Additional videos related to the subject of this chapter are available from the Medizinische Hochschule Hannover collection. The following videos are included with this chapter and may be viewed at expertconsult.inkling.com :
Leg lengthening with monorail technique.
Leg lengthening with intramedullary device.
The role of nerve decompression for acute and gradual deformity correction.
The hexapod fixator.
The management of traumatic limb-threatening injuries, especially to the lower extremity, remains a controversial topic in the orthopaedic literature. During the recent years, there have been tremendous technical developments in protection for the head and chest, improvements in prehospital care and medical evacuation, as well as organized regional trauma care and improved critical care within those trauma centers. As a result, orthopaedic surgeons are now challenged by severe extremity injuries that were infrequently seen in survivors in the past. Following the advances in care of severe soft tissue and bony injuries, there is an argument whether many limbs are salvaged to the detriment of the patient.
One of the most difficult problems is clinical decision making in a patient with an extensive limb injury. Is it in the patient’s best interest to perform a primary amputation of the “limb at risk” or to begin the complex limb salvage process ( Fig. 71-1 )? These patients may endure a prolonged medical and rehabilitation course that can leave them with a significant disability regardless of the surgical treatment. Late amputation is frequent in limb salvage patients. Dissatisfaction with function and complications have been associated with late amputation.
Recent clinical advances in general medicine, plastic, microvascular, and orthopaedic surgery provide the means to reconstruct limb injuries that would have been amenable only to amputation in the past. Military warfare, terrorist attacks, modern road traffic, and industrial accidents result in high-energy injuries. Natural disasters are another common cause of high-energy trauma. Hence, the prevalence of injuries that are survived that result in major limb damage is unlikely to decrease.
Limb injuries caused by high-energy trauma are characterized by extensive bone and soft tissue damage or loss. The initial assessment of explosion-related injuries can be particularly challenging because these patients may sustain combined penetrating, blunt, and burn, which makes judging tissue viability a challenge as the wound continues to evolve ( Fig. 71-2 ).
Early thorough débridement and irrigation, effective primary fracture stabilization, shunting or reconstruction of vascular injuries, modern methods of tissue coverage, improved options for delayed bone reconstruction, and advances in orthotics and prosthetics may contribute to improved outcomes compared with previous times in both limb salvage and amputation. Nevertheless, the treatment of limb-threatening injuries remains controversial because several small studies suggested that limb salvage had a negative impact on the well-being of the patient, but the largest study on the matter demonstrated no difference in patient outcomes.
Do the Limbs Matter?
When treating polytrauma patients with extremity injuries, the surgeon must first recognize the impact that severe extremity injuries have on overall patient recovery and return to preinjury status. It has been demonstrated in the literature that severe extremity injuries have a significant impact on long-term disability and functional outcome in polytrauma patients regardless of the functional outcome measure used. Furthermore, in polytrauma patients with extremity injuries, the majority of complaints are due to injuries below the knee, which drives long-term patient outcome in trauma survivors.
In addition to the patients’ overall physical and psychological outcome, extremity injuries pose a significant burden on resources in polytrauma patients. Masini and colleagues demonstrated that combat casualties with extremity injuries accounted for 54% of the injuries sustained, but they required even more resources (65%). This can likely be correlated to the civilian population because these injuries often require lengthy rehabilitation with lost work days and in some cases multiple operative procedures. These patients also are a frequent, if not the most frequent, cause of rehospitalization in polytrauma patients whether civilian or military. In fact, in civilian patient populations, rehospitalization for patients undergoing limb reconstruction can be expected to be as high as 48%.
Because of the nature of these injuries, many patients have long-term disabilities and have difficulties returning to work. In the landmark prospective observational study of patients with high-energy extremity injuries by Bosse and colleagues in 2002, the authors reported that only 49% of limb reconstruction patients returned to work at 2 years. The amputation group showed no difference in the rate of return to work at 53%. Until recently, no military study has directly compared return to work as a whole (military or civilian work after separating from the military). The Military Extremity Trauma Amputation/Limb Salvage (METALS) Study Group authors reported similar return to work or active duty in both the salvage group (48%) and unilateral amputation group (43.4%) at an average follow-up period of 3 years using questionnaires. This correlates with previously published data on return to active duty (not accounting for civilian jobs after leaving the military) for those sustaining combat-related type III open tibia fractures undergoing limb salvage (20%), which is nearly identical to amputees. A more detailed description of outcomes related to limb salvage can be found in the outcomes section at the end of the chapter.
Why so Many Extremity Injuries?
During the previous 2 decades, significant improvements have been made in automobile safety with universal application of airbags. Although newer designs are being modified to improve protection of the extremities, current mainstream airbags focus their protection on the head and thorax. As a result, the extremities, particularly the lower extremities, are exposed and susceptible to injury. This is a very similar injury pattern as seen in the military during the current conflicts because personal body army protects the head and thorax but leaves the extremities exposed.
In addition, many of these polytrauma patients are surviving despite greater burden of injury to the extremity and person because of improvements in response time, field application of aid, and advancements in hemorrhage control. Before 2009, tourniquets were not commonly applied in the field by emergency medical service (EMS) providers, but research performed by the military demonstrated the effectiveness of the tourniquet to prevent hemorrhage, leading to improvements in overall patient survival. Despite these improvements in extremity hemorrhage control, emergency control of junctional and intraabdominal hemorrhage remains a problem and is the focus of ongoing research.
Initial Management: Think Physiology, Not Anatomy
When approaching a patient with a mangled extremity, choosing a treatment strategy is difficult and bears an awesome responsibility. The orthopaedic surgeon must bear in mind that the treatment of the severely injured limb will always follow the patient stabilization— life before limb. Advanced Trauma Life Support should be the initial approach to critically traumatized patients. The initial physical examination of the threatened extremity is an evolution that occurs during the patient’s resuscitation. The overall condition of the patient, especially if pressed by the urgency of a vascular injury, should be the primary determinant in the decision between salvage or amputation. Unfortunately, when surveyed, many surgeons used anatomic factors rather than physiologic parameters to guide this decision. This decision for reconstruction or amputation must be made with mindful attention to the patient’s general medical condition, the patient’s and his family preferences (if able to express them), the surgeon’s personal experience, and the local medical system’s abilities to cope with the treatment and rehabilitation of limb salvage or amputation. Another important factor that influences the decision is the presence of mass casualty situation. In those situations, resources must be distributed in a timely and appropriate manner to preserve life, limb, and eyesight in as many people as possible.
The authors have developed an algorithm to guide surgeons during initial management of limbs at risk ( Fig. 71-3 ).
Common Factors Addressed with Initial Decision Making
In 1987, Dr. Sigvard T. Hansen challenged the orthopaedic community “to define clear, concise, acceptable guidelines to help decide which severely damaged extremities are handled by immediate amputation.” In attempts to make the decision easier and more calculated, several scoring systems have been developed during the years. Unfortunately, all of these scoring systems were developed and applied retrospectively in small number of patients. Further scrutiny in a large prospective study demonstrated a lack of utility in published scoring systems.
In 1987, Howe and colleagues published the Predicted Salvage Index (PSI) following combined orthopaedic and vascular injury. They found that limb survival was related to the interval from injury to arrival in the operating room (OR); the level of arterial injury; and the quantitative degree of muscle, bone, and skin injury. They combined these variables to the PSI and showed 78% sensitivity and 100% specificity. Johansen and colleagues published the Mangled Extremity Severity Score (MESS) in 1990. The MESS is a simple scoring system that stratifies four variables: skeletal or soft tissue damage, limb ischemia, shock, and patient age. They retrospectively reviewed 25 cases and showed that a MESS score of 7 or above predicted amputation with 100% accuracy. In 1991, Russell and colleagues published a seven-part predictive index, the Limb Salvage Index (LSI), to facilitate the decision making whether to amputate or to salvage a mangled extremity. They found that limb salvage was related to warm ischemia time and the quantitative degree of arterial, nerve, bone, muscle, skin, and venous injury. Limb salvage was not related to the presence or absence of shock and order of repair (orthopaedic or vascular). Reviewing 70 limbs in 67 patients, they showed that all of the patients with LSI scores less than 6 had successful limb salvage, and all of the patients with LSI scores of 6 or more had amputations. McNamara and colleagues reviewed their results of treatment of open tibial shaft fracture classified as Gustilo 3B or 3C using the MESS and their modified scoring system. They found that their modification of the MESS score, the Nerve Injury, Ischemia, Soft-Tissue Injury, Skeletal Injury, Shock, and Age of Patient Score (NISSSA), was found to be more sensitive (81.8% vs. 63.6%) and more specific (92.3 vs. 69.2%) than the MESS, although both scores were highly accurate in predicting amputations. Tcherne and Oestem published the Hanover Fracture Scale (HFS) in 1982 as the first score for severely injured limbs. It has undergone multiple modifications, the most recent of which was the HFS-98, which incorporates concerns for soft tissue damage and bone loss. Krettek and colleagues evaluated the modified score and compared it retrospectively with the MESS and NISSSA scores, finding it more specific and sensitive for predicting the need for amputation.
The presence of many scoring systems proves that no single scoring system is efficient enough to use as a good predictor for the results of either amputation or salvage of the mangled extremity. In a retrospective study in 1993, Bonanni and colleagues demonstrated that available scoring systems (MESS, PSI, LSI, and Mangled Extremity Syndrome Index) are not predictive of successful limb salvage. Despite this, these scorings systems continued to be used or in some cases modified in an attempt to improve their usefulness. The best available data regarding the usefulness, or lack thereof, of scoring systems was published in 2001 in a prospective evaluation of the utility of lower extremity injury severity scores. Bosse and colleagues studied 556 “high-energy” lower extremity injuries and found that the use of injury severity scores, including the PSI, the NISSSA, Hanover Fracture Scale-97, and the MESS, were not predictive of limb salvage potential. They concluded that the scoring systems have limited usefulness and should not be the sole criterion on which amputation decisions are based. However, the authors did not conclude that very low (good) scores were associated with limb retention. The same conclusion has also been reached on review of the application of scoring systems to predict the need for amputation in combat-related injuries.
Mangled upper extremity injuries are another major issue. All of the proposed scoring systems are based on injury to the lower limb, and in most cases, the tibial shaft. The assessment of the mangled upper extremity can be very different and is often not frequently discussed in the literature. In fact, there is no separate classification or scoring system that has been developed to specifically evaluate the mangled upper extremity. In 1994, Slauterbeck and colleagues reviewed their results of managing mangled upper extremity injuries and concluded that the MESS can be applied to the mangled upper extremity and is a good early predictor for the need of amputation. Other studies have failed to corroborate these results. Evaluating 52 patients with upper extremity vascular injuries, Prichayudh and colleagues found that a MESS score of 7 or greater did not correlate with amputation. However, a MESS score of 7 and lower was found to be a better predictor of patients who do not need an amputation. Additional authors have concluded that use of the MESS is not appropriate for the mangled upper extremity.
As a result of the data presented here, the authors conclude that mangled extremity scoring systems have limited value in guiding the decision to amputate or to salvage the mangled extremity. This statement applies for both lower and upper extremity, although the available evidence on treatment and outcomes on the mangled lower extremity is much larger. The orthopaedic surgeon must use the scoring systems with extreme caution based on personal experience and abilities.
Nerve Injury and Plantar Sensation
The absence of plantar sensation has been historically used as a predictor for the need for an amputation. In a survey of surgeons of the most important factor typically considered in the decision to amputate or reconstruct a limb published in 2002, absent plantar sensation was the number one reason for orthopaedic surgeons and number three reason for general surgeons behind high Injury Severity Scale (ISS) and limb ischemia. Recent data, however, suggest that it should not be an indication for amputation. The Lower Extremity Assessment Project (LEAP) Study Group identified 55 patients that presented with an insensate extremity and divided them into two groups: insensate and had an amputation ( n = 26) and insensate and had salvage ( n = 29). These patients were then compared with a sensate matched control group ( n = 29). There was no difference between the sensate control group and insensate salvage group at 2 years in terms of outcome or the need for late amputation. In fact, foot sensation was normal in more than half of the insensate control group (55.6%) at 2 years, which was similar to the sensate control group (55%). Only one patient in the insensate salvage group had absent plantar sensation at 2 years.
Peripheral Nerve Injury
In a series of combat-related type III open tibia fractures, the incidence of peripheral nerve injury was 22% with approximately 90% of the injured motor and sensory nerves with return of function at an average follow-up time of 20 months. Omer studied 917 upper extremity nerve injuries of different type. He showed that when the nerve is intact and in continuity, 70% of nerve injuries from gunshot and 85% nerve injuries from fracture dislocation regain spontaneous recovery after 1 to 9 months, depending on the cause of injury. When the nerve was severed and epineural sutures were performed, a 44% success rate was found in the fracture dislocation group and 25% in the gunshot group. Brien and colleagues reported that 60% of patients with peripheral nerve gunshot injuries to the lower extremities (sciatic and peroneal nerve) regained some degree of nerve function.
Vascular injuries do not occur often in combination with orthopaedic injuries but are more common in the setting of the mangled extremity. Typically, a vascular injury may be one of the few circumstances in the acute trauma setting in which a real-time decision must be made regarding acute limb salvage or amputation. This often requires a discussion with the vascular surgeon early to determine if vascular reconstruction is feasible, or depending on the setting and resources available, if temporary shunt placement is an option. In the case of the nonreconstructable vascular injury, a primary amputation can be performed or the injury can be temporized to allow assessment of collateral flow, with the understanding that an amputation may still be necessary.
Lerner and colleagues stated that vascular reconstruction or repair should be done as soon as possible, preferably in the golden period of 4 hours after injury for better results. However, they do not state what period of time is not appropriate for salvage. The options for vascular repair or reconstruction are numerous, increasing the chances for reviving the hypoxic limb. Poole and colleagues tried to determinate whether amputation can be predicted in a patient with mangled extremity. They retrospectively evaluated their experience of 48 mangled lower extremities from 46 patients. There was no single element, even ischemia time, that could predict primary amputation. They stated that if after revascularization and skeletal stabilization the extremity is clearly nonviable or remains insensate, then delayed amputation can be performed under more controlled circumstances.
The sequence of the surgical procedure should be discussed with the vascular surgeon to maximize care and minimize both ischemia time and risk of injury to a repair if the vascular repair is done before skeletal stabilization. It is the authors’ preference to leave a small footprint in the OR, débriding the injured extremity of contamination and nonviable tissue and stabilizing the extremity temporarily with traditional external fixation, which can be done quickly and safely without fluoroscopy. This can be done before, after, or optimally in conjunction with temporary vascular shunting if that is the vascular surgeon’s preference for the patient. If acute vascular reconstruction is the preference of the vascular surgeon, débridement, stabilization, and fasciotomy can all be performed while the vascular surgeon is achieving proximal control of the vascular injury and harvesting vein graft for reconstruction. This collaborative, simultaneous approach is possible if the orthopaedic surgeon maintains a small footprint in the OR for the temporizing procedure. The “keep yourself small” principle includes no fluoroscopy, no power, and self-service of instrumentation, thus allowing the surgical team to focus on life-threatening and vascular injuries while the orthopaedic surgeon can make strides in limb optimization as well as decreasing the necrotic burden of compromised tissue for the patient. Debates over surgical sequence disappear with this type of combined approach. Preparation for reperfusion injury needs to occur as well. Sudden death can occur from toxic metabolites released from damaged and dead cells in the ischemic areas. This preparation before limb reperfusion includes adequate resuscitation to normal or near-normal international normalized ratio, base deficit, temperature, and systolic blood pressure. Premedication with calcium and insulin can also help protect against the toxicity of hyperkalemia from cell lysis.
Cole developed a problem list to prioritize interventions at all stages of treatment for patients with mangled extremities in the following order:
Open fracture with massive contamination
Soft tissue devitalization
Then the team of surgeons and allied health professionals addresses each priority one by one before arriving at the decision point to save the limb. At each step during resuscitation and initial treatment, variables are carefully weighed and titrated according to the patient’s resources before a final commitment is made. This is a special challenge in the treatment of patients with bilateral lower extremity limb-threatening injuries. In addition, it clearly demonstrates the notion that the decision for limb salvage is individualized for each patient.
Based on the author’s experience, a limb is not likely to be appropriate for salvage if:
The salvage procedures will place undue risk to the overall health status of the patient
There is prolonged ischemia time
It is a mass casualty condition without the possibility to give the proper treatment for each injured individual. This is a relative contraindication.
In summary, the physiologic status of the patient after resuscitation should weigh heavily in reconstruction decision-making process. The common key elements to many of the classification systems of neurologic status and ischemia time should be weighed carefully, with respect to the surgeon’s experience, the local medical facilities, and the possibility of transportation to a higher level trauma center.
Limb Salvage: Surgical Reconstruction
Limb salvage process in severe high-energy trauma is based on staged treatment protocol. The process includes:
Initial management: Primary thorough débridement, stabilization of the bone fragments, and liberal use of fasciotomies
Secondary management: The second stage involves continued prevention of infection, including progressive surgical management of soft tissue defects, dead space management, continued débridement of evolving wounds, and reassessment of limb viability. As opposed to “washouts,” each procedure during this phase should have a clearly defined purpose aimed at moving the patient closer to definitive reconstruction (e.g., flap placement, depot antibiotic implantation).
Definitive management: The beginning of final reconstruction is marked by stabilization of the patient’s general health status as well as limb injury evolution. This definitive phase involves reconstruction of bone and soft tissue defects (if not already accomplished in phase 2) using a variety of surgical techniques. Two principal methods of urgent skeletal stabilization are usually applied in the treatment of complex high-energy fractures to the limbs: modern intramedullary interlocking nails and variable forms of external fixators.
Modern Intramedullary Interlocking Nails:
Modern intramedullary interlocking nails provide satisfactory biomechanical stability and therefore are widely used implants for the fixation of Gustilo type II, IIIA, and IIIB open fractures to the limbs and sometimes even for the treatment of patients sustaining concomitant vascular damage (Gustillo type IIIC fractures). Intramedullary fixation demands preliminary repositioning of the bone fragments and bone length restoration, providing stabilization of the fragments with secure control of alignment and rotation.
The benefits of intramedullary fixation for severely injured lower extremities are that it is a technique that is common and familiar to almost all orthopaedic surgeons, dissection within the zone of injury is less compared with traditional plating, all fixation is contained within the soft tissue envelope after reconstruction, and the implants are relatively inexpensive. One of the biggest drawbacks for intramedullary fixation in these severe injuries is the risk of deep infection.
For type IIIB femur fractures, deep infection rates have been reported as high as 11%; however, this may be acceptable given the difficulty of definitive management with external fixation for femur injuries. For type IIB tibia fractures, intramedullary nailing has resulted in infection rates from 12.5% to 35%. Despite these infection rates, intramedullary nailing remains a common technique in limb reconstruction for severe open tibia fractures in the United States and has even shown some advantages compared with external fixation when unilateral and circular were lumped together. Further study on the optimal technique is warranted.
Extensive tissue loss must be treated with bone grafting (often massive) and wound coverage using major complex soft tissue grafting procedures; microsurgical muscle skin flaps to cover the bone with living vascular tissue are often necessary.
The versatility of the current external fixation systems provides a good means for the fast and safe stabilization of severe open fractures, especially by using unilateral systems. External fixation frames maintain limb length; provide sufficient bony stability; and allow enough wound access for vascular and plastic surgery, if needed ( Fig. 71-4 ).