the nerves of the upper extremities due to an increase in surrounding tissue pressure occurs in specific locations and causes predictable signs and symptoms. Tissue edema from a variety of causes such as crushing injuries, vascular disorders, and prolonged repetitive hand motions can compress nerves traveling within tight compartments of the arm and produce nerve ischemia. Prolonged ischemia results in axonal destruction and sensory and motor dysfunction.

The median nerve can be compressed by local structures at the elbow (pronator syndrome), the anterior interosseous branch, and the wrist (carpal tunnel syndrome). Compression of the median nerve at the elbow causes forearm pain and sensory changes in the radial four fingers. The anterior interosseous branch of the median nerve is purely a motor nerve, and lesions produce only weakness of thumb and index finger flexion and no pain. Carpal tunnel syndrome presents with weakness in the hand, sensory abnormalities of the fingers sparing the small finger and ulnar aspect of the ring finger, and exacerbation of symptoms on forced flexion of the wrist (Phalen sign) or tapping the nerve at the wrist (Tinel sign). Shoulder, elbow, and forearm pain is also common. Atrophy of thenar muscles occurs in long-standing cases.

The ulnar nerve can be compressed at the elbow (cubital tunnel syndrome) or the wrist (Guyon canal). Sensory abnormalities in the small finger and weakness of intrinsic hand muscles occur with compression in either area. Segmental nerve conduction velocity tests help to localize the abnormality to one site or the other. Compression of the radial nerve occurs most frequently from fractures of the humerus. Compression of the nerve along the proximal radius (radial tunnel syndrome) causes diffuse pain around the elbow but occurs rarely.

Abnormal findings on nerve conduction studies and clinical manifestations of nerve compression are adequate for diagnosis. Electromyography (EMG) demonstrating denervation patterns in the corresponding muscles or slowing of nerve conduction velocities indicates injury to the nerve. Although helpful, these tests only complement the physical examination, since electrodiagnostic tests can occasionally be inaccurate.

Early or mild cases of compression are treated by controlling tissue swelling. Resting the extremity with splints and using nonsteroidal anti-inflammatory medications as well as local injection of steroids often resolves the problem. If repetitive motions, such as typing, are thought to be the cause, changing the motion or hand position should help. If clinical manifestations are severe or if nonsurgical therapy fails, surgical decompression of the nerve is advocated.

Carpal tunnel syndrome is the most common type of compression neuropathy and one of the most common hand disorders. Surgical therapy of median nerve entrapment in the carpal tunnel or any of the compression neuropathies requires detailed knowledge of the anatomy. Division of the constricting structures results in partial or complete reversal of the symptoms. In the carpal tunnel, the median nerve is surrounded on three sides by carpal bones. Incision of the transverse carpal ligament, which forms the roof of the tunnel, decompresses the nerve. Occasionally, internal fibrosis of the nerve occurs and internal neurolysis with an operating microscope is required to allow the nerve to recover. Endoscopic release of the carpal tunnel through a smaller skin incision has been advocated.

Nerve Injuries

Injury to individual peripheral nerves of the arm results in predictable and defined deficits. Proximal injuries involving the brachial plexus have more variable manifestations. Nerve conduction can be disrupted in the absence of structural changes due to compression, blunt injury, or ischemia (neuropraxia). More severe injury results in disruption of the axon with preservation of the epineurial covering of the nerve (axonotmesis). Both types of injury are followed by spontaneous recovery of function of good quality. Complete disruption of the nerve (neurotmesis), as with a laceration, requires surgical repair. Wallerian degeneration of the distal nerve occurs in both neurotmesis and axonotmesis, and recovery depends on the growth of the cut axon to the end organ. However, with neurotmesis, orientation of the proximal and distal axons is lost and recovery may be incomplete, especially in mixed motor and sensory nerves. Methods to differentiate sensory from motor fascicles have been used during repairs with some benefit.

A patient with loss of the radial nerve is unable to extend the fingers, wrist, and thumb. In addition, the patient will have sensory loss to the dorsum of the hand. Median nerve dysfunction causes problems with opposition of the thumb and grip of the fingers. Sensory loss is to the radial four digits and can significantly impair use of the hand. An ulnar neuropathy causes dysfunction of the intrinsic muscles of the hand, clawing of the ulnar two digits, and weakness in gripping smaller objects. Sensation is lost along the ulnar side of the hand.

Diagnosis of nerve injury is mainly by the physical examination. Understanding the functional anatomy of the peripheral nerves allows adequate evaluation of nerve loss. Electrodiagnostic studies are used to distinguish between partial and complete lesions and to follow functional recovery.

Obvious and complete disruption of the nerve is treated best by early surgical exploration and repair. An incomplete lesion or questionable disruption of nerve integrity is best treated with close observation, splinting to prevent contractures, and surgical exploration if no recovery occurs. Segmental loss of nerves requires nerve grafts, usually taken from a minor sensory nerve, such as the sural nerve, to bridge the gap. Results of primary repair are better than the results of grafts, and repairs done soon after injury are better than delayed repairs. Recovery of protective sensation of the hand is crucial for good functional recovery.

Motor dysfunction due to nerve damage can be treated by arthrodesis (stabilization of flail joints) and tendon transfers. Tendon transfers should utilize a muscle unit that is unaffected by the nerve injury, have direction of force and excursion similar to those of the damaged muscle, and produce no further deficits due to loss of the donor muscle. For radial nerve palsy, the pronator teres to extensor carpi radialis transfer provides wrist extension, the flexor carpi radialis to extensor digitorum communis transfer gives finger extension, and the palmaris longus or flexor digitorum superficialis of the fourth finger transfer to the extensor pollicis longus extends the thumb. Restoration of thumb opposition is most important with median nerve palsies, and the use of several donor muscles to achieve this result has been described including the extensor indices proprius and flexor digitorum superficialis from the middle or ring fingers. Tendon transfers to control claw deformity and strengthen key pinch are used for ulnar nerve palsies.

Small breaks in the skin or nails of the hand can lead to widespread infection and abscess. The original injury often cannot be identified. Poor venous and lymphatic drainage of the upper extremity, especially when held in a dependent position, aggravate the situation. Immunocompromised patients (diabetics, HIV-positive patients) are prone to develop extensive infections very quickly and should be treated more carefully.

The hallmark of infection (pain, swelling, and erythema) may be widespread in the hand and make localizing the infection difficult. Swelling of the dorsum of the hand is common even with palmar infections, and knowledge of the tissue planes of the hand is crucial to understanding how infections spread. Lymphatic streaks (lymphangitis) extending up the arm indicate rapid extension of the infection and must be treated urgently.

Oral antibiotics effective against staphylococcus and common anaerobic organisms (ie, first-generation cephalosporins and penicillin) are adequate to treat most infections. Infections from animal bites (Pasteurella multocida) and human bites (oral flora) also respond to penicillin. The intravenous route is reserved for severe infections or for those not responsive to oral antibiotics. Once the situation improves, oral antibiotics are given for 7-10 days. Equally as important, the infected hand needs to be immobilized and elevated. Pillows and trapezes help to elevate the arm, but elbow slings aggravate the dependent position of the arm and should not be used. The best results are obtained when the patient is convinced that elevation of the extremity is beneficial.

Once treatment of a hand infection has begun, improvement within 24 hours is expected. If prompt improvement does not occur, an occult abscess may be present. Obvious abscesses should be drained at the point of maximum tenderness or the point of maximum fluctuance, where the overlying tissues are thinnest. The drainage wound should run parallel to and not across the paths of nerves, arteries, and veins. Wounds should be made long enough and should be zigzagged, when necessary, to avoid secondary contractures. Ultrasonography may be useful when a definite abscess cannot be located.

Pyogenic Granuloma

Pyogenic granuloma is a mound of granulation-like tissue 3-20 mm (or more) in diameter. It usually develops under a chronically moist dressing and may form around a suture. A small granuloma (6-7 mm in diameter) exposed to the air will soon dry up and epithelialize, whereas larger ones should be scraped flush with the skin under local anesthesia and covered with a thin split-thickness skin graft. If the granuloma is adjacent to the nail and the nail is acting as a foreign body aggravating the reaction, the nail must be removed.

Nail Infections

The nail fold is often traumatized and becomes secondarily inflamed, leading to a paronychia on the radial or ulnar side. The lesion is termed an eponychia if it involves the base of the nail, although the entire fold can be involved; and it is called a subungual abscess if pus develops and extends under the nail plate. Because of the early and unrelenting tissue tension that develops, these entities are quite painful. Early treatment before abscess formation consists of soaking, elevation, immobilization, and antibiotics. Most abscesses can be drained painlessly with a scalpel; the insensate necrotic skin cap should be cut through where it points (Figure 42–16). Sagittal incisions, which form a “trapdoor” of the eponychium, should be reserved for the long-standing case in which a dense fibrous callus of the nail fold must be excised. Occasionally, the nail must be basally excised or totally avulsed, after which the eponychial fold should be separated from the nail matrix by a thin, loose pack. Chronically wet nails of dishwashers may develop tissue changes and nail deformities, which are best treated by removing the nail plate. Fungal infections should be diagnosed and treated, and the fingers should be protected from water or excessive sweating.

Deep Space Abscess

A felon is an abscess in the pulp of the fingertip and is often deep and very painful. Untreated or inadequately drained abscesses may lead to osteomyelitis of the distal phalanx. Incision and drainage with disruption of the many vertical fibrous septa of the pulp space are required to adequately drain the abscess (Figure 42–17). The traditional fishmouth incision is no longer recommended for drainage since it may expose the underlying bone and because it often heals in a tender scar. Instead, lateral through-and-through incisions or direct incisions on the pulp, where the abscess points, have better results (Figure 42–18).

The web spaces are the path of least resistance for pus from infected distal palm calluses, puncture wounds, and infections of the lumbrical canals. Infection and abscess formation in the dorsum of the thumb web may be the result of extension from the volar thenar space (collar button). A dorsal incision is usually made between the fingers to drain both spaces. A dorsal incision in the web of the thumb may be zigzagged to prevent contracture (Figure 42–10).

The midpalmar space becomes infected by direct puncture or by extension of infections from the flexor sheaths of the index, middle, or ring fingers (Figure 42–6). Only the skin should be incised over the point of fluctuance. The rest of the dissection should be carried out by gentle spreading with a blunt clamp to avoid injury to arteries, nerves, and tendons. Infection spreads easily from this space along the lumbrical canals and to the thenar space.

A hypothenar space abscess is usually a product of a penetrating wound and should be drained at the point of greatest fluctuance. The same is true for a thenar space abscess, which may point in the palm rather than the thumb web.

Infection within the synovium of the flexor tendon is difficult to diagnose. Pyogenic tenosynovitis spreads easily down the tendon sheath to affect the other fingers. Untreated, the infection causes adhesions of the tendon to the surrounding soft tissues and permanently limits movement of the fingers.

The signs of flexor tendon infection described by Kanavel include fusiform swelling of the digit, severe pain on passive finger extension, a fixed flexed position of the finger, and most importantly, tenderness over the extent of the tendon sheath into the palm. Ultrasonography of the distal palm can also be helpful when the diagnosis is unclear. The probe is held across the palm and reveals swelling of the involved tendon and fluid around the tendon at the proximal flexor sheath.

Only unresponsive, tensely swollen, and toxic cases need immediate incision and drainage. With rest, elevation, and antibiotics, it is safe to observe most cases for several hours. The most common method of incision and drainage (Figure 42–19) is to make a short sagittal midline distal wound immediately over the tendon and introduce a small plastic catheter into the synovial bursa for irrigating with an antibiotic solution. The catheter should pass through the sheath and exit by a counterincision in the palm to allow for drainage of the fluid. Not all surgeons advocate placement of an irrigation catheter, however. When a catheter is placed, it should remain for only 24-48 hours. These incisions do not cross flexion creases. The hand should then be elevated and immobilized in the position of function and covered by a dressing. Phlegmonous tenosynovitis usually requires opening of the entire synovial sheath (often through a lateral midaxial digital incision or longitudinally across the wrist for extensor sheath infections) and, frequently, excision of necrotic tendon and sometimes amputation of a digit.

Other Infections

Necrotizing soft tissue infections of the upper extremity are rare but devastating when they occur. The condition has been called many different names such as necrotizing fasciitis, Meleney ulcer, and streptococcal gangrene. The organisms responsible include clostridium species, Streptococcus pyogenes, and mixed infections. The hallmarks are the rapid spread of infection and the extensive necrosis of soft tissue. Treatment includes wide debridement of the necrotic tissue and intravenous antibiotics.

Human bite wounds of the hand occur most often during altercations when the fist strikes an opponent’s tooth. The MCP joint can be entered. The injury is often ignored by the patient until infection of the joint has begun. The joint must be explored and cleaned and the patient treated with antibiotics to cover oral flora (penicillin). Once the infection reaches the joint, destruction of the cartilage often occurs despite all therapy.

An inordinate amount of pain, with little or no swelling or induration, predating and accompanying the appearance of multiple tiny vesicles, suggests herpes simplex (herpetic whitlow). The vesicles may appear cyclically. They contain clear fluid and not pus and should be distinguished from paronychia. Antibiotics are not indicated in this self-limited viral infection. Acyclovir 5% ointment applied topically for 7 days decreases the severity and duration of symptoms but is of no value in prophylaxis.

Tuberculous infection of the hand is usually chronic and may be relatively painless. Some cultures take months to become positive. Tuberculosis commonly involves only one hand, which may be the only focus of infection in the body. Bones and joints may be infected, but the process more commonly involves the tendon synovium, which becomes matted to the tendons. Treatment is by synovectomy and antituberculous drug therapy for 6-12 months.

Leprosy causes neuritis of the median and ulnar nerves, resulting in sensory and motor loss to the hand. Crippling claw deformities develop as a result of intrinsic muscle palsy. Open sores appear on the hands as a result of trauma to anesthetic digits. Reconstructive surgery and occupational training are required.

Fungal infections involve primarily the nails. Tinea unguium (onychomycosis) may be caused by many organisms, including Epidermophyton floccosum, Trichophyton, and Candida albicans. Prolonged treatment with antifungal drugs—griseofulvin systemically or nystatin topically—may be necessary, along with daily applications of fungicidal agents such as tolnaftate. Removal of the nail is advocated for chronic intractable cases.

DUPUYTREN CONTRACTURE

Palmar Fasciitis

The cause of Dupuytren contracture, which is common particularly among white populations of Celtic origin, is not known. It occurs in one of three types (acute, subacute, and chronic), predominately in men over 50 who have been in sedentary occupations, and is bilateral in about half of cases. There is a hereditary influence, and the incidence is higher among idiopathic epileptics, diabetics, alcoholics, and patients with chronic illnesses. The contracture may develop in people who do not work and (in laborers) in the hand that does the least work, so that it is not considered work related. It is frequently found in the plantar fascia of the instep and occasionally in the penis (Peyronie disease).

Dupuytren contracture manifests itself most commonly in the palm by thickening, which may be nodular, and therefore mistaken for a callosity, or may be cord-like, and therefore mistaken for a tendon abnormality because it passes into the digits and restricts their extension. This process typically involves the longitudinal and vertical components of the fascia but at times seems to exist apart from anatomically distinct fascia. The skin may fuse with the underlying fascia and become raised and hard, or it may be greatly shrunken and sometimes drawn into a deeply puckered crevasse. The disorder invades the palm at the expense of fat but is never adherent to vessels, nerves, or musculotendinous structures (though it may be adherent to flexor tendon sheaths). It has an unpredictable rate of progression, but the earlier it starts in life, the more destructive and recurrent it is apt to be.

Dupuytren fasciitis may involve any digit or web space, but it affects predominantly the ring and small fingers. In long-standing cases, the fingers may be drawn tightly into the palm, resulting in secondary contracture of joint capsule and ligaments, flexor sheaths, and atrophic muscles.

The most recent addition for the treatment of Dupuytren contracture is enzyme (collagenase) injection. Based on early studies, it appears that this treatment works best on MCP contractures rather than PIP contractures in patients with a well-defined cord. This treatment does require two office visits, one for the injection and a follow-up visit to manipulate and rupture the cord.

Surgery is indicated when the disorder has progressed sufficiently, especially when it causes more than 30 degrees of flexion at the MCP joint or any flexion contracture of the PIP joint. The patient must be warned about the increasing technical difficulty with progressive flexion and adduction contractures and the potential for recurrence after surgery. Fasciectomy is the surgical procedure that gives the best long-term results. In selected cases where only the longitudinal pretendinous fascial band is involved and the skin moves freely over it, subcutaneous fasciotomy done through a small longitudinal incision may release a contracture quite well with only a few days of postoperative disability. In the occasional case with acute and rapid onset of a tender nodule, local triamcinolone may be used for subjective and even objective relief.

Depending on the amount of cutaneous shrinkage, skin grafts may be required for wound closure after fasciectomy. The overlying dermis has been implicated as an inductive mechanism in this process. Thus, skin grafting may diminish the recurrence rate in severe cases. The hopelessly contracted little finger must sometimes be amputated.

Motion should be started within 3-5 days after surgery. Dynamic splints and postoperative injection of corticosteroids into joints and the zone of surgery may help the well-motivated patient.

The potential complications of surgery are wound breakdown (loss of skin flaps), hematoma, fibrosis and stiffness, digital nerve injury, recurrence of contractures and digital ischemia secondary to digital artery injury. Reflex sympathetic dystrophy, a painful, debilitating neurologic disorder of the hand, can occur after surgery and must be treated aggressively. In general, the functional reward for the patient is great at any age.

DEGENERATIVE & RHEUMATOID ARTHRITIS

Arthritis of the hand is divided into two categories. Degenerative changes are usually due to some trauma resulting in damage to the bone or cartilage or to the supporting ligamentous structures. The increased wear to the joint results in inflammation and damage to the cartilage or underlying bone followed by reactive new bone formation (spurs). The wrists, hips, and knees are most commonly affected. Rheumatoid arthritis is a systemic disease characterized by synovial inflammation. The diseased synovium destroys adjacent tendons and joints in a specific way, leading to characteristic deformities in the hand.

Patients with degenerative arthritis complain of pain, aching, and stiffness in the area of the affected joint. Progression of the problem leads to immobility of the joint that affects the entire hand. Radiographic studies demonstrate joint narrowing and periosteal thickening early in the problem, progressing to bone spurs, loss of the articular surface, and bone destruction later. Patients with rheumatoid arthritis often present with very severe deformities without pain. Nodules around the olecranon and dorsum of the hand are often found. Both flexor and extensor tendons at the wrist can be inflamed, limiting tendon movement and resulting in rupture of the tendon. Involvement of the tendons and ligaments at the digits and MCP joints results in ulnar deviation of the digits, MCP joint destruction and dislocation, and swan-neck and boutonnière deformities. Destruction of the wrist joint is also common.

Arthritis is common among older patients and usually treated by primary care physicians and rheumatologists with anti-inflammatory medications and modification of the patient’s activities. In most cases, it is only when symptoms greatly hinder the patient’s lifestyle that they are referred to a hand surgeon. Physical therapy, splints, and medications are often no longer effective for these patients.

Surgical treatment of painful joints includes replacement with a prosthetic joint and partial or full fusion. Prosthetic joints of metal or Silastic permit near-normal movement but can become unstable and dislocate or degenerate over time. For a durable solution to the problem, fusion of the joint is recommended. Motion is severely limited, but pain relief is complete. There are more therapeutic options for the wrist, such as replacement, local fusion of only the affected carpal bone, or complete excision of the proximal row of carpal bones, leaving motion and stability to the distal carpal bones and ligaments.

Therapy for synovial inflammation in rheumatoid disease includes excision of the synovium to increase tendon excursion and prevent rupture, repair of ruptured tendons, and excision of painful nodules. Tendon-balancing procedures can help ulnar deviation of the MCP joints and improve joint movement. The most important concept of treating patients with rheumatoid hand disease is that often the patients have adapted well to their functional deficits. Correcting a physical deformity in a well-compensated patient may actually result in more problems for that patient.

SCLERODERMA & LUPUS ERYTHEMATOSUS

These systemic diseases of unknown cause have distinctive—though not necessarily pathognomonic—manifestations in the hands.

Scleroderma initially produces joint stiffness, hyperhidrosis, and Raynaud phenomenon. Unchecked, it leads to marked tautness of skin and rigidity of joints with associated osteoporosis (even atrophy and ultimate resorption of the distal phalanges) and soft tissue calcifications.

Lupus erythematosus, which may be initiated or aggravated by certain drugs, foreign proteins, or psychic states, often causes polyarthritis indistinguishable from that of rheumatoid arthritis. It does not usually lead to similar joint destruction. Vasospasm in both lupus and scleroderma can cause severe ischemia of the hand and digits and may require therapy to prevent gangrene.

GOUT

Gout is a metabolic disorder of uric acid metabolism that affects about 1% of the population; approximately 50% of patients with gout have cheiragra (gouty hands).

The diagnosis is suggested by a rapid onset of severe pain and inflammatory signs about the joints and musculotendinous structure, simulating a phlegmonous infectious cellulitis with marked induration (most dramatically seen about the elbow). The usual duration of an attack is 5-10 days. The serum uric acid is elevated in 75% of cases. Gout may coexist with rheumatoid disease. The diagnosis is confirmed by identification of uric acid crystals in joint fluid or tissue biopsy.

In time, typical tophi form, consisting of toothpaste-like infiltrates of urate crystals, arising in multilobulated form about soft tissue structures that have been invaded. X-rays show characteristic punched-out lesions at the margins of articular cartilage.

Prophylactic treatment of gouty arthritis consists of diet, colchicine, allopurinol (a urate-blocking agent) or probenecid (a uricosuric agent), and avoidance of stress. Colchicine, 0.6 mg/h with a glass of water for six to eight doses or to the point of gastrointestinal distress, is the time-honored means of interrupting an attack, but phenylbutazone, topical corticotropin gel, and systemic corticosteroids are also of value.

Surgical measures consist of drainage of abscessed tophi (seldom needed) and tophectomy. The latter procedure is more often of cosmetic rather than functional value. Tophectomy consists of removal of as much tophaceous material as can be fairly easily recovered. The surgeon should be careful not to destroy ligaments, tenoretinacular structures, nerves, and vessels in the process.

BURNS & FROSTBITE OF THE HAND

Thermal Burns

The hands are a common site of thermal (including frictional), electrical, chemical, and radiation burns. Function is imperiled in all instances by swelling and scar formation. Prompt measures to preserve existing function are often urgently required. Burns over other areas of the body may be more life threatening and require more urgent attention, but burns of the hand should never be neglected. Delay in therapy leads to irreversible impairment and deformity that are impossible to correct later.

As in other areas of the body, thermal burns are grouped into three degrees. Superficial (first-degree) burns are red and painful; partial-thickness (second-degree) burns develop blisters; and full-thickness (third-degree) burns are insensate and appear like leather or charred tissue. The prognosis and therapy depend on the location, depth, and extent of the burn.

All burns to the hand cause swelling of the tissues, and the need for elevation of the arm to relieve pain and prevent stiffness cannot be overemphasized. Tetanus immunization should be given. Cold compresses may help alleviate the pain in first-degree burns. Second-degree burns must be watched more carefully. Large blisters restricting motion are broken. Otherwise, since they are sterile, they should be left intact. Treatment with thrice-daily washing and silver sulfadiazine is usually adequate. Patients with third-degree burns or superficial burns that fail to heal and patients unable to care for their burns at home should be admitted to the hospital.

Deeper burns require close observation and more extensive treatment. In the first few hours after injury, circumferential or near-circumferential burns may cause ischemia in the extremity. Because evaluation of sensory function and capillary refill is nearly impossible in these limbs, escharotomies should be performed if compartment syndrome is suspected. If done correctly, escharotomies have few complications, since these burns usually require surgical debridement anyway. Incisions are placed to avoid exposure of neurovascular structures.

Partial-thickness burns heal spontaneously. Deeper burns on the dorsum of the hand are best treated with early excision of the eschar and placement of skin grafts to prevent contractures. Palmar burns are best left to heal spontaneously because skin grafts function very poorly in this area. Some hand surgeons believe that excision and grafting of superficial burns should be performed to prevent contractures. This is true if adequate therapy has not been available. In burn units with good rehabilitation services, surgeons are treating superficial second-degree burns without surgery and obtaining results as good as with skin grafting. Pigskin, cadaver homografts, or a number of commercially available biologic dressings can be used to cover the wounds temporarily, decreasing pain and keeping the wound moist until autologous skin grafts are placed.

Neglected burns of the hands result in contracture deformities that often require extensive surgery to restore function. Delayed healing and wound contractures often result in a claw hand with MCP hyperextension and fusion of the digits with loss of the web space (syndactyly). Burns on the volar surface leave flexion contractures. Some contractures can be treated with release and skin grafting of the tissue gap. Web space contractures and released contractures with exposed tendons or nerves must be covered with skin or muscle flaps. Web space release is done with skin flaps from the dorsum folded down to create the space. Large flaps can be obtained by attaching the hand to the groin, allowing the tissue to adhere and vascularize before cutting the flap away from the groin. Recently, free tissue transfer from other parts of the body using microsurgical techniques has allowed more extensive reconstruction of severely burned hands.

Electrical Burns

Electrical burns of the upper extremity may not appear extensive on initial inspection. The skin may be burned only in a very small area of the entry point of the current or by ignited clothing. The current tends to spare the skin but damage underlying muscles, vessels, and nerves. Often, the extent of dead tissue is not evident for several days.

Initial treatment is the same as for thermal burns. Since muscle damage may be extensive, it is important to prevent renal failure from myoglobinuria by maintaining a high output of alkaline urine. Arteriography, fluorescein injections, and radionuclide studies may help delineate the extent of necrosis. Examination of the patient in the operating room is still the most accurate method of assessing the extent of tissue damage. All obviously dead tissue should be removed during the initial evaluation. Two or three days later, the patient is reexamined in the operating room and any additional debris is removed. The wounds are closed when only clearly viable tissue remains.

Frostbite

Frostbite occurs most often in people under the influence of alcohol or with psychiatric illness. The lower extremity is affected more often than the upper. Freezing tissue causes cellular death and vascular thrombosis. Hypothermia of the entire body must first be treated. The frozen part should be quickly rewarmed by immersion in warm water (40°C). Elevation of the extremity minimizes edema. Skin wounds are treated like burns with silver sulfadiazine cream. The extent of necrosis may not be obvious for several weeks, and debridement or amputation should be delayed until demarcation of the injury occurs. Sympathectomy may help ameliorate the sequelae of frostbite, such as cold sensitivity and pain. Children with frostbite may develop premature closure of phalangeal epiphyses, which creates growth disturbances of the bone.

MASSES OF THE HAND

Only 2% of all masses in the hand are malignant lesions; the majority are benign neoplasms, cysts, or a myriad of other masses. Though the clinician must be ever vigilant to identify malignancy, a mass of the hand is highly likely to be benign—excisional biopsies are thus reserved for subcutaneous lesions that are rapidly growing or for skin lesions that may be carcinomas. Otherwise, masses can be observed over a period of time to determine that they are not growing. They may be removed for functional or cosmetic reasons.

Ganglions are formed by herniation of the synovial lining of joints or tendons into the surrounding soft tissue. These cysts are filled with a viscous fluid thought to be modified joint fluid. Trauma to the wrist or hand may cause extrusion of the synovium, but it is more likely that the ganglion was already present and that trauma to that area merely brought the lesion to the surgeon’s attention.

Ganglions can arise from any joint of the hand but most commonly appear on the dorsal wrist over the scapholunate ligament and the volar wrist near the radial artery. Tendon ganglions are most common on the flexor sheath at the metacarpal head (A1 pulley). Pain and tenderness are due to compression of adjacent nerves by the mass.

Ganglions have a typical appearance, and diagnosis is simple. If any doubt exists, aspiration with a large-bore needle of the viscous fluid confirms the diagnosis and occasionally cures the lesions. Injection of the empty sac with steroids and lidocaine may help to keep the mass from reappearing, but the majority recurs. Ganglions need not be treated unless they cause pain or interfere with hand function. Often, it is enough just to reassure the patient that the mass is benign.

Operative removal of ganglions should be done using loupe magnification and a tourniquet. The entire ganglion should be removed, including all attachments to the joint capsule and the underlying ligament, without injuring the surrounding structures. Prolonged splinting after removal of ganglions does not decrease recurrence rates but does cause hand stiffness. Unfortunately, despite careful surgical removal of the lesion, recurrence of ganglions is relatively common.

Epidermal cysts are rests of epidermis located in the subcutaneous tissue. Many are thought to be due to traumatic disruption of epidermal cells into the soft tissue (inclusion cyst). The cells proliferate just as skin does and form a cyst filled with creamy keratin, the remains of dead epidermal cells that usually desquamate from the skin. Infected cysts become inflamed and form abscesses. Removal of the entire cyst wall is required to prevent abscess formation.

Pyogenic granuloma may form in any chronic wound. Histologically, it consists of vascular tissue identical to granulation tissue. Just as for hypertrophic granulation tissue elsewhere on the body, excision or cautery of the material flush to skin level allows epidermis to migrate over the wound.

Giant cell tumors are benign, multilobulated, solid masses found on the lateral aspects of the finger. They are often attached to the tendon sheath. The mass may be quite complex and extend throughout the adjacent nerves, vessels, tendons, and ligaments. The entire lesion should be removed, but recurrence is relatively common.

The most common bone tumors are enchondromas. Multiple enchondromas (Ollier disease) are associated with other skeletal deformities. The lesion appears on x-ray as thinned cortical bone with speckled calcifications. Fractures through the tumors usually do not heal spontaneously. The tumor should be removed with a curette. Bone graft taken from the distal radius is used to fill the gap if needed.

A carpal boss is due to abnormal bone formation at the base of the second or third metacarpal bones and presents as a hard mass on the dorsum of the hand. The excess growth of bone can be removed if symptomatic.

Glomus tumors are composed of blood vessels and unmyelinated nerves of a heat-regulating arteriovenous malformation. They are usually found in the fingertip or under the fingernail and can be extremely painful. Local excision of the tumor is curative. Occasionally, when the tumor is large and disrupts the nail matrix, a split-thickness nail graft from another digit is needed to reconstruct the defect.

The most common malignant tumor of the hand is squamous cell carcinoma, though basal cell carcinomas and melanomas also occur. Subungual melanomas are often difficult to diagnose because they are difficult to examine. These tumors should be treated just the same as elsewhere on the body. Particular care should be taken to examine for spread of tumor in the lymphatic drainage at the supratrochlear and axillary nodes.

Other tumors include lipomas, fibromas, hemangiomas, arteriovenous malformations, neurofibromas, sarcomas, and various skin lesions. These tumors act no differently in the hand than elsewhere in the body. However, because of the close proximity of the nervous and vascular structures within the small spaces of the hand, these tumors cause compressive signs and symptoms sooner. CT scans or MRI help delineate the extent of soft tissue tumors and may help in preoperative planning.

COMPLEX HAND INJURIES

Crush Injuries & Amputations

Advances in microvascular surgery have greatly increased our ability to treat complex hand injuries. Mangled and amputated digits, hands, as well as entire upper extremities have been replanted or repaired. Complex nerve repairs, microvascular free tissue transfers of muscle flaps, and toe-to-hand reconstructions have made it possible to restore more function to severely injured hands. The end result must be a sensate, painless, and useful extremity. Patients who undergo multiple surgical procedures and prolonged rehabilitation with only marginal results would have benefited from early amputation. A surgeon with extensive experience can best assess the patient’s injuries, occupational requirements, and psychosocial needs to determine if salvage is worthwhile.

Complex hand injuries often result from improper use or malfunction of machinery. Heavy machinery in the workplace or motorized cutting tools at home, such as rotary saws, are often cited as the mechanism of injury. Sharply amputated or partially devascularized parts are most likely to be saved. Severe crushing or avulsion of the part produces wider nerve and vessel injury. The extent of this type of damage is difficult to determine and often impossible to repair.

The decision to try to salvage a damaged part must be individualized to each situation, but some general principles apply. The thumb is crucial to hand function, and all efforts are made to save the entire digit or as much length as possible. When multiple digits or half of the hand is damaged or amputated, a greater effort is made to repair the part. Children can recover function in badly damaged extremities far better than adults can, and any amputated parts in children should be replanted. Replantation of the entire arm at the elbow and above is controversial. The usefulness of these replanted limbs is limited by the slow nerve regeneration, and some hand surgeons believe that amputations in these cases result in better function.

Patients with complex hand injuries should be immediately referred to a regional center with the staff and facilities to manage the problems. Occasionally, in the rush to transfer patients with these very obvious injuries, intra-abdominal, neurologic, and other less obvious injuries have been overlooked. The entire patient must be evaluated and stabilized prior to transfer. A clean, moist dressing should be placed on the wound and the extremity elevated. The amputated part is wrapped in a plastic bag and placed in ice water. The amputated part should never be frozen.

The accepting hand surgeon evaluates the patient’s overall condition, potential for rehabilitation, and personal wishes before coming to a decision. To revascularize or replant a part, the patient must be taken urgently to the operating room. Ischemia over 6 hours is often associated with failure of revascularization, but—depending on the metabolic needs of the constituent tissues—extremities that have undergone periods of ischemia longer than this can be successfully replanted.

Bone must first be stabilized with Kirschner wires or metal plates before vascular repairs are performed. Arterial and venous repairs are done with microscopic magnification, and the ischemic tissue is reperfused. Failure of a replanted part is more often due to venous outflow problems than arterial inflow. Systemic and local anticoagulants help to maintain perfusion but are not always needed. Leeches placed on the part release a potent local anticoagulant and can decrease venous congestion. Nerve and tendon repairs must also be performed. When there is inadequate local soft tissue to cover the repaired structures, muscle or skin flaps from a distant site must be transferred using microsurgical methods to the area. Although these operations are not life threatening, blood loss can be extensive and transfusions are sometimes required.

Secondary procedures to free tendon adhesions, reduce bulky flaps, and transfer tendons in motor nerve injuries may need to be done. Reconstruction of unsuccessful replantations is being done more often. The original method using toes to reconstruct thumbs has also been used to make fingers. These reconstructions give patients the ability to grasp objects. Because these digits are sensate, they can even perform fine movement tasks not possible with prosthetic devices. Patients with loss only of the thumb are better treated with transfer of the index finger to the thumb position (pollicization).

Partial or total loss of a single digit is less critical. Hand function is better without a stiff or painful digit. When a decision is made to amputate a digit, care must be taken to leave a painless stump with good sensate soft tissue coverage. The flexor tendon must not be sutured to the extensor tendon for soft tissue coverage, since this will cause the tendons to pull each other rather than move the joint. Local flaps to cover the stump are preferred to skin grafts or cross-finger flaps, since they usually provide better sensation. A short amputation stump on the long or ring finger is often bothersome because small objects such as coins tend to fall out of the palm, and a ray amputation eliminates the problem. For cosmetic purposes, ray amputations are far less noticeable than partial amputations. The loss of hand breadth with a ray amputation can decrease grip strength, however.

The loss of part of all of the hand can be compensated both functionally and cosmetically by a variety of prostheses. Their use involves careful adaptation to the requirements of the patient, who must receive appropriate training to ensure success.

INJECTION INJURIES OF THE HAND

High-pressure devices used in industry to apply material such as air, grease, paint, and oil cause a unique hand injury. The typical case is injection of the material into the index finger of the nondominant hand of a factory worker. A pinpoint injection site may be the only external evidence of injury, and the hand appears discolored or pale, or swollen due to the injected material.

The examination should include a careful hand evaluation and an x-ray to demonstrate the distribution of material or gas in the hand. All such cases require continued, unrelenting scrutiny, even if the part seems completely normal. If there is any evidence of retained foreign material, swelling, or ischemia, early surgical exploration is advocated to release the tourniquet effect of the skin and fascia and to remove as much of the material as possible without injuring healthy tissue. Prophylactic antisludging agents (dextran 40), corticosteroids, and antibiotics may help.

Often, the pressure forces the material to spread along the tendon sheaths throughout the hand and even into the forearm. Expansion of the foreign material in a closed space and the chemical irritation cause congestion, inflammation, vascular thrombosis, and gangrene. The injected material is difficult to remove completely, and a foreign-body response leads to fibrosis so extensive that it often destroys the function of the hand.

The goal of reconstructive hand surgery is return of normal function, including pain-free movement, normal active and passive range of motion, premorbid strength, and intact sensation. Yet the process of incising, dissecting, and sewing is associated with significant scarring and pain. Scarring is especially troublesome in the hand, since it leads to stiffness, ligamental tightening, and arthritis. As a result, any procedure in the hand that minimizes postoperative scarring or pain will contribute to an improved result.

Surgical care in the past decade has been revolutionized by the introduction and incorporation of minimally invasive surgical techniques. Laparoscopies and thoracoscopies have permitted the resection of hollow and solid organs through 1 cm incisions, reducing the need for laparotomies and thoracotomies. Likewise, urologists have employed cystoscopy for evaluation and treatment of bladder and kidney disorders, while orthopedic surgeons have used arthroscopy to similar effective ends in the knee, ankle, elbow, and shoulder.

Two areas of hand surgery incorporate minimally invasive techniques: Wrist arthroscopy has expanded the options for evaluating the chronically painful wrist, and endoscopic carpal tunnel release (ECTR) provides a less invasive method than open release for decompressing the median nerve. While ECTR theoretically allows for a faster recovery, it may in fact offer only limited advantages.

WRIST ARTHROSCOPY

Diagnostic wrist arthroscopy was first successfully used in 1970. Over the past three decades, it has taken its place among traditional imaging techniques as a low-morbidity method for evaluating chronic wrist pain. As the hardware for examining the wrist has become more sophisticated and as hand surgeons have become more familiar with the arthroscopic view of the wrist, increasingly aggressive attempts have been made to use the arthroscope to treat as well as to diagnose wrist problems.

Indications & Contraindications

Diagnostic wrist arthroscopy is a useful technique to evaluate patients with wrist pain, whether chronic or acute. In patients with chronic pain, this technique can be used to augment information offered by plain radiographs, CT, MRI, or wrist arthrography. It can confirm an uncertain diagnosis or be used to reevaluate a patient who has failed other treatments. In contrast, patients with acute symptoms—such as those suffering from mechanical wrist pain—may complain of pain localized over the joint, catching and popping sensations, and relief with rest. Here, the wrist can be manipulated during arthroscopy to localize the source of the symptoms. In general, the technique is useful for evaluating articular cartilage, ligaments, the triangular fibrocartilage complex (TFCC), and the synovium. Interestingly, diagnostic wrist arthroscopy may provide too comprehensive an examination. Only some of the lesions that are visualized during an examination may be responsible for a patient’s symptoms. The hand surgeon must critically correlate arthroscopic findings with the patient’s examination to arrive at the appropriate diagnosis.

Therapeutic wrist arthroscopy is useful for the treatment of ligament tears, TFCC lesions, articular cartilage lesions, subtle distal radius and carpus fractures, dorsal wrist ganglions, removal of isolated carpal bones up to and including the proximal carpal row, and disorders of the distal radioulnar joint. It is useful also in the management of lesions arising from rheumatoid arthritis. It has been successfully used in completing synovectomies, proximal row carpectomies in the case of scaphoid nonunion or scapholunate collapse, radial styloidectomy, and isolated symptomatic chondral defects.

Procedure

Equipment for diagnostic wrist arthroscopy includes an apparatus for elevating and distracting the wrist, an arthroscopic telescope, a video camera, a fluid infusion system, and both manual and powered instruments.

Either general or regional anesthesia may be used. A tourniquet is placed at the mid-arm to provide a blood-free field during the operation. The distal forearm, wrist, and hand are prepared into the operative field. Traction is applied to the hand, usually via sterile finger traps, and a distraction force is applied across the wrist.

Individual skin incisions are then made at standard portal sites determined by the goal of the operation. Portal sites are described according to their relationship with the radius and ulna, the carpal bones, and the extensor tendons. The relationship to the extensor tendons is indicated by listing the extensor compartments on either side of the incision. Typical portals include the 3-4 radiocarpal, through which the scaphoid and lunate facets can be visualized; the 4-5 radiocarpal, through which the TFCC and the ulnocarpal ligaments can be seen; and the 6R radiocarpal, through which the extensor carpi ulnaris tendon and ulnar wrist are approached. The midcarpal joint is approached through any of three portals, including the midcarpal ulnar, the midcarpal radial, and the scaphotrapezial-trapezoid.

Once abnormalities are identified, therapeutic wrist arthroscopy can be used to effect repairs. Partial ligament tears and tears of the TFCC can be debrided arthroscopically using knife blades and motorized shavers. Carpal bone resections can be completed with miniature osteotomes and powered saw blades.

Outcomes

Operations employing diagnostic and therapeutic wrist arthroscopy typically result in less swelling, less postoperative pain, and less stiffness than comparable open wrist procedures. There is a concomitant earlier return to function and work. Therapeutic wrist arthroscopy even of dorsal wrist ganglia, the most superficial of wrist abnormalities, is followed by fewer—or no more—recurrences than the open technique.

Complications

The rate of complications associated with diagnostic and therapeutic wrist arthroscopy is estimated to be 2% and is due to a variety of causes. The continuous traction necessary to properly distract the wrist can cause problems, including ligamental strain at the MCP joints with concomitant joint edema and stiffness and stretching of peripheral nerves. Establishment of the operative portals can damage articular cartilage, ligaments, tendons, cutaneous nerves, the radial artery, and cutaneous and deep veins. Such injuries include abrasions, contusions, lacerations, and transections. A high proportion of complications of therapeutic wrist arthroscopy are associated with inadequate relief of symptoms or a diminished return of function. A now less common complication of therapeutic wrist arthroscopy results from the fluid infusion. Forearm compartment syndromes have resulted from extravasation of infusion fluid during endoscopic repair of distal radius fractures; this problem is now avoided by circumferential compression of the forearm during the procedure.

ENDOSCOPIC CARPAL TUNNEL RELEASE

Endoscopic release of the transverse carpal ligament is an increasingly popular method of treating carpal tunnel syndrome. Advocates of the procedure claim that it is associated with decreased postoperative morbidity and earlier return to work. Others caution that there is little if any short-term difference between endoscopic and open carpal tunnel release, no long-term difference, and that endoscopic carpal tunnel release is associated with an increased likelihood of significant nerve injury.

Indications & Contraindications

Endoscopic carpal tunnel release is easier to perform in patients with larger wrists. Ease of access to the carpal tunnel correlates with the wrist circumference and the height and age of patients. Surgeons should be aware that the procedure is likely to be more difficult in small patients with small wrists and are advised to maintain a lower threshold for conversion to the open technique to avoid neurologic complications.

Absolute contraindications to endoscopic carpal tunnel release include masses in the carpal canal and other space-occupying lesions, abnormalities in canal anatomy, and wrist stiffness that precludes proper positioning.

Procedure

In the United States, most surgeons use one of two techniques—either Chow or Agee. The two differ primarily in the number of incisions, or portals, needed to gain access. The Chow technique, first described in 1989, employs two portals, while the Agee technique requires only one.

Either operation can be performed under local anesthesia with a brachial tourniquet. An initial transverse incision is made proximal to the wrist flexion crease between the palmaris longus and flexor carpi ulnaris tendons. The space between the transverse carpal ligament and the flexor tendons is defined with a dissector. In the Agee procedure, the endoscope is advanced under the transverse carpal ligament, radial to the hook of the hamate along the axis of the ring finger. The ligament is incised along its entire length, with care taken to avoid the Guyon canal and the superficial palmar arch. In the Chow operation, a second transverse incision is made just distal to the transverse carpal ligament along the axis of the ring finger. The wrist is dorsiflexed, and a slotted cannula is advanced into the proximal incision, deep to the transverse carpal ligament, and out the distal incision. The endoscope is then used to visualize the ligament while the knife divides it. The wounds are closed, and the patient’s wrist placed in dorsiflexion.

Outcomes

Several studies have compared open versus endoscopic carpal tunnel release, focusing on the incidence of recovery from symptoms, the time span until the patient returns to work, and the incidence of recurrence of symptoms. Overall, both techniques have equivalent outcomes.

Many of the most convincing studies are prospective randomized trials. One such study, comparing open and endoscopic carpal tunnel release among 32 hands in 29 patients, found no difference in postoperative recovery time or surgical result. The only significant difference noted by the authors was transient numbness on the radial side of the ring finger in three endoscopic carpal tunnel release patients.

In another study, the authors compared in a prospective randomized manner the early outcome of carpal tunnel release using either a conventional open carpal tunnel release procedure in 40 patients or a two-portal endoscopic release in 56 patients. They found no statistically significant difference between the groups in postoperative pain, recovery from paresthesias, or time taken to return to work. However, the endoscopic group demonstrated better grip strength recovery at 1 and 3 months. No surgical complications were observed in either group.

Nonrandomized studies have supported this trend. An analysis of 191 consecutive patients undergoing carpal tunnel release with an average 2-year follow-up showed that none of the patients undergoing open release had a recurrence, while 7% of patients undergoing endoscopic release had recurrences. Another study observed a higher incidence of incomplete release of the carpal tunnel with endoscopic techniques than with standard open releases.

The factors identified with poor outcomes in endoscopic carpal tunnel release are similar to those seen in open release. Less satisfactory results were present in workers’ compensation cases; patients with normal motor latencies on nerve conduction studies; patients with preoperative hand weakness, widened two-point discrimination, myofascial pain syndrome, or fibromyalgia; and patients involved in litigation, those with multiple compressive neuropathies, and those with abnormal psychologic factors.

Complications

Only a limited number of studies include a sufficient number of patients to compare complication rates and type between endoscopic and open carpal tunnel release. Overall, the types and rates of complications between the two forms of release are similar. Nonetheless, isolated but severe complications from endoscopic release over the past decade tend to dramatize its risk.

The study by Boeckstyns and Sorensen is perhaps the most comprehensive to date. These authors analyzed 54 published series of endoscopic and open releases comprising 9516 and 1203 patients, respectively. Irreversible nerve damage from the procedure occurred in 0.3% of endoscopic and 0.2% of open releases, including such injuries as transection of the median nerve. While reversible nerve injuries were more common with endoscopic release than with open release (4.4% vs 0.9%, respectively, among prospective controlled and randomized studies), tendon lesions, reflex sympathetic dystrophy, hematoma, and wound problems were equally common with either technique.

A less compelling analysis—a retrospective survey of hand surgeons who had performed either open or endoscopic carpal tunnel release over the preceding 5 years—found major complications with both approaches, including median nerve lacerations, ulnar nerve lacerations, digital nerve lacerations, vessel lacerations, and tendon lacerations. While the authors could not reach a conclusion about the rate of complications for one procedure versus the other, their results demonstrate the potentially devastating sequelae of carpal tunnel release even in experienced hands.

Carpal tunnel symptoms may persist or recur following either open or endoscopic release. In patients who have persistent symptoms following endoscopic release, many authors recommend open carpal tunnel release as definitive therapy.