Chapter 40: Lower Extremity

Lower extremity injuries represent the primary cause of more than half of all hospitalizations for trauma. Their frequency, severity, and costs emphasize the impact of those injuries on society.^1,2 Lower extremity fractures may be caused by either low- or high-energy forces and occur both in isolation and as multiple injuries. The mechanism of injury defines the specific individual fracture pattern. Typical trauma mechanisms include blunt versus penetrating trauma, low-energy versus high-energy forces, twisting, bending, or crushing forces. Significant lower extremity injuries compromise functional outcome and can lead to long-term pain, abnormal gait, degenerative joint disease, chronic infection, and limb loss.

Dislocations of the hip, knee, or more distal joints, as well as displaced fractures, may cause pressure on nerves, vessels, or skin that can result in permanent deficits if not dealt promptly. Many of these injuries are either surgical emergencies or, at the very least, require urgent treatment in the operating room. Failure to recognize the significance of these injuries can lead to sequela as significant as amputation or death. While not true emergencies, open fractures of the lower extremities require timely surgical treatment to minimize the risk of infection and limb loss.

The wide prevalence of safety belt usage and changes in vehicular design such as crumple zones and mandatory airbags has led to an increased number of survivors of high-energy crashes who consequently suffer from a higher severity of lower extremity injuries. For example, Shock Trauma in Baltimore noted a drop in the mortality associated with bilateral femur fractures from 26 to 7% over a 15-year period. There was an associated drop in Injury Severity Score (ISS) that suggested a contribution to this decrease in mortality from changes in motor vehicles.³ Any trauma victim involved in a high-energy trauma mechanism may have associated potentially life-threatening injuries to the head and torso. Thus, the initial evaluation of lower extremity fractures must focus on the patient as a whole, and not focus exclusively on the injured limb.^4,5,6

The concept of “damage control orthopedics” (DCO) was established based on the principle that prolonged early definitive treatment of long bone fractures can be detrimental for severely injured patients who are in unstable physiological conditions.^7,8 In these patients, the early mitigation of the “lethal triad” of persistent metabolic acidosis, hypothermia, and coagulopathy represents the prime goal for survival.⁴ More recently, however, our ability to resuscitate patients has improved, and multiple high-powered studies have shown improved outcomes while utilizing an “early total care” (ETC) model. In resuscitated patients, definitive intramedullary nailing of femur fractures and open fixation of pelvic and acetabular fractures has proceeded within 24–36 hours after injury with subsequently shorter ICU stays and fewer pulmonary complications, all at an overall lower cost.^9,10,11,12 The controversial concept of “limb for life” entails the early amputation of a mangled lower extremity in critically injured patients with the aim of increasing the likelihood of survival.

A relatively recent concept in lower extremity fracture care is that the majority of fractures can be treated entirely or in part with minimally invasive fixation. The evolution of techniques for percutaneous reduction and fixation of fractures, coupled with technological adaptation of fracture implants, has completely revolutionized fracture fixation.¹³ While intra-articular fractures usually require some form of open reduction to restore articular congruity, most diaphyseal and metaphyseal lower extremity fractures can be treated with minimally invasive surgery. The decreased blood loss, lowered risk of infection, and increased rate of healing likely have positive implications for the injured patient with lower extremity fractures.

Orthopedic surgery has developed through the need to alleviate pain, correct deformity, and restore function following fractures. Evidence of splinted fractures and the first successful amputations dates as far back as the fifth Egyptian Dynasty, about 4500 years ago. The Corpus Hippocrates described the principles of traction, countertraction, and external fixation. Surgeons have built on these past foundations with the advancement of technology. In England, Thomas described the traction splint that still bears his name. In France, Malgaigne described the external fixator, and Delbet reported use of a weight-bearing cast for tibial fractures. In the United States, Buck described skin traction, while Steinmann in Switzerland and Kirschner in Germany introduced skeletal traction. Another German, Küntscher, made many contributions to modern intramedullary nailing. In Austria, Böhler established hospitals devoted to the care of injuries and published a comprehensive text on fracture surgery. Lambotte, a Belgian, is the father of modern internal fixation, which was advanced further by his countryman, Danis, who demonstrated that rigid fixation could result in direct bone healing without callus formation. The Swiss-based “Arbeitsgemeinschaft für Osteosynthesefragen” or “Association for the Study of Internal Fixation” (AO/ASIF) was founded in 1958 by a group of Swiss surgeons to produce and disseminate a system of fracture care based on stable fixation with preservation of soft tissue, active motion, and functional rehabilitation.¹⁴ This association has earned itself a worldwide reputation as an international authority in the treatment of trauma through its continuing research and development of instrumentation. Further advances continue, with emphasis on indirect reduction techniques, closed or minimally invasive fracture fixation, and stable but less rigid fixation that promotes rather than suppresses indirect, callus-dependent healing of bone.¹³

At about the same time in the Soviet Union, Professor Ilizarov, working in the Siberian town of Kurgan, developed and refined the concept of distraction osteogenesis, permitting healthy de novo bone to be created in vivo through distraction with a ring external fixator system with Kirschner-type wires. His work led to significant advances in the use of external fixators as definitive treatment for a variety of traumatic injuries and post-traumatic complications.

The increasing ability of orthopedic surgeons to obtain early fracture stability with relatively low complication rates has led to improvements in post-injury rehabilitation. Rehabilitation concepts have changed from the prolonged rest suggested by Thomas to the present emphasis on rapid restoration of skeletal stability that allows for prompt mobilization of injured extremities and patients. Early weight bearing is encouraged, whenever possible to promote bone healing and overall physiological restoration. Detailed knowledge of a patient’s musculoskeletal injuries, his or her treatment, and his or her response is crucial for appropriate decision making in both the acute and late phases of care. Therefore, the orthopedic surgeon should ideally be directly involved from the trauma bay to the entire recovery process.

Fractures occur when the applied load to the bone exceeds its load-bearing capacity. Fracture patterns relate to bone strength and the forces that cause the injury. Young, active individuals have strong bone. Children’s bones can undergo plastic deformation and may bend without breaking. Elderly, osteoporotic individuals have diffusely weak bone. Focal bone defects may weaken a bone so significantly that it fails under a load that would normally pose no problem, resulting in a pathologic fracture. Such pathologic fractures may be due to tumor, infection, or dysplasia, as well as more generalized conditions that severely weaken bone, such as osteoporosis. The amount of energy that produced a given fracture is suggested by the patient’s history and the fracture pattern. Basic physics is implied: kinetic energy equals ½(mass)(velocity)². Thus, the greater the velocity is, an exponentially higher amount of energy is stored within a system. Upon impact, that energy is absorbed by the body and the musculoskeletal system. This energy is realized as comminution (multi-fragmentary fractures) and local damage to soft tissue.

The impact to a bone may be a bending or twisting moment, or it may result from a pointed impact such as a projectile. Bones are weakest in torsion, and spiral fractures result from torsional forces. Less local soft tissue damage is generally present. Transverse fractures result from directly applied forces where the bone is “bent” over an object or fails under off-axis loading. Bending moments can also cause wedge or “butterfly” fragments formation. When a bending moment is applied to a bone, there is a resultant compressive force on the bone closest to the concavity of the bend and a reciprocal tension on the convex side. Bone initially fails in tension, and as the fracture propagates toward the concavity, the fracture will move around the compressed bone both proximal and distal to it, creating a wedge-shaped fragment.

Obtaining a thorough patient history provides the physician with useful information to begin forming a list of differential diagnoses in his or her mind prior to radiographic examination of the patient. The history should specify the mechanism of injury, provide information regarding the severity of the applied forces, and alert the physician to associated injuries, illness, or medically relevant problems. While an accurate history may be difficult or impossible to obtain initially in a seriously injured patient, more details should always be sought and reconfirmed as the patient improves or more information becomes available. The history may be particularly helpful in managing open fractures by providing information on the following: the identification of the source and extent of contamination, the time elapsed from the moment of injury, and whether bone was initially protruding from an extremity wound.

A history inconsistent with the extent of injury suggests either a pathologic fracture or the possibility of abuse. A normal child, particularly less than 2 years, should not fracture his or her femur while playing, even roughly, with a friend or parent. An elderly patient will not normally sustain a hip fracture from turning over in bed. Although pathologic fractures should be suspected in a patient with known malignant or metabolic disease and can be preceded by local pain, fractures may occur in completely asymptomatic patients as the initial presentation of an underlying disorder. In a young child, multiple fractures at various stages of healing are pathognomonic of child abuse, the diagnosis and appropriate management of which may be lifesaving. The report of pain or impaired function of an extremity requires careful evaluation to exclude a fracture or injury to a joint, nerves, muscles, or vascular structures.

Examination according to the Advanced Trauma Life Support (ATLS) protocol provides a systematic method of thoroughly examining the trauma patient and minimizing missed injuries.^4,15 In addition, the importance of continuous detailed documentation of the physical findings cannot be overemphasized. Patients should be thoroughly examined at multiple time points by multiple members of the clinical team. All assessments should be well-documented for easy comparison. A thorough exam should be revisited when an initially obtunded patient is first extubated. While tenderness, deformity, and swelling almost inevitably occur with fractures or dislocations of the lower extremity, these can easily be masked: an intubated patient cannot complain of pain; and diagnosing deformity or swelling in even a moderately obese patient can be difficult.

That said, many lower extremity injuries are quite obvious. Displaced long bone fractures result in shortening, malrotation, or angulation. Dislocations typically assume characteristic positions but may be masked by associated fractures. Intra-articular injuries usually cause a hemarthrosis unless the joint capsule is disrupted, in which case more diffuse soft tissue swelling occurs about the joint. Instability or abnormal motion when stressing a bone or joint, while it may be difficult to elicit if the region is tender, is particularly important and useful in the anesthetized patient. When in doubt, obtain imaging—a simple x-ray gives a great deal of information. Immediate reduction of dislocated joints and splint placement where applicable reduce pain and blood loss, often restoring circulation to a pulseless extremity in the process.

As per ATLS protocol, an anteroposterior (AP) chest and pelvis, and adequate lateral cervical spine radiographs are indicated early in the evaluation and resuscitation of the injured patient during the primary survey.^4,15 The improved imaging capabilities of CT have led to a tendency to skip over the pelvis and cervical spine x-rays. While the cervical spine is better imaged using more advance imaging, a tremendous amount of information can be gleaned form a simple AP pelvis x-ray, and it should not be neglected.

X-rays of injured extremities are of much lower priority and fall into the secondary survey. Resuscitation of the patient should never be delayed or interrupted for x-rays of the extremities. X-rays can be taken after urgent surgical treatment for other life-threatening problems. In the unstable patient, care should be concurrent and not contiguous, implying that x-rays and fracture stabilization can occur concomitantly in the operating theater or resuscitation bay with lifesaving maneuvers such as laparotomy or thoracotomy. If adequate extremity radiographs can be obtained without delaying other essential aspects of the evaluation and treatment of the trauma patient, they can be valuable in making the initial care plan.

Extremity x-rays should include orthogonal views (AP, lateral) of the entire bone in question. Generally speaking, injury films should be obtained prior to reduction and splint placement. Not only is the quality of the image improved without overlying splint material but also knowledge of the injury pattern guides surgical decision making. In the event of vascular compromise upon initial physical examination, reduction should proceed prior to imaging. This is more common with fractures and dislocations about the knee and ankle. After reduction and splinting, the clinical exam should be repeated and x-rays obtained. In the event of a change in exam (new onset vascular or neuropathic compromise) or a failure of reduction, the reduction should be repeated. Certain complex articular fractures are best visualized with computerized tomography (CT) scans. If a patient is hemodynamically stable and requires other CT studies, extremity CTs may be obtained at the same time, although if external fixation is indicated the CT is often more useful after external fixation. Early involvement of the orthopedic surgeon ensures proper imaging and avoidance of unnecessary diagnostic studies.

Vascular Injuries

A high level of suspicion for a significant associated vascular injury, in conjunction with a thorough clinical exam (Table 40-1), should help in the guidance of the acute management of joint dislocations. Any pulse deficit or measurable reduction in arterial pressure index (API), before or after manipulation, must be considered evidence of a vascular injury. The accuracy of pulse examination alone for the detection of an arterial injury is very low. The five clinical hard signs of an arterial injury (see Table 40-1)¹⁶ are present in more than two-thirds of all dislocations with an associated significant vascular injury and are of paramount importance in the clinical guidance for decision making related to the acute management concept.^16,17,18 In presence of a hard sign of arterial injury, intervention is indicated. In penetrating injuries, exploration can proceed immediately. In a portion of blunt trauma, an angiogram prior to exploration—either preoperatively or on the operating table—should be considered. The majority (>95%) of arterial injuries occur in proximity to the site of the fracture or joint dislocation. Delay in diagnosis secondary to missing a hard sign can result in limb loss. The use of soft signs to detect occult vascular injury is less clear (Table 40-1). The yield of arteriography in the setting of clinical soft signs is very low and the lesions that are typically identified are nonocclusive lesions: intimal flap, contusion, spasm, and pseudoaneurysm. The natural history of these lesions is benign and self-limiting, and they rarely require expensive surgical repair.^19,20 In the setting of late presentation, angiography is indicated for surgical planning.²¹

The neurovascular status may be difficult to assess clinically in a severely injured patient. Therefore, a high level of suspicion is required for identifying and treating potentially catastrophic vascular injuries. Capillary filling is not, by itself, adequate clinical evidence of an intact proximal vascular flow. Distal pulses may be present after a significant arterial injury. Perhaps the most familiar arterial injury in the lower extremity involves the popliteal artery in association with knee dislocations or periarticular fracture. Vigilance must be maintained: knee dislocations will often spontaneously reduce, thus appearing relatively benign; and fracture severity may be underappreciated. The popliteal artery is tethered at the adductor hiatus to the distal femur and at the soleus muscle on the proximal tibia, and thus any fracture with significant displacement of the adjacent bone should be checked for vascular injury. In particular, fractures of the medial tibia plateau are often underestimated and should be considered akin to a knee dislocation.²¹

Late thrombosis of an initially nonocclusive injury may result in limb loss. Frequent assessment of pedal pulses is required for such patients. Any alteration of pedal pulses requires assessment, at least with Doppler pressure measurement. Assessment of ankle systolic blood pressure is an important adjunct to the physical examination. Pressure below 90% of that in the arms or the opposite leg requires prompt evaluation by a vascular surgeon. Doppler sonography or contrast arteriography may be considered if pulses decrease, but should not delay consultation with a trauma surgeon. Risk factors for limb loss include delayed surgery, arterial contusion with consecutive thrombosis, and, most importantly, failed revascularization.

An arterial injury in combination with an orthopedic injury, such as a traumatic joint dislocation or fracture–dislocation, requires a coordinated approach by the acute care surgery and orthopedic teams. Initially, a temporary arterial shunt is placed to restore limb perfusion and minimize tissue ischemia (Fig. 40-1). Frequently, after shunt placement, the limb is pulled out to length and stabilized using external fixation by the orthopedic surgeon. Subsequent to this, arterial repair is completed by autologous repair of the vessel. While these two events can be interchanged, care must be taken to avoid repairing the artery in a shortened position, thus risking damage to the repair when the limb is lengthened and stabilized. Time to revascularization is of utmost concern since delays in excess of 8 hours after injury carry a risk of amputation in excess of 80%. In contrast, successful operative vascular repair within 8 hours of injury yields excellent rates of limb salvage.”

Nerve Injuries

The neurological status of the extremity should be documented before any definitive treatment, whenever possible. The neurological examination, like the vascular examination, may be unreliable in the severely injured patient or extremity, and it may also be subject to change. While deficits that are specifically dermatomal or isolated to a single motor nerve are more likely real, there can still discrepancies in the exam. The vast majority of acute nerve injuries recover spontaneously, at least partially.

Specific to the lower extremity, the peroneal nerve is prone to injury. While the entire sciatic nerve may be injured in hip dislocations and thigh injuries, frequently the peroneal nerve is injured and the tibial nerve is spared. The peroneal nerve is a smaller nerve with less neuron redundancy, and it is tethered as it passes around the fibular neck, which makes it more prone to traction injuries.²² Dislocations and fractures about the knee can directly affect the common peroneal. These injuries typically manifest as a foot-drop with or without sensory involvement. Because nerves about the foot and ankle are relatively superficial, have less soft tissue padding, and are typically tethered to local structures, lacerations or deformity to the distal leg can easily affect any of the nerves—superficial peroneal, deep peroneal, saphenous, sural, or posterior tibial. These injuries typically manifest with primarily sensory deficits.

Most peripheral nerve injuries of the leg are neurapraxias the result from stretching mechanisms or blast effect secondary to projectiles. Most commonly resolve without intervention. A peripheral nerve injury is assessed and followed using the clinical exam. If there is no recovery, nerve conduction studies within 6–12 weeks after trauma can aid in defining the extent and prognosis of injury. If complete nerve injury is confirmed, depending on the level of the nerve, a delayed nerve repair can be considered. Given that, even with a successful surgery, prognosis is often poor, patient factors such as age, comorbidities, and social situation all play a role in the surgical decision making at this point.

Injury Combinations

Awareness of typical combinations of lower extremity injuries aids diagnosis and may decrease the risk of missing important injuries. One mechanism can produce several injuries. An unrestrained passenger in a head-on motor vehicle collision may strike his or her knee against the dashboard, sustaining a patellar fracture or injury to knee ligaments, depending on the point of impact. The force indirectly applied along the femur then dislocates the flexed hip, concurrently producing a posterior wall acetabular fracture and/or fracture of the femoral head. Some other associations are as follows:

• Femur shaft and pelvis/acetabulum fractures

• Femur shaft and femoral neck fractures

• Calcaneus and thoracolumbar spine fractures

• Thoracic aortic injuries and pelvis fractures

• Combined femur/tibia shaft fractures (“floating knees”) and soft tissue or vascular injuries about the knee

• Knee dislocation/tibial plateau fracture and neurovascular injury

• Fibular neck fracture and peroneal nerve injury

Vigilance for these injury combinations must be maintained. Some can have a very nuanced presentation. For instance, for diagnosing subtle femoral neck fractures that occur in conjunction with femoral shaft fractures, plain radiographs and CT have similarly unimpressive sensitivities (56–64%). Thus, intraoperative and postoperative imaging must be assessed carefully.²³ While fractures are often distractingly obvious on x-rays, injuries to joints such as subluxations and even dislocations may easily be overlooked unless one is suspicious.

While most orthopedic injuries frequently take a backseat to other, more critical, injuries, compartment syndrome remains a true surgical emergency. Vigilance must be maintained—while there are certain injuries that commonly cause compartment syndrome, there have been reports of compartment syndrome from all over the body: gluteal muscles, paraspinal muscles, deltoid, thigh, foot, carpal tunnel, abdomen, leg, and forearm. Compartment syndrome can occur in open fractures. The pathophysiology behind compartment syndrome is the same in all cases: there is raised pressure within a confined space that causes permanent and irreversible damage to the contents of the space. It is a circular mechanism in which increased compartment pressures cause decreased local blood flow, resulting in decreased muscle perfusion, which causes an inflammatory release and an increase in capillary permeability, subsequently causing increased muscle swelling, thus further increasing the compartment pressures. Within the first 4 hours the damage is reversible, and after 8 hours the damage becomes irreversible.²⁴

Compartment syndrome can result from either increase in compartment volume—hemorrhage, swelling from traumatized tissue (crush, burn), etc—or it can result from decreased volume, as in the setting of a tight dressing or cast. The most common cause is muscle injury that leads to edema, and there are certain clinical settings in which compartment syndrome is more frequently seen: high energy or crush injuries, segmental or widely displaced fractures—particularly in the forearm or leg, severely comminuted fractures, and patients with impaired sensorium.

The key with the successful treatment of compartment syndrome is making the diagnosis in a timely manner. Certain physical exam findings should trigger an evaluation for compartment syndrome. As seen in Fig. 40-2, fracture blisters, diffuse eccymosis and swelling, and tissue crepitis are all indicative of significant tissue injury. Compartment syndrome should be suspected when pain is disproportionate to the injury and worsens over time and across multiple exams, when there is pain with passive extension of the involved muscle compartment, and when there are paresthesias. Compartment pressure measurement, when utilized, should be performed in all compartments and within 5 cm of the fracture.²⁵ Either an arterial line setup, a slit catheter, or a side-port needle can be used, but one must be cognizant of the fact that the arterial line will read 5–15 mm Hg higher than a side-port needle. Typically, a threshold for diagnosis of within 30 mm Hg of the diastolic blood pressure is used rather than absolute pressures.^26,27,28,29 The above aside, there are multiple issues involved that make diagnosing compartment syndrome difficult:

• The clinical evaluation between treating physicians can be unreliable.²⁸

• One-time compartment pressure measurement has a high false-positive rate.³⁰

• Clinical exam and pressure measurements can be unreliable in an obtunded or anesthetized patient.³¹

One solution is continuous pressure measurement, but this is frequently not available and difficult to perform on all patients.³² What seems to be the most attainable solution is the establishment of an institution-wide protocol that empowers all team members (nurses, residents, faculty, etc) and has rapid escalation when compartment syndrome is suspected.^33,34 Regular, documented clinical exams are used for diagnosis with compartment measurements to confirm the clinical decision. Documentation is important both to compare physical examination findings as well as for medicolegal reasons: increasing time from onset of symptoms to the actual fasciotomy is linearly associated with an increase in indemnity payments.³⁵

Fasciotomy techniques differ among the part of the extremity affected, but the goal is always the same. The thigh is typically treated with a single lateral incision; the tibia can be treated with either single or dual incisions, and the foot requires multiple incisions.³⁶ While it is emergent and limb-saving, it should be kept in mind that a fasciotomy is extremely morbid and expensive: tibia fractures are much more likely to become infected or go on to nonunion; there are significant scarring, weakness, and chronic pain issues; and the cost and length of the hospital stay are more than doubled.^37,38

Open fractures should be quickly assessed on arrival of the patient in the emergency room. The most important determinant of the patient’s outcome is the time from injury to the administration of appropriate antibiotic coverage.³⁹ The choice of antibiotic depends on the grade of the fracture. The grading systems most often used for open fractures was that described by Gustilo et al⁴⁰ (Table 40-2). Despite a significant interobserver variability and limitations related to the wide spectrum of open fracture types covered in three categories, the Gustilo classification is very practicable and therefore well accepted among orthopedic surgeons. Newer classification systems, such as the Ganga Hospital Score from India,⁴¹ attempt to overcome the shortcomings from the Gustilo classification by increasing the number of categories and correlating the total score with a guideline for treatment. As such, the Ganga Hospital Score for open fractures will mandate treatment protocols including the “Fix and close” protocol, “Fix, Bone Graft and Close” protocol, “Fix and Flap” protocol, or the “Stabilise, Watch, Assess and Reconstruct” protocol.⁴¹

Once the grade of the fracture has been determined, the antibiotic to be administered should be chosen. The higher-grade fractures are considered to have a greater risk of contamination and are thus covered for more bacteria using broad-spectrum antibiotics. For simplicity, open fractures can be divided into two subsets: “Low energy” fractures that are grades I and II, and “high energy” fractures (all grade III fractures). Different antibiotics are given whether a fracture is “low energy” or “high energy.” There can be some blurring of the fracture grade definitions: a segmental tibia fracture that has just a poke-hole in the skin is by strict definition a grade I fracture, but clearly this is a “high energy” fracture. Given the number of physicians who might be part of the emergency center care of an open fracture patient, the authors have found the most effective way to improve adherence to antibiotic guidelines was to simplify it as above.

So, what are the best antibiotics to give for “low energy” and “high energy” fractures? If only it was so simple. There is only moderate consensus on what antibiotic to give: a recent survey of Orthopedic Trauma Association (OTA) members from around the world found that, while 86% of respondents agreed that antibiotics should be administered within one hour of determination of the presence of an open fracture, there was little consensus on what antibiotics to give and for how long to give them.⁴² Despite concerns regarding efficacy and nephrotoxicity, aminoglycosides were the most commonly prescribed antibiotic. Typically, intravenous antibiotics are given for 48–72 hours, but there is considerable variation among practice habits.⁴² It is the authors’ opinion that thought should be given to the prevalence of certain bacteria such as Methicillin Resistant Staph aureus (MRSA) within one’s geographic area of practice. For example, the authors practice in South-Central United States in a warm and humid climate with a community prevalence of MRSA of 38%.⁴³ The antibiotic regimen that we have chosen to use is illustrated in Table 40-3. Despite the general consensus to give aminoglycosides, we chose not to do so, opting for greater gram positive bacterial coverage. Given that the most common bacteria is different in different communities, surgeons are encouraged to examine their own region and adjust treatment appropriately. Of note, there are considerations within the table for patients with soil and marine contamination as well as gunshot injuries. While ballistic injuries have historically been considered sterile, examination of our patient base, which includes a large number of ballistic injuries, found a higher than expected rate of infection with MRSA and enterococcus being the most commonly cultures bacteria. We adjusted our antibiotic protocol in response.

Having given antibiotics, the open fracture wound should be covered with a sterile saline dressing and only examined in the operating room in order to avoid further contamination and soft tissue damage. Extensive exploration or manipulation of exposed bone should not be attempted in the emergency department. Bleeding, even from amputation wounds, can almost always be managed with a pressure dressing. A tourniquet should be reserved for uncontrollable hemorrhage from penetrating lower extremity injuries.⁴⁴ A “mangled extremity” defines a severely injured limb secondary to trauma in which there is a significant risk of amputation as a potential outcome. More specifically, a functional limb is composed of the following critical elements: skin and subcutaneous tissue, blood vessels, muscles and tendons, bones, joints including cartilage and ligaments, and peripheral nerves. Irreparable injury to one or more elements may significantly impair the function of a limb and lead to disability. A mangled extremity, the most severe form of injury, encompasses significant injury to multiple elements critical to limb function.

In the event of multiple injuries, hemorrhagic shock, prolonged delay to definitive care, and/or risk of death, amputation may be the preferred option: the “limb for life concept.” Once the patient responds to resuscitative efforts, the extremity is carefully examined during the secondary survey. Evaluation focuses on signs of arterial injury, extent of soft tissue and bone injury, and degree of contamination. A search for “hard signs” and “soft signs” (see Table 40-1) of arterial injury is essential since both civilian and combat experiences demonstrate that the risk of limb loss correlates with a delay in revascularization beyond 6 hours. The risk of limb loss is further increased in the setting of ischemia with associated major venous, soft tissue, and muscle injury.⁴⁵ Since a significant percentage of injuries, particularly those involving the distal extremity and the major joints, are missed during the initial trauma evaluation, repeated exams are essential, especially as the patient’s recovery permits more cooperation. At least one “tertiary” survey is an important part of each significantly injured patient’s diagnostic evaluation.

All open fractures require prompt surgical treatment to reduce the risks of infection, soft tissue damage, and ongoing bleeding. As soon as the patient’s condition permits, radiographs of the injured limb are obtained. Operative care of the open fracture must fit appropriately into the care of the patient’s other problems. This should be done in an operating room with general or regional anesthesia. While previously it was thought that debridement should be performed within six hours of injury, more recent data has shown that time to debridement is not a predictor of infection as long as it is performed within 24 hours of injury.⁴⁶ A thorough debridement includes the sharp excision of all devascularized muscle, fascia, subcutaneous tissue, skin, and bone, the removal of all foreign material, and the copious irrigation of the wound bed using low pressure fluid lavage.⁴⁷ Pulse lavage and antibiotics in the irrigant are generally avoided as they have been found to damage tissue unnecessarily.⁴⁷

In the setting of a “high energy” fracture or extensive contamination, definitive fixation is deferred until a second or third debridement can be performed to ensure an appropriately clean wound bed. Often antibiotic-eluting methylmethacrylate beads are placed that contain vancomycin and tobramycin. These act to increase the local antibiotic delivery.⁴⁸ Often temporizing external fixation is placed until the definitive fixation can proceed. Primary closure of all wounds is attempted. Leaving an otherwise closable wound bed open effectively buys that patient flap coverage. Vacuum-assisted closure (VAC) has a significant utility in closed incisions/lacerations, and it can greatly help the healing of a wound in the immediate postoperative period.⁴⁹ VAC therapy is also frequently used, in conjunction with or without antibiotic beads, for grade IIIB fractures, or those in which primarily closure is not feasible. For these fractures, the time to flap-coverage is of the utmost importance and should be performed definitively within seven days of the injury.³⁹ Despite recent advancements, open fractures of the lower extremity remain one of the most difficult challenges faced in orthopedic trauma (Fig. 40-3).

Damage Control Orthopedics Versus Early Total Care

The large volume of musculoskeletal tissue in the lower extremities, including the pelvis, increases the potential systemic effects of lower extremity injuries. Bleeding and accumulation of extracellular fluid may cause hypovolemia and contribute to systemic hypotension.⁵⁰ Several units of blood can be lost into severely injured thighs, and preoperative blood loss associated with a single femur fracture is up to 1500–2000 mL. A crushing wound of the lower extremity releases intravasated debris (eg, bone marrow), myoglobin, related muscle breakdown products, and various inflammatory mediators. The release of these substances may cause fat embolism and adult respiratory distress syndrome (ARDS), acute renal failure, and multiple organ failure (MOF).^51,52,53

As demonstrated by Tscherne, Bone et al, Trentz and coworkers, and others, prompt surgical treatment for severe extremity injuries benefits the whole patient.^6,54,55 Early fracture stabilization reduces the systemic effects of fractures, including SIRS, sepsis, MOF, and ARDS. Early stabilization reduces pain and the need for analgesic medication, and promotes mobilization of the patient with attendant benefits to the respiratory and gastrointestinal systems. While fracture fixation is particularly beneficial for the patient with injuries to the lower extremity and pelvis, “damage control” procedures should be undertaken if the patient is in shock, coagulopathic, hypothermic, or has an actively developing traumatic brain injury.^4,5,56,57,58 The concept of damage control orthopedics (DCO) emphasizes rapid provisional skeletal stabilization with simple external fixators, followed by delayed definitive fixation when the patient is stable and the inflammatory system is less primed, usually at 5–10 days post-injury, thus minimizing the risk of the second hit phenomenon.^4,7,8,56,59 There is a large body of evidence illustrating that intramedullary nailing has significant consequences on the immunologic status of a patient.^60,61,62 While most surgeons are in agreement regarding the use of DCO for patients in extremis and early total care (ETC) for stable patients, controversy exists concerning the subset of patients who are “borderline,” neither in extremis or stable.

There is a substantial body of evidence on both sides of the argument concerning the treatment of “borderline” patients. DCO has been championed by Pape and others in increasingly improving literature.^8,63,64,65 More recently, there has been a considerable body of evidence that expands the indications for ETC, absorbing the majority of the “borderline” patients.^{9,11,66,67,68} Pape’s original study has been repeated with results that clearly support the use of ETC for the same subset of patients for which he found DCO to be better.⁶⁹ There is likely a large part of this shift that has resulted from improvements in resuscitative efforts: patients are improving from “borderline” to stable and resuscitated before there has even been an opportunity to initiate DCO. Thus, ETC becomes the more viable option.

Limb Salvage Versus Amputation

One of the most challenging decisions involved in the care of an injured patient is whether or not to attempt salvage of a severely injured limb.⁷⁰ Although every appropriate effort should be made to preserve functional and anatomic integrity, for some severe lower extremity injuries, an amputation and prosthesis may be more effective for the patient than a limb that is still attached but is of limited use. In the acute phase, the decision to amputate will depend primarily on the immediate condition of the patient and the feasibility of stabilizing/revascularizing the injured limb (see Fig. 40-1). In those cases in which the patient is hemodynamically unstable and revascularization cannot be accomplished without increasing the chance of death, amputation is the only choice. In these cases a guillotine-type amputation is appropriate, but every effort should be made to preserve length and coverage options. In particular, efforts to preserve the potential for a below-knee amputation (BKA) by preserving any viable distal muscle and/or skin will improve the patient’s outcome.⁷¹ Free tissue transfers, rotational flaps, and skin grafts can all be used effectively to improve length and provide a durable, useful stump. Many surgeons are unaware that well-padded stumps can be skin-grafted and that free flaps are even feasible. A correctly made BKA prosthesis should load through the thigh and not be end-bearing. Unfortunately, in many cases, the decision to amputate is made in the middle of the night, without opportunity for consultation with experienced salvage surgeons. Multidisciplinary decision making in these severe cases may provide increased reconstructive options whether the limb is salvaged in entirety or amputated.

If the limb is initially salvaged, then further decisions must be made regarding the desirability of maintaining the salvage effort, which usually involves multiple further operations. The doctor-patient relationship becomes very important at this point. The psychosocial factors that play into losing a limb are similar to the patterns of grief associated with losing a loved one.⁷² Generally speaking, a patient who has sustained a catastrophic lower extremity injury will never have the same level of function as prior to the injury; and how well that patient recovers—whether salvage or amputation is performed—is more determined by economic, personal, and social factors than by injury or surgical factors.⁷³ If a patient is low-functioning at baseline, it is unlikely he will have a good outcome regardless of which operation is performed. The more cost-effective option at that point is therefore amputation. It can take a considerable amount of time spent with the patient to elucidate the characteristics that will define their recovery.

At times, the decision between salvage and amputation is made simpler by certain clinical findings. For example, while a limb can still be salvaged despite necrosis of the plantar skin, free flaps and skin grafts to the sole of the foot are frequently not tolerated and are unlikely to be very functional. Similarly, systemic consequences of the initial injury can supersede decisions regarding the limb. Historically, there were clinical indicators that were used to help guide this decision such as injury scoring systems and the presence or absence of plantar sensation. The Lower Extremity Assessment Project (LEAP) is the best recent effort to characterize these injuries, and it found that injury scores were not predictive of a patient’s likelihood to have success with reconstruction.^74,75 Similarly, the presence or absence of plantar sensation upon initial presentation was not predictive of plantar sensation after reconstruction.⁷⁶ Despite improvements in the body of evidence surrounding this difficult subject, much of the decision making remains out of the hands of the surgeon: it requires a discerning eye to provide the best care for each individual patient faced with this difficult decision.

If the decision is made to amputate, the level of amputation greatly impacts future function. Proximal amputations have greater functional impairment and are often less satisfactory then prosthetic alternatives. Prosthetic replacement of the foot and ankle is highly functional whereas the prosthesis for an above-knee amputation requires more energy for ambulation and is less functional. Thus, every reasonable effort is appropriate to preserve the patient’s own knee joint and enough proximal tibia (at least 10 cm below the joint) to provide for good prosthetic fitting. If this cannot be done, a Gritti-Stokes amputation can be considered. This is a through knee amputation where the patella is attached to the cut end of the femur (see Fig. 40-3). Different from a BKA, this is an end-bearing amputation that can be used with a prosthesis that is not too different from that for a below knee. Prostheses for very proximal femoral amputation levels, hip disarticulation, or hemipelvectomies are rarely functional for ambulation; therefore, efforts are also appropriate to preserve an adequate above-knee amputation level.

Replantation

Technically, replantation is possible for complete and subtotal lower extremity amputations. However, given the current near impossibility of lower extremity nerve regeneration in adults, the functional outcome is questionable. In general, only cleanly separated traumatic amputations in young individuals without significant systemic risk factors, including smoking, deserve consideration for replantation. Revascularization in the face of severe neuromuscular injury may result in a viable but painful, dysfunctional limb. Consultation with an experienced replantation team is essential. Preservation of the amputated part is according to the same principles for upper extremity replantation. Care must be taken to not jeopardize the patients’ life in lower extremity replantation and revascularization. Reestablishment of blood flow after a period of prolonged hypoxia can have a toxic effect, causing systemic inflammation and MOF. Consideration should be given to rapid external fixator and arterial shunt placement to “buy time” and permit an overall reassessment of the patient and of the desirability of reattachment of the limb.

Fracture/Dislocations About the Hip

Acetabular Fractures

Successful open reduction and internal fixation (ORIF) of displaced acetabular fractures significantly improves the prognosis of these potentially devastating injuries and permits early mobilization of a patient who might previously have been managed with many weeks of skeletal traction and bed rest.

Fractures of the acetabulum are articular injuries of the pelvic portion of the hip joint with profound implications for the long-term function of the hip joint. One of the first historical citations of these injuries was in Homer’s Iliad: “Just as Diomedes hefted a boulder in his hands, a tremendous feat…flung it and struck Aeneas’s thigh where hipbone turns inside the pelvis, the joint they call the cup—it smashed the socket.”⁷⁷ Judet and Letournel’s seminal work has led to our current classification, understanding, and management of acetabular fractures.⁷⁸ Today, there is a bimodal distribution in the patients presenting with these fractures: high energy in young patients, and low energy fall in the elderly. The fracture pattern is a result of the position of the femoral head when it impacts the acetabulum. There is a high association of other injuries whether they are orthopedic or systemic.⁷⁹ The AP pelvis view obtained in the original ATLS survey has six radiographic landmarks used to quickly identify an acetabulum fracture. Prompt orthopedic consultation is warranted with all acetabular fractures. Fractures associated with subluxation of the femoral head or incarcerated fragments may require skeletal traction until the patient is medically cleared for surgery. Oblique x-rays and CT scans are used to classify the acetabular fracture, to assess displacement and need for surgical treatment, and to determine the best surgical approach. There are multiple surgical approaches to the acetabulum including the Kocher-Langenbeck, the ilioinguinal, the extended iliofemoral, the modified iliofemoral, the Stoppa, the triradiate, combined anterior/posterior approaches, and percutaneous.⁸⁰ The surgical approach is dictated by the fracture pattern and the overall condition of the patient. Certain approaches that may be otherwise ideal may have to be abandoned secondary to prior interventions, including a very distal laparotomy incision or embolization to major pelvic vasculature, such as the superior gluteal artery. A complete three-dimensional understanding of the fracture is essential for formulating a preoperative surgical plan. Preservation of soft tissue attachments is needed to promote healing and avoid osteonecrosis of the fracture fragments. Vital neurovascular structures must be protected. A precise anatomic reduction must be achieved and fixed stably, generally with screws and plates, which must not encroach upon the articular surface. Intraoperative fluoroscopy has become a valuable tool for ensuring appropriate placement of orthopedic hardware around the acetabulum. Minimally invasive percutaneous screw fixation represents a challenging but valid alternative to open reduction with internal fixation in minimally displaced fractures or in patients with significant risk for wound complications or a “second hit” insult related to extensive surgical procedures. Complications and poor results become less frequent with increasing experience of the acetabular surgeon. Acetabular fracture surgery remains among the most challenging procedures in orthopedics. These difficult and dangerous reconstructive surgeries should generally be done in specialized centers to ensure that each patient receives optimal treatment.⁸¹

Acetabular fractures in osteoporotic individuals pose special problems. There is frequently significant comminution, often with a protrusio deformity (Fig. 40-4), and bone quality so poor that conventional fixation techniques are doomed to failure. In these instances, total hip arthroplasty with specialized acetabular reconstruction devices allows improved fixation and early weight bearing of the elderly patient. Because the femoral head is removed in total hip arthroplasty, extensile or combined exposures may not be required, and operative morbidity may be reduced.⁸²

Acetabular fractures are usually closed injuries, without need for immediate operation. If surgery is delayed for 3–5 days, operative bleeding is reduced, and preoperative planning may be improved. In some instances, percutaneous fixation (Fig. 40-5) can be performed with good results and much less intraoperative bleeding. Patients with pelvic and acetabular fractures have a significant risk of thromboembolic complications. Intermittent venous compression devices, anticoagulation with fractionated or low-molecular-weight heparin, and insertion of retrievable inferior vena cava filters for high-risk patients are all appropriate strategies for these injuries. Depending on the surgeon and institutional protocol, some patients may require either pharmacologic and or radiation based prophylaxis against heterotopic ossification following open reduction.⁸³

Hip Dislocations

Posterior dislocations of the hip result from direct blows to the front of the knee or upper tibia of a sitting patient, most typically an unrestrained passenger in a motor vehicle (Fig. 40-6). A fracture of the posterior wall of the acetabulum occurs if the leg is more abducted and pure dislocations occur if the leg is adducted and flexed at the time of impact. The typical appearance of a patient with a posterior hip dislocation is with a hip that is flexed, adducted, internally rotated, and resistant to motion. This appearance may be lacking if a significant fracture of the posterior wall exists. Any leg length discrepancy in a polytrauma patient should raise suspicion for injury to the pelvis and or femur. Anterior dislocations are more rare (5%) and are because of forced abduction and external rotation, which are also the characteristic deformity. Often times there are other associated injuries, most commonly the ipsilateral knee and femur, although other systemic injuries such as thoracic aortic injuries may be seen in deceleration injury patterns.⁸⁴ Ipsilateral sciatic nerve injury, particularly the peroneal component, is not uncommon and should be checked for after reduction. Nerve injuries are usually monitored expectantly and a small portion of them may never resolve, resulting in chronic foot drop.

An AP pelvis should be obtained in the shock room as part of the ATLS protocol. X-ray usually shows obvious signs of a hip dislocation or fracture–dislocation. A posterior hip dislocation will show a smaller femoral head on the injured side as the femoral head is brought closer to the cassette. An anterior dislocation, in contrast, will demonstrate a larger femoral head as the femur is brought further from the cassette, creating a larger radiographic shadow. Anterior dislocations may show combined superior (pubic) or inferior (obturator) dislocation if the hip is in extension or flexion at the time of injury, respectively. Care should be taken to scrutinize for ipsilateral femoral neck fractures which is a contraindication for closed reduction in the emergency room.

Urgent reduction of the hip joint should be performed within 6–8 hours to decrease the risk of irreversible avascular necrosis of the femoral head. The importance of prompt reduction has been demonstrated in multiple retrospective and prospective studies.⁸⁵ Closed reduction is best performed with adequate IV sedation and muscle relaxation. There are various described techniques in order to close reduce the hip joint, with the general principle being in line traction combined with recreation of the injury pattern. Care must be taken to avoid unnecessary force as iatrogenic fracture particularly of the ipsilateral femoral neck is a rare and devastating complication. After reduction, the hip should be ranged in order to examine for stability that will guide treatment. A CT scan is required after reduction of a dislocated hip to assess its adequacy and the integrity of the acetabulum, as well as to exclude intra-articular bone fragments.⁸⁶ Whenever possible, the hip should be close reduced prior to obtaining CT of the chest, abdomen, and pelvis in order to avoid delays in reduction and to prevent unnecessary radiation, as the hip will need a repeat CT postreduction.

Postreduction skeletal traction may be necessary if the hip remains unstable and or there are incarcerated fragments in the joint. Acetabular wall fractures of any significant size can result in instability, which, if present, is an indication for surgical repair within a few days after injury. Purely ligamentous injuries are usually inherently stable and require protected weight bearing for 4–6 weeks. While applying weight to the hip in an unstable position (eg, getting up from a low chair or toilet or getting into or out of a car) must be avoided until soft tissue healing has occurred, most patients can get out of bed and ambulate as soon as they can move and control their leg. Anterior or posterior approaches may be utilized depending on the presence of concomitant musculoskeletal injuries. If the hip is reduced, the surgery can be delayed days until the patient is properly resuscitated. Long-term outcome of hip dislocations includes an acknowledged significant risk of osteoarthritis, as well as some stiffness and limping that may never resolve. Avascular necrosis, the risk of which increases dramatically (from about 2 to 15%) if initial reduction is delayed more than a few hours, usually appears during the first year, with essentially all cases evident within 3 years after injury.

Femoral Head Fractures

Fracture of the femoral head is a rare injury pattern often times associated with hip dislocations.⁸⁷ The presence and size of a femoral head fragment depends on the position of the hip at the time of impact, with decreased hip flexion, internal rotation, and adduction associated with larger fracture fragments. These injuries are usually seen in a high mechanism injury patterns, such as a fall from a height, sports-related injuries, or most commonly motor-vehicle related accidents (ie, dashboard injuries). There is a high association of ipsilateral limb injuries, including femoral neck and acetabulum fractures as well as ligamentous knee injuries. The incidence of femoral head fractures are increasing as the resuscitation protocols are improving.⁸⁸

Patients will usually present in the emergency room with a shortened or rotated leg if there is an associated hip dislocation, femoral neck fracture, and or acetabulum fracture. AP pelvis films obtained in the shock room as part of the ATLS protocol is sufficient in identifying a femoral head fracture. Associated dislocations should be reduced promptly in the emergency room within 6–8 hours. Reductions should be performed with care and unnecessary force should be avoided as fracture fragments may be impacted into the articular surface or an iatrogenic fracture may be created. Irreducible fractures should be taken promptly to the operating room for an open reduction.⁸⁷ Postreduction skeletal traction should be placed in the setting of an unstable hip joint and or incarcerated fragments. Postreduction CT scans should be obtained in order to assess the concentricity of reduction, size and location of the fracture fragment, and for associated bony injuries (ie, acetabulum or femoral neck).

Non-displaced femoral head fractures not involving the weight-bearing portion can be treated closed with a period of protected weight bearing. Displaced and large fracture fragments should be treated surgically with open reduction internal fixation.⁸⁹ Older patients with osteoporotic bone or highly comminuted fractures may be treated with arthroplasty with the advantage being immediate mobilization and weight bearing. The approach may be posterior or anterior depending on the size and location of fracture and the presence of associated injuries. Complications following femoral head fractures mimic those of the associated injuries. Post-traumatic arthritis is the most common complication with avascular necrosis being the most devastating. Heterotopic ossification can be seen, particularly with extensive anterior exposures in patients with concomitant head injuries. In these patients postoperative prophylaxis, radiotherapy or pharmacologic, may be warranted. Sciatic nerve injury, particularly the peroneal portion, is not uncommon and should be managed expectantly with the majority resolving spontaneously.⁹⁰

Fractures of the Proximal Femur—”Hip Fractures”

“Hip fractures” is the general name used for a group that can be simplified to femoral neck fractures and intertrochanteric (in and around the greater and lesser trochanters) fractures. Both can be subdivided in ways that help the define treatment options:

• Intracapsular versus basicervical femoral neck fractures. The ascending cervical arterial branches that supply the femoral head arises from an arterial ring at the base of the neck. Fractures at the base of the neck (basicervical) usually do not damage these arteries whereas fractures across the neck risk injury. In addition, an intracapsular fracture will be exposed to the synovial fluid within the hip joint, which can interfere with healing of the fracture.

• Nondisplaced versus displaced femoral neck fractures. Similarly, the blood supply to the femoral head is considered intact in nondisplaced fractures and damaged in displaced fractures. Again, a displaced fracture will be exposed to synovial fluid whereas a nondisplaced fracture will not.

• Stable versus unstable fracture pattern. This can apply to both femoral neck and intertrochanteric fractures. Some fractures are innately unstable secondary to their orientation relative to forces generated by weight bearing. For instance, a vertically oriented femoral neck fracture (Fig. 40-7) will tend to shear and displace with weight bearing while a horizontally oriented fracture will compress. Intertrochanteric fractures that are a simple fracture pattern without comminution or multiple fragments are considered stable. Of particular importance is the integrity of the calcar, the portion of bone just proximal to the lesser trochanter. Fracture lines that separate the lesser trochanter and the calcar from the rest of the proximal femur are significantly less stable and must be approached with a different surgical technique.

Like many orthopedic injuries, hip fractures have a bimodal distribution. In young patients, who for the hip are aged 50–55 and younger, fractures of the proximal femur are typically high energy while the far more common geriatric hip fractures tend to be lower energy. While there are many similarities in the treatment options, there are some key differences. An intracapsular femoral neck fracture in a young patient should be addressed as soon as possible as viability of the hip joint is at risk. Not only can the ascending arteries along the femoral neck be severed or avulsed if the fracture is displaced but the arteries can be kinked and subsequently clot. Even in nondisplaced fractures, the pressure from a fracture hematoma expanding within the confined space of the hip capsule can halt or slow blood flow. Clearly, those vessels that are torn cannot be repaired, but the timely reduction of the fracture can reestablish blood flow in kinked or partially blocked vessels. In addition, the intracapsular hematoma can be evacuated. Because there is no way to reliably know if the blood vessels to the head are in continuity, any attempt to preserve the viability of the femoral head must proceed urgently.

Even if the fracture is fixed anatomically and in a timely manner, the femoral head still may die within the coming months. As this happens, portions of the subchondral bone will collapse, leaving the joint surface uneven and the head no longer spherical. This avascular necrosis frequently degenerates over the coming months/years, contributing to a reoperation rate ranging from 17% in young patients to as high as 53% in the older population.^91,92,93 Despite the high rate of failure, urgent internal fixation remains the standard of care for patients less than 50–55. For those over that age cutoff, the high rate of revision surgery pushes the pendulum toward primary total hip arthroplasty in healthy patients and hemiarthroplasty in less active, older patients.

Outside of the difficult decision making associated with displaced, intracapsular femoral neck fractures, the remaining hip fractures—basicervical femoral neck fractures and intertrochanteric fractures—are treated similarly. In young patients, the concept of early total care is followed, and surgical fixation is pursued as soon as the patient is resuscitated. For older patients, the surgery is similarly expedited once the patient has been medically optimized. It is at this point when the nuances of the fracture pattern and its relative stability become important, primarily regarding the choice of orthopedic implant. For stable fractures, the dynamic hip screw (DHS) is a tested, inexpensive solution (Fig. 40-8). For unstable fractures, a cephalomedullary nail (CMN—a rod down the canal of the femur with a large, fixed-angle screw into the femoral head, illustrated in Fig. 40-9) is the implant of choice. In the past decade, there has been considerable data to suggest a disproportionate use of the newer, more expensive CMN for fractures that are stable, despite historically similar outcomes.⁹⁴ This is likely secondary to younger surgeons being more familiar with the newer technology and their general preference for the CMN as an implant.⁹⁵ More recently, an analysis of American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) illustrated that, while the overall outcomes are similar between the DHS and CMN, patients treated with the CMN had over a day shorter hospital length of stay post hip fracture, thus negating any extra cost incurred by using the implant.⁹⁶ Likely as it is, the trend will proceed in favor of the CMN as the implant of choice for basicervical femoral neck fractures and intertrochanteric femur fractures, whether stable or not.

The Fracture Liaison Service—organized geriatric fracture care

While there is a bimodal distribution of hip fractures, the vast majority occur in elderly patients and are generally low energy in nature, usually from a ground-level fall. Worldwide there were 1.7 million hip fractures in 1990, and this is projected to increase to 6.3 million in 2050. In the United States alone this number is expected to be between 500,000 and a million hip fractures per year.^97,98 Hip fractures are a significant source or morbidity: 20% of hip fracture patients require long-term nursing home care and only 40% regain their prefracture level of independence.⁹⁹ By definition, a patient more than the age of 55 who sustains a hip fracture has osteoporosis and carries a risk of future osteoporotic fractures as high as 17 times that of age-matched controls.^{100,101,102,103} The mortality associated with osteoporotic fractures is greater than the combine mortality of breast and ovarian cancer.¹⁰⁴ A large and increasing burden on society, hip fractures and bone health have come into the spotlight as a target for streamlined care with a focus on value-added health care delivery—basically, more bang for the proverbial buck.

Most hospitals either have some version of the Fracture Liaison Service (FLS) or are moving toward it. The main goal of the FLS is to provide expedited preoperative medical optimization of geriatric fracture patients with a focus getting the patient to the operating room within 24–48 hours after injury. Perioperative pain management is protocoled, with a push toward regional anesthesia when possible. Surgical decision making focuses on choosing an implant that allows the patient to be weight bearing as tolerated immediately postoperatively—arthroplasty for the displaced femoral neck fracture and a CMN for most other hip fractures. A coordinated inpatient team that includes the orthopedic surgeon, hospitalist or geriatrician, dietician, physical therapist, social worker, and case-worker focuses on initiating osteoporosis management, delirium prevention, mobilization, and finding a place for the patient to go. Close, multidisciplinary follow-up is established to facilitate further characterization of the patient’s bone health during the healing stages of the fracture with delineation of an osteoporosis treatment plan.

There is considerable evidence to illustrate how this streamlined approach is working: multiple studies have documented either trends or significant improvements in regards to decreased complications, decreased opioid use, shortened length of stay, decreased readmission, improved 30-day and long-term mortality, and an increasing return to activities of daily living, all without an increase in costs.^{105,106,107,108} The numbers in support of expedited operative care are staggering: a meta-analysis of 257,367 patients found that a delay of more than 48 hours for surgical treatment, when compared to surgery less than 48 hours, had Odds Ratios of 1.44 and 1.30 for 30-day and 1-year all-cause mortality, respectively.¹⁰⁹ Certainly, some of this is secondary to the preadmission health of the patient; that is, unhealthy patients do worse, particularly if they require extensive medical optimization prior to surgery.^110,111,112 Overall, the FLS model of streamlined geriatric fracture care, while being a work in progress, has yielded a significant improvement in patient outcomes after what is a debilitating injury, all at little to no increase in the cost of providing the care and in some areas, decreasing the overall cost of care. As our health care delivery system is forever crunched between an ever-increasing demand for care and a relentless pursuit to limit costs, expect this type of value-added medical care to play a larger role in many areas of medicine in the coming decades.

Subtrochanteric and Femur Shaft Fractures

Physiologically, femoral shaft and subtrochanteric fractures are very similar. Biomechanically and clinically, there are some nuances involved in the treatment algorithm that define them from each other. For the majority of this discussion, they can be considered the same entity. Femoral shaft fractures (FSF) invariably represent severe injuries due to high-energy trauma and are associated with a significant blood loss of up to 1500–2000 mL. Thus, an isolated femur shaft fracture alone can be the cause of a traumatic hemorrhagic shock. Most patients, however, suffer severe associated injuries to the torso, pelvis, and soft tissues. Thus, every femoral shaft fracture must be appraised as a highly critical, potentially lethal injury pattern. As discussed previously in regards to DCO versus ETC, early fixation of femur fractures is essential, in order to avoid or reduce the incidence of complications such as fat embolism syndrome, and ARDS.¹¹³ Furthermore, early fracture fixation pays tribute to the intrinsic load to the patient by reducing stress and pain, which represents an important cardiovascular risk factor and may contribute to secondary deterioration of traumatic brain injuries due to increases in intracranial pressure.^{4,5,56,59,114,115}

Intramedullary nailing of a femoral shaft fracture was performed for the first time by the German surgeon Gerhard Küntscher in November 1939. Despite the revolutionary innovation introduced by this new “biological” osteosynthesis, intramedullary nailing of long bone fractures has fallen into oblivion for several decades and had its “renaissance” only in the late 1980s by the introduction of solid and cannulated nails. Currently, the concept of closed reduction and fixation with a reamed interlocked intramedullary nail represents the “gold standard” for the treatment of femoral shaft fractures (Fig. 40-10). This procedure is associated with 99% union rates in the literature, a low complication rate, and the possibility of early functional aftercare with weight bearing. Intramedullary nailing provides generally reliable fixation for any femoral fracture with sufficient intact bone proximally and distally. Interlocking screws were adopted to improve rotational control of comminuted fractures. Intramedullary reaming permits use of a larger-diameter nail with larger-diameter interlocking screws. Small femoral medullary canals may not permit insertion of an implant with sufficient strength and durability to avoid the risk of fixation failure. As a result, reaming has generally been recommended as a routine. Awareness of intravasation of reaming debris (fat, bone marrow fragments, inflammatory mediators, etc) has led to concerns that their embolization to the lung might increase the risk of pulmonary complications and induce ARDS.¹¹⁶ Clinical trials and experimental animal studies in recent years have ended the decade-long debate on the clinical relevance of reaming the intramedullary canal as opposed to using unreamed femoral nails.^117,118 The current consensus implies that the reaming procedure does in fact not increase the risk of intraoperative and postoperative pulmonary complications.^51,119 Thus, the reamed interlocking nail represents the current standard of care for femoral shaft fractures.

Intramedullary nailing has been demonstrated to be a safe treatment modality also for open femur fractures (types I, II, and IIIA). Retrograde femoral nails can be placed through open knee lacerations.¹²⁰ Patients with severe open femoral shaft fractures (types IIIB and IIIC) need individualized decisions about fixation techniques. Preferably, external fixation represents a safe modality for early stabilization of these severe open injuries, followed by conversion to an internal fixation (nail or plate) at the time of definitive soft tissue coverage.

Subtrochanteric fractures, a less frequent variety of hip fracture, represent challenging injuries because of frequent failures of surgical fixation. Significant advances in understanding of fracture healing and of fixation techniques have improved the management of these fractures. Each of the typical modalities for osteosynthesis of subtrochanteric fractures has its pitfall. When treated by closed reduction and intramedullary nailing, the proximal fragment is difficult to reduce adequately and is at risk to be malreduced in a position of varus and flexion as a result of the muscle forces on the proximal short segment. The cognizant orthopedic surgeon should be able to overcome this difficulty, but often this is not the case. Failure to reduce and maintain the reduction of these fractures while placing intramedullary fixation can lead to nonunion and subsequent implant failure, a vastly more difficult problem to treat. The other option, open reduction with plate fixation using either a 95° angular blade plate or a proximal femoral locking plate remains challenging. Such operative techniques that fully expose the fracture and devascularize bone fragments may produce a “nicer x-ray,” but interfere significantly with fracture healing and thus lead to delayed union with loosening or fatigue failure of fixation.

Recently, a second cohort of subtrochanteric femur fracture patients has been identified that differ from the usual young patients that are seen. This cohort consists of patients who have been taking bisphosphonate medication for the treatment of osteoporosis for several years. The mechanism of action of bisphosphonate medications interferes with normal bone turnover. Subsequently, the ability of bone to repair itself is altered. Patients with these fractures have a typical step-cut fracture pattern with lateral beaking of the bone at the fracture site that is representative of a long-standing stress reaction of the bone. While these fractures are treated typically, care must be taken to question the patient about activity-related contralateral thigh pain to avoid missing antecedent symptoms prior to another femur fracture. In addition, these patients should be changed to another medication for osteoporosis that does not work by the same pathway as do the bisphosphonates.

Fractures of the Distal Femur

Fractures of the distal femur where the femur flares distally into its metaphyseal and articular components about the knee have historically been a significant challenge. As opposed to the thicker cortex of the shaft, bone in this area lends itself less to fixation, especially in osteoporotic patients, predisposing to loss of fixation. Distal femur fractures account for approximately 7% of all femur fractures.¹²¹ Similar to hip fractures, distal femur fractures are mostly seen in two patient populations: young patients sustaining high-energy trauma and following low energy injuries in the elderly. There are a number injury patterns seen in this part of the bone that varies from complex intra-articular injuries to simple transverse extra-articular fractures.

When noted, fractures of the distal femur warrant a close examination of the entire patient, particularly in the polytraumatized patient. The most common mechanism for a distal femoral fracture is a dashboard type injury with direct trauma to the flexed knee. These injuries are associated with concomitant acetabular fractures, hip dislocations, femoral neck and shaft fractures, and patella fractures. The soft tissues should be assessed and the patient should be evaluated for a compartment syndrome. Radiographic evaluation should include standard AP and lateral films. With significantly comminuted fractures, films with manual traction help elucidate fracture morphology. If there is concern for possible intra-articular extension, a CT should be ordered and is often very useful for preoperative planning. Images of the entire femur and pelvis are ordered to rule out additional associated injuries. Vascular studies are indicated if there is a concern for vascular injury as detailed previously.

The primary aim, whether operative or non operative, is restoration of the native length, rotational, coronal, and sagittal alignment of the femur. Failure to do this results in alterations of the patient’s gait mechanism and can lead to arthritis and poorer patient satisfaction. Operative intervention is mandated for fractures that extend into the joint. In these cases, particular attention is directed to achieving an anatomic reduction of intra-articular fragments. Any residual step-offs within the joint accelerate the development of post-traumatic arthritis. In recent years, there has been more interest more minimally invasive techniques that limit additional soft tissue disruption. These include minimally invasive plating techniques and retrograde intramedullary nail placement for the treatment of distal femoral fractures.¹²² These nails are inserted in a minimally invasive fashion through the knee across the fractures site and secured proximally and distally with screws. In patients with significant soft tissue disruption or swelling a temporary external fixator may be applied as a staged procedure in order to maintain length and stability until definitive fixation is appropriate (Fig. 40-11).

Distal femur fractures have historically been characterized by high rates of malunion, nonunions, infection, and hardware failure. Recent literature has supported use of less traumatic forms of fixation that require less stripping of the already injured periosteum. Coupled with implant designs that are angularly stable, outcomes have improved.¹²³ Whether treated operatively or nonoperatively, the main goal, particularly for operative fixation is early functional rehabilitation preservation of knee mechanics and range of motion, and uneventful fracture healing. Patients with factures that extend into the knee typically have their weight bearing limited for 6–12 weeks to avoid loss of fracture reduction. One exception is elderly patients who are generally allowed to weight bear as tolerated.

Patella Fractures and Extensor Mechanism Disruptions

The patella is the largest sesamoid bone in the body and is encased within the extensor mechanism of the knee. The extensor mechanism allows the quadriceps muscles to extend the knee through pull on the anterior tibia. Fractures of the patella are clinically significant if they disrupt the patient’s ability to extend the knee. Tears of the quadriceps tendon proximally or the patellar tendon distally would also result in a similar clinical picture. Optimal function requires a smooth articulation between the underside of the patella and the trochlear groove of the femur. The patella is stabilized within this groove with contributions of medial and lateral retinacular attachments between the patella and the medial and lateral aspects of the femur respectively. Disruptions of these structures are implicated in patellar subluxations or dislocations which typically reduce on their own though require attention if they are recurrent.

Patella fractures and extensor mechanism disruptions are frequently diagnosed by history and physical examination. Patients will frequently present with knee pain, a knee effusion or hemarthrosis, and the inability to actively extend the knee. Since the patella is not a weight-bearing structure, some patients may report be able to continue weight bearing if they maintain their knee in extension. Some patients may retain some extension in the setting of a patellar fracture if the surrounding retinacular tissues are not injured. A soft tissue defect distal to the patella and a high-riding patella suggest a patellar tendon disruption. Conversely, a palpable defect proximal to the patella and a distally lying patella suggests a quadriceps tendon disruption. Standard imaging in the setting of suspected extensor mechanism disruption includes AP, lateral, and tangential views. Advanced imaging is rarely indicated in the acute setting of recurrent patellar dislocations.

Patellar fracture management depends on the fracture morphology. Operative interventions include wiring, screw-based fixation, partial patellectomies, and total patellectomies. Nonoperative treatment is reserved for patients with a nondisplaced patellar fracture who are able to extend against gravity. In these cases, the leg is initially braced, splinted, or cast in extension for 4–6 weeks. These patients are initially allowed to weight bear in a knee immobilizer. Inability to extend at the knee generally requires operative fixation and attempts to manage these nonoperatively have poor results. The method of patellar fracture fixation depends on the fracture morphology, location, and degree of comminution. Given the superficial nature of the patella, it is not uncommon for implants to become symptomatic and to be removed after successful fracture healing. Tears of the quadriceps or patellar tendon are repaired. Chronic quadriceps or patellar tendon tears typically require tendon lengthening procedures and reconstructions in order to overcome the shortening that results from quadriceps retraction. Postoperatively patients are generally allowed to weight bear in extension with progressive range of motion over time.

Injuries About the Knee

Knee dislocations and tibial plateau fractures are easily underappreciated. As with many orthopedic injuries, the position of presentation often understates the position of injury. This is of particular importance around the knee because of the close proximity of the relevant neurovascular structures. Thus, while a knee injury on presentation could present in a relatively benign fashion, it could be masking a potentially limb-threatening injury.

Complete knee dislocations frequently produce obvious deformity and difficulty moving the involved joint, as well as a radiographically evident dislocation, usually anteriorly or posteriorly, but sometimes medially or with rotation to any quadrant. Multiligamentous injuries in the knee with similar neurovascular concerns may be present without obvious deformity on exam or x-rays. The bony constraints of the knee joint are minimal when compared to other joints such as the hip. When a hip dislocates, it stays dislocated until a difficult maneuver is performed to reduce it. A dislocated knee generally just requires gentle to moderate traction to reduce it. For this reason, a knee can dislocate and then spontaneously reduce. If that is the case, it presents in the form of multiligamentous knee injury. Frequently, ligamentous injuries can include small fragments of bone. Within this same spectrum, those fragments can sometimes be large enough to be considered tibial plateau fractures. Further on this continuum, some tibial plateau fractures are effectively knee dislocations. This is particularly true with fractures of the medial tibial plateau. Looking at Fig. 40-12, the constant fragment is not the tibial shaft but rather is the portion of the medial tibial plateau that is still attached to the femur by its ligamentous attachments. The remainder of the proximal tibia is dislocated from its articulation with the femur. Similarly, some very comminuted bicondylar proximal tibia fractures are effectively knee dislocations, where the bone breaks rather than the ligaments tearing.

The importance of establishing the relationship between these injuries is to illustrate the variability with which a knee dislocation or equivalent injury can present. Vigilance must be maintained: a knee joint that feels a little loose or a plateau fracture that is only minimally displaced may have actually been much worse. All of these patients require a careful neurovascular exam, and an ankle-brachial index (ABI) should be obtained. The clinical relationship also works in reverse: in the presence of a neurovascular injury, a knee fracture/dislocation should be considered.

The early recognition of an associated popliteal artery injury is crucial, which has been described in 14–34% of all cases with traumatic knee dislocations. While a complete arterial disruption may be obvious early after trauma due to clinical signs of peripheral ischemia, an incomplete dissection or intimal injury by stretching forces may be missed. Intimal tears can lead to delayed thrombosis and secondary limb ischemia in spite of the absence of apparent early clinical evidence for a vascular injury. Because of the often asymptomatic nature of blunt popliteal injuries, the amputation rate for blunt vascular trauma is about three times higher than that after penetrating injuries and lies in the range of 15–20%. Thus, a high index of suspicion is required for blunt popliteal injuries in all cases of knee dislocation and defined diagnostic algorithms should help establish an accurate diagnosis early on. Any pulse deficit or measurable reduction in ABI Doppler-assisted, before or after manipulation, should be considered evidence of a vascular injury. This includes the reported absence of pulses at the accident site even when pulses return to normal after reduction of the knee dislocation. Based on large meta-analyses in the literature, the accuracy of pulse examination alone is very low, yielding a sensitivity of only about 79% for the detection of an arterial injury.^16,124 The five clinical “hard signs” for an arterial injury, which are present in about two-thirds of all cases, are outlined in Table 40-1.

In cases of a suspected arterial injury, either an (on-table) arteriography or a surgical exploration is mandatory, since observation alone will have detrimental consequences for the patient. Injuries to the peroneal or tibial nerve, with motor and/or sensory impairment, may be associated with an arterial occlusion. Such neurological lesions also interfere with recognition of ischemic pain due to arterial occlusion or an acute compartment syndrome.

A popliteal artery injury associated with dislocation of the knee is repaired in the operating room with both vascular and orthopedic surgeons present. Adequate reduction and stabilization of the knee dislocation is required, and external fixation is well suited for provisional stabilization. A simple external fixator, connecting two self-drilling pins in the femur to two similar pins in the tibia with a bridging bar anterior to the knee, can be applied so rapidly that it will not delay arterial repair. It can readily be adjusted to allow intraoperative motion of the knee, should that help with vascular repair, and furthermore provides a nonconstricting splint for postoperative immobilization and protection of the vascular graft. With regard to ligamentous injuries, the currently favored concept of treatment consists of an early, but not immediate, surgical repair. While the incision for arterial repair must be chosen by the vascular surgeon, consideration should be given to the exposure required for secondary ligamentous repair and whether or not this might safely and appropriately be combined with the emergency vascular repair. Trauma teams that treat these relatively rare injuries may manage them more effectively by developing collaborative protocols for knee dislocations with concomitant injuries to the popliteal artery. Below-knee four-compartment fasciotomy is routinely advisable after popliteal artery repair in order to avoid a secondary compartment syndrome due to ischemia–reperfusion injuries. Again, the lines of communication between the vascular and orthopedic surgeons should be open: if there are fractures of the proximal tibia that require surgical fixation, the correct placement of the fasciotomy incisions is important. These are particularly morbid procedures in the setting of proximal tibial fractures; the rate of infection approaches 40%, and the rate of nonunion is significantly higher.¹²⁵

Ligamentous and meniscal injuries without dislocation of the knee may occur in multiple trauma patients or as isolated injuries. Hemarthrosis, swelling, pain, tenderness, and impaired motion of the joint are typical findings. If a knee cannot be examined initially because of adjacent fractures, ligamentous stability must be assessed as soon as those fractures are stabilized. Associated knee injuries are not uncommon with femoral or tibial fractures and particularly when both are present in a so-called floating knee. Inability to passively extend the knee suggests a mechanical block, usually a meniscal tear, whereas instability indicates a ligamentous injury. Both knees should be examined for comparison, because individuals have different amounts of intrinsic laxity. Initial examination of the knee requires x-rays to rule out associated fractures. Aspiration of a tense hemarthrosis under sterile conditions can relieve pain. Complete evaluation may also require arthroscopy or magnetic resonance imaging (MRI) to identify ligamentous or meniscal injuries, but such studies are rarely needed emergently. Although many acute ligamentous injuries of the knee can be treated nonoperatively, major reconstructions may be required to restore function. Accurate diagnosis of ligamentous injuries is crucial for planning appropriate treatment. Relatively infrequent disruptions of the posterolateral ligamentous complex should be repaired within the first 2 weeks. Isolated ruptures of the medial collateral ligament do well with nonoperative management in a hinged knee brace. Delayed reconstruction is often advisable for disruptions of the cruciate ligaments, unless avulsed with a bone fragment, for example, in combination with Moore-type fracture–dislocations of the tibial head.

The aforementioned knee dislocations are all dislocations of the tibiofemoral joint. The patellofemoral joints may also be dislocated. Lateral patellar dislocations typically occur in adolescent females with a genu valgus alignment. Patellar dislocations are usually lateral and involve indirect stresses applied by the patient pivoting on or forcefully extending a flexed knee in valgus. A hemarthrosis or effusion soon develops. Recurrent patellar dislocations are not infrequent, because anatomic abnormalities are often predisposing factors. The dislocated patella is palpable laterally, although it may have been reduced by straightening the knee for immobilization or x-ray. Closed reduction, if necessary, is obtained by passively extending the knee, flexing the hip to relax the rectus femoris, and applying medially directed pressure to the patella. Immobilization for 4–6 weeks allows healing of the medial retinacular tear that typically accompanies an initial dislocation, although acute repair of the medial patellofemoral ligament may be considered. Recurrent dislocations should be evaluated for elective surgical reconstruction.

Proximal Tibia Fractures

Proximal tibia fractures are differentiated as extra-articular metaphyseal fractures, intra-articular tibial plateau fractures, and fracture–dislocations. While the typical split-depression-type fractures of the lateral condyle are usually due to low energy, indirect valgus stress mechanisms of injury, the more severe bicondylar fractures and fracture–dislocations are mainly due to direct high-energy forces with significant soft tissue compromise and a risk for acute compartment syndrome.¹²⁶ Those fractures are inherently unstable, difficult to reduce and stabilize, and associated with a high rate of complications, such as malreduction, secondary loss of reduction, infections, and nonunions. Isolated fractures of the medial condyle are more rare and often require special approaches for adequate reduction and stabilization, for example, by a direct posterior approach (Fig. 40-13).¹²⁶

For the accurate diagnosis of a tibial plateau fracture, routine x-rays of the knee should be complemented by a CT scan with 2D reconstruction, in order to allow an adequate planning of surgical approaches and fixation strategies. Nondisplaced proximal tibial fractures can usually be treated with early motion and touchdown weight bearing in a hinged knee brace for 6–12 weeks. The need to stabilize a severely injured limb, especially in a multiply injured patient, can be met initially with a spanning external fixator. Significant deformity of the articular surface, instability, and/or displacement are frequent indications for surgical treatment. To be successful, this must achieve stable fixation and early motion of an anatomically reduced articular surface. Often, there is significant swelling or soft tissue injury that precludes immediate definitive treatment—1 week or 2 of patience, allowing the soft tissue to recover, goes a long way toward preventing surgical site infections. If the fracture is not length stable, as many of the higher energy fractures are not, then an external fixator is used to stabilize the limb, allowing for soft tissue recovery. Most proximal tibia fractures are fixed with plates and screws, but certain fracture patterns are amenable to intramedullary nailing.

Tibial Shaft Fractures and Ankle Injuries

Tibial Shaft

Fractures of the tibial shaft range from low-energy, indirect torsional injuries that do well with nonoperative treatment to severe high-energy fractures with severe soft tissue damage and a high incidence of acute compartment syndrome. The amount of energy absorbed by the leg is suggested by the radiographic appearance of a fractured tibia. The severity of the soft tissue injury, whether open or closed, is most important for the overall outcome of tibial shaft fractures. For example, the presence of severely crushed soleus and gastrocnemius muscles makes a plastic coverage of an open tibia fracture by a local rotational flap impossible. The soft tissue envelope on the medial border of the tibia is very thin; thus, minor open fractures may have major therapeutic implications for covering the exposed bone, ranging from skin grafts to local or free flaps to a lower limb amputation.

Compartment syndromes develop frequently in tibial shaft fractures because of direct compression forces. They are especially common if the soft tissues have been crushed or if a period of ischemia has occurred. Of all fractures, tibia fractures require the most vigilance regarding the development of compartment syndrome. As mentioned previously, the diagnosis is primarily clinical, and a coordinated effort by all members of the medical team is necessary to prevent any delays in treatment.

Timing and treatment modalities for tibial shaft fractures are dependent on the severity of injury and associated problems. Limb-threatening complications such as open fractures, vascular injuries, and compartment syndromes require immediate surgery. In absence of such complications, a provisional closed reduction and application of a long leg cast provide initial immobilization. In tibial shaft fractures of minor severity and dislocation, closed treatment is the method of choice.¹²⁷ Weight bearing begins as tolerated in the long leg cast, proceeding to a patella tendon bearing short leg cast or brace, as soon as patient comfort and stability of the fracture permit. Although this approach can succeed with more severe tibial shaft fractures, it is often associated with delayed union, deformity, and prolonged disability. Surgical fixation, which provides better control of alignment and allows motion of the foot and ankle as well as the possibility of earlier weight bearing, is more appropriate for these injuries. Intramedullary reamed nailing is the fixation of choice. The indications for intramedullary nailing are increasingly expanding to more proximal and distal metaphyseal fractures because of the availability of new-generation interlocking nails that allow three-dimensional interlocking in very proximal and distal areas of the tibia (Fig. 40-14). The greater the proximity to either the knee or the ankle, the greater the challenges of maintaining overall alignment become. Appropriate fracture fixation requires control of the bone both proximal and distal to the zone of injury. As a fracture moves toward a joint, one side of the fracture necessarily becomes smaller and more difficult to control. Adding to this, the deforming muscle forces tend to be greater as well. There are a variety of tricks that the surgeon can use to avoid malalignment; but as always, the first requirement is awareness of the risks involved.

Reaming of the tibial medullary canal permits use of nails with large enough diameters to provide adequate fixation for most tibial shaft fractures. Such nails have large enough diameters to permit the use of locking screws of adequate strength to ensure definitive control of alignment. The strength and fatigue life of smaller-diameter unreamed nails, and especially of their small-diameter locking screws, is not sufficient for keeping the reduction of tibial fractures throughout their healing period.¹²⁸ Thus, the unreamed tibia nail has been associated with a high risk of complications, such as breaking locking bolts, malunion, and nonunion (Fig. 40-15). Multiple large clinical trials have demonstrated that both the nonoperative treatment and unreamed nailing strategies have the highest incidence of nonunion and malunion, as opposed to fracture fixation by reamed cannulated nails. The use of blocking (“Poller”) screws represents an important intraoperative trick for achieving and maintaining reduction and axial alignment.^129,130

External fixation is still a valuable technique for selected tibial fractures. These include high-energy trauma with significant soft tissue injury, vascular injuries requiring repair, and in the setting of polytrauma patients, as a “damage control” procedure.⁴ External ring fixators (Fig. 40-16) may furthermore be applied for segment transport in situations with significant bone loss, and for correction of malunions and nonunions. Long-term use of an external fixator (>14 days) is associated with bacterial colonization of the pin tracts and a risk of infection from subsequent intramedullary nailing. Use of an external fixator for only a few days, however, can safely precede intramedullary nailing for definitive management of tibial shaft fractures. Many open fractures of the tibia require staged treatment: the wound bed is debrided and closed if possible during the first operative setting with or with antibiotic bead placement. An external fixator is placed at that time. The patient then returns to the operating room when the soft tissue has recovered for definitive treatment, usually within a week. In the setting of open tibia fractures, there is some evidence that favors the placement of unreamed tibial nails; however, the evidence is only a trend, and there is no difference outcomes between reamed and unreamed nails at one year.^131,132,133

Plate fixation of acute fractures of the tibial shaft is generally reserved for periarticular injuries too proximal or distal for intramedullary nailing.¹³⁴ If severe injuries to soft tissue are present, such plating involves a significant risk of sloughing of the incision and/or infection. Techniques of plating that emphasize gentle handling of soft tissues, the avoidance of devascularizing flaps, and use of indirect reduction methods can further reduce the risk of surgical complications of plate fixation.¹³⁴ Locking plates that allow less invasive or minimally invasive plating techniques are ideal for bridging comminuted metaphyseal fractures that may be too proximal or too distal for intramedullary nailing techniques.

Pilon Fractures

Tibial pilon (plafond) fractures are highly challenging intra-articular injuries of the distal tibia that are typically caused by axial loading forces with concurrent distortion and of the ankle, leading to a disruption of the tibial articular surface by the twisted and rotated body of the talus. These fractures typically involve significant damage to soft tissue, whether or not an open wound is present. Traditional ORIF techniques have a high risk of wound dehiscence and infection, particularly if surgery is performed during the phase of post-traumatic inflammation and soft tissue swelling within the first days after trauma. Clinical studies have clearly revealed an improved outcome of tibial pilon fractures when staged procedures are applied, such as early external fixation and later conversion to ORIF once the soft tissue swelling has subsided.¹³⁵ The concept of definitive surgery for pilon fractures involves a standard technique in four “classical” steps: (1) plating of the fibula for anatomic length of the lower leg, (2) anatomic reconstruction of the tibial articular surface, (3) bone grafting of the metaphyseal gap, and (4) buttress plating of the distal tibia. Depending on the degree of comminution, the individual bone quality, and the extent of soft tissue compromise, the postoperative rehabilitation of pilon fractures is either by early functional after treatment or by immobilization in a lower leg cast for about 6 weeks. As for all metaphyseal fractures, weight-bearing status must be restricted to touchdown weight bearing until the fracture is healed, usually for 10–12 weeks.

Ankle Injuries

Ankle injuries represent overall the most frequent musculoskeletal injuries. The mechanism and severity of injury has been historically classified by the Lauge-Hansen classification system.¹³⁶ The ankle is a hinge joint, in which the body of the talus dorsiflexes and plantarflexes within a mortise-like socket formed by the distal tibia (medial malleolus and plafond) and distal fibula (lateral malleolus). Integrity of the mortise is maintained by the ligamentous connections between tibia and fibula, just above the ankle joint (anterior and posterior syndesmosis). Widening of this mortise results in talar instability, which predisposes to post-traumatic arthritis. The lateral malleolus is the prime determinant of talar alignment. Restoration of its proper relation with the distal tibia is “key” to treating malleolar injuries. This may require anatomic ORIF of a displaced lateral malleolar fracture and/or restoration of the disrupted syndesmosis by returning the fibula precisely to its location adjacent to the tibia. Stable, minimally displaced lateral malleolar fractures can be managed nonoperatively with closed treatment, typically with about 6 weeks of immobilization, followed by rehabilitative exercises to restore the range of motion. If the ankle is unstable, it will need to be temporarily fixed with a syndesmotic screw until ligamentous healing is secure, usually for 6 weeks. Patients who require syndesmotic fixation have a significantly worse long-term outcome than patients with ankle fractures and a stable syndesmosis.¹³⁷

Medial ankle disruptions may involve the medial malleolus, which should be reduced and fixed, or the deltoid ligament, which need not be repaired if the remainder of the joint is reduced and repaired properly. Several authors have determined that a widened “medial clear space”—under stress exam or gravity stress test—of more than 4–5 mm represents an indication for surgical ankle fracture fixation.¹³⁸ The posterior lip of the tibial plafond, the so-called posterior malleolus or Volkmann’s triangle, is frequently fractured in malleolar injuries. The designation of a “trimalleolar” fracture implies those injuries that involve the posterior tibial plafond in addition to the medial and lateral malleoli. Large posterior tibial plafond fractures of more than one-fifth of the articular surface should be reduced and fixed to avoid posterior subluxation of the talus and/or incongruency of the joint. Malleolar fractures are produced by indirect forces, generally caused by the body’s momentum when the foot is planted on the ground in one of several typical positions. Depending on the position of the foot and direction of motion, typical combinations of fractures and ligamentous injuries result, with progressively greater damage and displacement, up to and including talar dislocation. Knowledge of these patterns improves the surgeon’s understanding and treatment of such injuries. The basic principle of treatment remains open reduction of displaced injuries, with anatomic reduction and rigid fixation. If significant displacement is present, prompt closed reduction is urgent, while definitive fixation can be delayed, depending on the quality of the individual soft tissue situation. As with pilon fractures, significant swelling is an indication for a delay in surgery to decrease complications with wound healing.¹³⁹ Some authors have suggested a staged protocol for complex ankle fractures with significant soft tissue compromise, with initial closed reduction and transarticular pin fixation, followed by delayed ORIF once the soft tissue swelling has subsided.¹⁴⁰ The soft tissue envelope about the ankle and foot is thin, with little muscle coverage. This renders simple lateral malleolar fractures susceptible to significant soft tissue complications, including skin necrosis, wound dehiscence, and infections. Open fractures of the malleoli may require a microvascular free flap transfer due to the bad quality soft tissue coverage and the impossibility of local rotational flap in this distal area of the leg. Recognition and appropriate management of open ankle injuries is essential to minimize complications and avoid adverse outcomes, which may require a BKA. This notion emphasizes again, as mentioned above for the pilon and tibial shaft fractures, the “key” aspect of the soft tissues for uneventful fracture healing.

Ligamentous injuries of the ankle most commonly involve the lateral collateral ligament complex, which provides inversion stability of the talus within the mortise. Inversion of the foot normally occurs at the subtalar joint, between the talus and calcaneus. If forced to the limit, however, the lateral collateral ligament stretches or ruptures, producing the typical “sprained ankle” with lateral pain, swelling, and ecchymosis and tenderness over the injured ligament distal and anterior to the lateral malleolus. Minor ankle sprains can be treated symptomatically, with restricted activities, elevation, ice, and support as needed for comfort. More severe sprains require immobilization and/or crutches for comfort and to decrease the risk of late instability, which is manifested by recurring episodes of “giving way” of the ankle. After a brief period of rest, most injuries to the lateral collateral ligament of the ankle are effectively treated with a functional brace.

Since it is difficult to differentiate a simple distortion from a fracture in the acute phase because of nonspecific symptoms such as pain, tenderness, and swelling, a precise diagnosis usually requires adequate radiographs. A “true” AP view of the ankle (so-called mortise view) requires internal rotation of about 15–20° to position the joint axis, which runs between the tips of the two malleoli, in a plane parallel to the x-ray film. The mortise view and a lateral view are usually sufficient to adequately diagnose most ankle fractures. Oblique views and foot x-rays may be required to identify more occult or associated injuries, such as a base of the fifth metatarsal avulsion fracture, lateral process of talus (“snowboarder’s injury”), or anterior process of calcaneus fractures.

Fractures and Dislocations of the Foot

Injuries of the foot typically result from direct blow or crushing force. They are often found in the polytrauma patient, particularly when associated from falls from a height or high-speed auto-mobile related injuries. Management can prove to be challenging, particularly when they are associated with surrounding soft tissue injuries. Given the high incidence of concomitant injuries associated with foot fractures/dislocations, these injuries can be unrecognized resulting in a delay in definitive treatment which may compromise outcome. Radiographs of the foot should be obtained in any polytrauma patient with foot swelling or abrasions. A CT scan should be obtained if there is high suspicion for a fracture in the setting of normal x-rays.

Calcaneus Fractures

Calcaneus fractures are often times a result of an axial load to the heel. Concomitant injuries are common with 7–15% of patients with calcaneal fractures having associated spine fractures, particularly if presenting after a fall from a height.^141,142 In these patients, a spine exam should be thorough, with a low threshold for spine imaging, particularly of the lumbar spine. Although non-displaced and/or extra-articular fractures may be treated nonoperatively, there is a type of displaced calcaneus fracture, the ‘tongue-type’ (Fig. 40-17), which puts immediate risk to the surrounding soft tissue, and must be reduced urgently.¹⁴³ The majority of displaced calcaneus fractures are treated in 2–3 weeks when the swelling has significantly subsided. Operative interventions bear a high risk for severe soft tissue complications, since the surgical approach typically dissects through the thin skin envelope over the lateral calcaneus. The blood supply to the skin is so tenuous that poor surgical candidates including smokers and those with peripheral vascular disease will be treated nonoperatively even in the setting of displaced fractures.¹⁴⁴ Other than soft tissue complications, varus malunion and subtalar arthritis are common long-term complications.¹⁴⁵

Talus Fractures

Talar neck fractures are the most common type of talus fractures accounting for roughly 50%. They are usually the result of high-energy mechanism involving an axial load through the heel with forced ankle dorsiflexion, such as when a car pedal impacts on a planted foot. Ipsilateral lower extremity fractures are common. Displaced talar neck fractures are often times associated with surrounding dislocation (subtalar, talonavicular, and or tibiotalar).¹⁴⁶ Displaced fractures require emergent reduction in the emergency room in order to restore the blood supply to the already tenuously vascularized talus. The thought is that by promptly reducing the talus, blood supply will be restored by any kinked blood vessels. In reality, the majority of the insult occurs at the time of injury when the blood vessels are avulsed. Ideally these fractures should be close reduced in the emergency room immediately and then surgically stabilized in a delayed fashion once the patient and overlying soft tissues are stabilized. If the fracture cannot be reduced closed, the patient should be taken emergently to the operating room for an open reduction.¹⁴⁷ The most common complication following these injuries is post-traumatic arthritis of the subtalar and or tibiotalar joint. Medial comminution is frequently seen and is responsible for late varus malunion of the talus.^148,149

Other fractures of the talus, include the talar body, head, and lateral process. Unlike talar neck fractures, these fractures often times do not require prompt intervention. However, these fractures are often times missed on x-ray.¹⁵⁰ A CT should be obtained in any situation in which there is high suspicion for a fracture and the radiographs are negative.¹⁵¹

The subtalar joint is the articular unit between the calcaneus and talus. Dislocations of the subtalar joint are another devastating injury of the foot seen secondary to high-energy mechanisms. These injuries can be open and are frequently associated with fractures of the calcaneus, talus, cuboid, and or navicular.¹⁵² Prompt reduction in the emergency room is again recommended to reduce the chances of irreversible avascular necrosis of the talus. The reduction mechanism involves knee flexion and ankle plantarflexion in combination with either foot supination in lateral dislocation or pronation in medial dislocation. A postreduction CT is needed in order to scrutinize the articular reduction and to assess for associated fractures or loose bodies in the joint. Purely ligamentous injuries can be treated closed in a cast, but fracture dislocations often require surgical intervention. As with talus fractures, post-traumatic arthritis is the most common long-term complication.¹⁵³

Mid- and Forefoot Injuries

Jacques Lisfranc de St Martin, a French surgeon in Napoleon’s army, first described the injury that bears his name in the early 1800s. Cavalry men were suffering terrible midfoot injuries after being thrown from their horses and many were treated with transmetatarsal amputations. Figure 40-18 illustrates a severe midfoot injury that is catastrophic without surgical reconstruction. The Lisfranc joint is the articulation between the medial cuneiform and second metatarsal base. The joint is responsible for stabilizing the second metatarsal and maintaining the midfoot arch. There are variable patterns of dislocations and fracture dislocations that can involve any and all of the tarsometatarsal joints.¹⁵⁴ The mechanism is usually indirect rotational or axial load on a hyper-plantarflexed foot, often times seen in athletic competitions, falls from a height, or motor-vehicle accidents. These injuries present with severe swelling, pain, and plantar ecchymosis of the midfoot, frequently with only subtle radiographic findings. If highly suspicious of an injury in the setting of normal radiographs, standing radiographs should be obtained in order to stress the Lisfranc ligament. If the patient is unable to cooperate with standing films, a CT scan of the foot can be used to better visualize any avulsion injuries.¹⁵⁵ These injuries require urgent closed reduction of the midfoot and eventual surgical fixation once the soft tissue swelling has subsided. Midfoot arthrosis is the most common complication following these injuries.

Metatarsal fractures are the most common fractures of the foot.¹⁵⁶ Because of multiple muscle and ligamentous attachments that maintain alignment, the majority of these fractures are treated without surgery. However, if a malunion does develop, the force dissipation in the foot may be altered resulting in transfer metatarsalgia.¹⁵⁷ Multiple metatarsal fractures may require surgical intervention to restore alignment: the intermetatarsal ligament can no longer prevent migration of fracture fragments if multiple metatarsals are fractures. Multiple fractures of the metatarsal bases should be highly suspicious of a Lisfranc injury.¹⁵⁸ Again with any fracture of the foot, care should be made to assess the overlying soft tissue injury which will often times dictate the course of treatment and overall prognosis.¹⁵⁹

Fractures of the toe phalanx are treated nonoperatively in the majority of cases. Buddy taping to an adjacent nonfractured toe with protected weight bearing in a hard sole shoe is usually sufficient. Subungual hematoma in association with a fracture should be considered an open fracture until proven otherwise. These open injuries are often times missed, particularly in the great toe, and should be treated with prompt irrigation and a course of antibiotics.¹⁶⁰ Dislocations of the phalanges should be reduced promptly which is usually sufficient treatment. Mangled injuries of the toes are usually treated with amputation.¹⁶¹

Nonunion

Historically, the diagnosis of nonunion was made when there is failure of complete healing within a 6- to 9-month time period following definitive fracture care. More recently, nonunions have been more loosely defined as any bone that is unlikely to heal. This appropriately encompasses fractures with partial circumferential or segmental defects. Fractures have different expected time periods of healing depending on the type of fracture and the location. Tibia fractures are relatively slow healing, particularly open fractures. Femur fractures heal more rapidly. Nonunions complicated by bone loss, significant malalignment, or infection are extremely difficult challenges for the patient and surgeon (Fig. 40-19). Treatment to gain union may require 2–5 years and numerous revision surgeries.

Nonunions are categorized as hypertrophic, oligotrophic, and atrophic. These distinctions are critical in that they describe the underlying cause of the nonunion and therefore point toward correct treatment options. Hypertrophic nonunions are fractures that have failed to heal in spite of a good local blood supply and obvious formation of callus. Mechanical stabilization alone usually produces union in this situation. Oligotrophic nonunions show minimal callus formation but no bony resorption. These need mechanical stabilization and some improvement of the local biology, usually by local autogenous bone grafting. Atrophic nonunions show little to no callus formation and have local bone resorption. The atrophic nonunion has poor local blood supply and will require rigid mechanical stabilization, local bone grafting, and in many cases resection of dead bone and flap coverage. If the bone resection is significant, distraction osteogenesis with a ring or monolateral transport external fixator will be necessary. If deformity coexists with a nonunited fracture, both problems should be addressed simultaneously if possible.

Malunion

Malunion involves shortening, angulation, and/or malrotation following fracture. While some amount of shortening is well tolerated, shortening greater than 2 cm in the lower extremity requires a built-up shoe to equalize leg length for stance and gait. Elective limb lengthening, contralateral extremity shortening, and even amputation are surgical alternatives to a significant leg length discrepancy. A variety of techniques are available using external fixators or specialized lengthening intramedullary nails to regain limb length.

Rotational and angular deformities may be better tolerated in the femur than in the tibia. Varus or valgus deformity may be cosmetically unacceptable and can produce knee and ankle symptoms that warrant corrective osteotomy. Significant deformity may also predispose to progressive osteoarthritis from asymmetric loading of joints. Malunion of hindfoot or metatarsal fractures may result in painful weight bearing, requiring osteotomy for realignment, with or without arthrodesis of adjacent joints.

Sequelae of Joint Trauma

Stiffness, ankylosis, and contracture may follow an injury to a joint or to the proximal muscles that control it. Direct injury to articular cartilage, joint malalignment, or incongruity increases the risk of post-traumatic arthritis. Significant arthritis leads to pain with weight bearing and eventually loss of normal functional activities, necessitating joint replacement or fusion.

Anatomic reduction and early motion of injured joints provides the best chance of preventing post-traumatic arthrosis. Unfortunately, perfect postoperative reductions do not guarantee perfect functional outcomes. Factors out of the control of the surgeon such as cartilage damage occurring at the time of injury, soft tissue injuries, and post-injury psychological distress have significant impact on the overall outcome.

Flexion contractures of the hip, knee, and ankle may occur in patients who do not perform frequent prophylactic extension stretching exercises of these joints. This is particularly true for intensive care patients who remain intubated for extended periods of time. Equinus ankle contractures predictably develop if appropriate splinting and stretching exercises are not provided for the posterior calf muscles. Flexion contractures of the toes may follow injuries to the leg and foot. Passive toe stretching is required to ensure adequate dorsiflexion for normal gait. Toe clawing is the result of contractures of the leg and/or foot muscles following injury, scarring, traumatic neuropathy, or ischemic contractures from a compartment syndrome. Surgical correction may be required. Prevention of contracture with appropriate splinting and early exercises is more effective than late correction.

Traumatic arthritis may develop in any injured joint. While ankle and subtalar joint arthrosis is usually evident within 1 year, the hip and knee may require several years before symptoms are significant. Rapid deterioration of the hip joint may be caused by avascular necrosis, typically after delayed reduction of a hip dislocation or a displaced femoral neck fracture. Avascular necrosis eventually results in segmental joint collapse, typically seen in 1 or 2 years after injury. Pain and disability do not always correlate with x-ray findings. Pain with activity is the typical major symptom of post-traumatic arthritis. If symptoms are not too disabling, then conservative measures such as a cane or brace or intermittent use of anti-inflammatory drugs are indicated. Although arthroplasty of the hip or knee is a satisfactory reconstructive procedure for elderly adults with severe symptoms of traumatic arthritis, there is still no uniformly satisfactory procedure for alleviating the condition in the young, vigorous patient.

Lower extremity injuries have an enormous impact on the acute and long-term functional outcome of the traumatically injured patients. Advances in orthopedic trauma care center in multidisciplinary cooperation and management, with an emphasis on prudently aggressive stabilization of the multiply injured patient. The plethora of effective techniques and approaches to early stabilization mandates an ongoing conversation between the orthopedic surgeon, general/trauma surgeon, plastic surgeon, and neurosurgeon regarding the management of individual patients. Clearly, in this day and age, the placement of multisystem trauma patients in splints and traction is suboptimal for most major lower extremity injuries. Whether “damage control” external fixation or definitive minimally invasive fixation is chosen, early aggressive care is part of an optimal management paradigm.

Isolated lower extremity injuries can be devastating with potential loss of life and limb or appear to be relatively benign. Unfortunately, nondramatic injuries such as foot fractures can have lifetime consequences and prevent a patient from returning to his or her work and life activities. Therefore, each injury should be carefully evaluated, thoughtfully treated, and followed long term to ensure the best possible physical and psychological result.