Fracture/Dislocations About the Hip
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
An anterior column acetabulum fracture in an elderly patient. The injury film illustrates the impaction of the articular surface as well as the protrusio, or the migration of the femoral head into the pelvis (A). After fixation, the femoral head is back in the hip socket and the quadrilateral surface medial to the acetabulum has been reinforced (B).
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
Polytrauma patient with combined pelvic ring and acetabular fracture. Due to the high-risk constellation in this patient, all fractures were treated by closed reduction and percutaneous cannulated screw fixation.
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.
Traumatic posterior hip dislocation in a 25-year-old woman who sustained a high-velocity motorcycle accident (A). After closed reduction, a traumatic defect of the femoral head is seen on the AP x-ray, classified as a Pipkin type II fracture (B, arrow). A trochanteric Ganz osteotomy was performed with a surgical hip dislocation to assess and repair the defect (C). Postoperative x-ray shows the partially filled defect by an osteochondral autologous graft (D, arrow).
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.
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.
Displaced, intracapsular vertical femoral neck fracture in a 65-year-old male patient who fell 6 ft from a tree (A). Anatomic reduction was achieved on a fracture table, with lag screw fixation using three 7.3 mm cannulated screws in an inverted triangle pattern (B and C). Despite anatomic reduction and adequate fixation (D), the fracture collapsed into varus and the patient developed a nonunion at 6 months (E). The arrows point out the nonunion and the lateral protrusion of the screws. This complication emphasizes the inherent instability of Pauwels type 3 fractures and the rationale for a primary joint arthroplasty in elderly patients with displaced femoral neck fractures.
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.
Stable intertrochanteric femur fracture in a 51-year-old construction worker who sustained a fall from a ladder (A and B). The fracture was treated by closed reduction and fixation with a gliding hip screw/plate device. X-rays taken at follow-up after 4 months show a healed fracture in anatomic position (C and D).
Unstable trochanteric femur fracture in a 20-year-old female medical student who was involved in a motor scooter crash. The unstable fracture pattern with a breach to the lateral wall (arrow in A) mandates fixation with a cephalomedullary nail (B). The fracture healed uneventfully with full weight bearing within 6 weeks (C). The nail was removed after 1 year due to symptomatic hardware.
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.
“True” percutaneous femoral nailing technique by the use of a cannulated femoral nail that is reamed through a small 1 cm proximal skin incision (A). This 51-year-old polytraumatized patient sustained a transverse femur shaft fracture that was treated by closed reduction and stabilization with an interlocked cannulated femur nail (B–D) and an ipsilateral, comminuted meta-diaphyseal proximal tibia fracture that was stabilized by a minimally invasive locking plate (E and F). Both measures are considered “biological” techniques since they spare the soft tissue envelope by the use of minimally invasive skin incisions.
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).
A 40-year-old dentist who sustained bilateral femur fractures (A–D) after a high-energy motorcycle crash, with a nondisplaced left extracapsular femoral neck fracture, an ipsilateral femur shaft fracture, and a proximal pole transverse patella fracture. The injury on the right side consisted of a distal femur fracture with a comminuted metaphysis and an intra-articular split. The femoral neck fracture was closed reduced and fixed with a dynamic hip screw (DHS) and an antirotation screw on day 1 (D), whereas both femur fractures were stabilized by external fixation for “damage control.” Five days later, the patient was taken back to surgery for conversion to a minimally invasive locking plate on the right side (E and F) and a retrograde femur nail on the left side (G). This latter procedure was chosen due to the impossibility of using an antegrade nail related to the proximal DHS. The bilateral femur fractures showed progressive callus formation within 5 months after injury (H and I) and the left femoral neck fracture was healed at this time (J). The patient was ambulating with full weight bearing bilaterally and a free range of motion of both knee joints.
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.
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.
A fracture of the medial tibial plateau. The medial tibia remains attached to the femur and is considered the “constant” fragment. The remainder of the tibia—the lateral portion of the plateau and the shaft—are partially dislocated, as noted by the incongruency of the lateral joint space. The joint was very likely further displaced at the time of injury and should be considered a knee dislocation.
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 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
Bilateral complex tibia fractures in a 52-year-old lady who sustained a collision as a car driver against a truck. She sustained a severely comminuted tibial pilon fracture on the right side (A and B) as well as a contralateral, unstable bicondylar tibial head fracture (E and F). Both injuries were initially immobilized in an external fixator due to the critical soft tissue conditions. Once the soft tissue swelling subsided within 10 days, the fractures were converted to internal fixation. The bicondylar tibial head fracture was stabilized through a direct posterior approach with a posterior antiglide plate and completed by a lateral buttress plating with a locking plate (C and D). The pilon fracture was stabilized by initially fixing the fibula for correct length and rotation and by open reduction of the articular part of the pilon fracture with two lag screws and minimally invasive osteosynthesis with a locking plate (G–I). The patient recovered well without postoperative complications and was non-weight-bearing bilateral for 10 weeks.
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
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.
(A and B) A 19-year-old girl who was accidentally shot in the right leg as a victim of a drive-by shooting. She was immediately taken to the OR and treated by local wound debridement and intramedullary fixation of her tibial shaft fracture. She did not have any neurovascular injuries. Her postoperative course was uneventful and she was allowed to ambulate with weight bearing as tolerated on the right side. No postoperative infection occurred.
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
Varus malunion of a tibia shaft fracture after failure of fixation with an unreamed interlocking tibia nail. This is a typical complication of the first-generation unreamed solid tibia nails due to the thin diameter of the implant and interlocking bolts.
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
Segment transport using an external Ilizarov frame in case of a severely comminuted and contaminated tibial shaft fracture (A and B). After a proximal corticotomy (C and D), the bone loss was replaced by means of a distraction osteogenesis, and the distal docking site healed uneventfully (E and F).
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.
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 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 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
An Essex-Lopresti (tongue-type) fracture of the calcaneus. The proximity of the proximal fragment should be noted. The overlying skin is at risk for full-thickness necrosis within a few hours after presentation. This fracture should be reduced and fixed urgently.
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.
Combined navicular fracture–dislocation and metatarsal I Lisfranc dislocation of the left foot (A and B) in a severely injured polytrauma patient. The foot injury was treated by open reduction and internal fixation of the navicular fracture with two 2.0-mm mini-AO screws and a 3.5-mm joint-transfixing screw as temporary arthrodesis (C). This screw was removed after 3 months and the patient could walk with full weight bearing without pain.
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