Amputations in Trauma




General Principles


History


Amputation is no longer only the result of traumatic amputation or the real or perceived failure of limb salvage. Rather, amputation is now considered a viable and reasonable treatment option for extensively injured extremities and as such should be considered a reconstructive, rather than ablative, procedure. Amputation surgery has developed extensively since it was first recorded in Neolithic times, when the procedure was done in rudimentary fashion for trauma and disease and to “appease the gods.” Also gone, however, are the days when the amputation was done as a primary treatment for open fractures as Larrey did in the Napoleonic Wars. Presently amputations are done both urgently and electively to reduce pain, provide independence, and restore function. Presently, there are approximately 1.7 million individuals living in the United States with an amputation, or one of about every 200 people. The vast majority of lower extremity amputations are not caused by trauma but rather vascular insufficiency either due to peripheral vascular disease or diabetes. About 80% of amputations are performed for complications related to vascular insufficiency. Upper extremity amputations, on the other hand, are most frequently the result of trauma; oncologic amputations accounted for approximately a third of amputations from 1988 to 1996. A smaller but significant number of amputations are done for congenital deficiencies, thermal trauma, and infections. Recently, the military has gained much experience with both performing amputations and improving prosthetic function. One of the primary lessons learned are that it is imperative to work as a team. Orthopaedic surgeons need to be comfortable working alongside of general trauma surgeons, vascular surgeons, and plastic surgeons. After the residual limb is closed, close working relationships with rehabilitation physicians, prosthetists, and physical therapists, as well as psychiatrists and social workers, are essential to provide the patient with the best outcome.


When looking at amputations with regard to futile or failed limb salvage, there have been several attempts to quantify the damage done to a limb and establish a prospective criteria or a scoring system for which limbs would benefit from early amputation versus limb salvage. To date, no system has been able to make this distinction reliably, with most systems showing that some patients with less severe injuries eventually go on to request an amputation even though the limb had been successfully salvaged from a surgical perspective. Factors that have been retrospectively associated with the need for an amputation include vascular status and more severe classification of fracture and severe soft tissue damage. However, no system has been able to adequately predict eventual amputation.


Three recent studies have shown that the functional outcomes of amputations and limb salvage are similar. First, the Lower Extremity Assessment Project (LEAP) studies have shown patient-reported outcomes between limb salvage and amputations are similar at both 2 and 7 years after the traumatic event ( Table 72-1 ). Second, the Military Extremity Trauma Amputation vs. Limb Salvage (METALS) study demonstrated slightly better results in the amputation group with regards to patient-reported outcomes ( Table 72-2 ). Finally, the Naval Health Research Center did a study looking at the differences between amputation and limb salvage and found comparable outcomes for those undergoing limb salvage versus those undergoing amputation. One interesting thing they found was that those undergoing amputation greater than 90 days after injury had significantly higher rates of mental- and health-related diagnoses. They also found that early amputees had significantly reduced odds of important psychological outcomes, including posttraumatic stress disorder (PTSD) and substance abuse than late amputees and limb salvage patients ( Table 72-3 ). All three studies, however, showed significant and persistent disability among patient with either limb salvage or amputation after severe extremity trauma. One downside to amputation as a treatment is the demonstrated greater permanent energy expenditure requirements for ambulation in a prosthesis versus normal control participants; however, comparative data are generally lacking for similar cohorts of limb salvage patients.



TABLE 72-1

LEAP DATA SHOWING NO DIFFERENCE IN OUTCOMES BETWEEN LIMB SALVAGE AND AMPUTATION WITH REGARD TO SICKNESS IMPACT PROFILE (SIP) AND RETURN TO WORK (RTW)
















LEAP Study Amputation Limb Salvage
SIP 12.6 11.8
RTW 53.0% 49.4%

LEAP, Lower Extremity Assessment Project.


TABLE 72-2

METALS DATA: SLIGHT IMPROVEMENT IN AMPUTEES WITH REGARD TO SHORT MUSCULOSKELETAL FUNCTION ASSESSMENT (SMFA), PERCENT ENGAGED IN VIGOROUS SPORTS (VS), AND POSTTRAUMATIC STRESS DISORDER (PTSD)




























Metals Amputation (%) Limb Salvage (%)
SMFA overall 22.1 29.4
SMFA mobility 28.3 36.5
SMFA emotional 40.0 47.1
VS 44.4 25.2
PTSD 14.8 26.8


TABLE 72-3

NAVAL HEALTH RESEARCH CENTER (NHRC): SIGNIFICANTLY INCREASED RATES OF OSTEOMYELITIS, CELLULITIS, NONHEALING WOUNDS, POSTTRAUMATIC STRESS DISORDER (PTSD), AND SUBSTANCE ABUSE BETWEEN EARLY AMPUTEES (<90 DAYS AFTER INJURY) VERSUS LATE AMPUTEES (>90 DAYS AFTER INJURY)




























NHRC Early Amputation (%) Late Amputation (%)
Osteomyelitis 33 47
Cellulitis 25 40
Nonhealing wound 11 19
PTSD 19 33
Substance abuse 12 23


Initial Management Principles


Regardless of the specific level or type of amputation, several principles should be adhered to when addressing either a traumatic amputation or a limb-threatening injury undergoing amputation. First and foremost, viable and functional residual limb length should be maintained whenever possible. Successful salvage of a functional joint level will generally result in improved function, and limb length should be determined by the ability of the residual or reconstructable soft tissue envelope to functionally support that level of amputation. One should neither sacrifice residual length in order to facilitate a conventional wound closure provided adequate soft tissue is available nor amputate at a more proximal level simply because of the presence of a proximal, otherwise manageable, fracture. Studies have demonstrated that residual limbs can still have excellent function with a terminal skin graft, provided otherwise robust soft tissue coverage is present. In some patients, even consideration of free tissue transfer may salvage a joint level, and some initial success has been seen with this approach. Similarly, stabilizing fractures proximal to an amputation has been shown to be successful in salvaging both residual limb length and amputation levels versus more proximal amputation through the fracture.


Bone ends should be well padded with muscle and have sharp prominences removed to decrease the likelihood of late irritation or ulceration. In most instances, a good myodesis (suturing of the terminal muscle or tendon to the bone) should be done to both stabilize the padding and maximize terminal residual limb control. In upper extremity amputations in which a myoelectric prosthesis will often be contemplated, critical muscles groups should individually be myodesed into the bone so that the electromyographic (EMG) signal can be independently recorded without triggering involuntary antagonist muscle co-contraction. In this setting, myoplasty (suturing of antagonist or opposing muscles together), can confuse myoelectric signals and diminish prosthetic functionality.


Nerves should be transected proximally enough to allow them to be buried in muscle so that the inevitable neuromas are less likely to be painful and symptomatic. It is important to identify and transect all the nerves in an extremity to include superficial sensory nerves because these are often identified at the time of symptomatic neuroma resection.


All major vessels should be individually ligated regardless of whether or not they have already thrombosed. Dual ligation with suture ligature and large-caliber silk ties is advocated for larger, proximal vessels to guard against catastrophic late hemorrhage or hematoma formation. Ligature clips, particularly for larger vessels, are generally discouraged in amputation surgery because they are subjectively less reliable than ties and can be a nidus for infection as well as cause pain. Management of the arterial ligature is usually best accomplished with a tourniquet in place. After all required muscle has been resected, the tourniquet should be let down before myodesis, myoplasty, and skin closure to ensure adequate hemostasis is achieved.




Upper Extremity Amputations


Amputation of an upper extremity is a catastrophic event primarily performed as the result of high-energy trauma in a young, otherwise healthy patient population. Upper extremity limb loss was estimated to account for 34% (541,000) of the 1.6 million people living in the United States with limb loss in 2005. Trauma accounted for 92% of hospital discharges because of upper extremity limb loss, of which 41,000 were proximal to the finger. Of the more than 1600 amputees produced by the conflicts of the past decade, including Operation Iraqi Freedom and Operation Enduring Freedom, 40% have occurred in the upper extremity, including 276 major upper limb amputees at or proximal to the wrist and 370 additional minor amputees. There have been 17 service members with bilateral upper extremity amputations to date.


Although the surgical principles of upper and lower extremity amputations are similar, there are key differences in morphology and function that require special attention when considering an upper extremity amputation. The primary goal in lower extremity amputation is to provide a well-padded and durable residual limb that will allow for weight bearing, maximize ambulatory function, and minimize energy consumption required for ambulation; the goal in the upper extremity is to maximize precision function and provide a cosmetic result. Knowledge of these differences and an awareness of the functional outcomes, prosthetic capabilities, and prosthesis acceptance rates associated with each amputation level is essential to ensure appropriate preoperative planning and to optimize patient outcomes.


The goals of amputation surgery in the upper extremity are the following: (1) preservation of functional length, (2) preservation of useful sensibility, (3) prevention of symptomatic neuromas, (4) prevention of adjacent joint contractures, (5) minimal and short morbidity, (6) early prosthetic fitting (when applicable), and (7) early return of patient to work and recreation.


An integrated team approach has been shown to improve amputee care. In addition to orthopaedic surgeons, additional specialties involved in the care of the upper extremity amputee include trauma surgery, physiatry, occupational therapy, physical therapy, anesthesiology and pain management, mental health, social work, nursing, and prosthetics. Involving the patient and family in the decision-making process is crucial to maximize functional and aesthetic outcomes in addition to patient acceptance of and satisfaction with outcomes. A multidisciplinary approach to care is essential for multiple extremity amputees, as frequently seen resulting from combat trauma, because numerous comorbid conditions are likely to be encountered, and the complexity of comprehensive treatment is greatest. Fortunately, good functional outcomes and prosthetic acceptance rates can be expected with a well-coordinated rehabilitation protocol and timely prosthetic fitting.


Amputation versus Limb Salvage and Replantation in the Upper Extremity


A mangled upper extremity has a far greater impact on overall function of the individual than does a mangled lower extremity. Unfortunately, no reliable injury severity score exists as a guide for treatment decision of amputation versus limb salvage. Although extremity injury severity scores for the traumatized lower extremity have been developed (with variable clinical utility as noted earlier), their application in the upper extremity has not been validated.


Anatomic and functional differences make the upper extremity more amenable to limb salvage or replantation than the lower extremity. Because the upper extremity is essentially non–weight bearing, length inequality is not a concern. This allows significant shortening of the limb to achieve primary vascular and nerve repairs and achieve soft tissue closure or coverage more readily. Results of nerve repair and reconstruction are more successful in the upper extremity than the lower extremity. Decreased muscle mass in the upper extremity also decreases the risk of crush or reperfusion syndrome. In addition, increased collateral circulation in the upper extremity may allow for reperfusion times to be extended to 8 to 10 hours after critical vascular injury.


A major consideration in upper extremity amputation is the dramatic difference in functional capability of even modern prostheses when compared with the normal hand. Despite dramatic improvements in prosthetic technology in the past decade, the numerous degrees of freedom of the human arm and the dexterity and sensory feedback of the hand are still only partially replicated with current prosthetic technology. For this reason, the adage “a bad hand is more functional than a good amputation” remains relevant to the treating surgeon and is likely the reason few will request late amputation after initial limb salvage of the upper extremity.


In general, superior functional outcomes can be expected in replanted limbs compared with upper extremity amputations, especially when there is the expectation for preserved hand prehension. This concept must be counterbalanced by the expectation for diminishing outcomes with attempts at higher level replantation, especially above the elbow. However, replant attempts above the elbow in the past have resulted in limb salvage at a more distal amputation level than would otherwise be expected.


Length Selection and Preservation


Maximum preservation of length is desirable in the upper extremity amputee. With increasing length and preservation of joints, the amputee becomes more capable of positioning the terminal extremity or prosthetic device in space, allowing for the greatest functional result and leading to improved outcomes. In the setting of traumatic amputation, the scope of injury often determines the level of amputation. However, it is important for the surgeon to understand the requirements and capabilities of prostheses for each amputation level and therefore direct opportunities for limb length preservation when available.


When residual tissue flaps are inadequate to provide distal amputation coverage and shortening will diminish prosthetic fitting and functional outcomes, additional soft tissue coverage options, including skin grafts and flaps, should be strongly considered. This is perhaps most important in shoulder and elbow joint preservation but is also important when optimizing the length of the transhumeral and transradial amputee. Use of microvascular free tissue transfer in well-selected patients to maximize length and provide durable soft tissue coverage has proven successful in upper extremity amputations ( Fig. 72-1 ). Indications for free tissue transfer include (1) shoulder joint preservation by preserving a transhumeral amputation level, (2) elbow joint preservation, and (3) preservation of bone greater than 7 cm below the shoulder or elbow. Relative indications include wrist joint preservation and skeletal preservation between 5 and 7 cm below the shoulder or elbow. While upper extremity amputations requiring skin grafts or flaps will take longer to heal, the functional benefits of joint or length preservation will usually outweigh any delays in rehabilitation and prosthetic fitting ( Figs. 72-2 and 72-3 ).




Figure 72-1


Salvage of joint level. A, Short transradial amputation level requiring soft tissue coverage to preserve the elbow joint. B, A free anterolateral thigh flap was performed to provide durable distal amputation coverage. The remaining wound was covered with a skin substitute followed by staged split-thickness skin grafting.



Figure 72-2


A transradial amputation with optimal length requiring soft tissue coverage.



Figure 72-3


The same transradial amputation after application of a dermal substitute to enhance durability of split-thickness skin grafting.


Nerve and Muscle Management


Careful attention to nerves and muscles is critically important in the upper extremity amputation because symptomatic neuromas are common. Before final closure of amputation in the upper extremity, all named sensory and motor nerves should be identified. All motor branches to muscle flaps within the operative field should also be preserved to prevent denervation, with resulting loss of muscle mass for limb padding and possible loss of sites for myoelectric signal. However, all nerves should undergo gentle traction neurectomy to locate neuromas away from the distal amputation myodesis or skin closure. Whereas more aggressive traction neurectomies of large peripheral nerves with motor function were recommended in the past, preservation of additional nerve length, while still preventing more distal exposure of neuromas, can reserve the future ability to perform targeted reinnervation, a technique to enhance myoelectric prosthetic control (discussed later in this chapter).


Stabilizing the muscle–tendon units of the residual limb under physiologic tension at the time of amputation closure serves two main purposes. First, it serves to provide robust coverage over the distal bone end, providing comfortable padding for the prosthetic socket while preventing formation of painful bursa formation from mobile muscle units. Second, optimal contractility characteristics of the muscle are preserved, improving muscle signal quality and maximizing myoelectric prosthesis control while also maximizing terminal residual limb control for body-powered prostheses. Myodesis, the process of attaching muscle–tendon units directly to bone, is the surgical technique that provides the most stable construct over the distal bone end. This is typically achieved by suturing the muscle, tendon, or both to the bone end, usually through drill tunnels, or less commonly, to periosteum. Myoplasty, attaching agonist muscles to antagonist muscles over the bone end to create physiologic tension, and myofascial closure, or suturing of muscle and fascia together, are less stable constructs that may be indicated when myodesis cannot be achieved, for secondary muscles after primary myodesis is performed, or to contour remaining muscle bellies before closure. Although there are no data in the literature to support the superiority of myodesis over myoplasty, myodesis is recommended in upper extremity amputations to provide the most stable limb and to best isolate muscle signals and myoelectric prosthetic control.


Partial Hand Amputation and Amputations through the Carpus


The mangled hand is a common traumatic injury in young individuals, most commonly occurring from agricultural, industrial, household, and motor vehicle accidents, as well as combat-related injuries. According to the American Medical Association (AMA) Guidelines to the Evaluation of Permanent Impairment, the thumb accounts for 40% loss of the function of the hand and 25% loss of whole body function, with the loss of the index through small fingers causing less disability. However, the ring and small finger are considered vital for grip strength and power grasp as would be critical in young laborers and military service members. More proximal amputation levels should be discouraged if preservation of basic prehensile function with two sensate digits able to oppose one another can be accomplished. However, a more stable terminal pinch can be expected with preservation of the thumb and at least two additional digits. Although outside the scope of this chapter, the decision to perform digital salvage versus amputation can be difficult; there is currently no specific algorithm or digit scoring system to guide the surgeon. Consultation with an upper extremity specialist is highly recommended, if available. Surgeon experience, a patient-centered approach to treatment, and multispecialty consultation all help guide decision making.


Amputations through the carpus present a special consideration. Reconstruction to allow pinching and grasping are not practicable at this level. Consideration can be made to revise the amputation to a wrist disarticulation or transradial level to permit greater prosthetic functionality. However, if the radiocarpal joint is preserved, consideration can be made to salvage a transcarpal level when soft tissue coverage is available. The advantage of this level is the long limb that may allow functional use for rudimentary tasks or to assist a contralateral normal limb, without the need for prosthetics. The perceived disadvantage is the same as that for wrist disarticulation; historically, this level has been difficult to fit with a highly functional prosthesis compared with the transradial level. However, this may be changing with advancing prosthetic technology, and therefore, consultation with a prosthetist, when feasible, is recommended before deciding on the final amputation level.


Wrist Disarticulation


The advantages of the wrist disarticulation level amputation are the following: (1) full forearm rotation is preserved when the distal radioulnar joint (DRUJ) is preserved, (2) there is no risk of impingement or abutment of the distal radius and ulna as sometimes seen in transradial amputations, (3) the large surface of the distal radius can allow weight bearing through the terminal end, (4) the long sensate residual limb increases functional length, and (5) it is a better platform for prosthetic fitting. The main disadvantage, historically, has been limited prosthetic options because of the very short working length of and space available for the terminal device, while attempting to achieve an acceptable limb length and cosmetic result. A survey of United States surgeons conducted by Tooms in 1972, before the introduction of modern wrist prostheses, indicated a preference for distal transradial amputations over wrist disarticulations. However, more recent advances in prosthetic design and materials have greatly improved function for wrist disarticulation amputees. It may thus be helpful to consult with an upper extremity prosthetist when a decision must be made to preserve a wrist disarticulation level or to revise to a transradial level. Additionally, the advent of vascularized composite tissue allotransplantation, or hand transplantation, may prompt additional consultation with a center performing this procedure when considering definitive wrist disarticulation.


Successful wrist disarticulation level amputation requires a healthy and intact DRUJ. Preservation of the triangular fibrocartilage complex and radioulnar ligaments will allow for stable pronation and supination. Every attempt should be made to use the thick palmar skin of the hand for distal coverage, but often skin flaps for final wound closure are dictated by the injury. Although the radial styloid should be saved for prosthetic suspension, it can be contoured to prevent prominence and prevent prosthetic interface skin irritation or breakdown. It is crucial to perform a myodesis of the flexor and extensor tendons to maintain tension in those muscles that will provide necessary myoelectric prosthesis function; this is usually done by suture attachment of tendons through drill tunnels or at least suturing them to residual radiocarpal capsule and ligaments. The radial and ulnar arteries are double ligated, and large veins also usually require ligature. Important nerves to address not only include the median and ulnar nerves but also the superficial radial nerve, the palmar cutaneous branch of the median nerve, the dorsal ulnar cutaneous nerve, and possibly the terminal median and lateral antebrachial cutaneous nerves. These named nerves should be divided proximal to the level of amputation closure by gentle traction neurectomy and buried under muscle to prevent development of painful neuroma. An exception is preservation of cutaneous nerves to a skin flap required for distal amputation coverage.


Transradial Amputation


The transradial amputation is the most common upper extremity amputation. This level of amputation also has the highest prosthetic acceptance rates in the upper extremity. In distal transradial amputations, the long lever arm, available forearm rotation, and preserved shoulder and elbow allow the terminal prosthetic device to be easily positioned in space. The transradial amputation level is also cosmetically appealing because of the ability to fit body-powered or myoelectric prostheses with quick-disconnecting components while still maintaining equal limb lengths. The transradial amputation level is a possible candidate for hand transplantation (discussed later in this chapter), as well as a potential candidate for targeted reinnervation technology, so additional consultation with transplantation centers or prosthetists and centers performing targeted reinnervation are currently warranted.


When practical, at least two-thirds of the forearm should be maintained. Removal of 6 to 8 cm of bone is recommended to offer a robust soft tissue envelope and permit a wide variety of prosthetic options ( Figs. 72-4 and 72-5 ). Consideration for soft tissue interposition between the radius and ulna should be made to decrease the potential for painful convergence and instability. This is generally accomplished with the pronator quadratus for more distal amputation levels and more proximally can be performed by one interposed extensor and flexor tendon. Nerves are managed as for the wrist disarticulation amputation; ensuring motor branches to muscles for myodesis are preserved will maximize myoelectric prosthesis function.




Figure 72-4


A transradial amputation with a long posterior flap to cover the distal end. Note myodesis of the flexor and extensor tendons to bone.



Figure 72-5


Previous transradial amputation closure.


Residual ulna length of at least 5 cm is required to allow for prosthetic fitting and elbow motion. However, useful pronation and supination are not generally preserved when the amputation level must be in the proximal third of the forearm and may affect use of a body-powered prosthesis ( Fig. 72-6 ). At this proximal level, consideration should be made to transfer the distal biceps tendon to the proximal ulna. The obvious prosthetic and mechanical advantages of the transradial level coupled with the superior prosthetic acceptance rates should prompt the surgeon to consider all reconstruction options, including free tissue transfer, to preserve an amputation at this level.




Figure 72-6


Very short transradial amputation. Elbow flexion is preserved, but heterotopic ossification prevents forearm rotation.


Elbow Disarticulation and Distal Transhumeral Amputations


Elbow disarticulation and distal transhumeral amputations are functionally quite similar, maintaining a flare to the distal humerus allowing improved suspension and improved rotational control of a prosthesis compared with more proximal amputation levels. The major disadvantage of this level is the cosmetic appearance of length inequality with the prosthetic elbow joint distal compared with the contralateral normal elbow, or with the center of rotation placed lateral to the axis of the humerus to minimize the length inequality. However, the improved suspension and rotational control usually outweigh any cosmetic concerns for most patients. Consideration can be made for a (generally delayed or elective) shortening osteotomy of the humerus to improve the cosmetic result, but this is rarely indicated or performed. Consultation with the prosthetist and discussion with the patient help guide whether to preserve the elbow disarticulation level or to resect to a more proximal level.


Although a posterior-based flap provides excellent coverage when available, the injury will usually dictate the skin flaps available for closure. Consideration for additional bone resection can usually be made to ensure a robust myodesis of the elbow flexor and extensor tendons and muscles and a well-padded covering over the distal bone end. Residual flexor and extensor origin muscles can provide additional coverage of the distal humerus after primary myodesis is performed. Split-thickness skin grafts are usually well tolerated at this amputation level, and consideration for use of a dermal substitute before final skin grafting improves the durability of the skin–socket interface. Proper nerve management remains critical; careful identification of the median nerve, radial nerve, ulnar nerve, medial and lateral antebrachial cutaneous nerves, and usually small posterior cutaneous nerves followed by gentle traction neurectomy proximal to the myodesis will limit development of painful neuromas.


If the condyles of the distal humerus are not preserved, the ideal level for amputation is approximately 4 to 5 cm proximal to the elbow joint. Adequately suspended and standard prosthetic components are expected at this level, but rotational control is decreased compared with the elbow disarticulation. Anterior angulation osteotomy, described by Marquardt in 1972, can be performed to the distal humerus to allow a rotation-stable prosthesis and a free-moving shoulder. The osteotomy is generally angulated 70 degrees anterior, and fixation with either interfragmentary screw fixation or a compression plate and screw construct is performed ( Fig. 72-7 ).




Figure 72-7


Example of a Marquardt distal humerus flexion osteotomy to improve suspension of a prosthesis.


Proximal Transhumeral Amputation and Shoulder Disarticulation Amputation


In the proximal transhumeral amputation level, maintenance of length is critical, with most sources recommending preservation of at least 5 to 7 cm of length from the glenohumeral joint to preserve reasonable function. At this proximal level, however, prosthesis fitting is difficult, resulting function limited, and prosthesis rejection rates are increased. As in the transradial amputation level, use of dermal substitutes, skin grafting, and local and free flaps are strongly considered to preserve adequate length. Preservation of the deltoid, pectoralis major, and latissimus dorsi insertions to the humerus allows for both body-powered and myoelectric prosthesis control. The brachial artery and veins are identified and double ligated, and gentle traction neurectomy is performed to the median, radial, and ulnar nerves. Myodesis of the triceps, biceps, and coracobrachialis is made to the distal bone end through drill tunnels.


Amputation proximal to these named tendon insertions will functionally result in a shoulder disarticulation level amputation. In such instances, preservation of the humeral head will improve body contour and the cosmetic result and may aid in force transmission. Unless stabilizing myodesis can be performed with available muscles, the unopposed pull of the rotator cuff muscles may cause painful or disfiguring abduction contracture or subluxation ( Fig. 72-8 ). As a result, glenohumeral arthrodesis, often as a planned, staged procedure, is strongly recommended.




Figure 72-8


Very short transhumeral amputation with dislocation of the humeral head. Arthrodesis can retain shoulder contour and prevent painful subluxation or dislocation.


Outcomes of Upper Extremity Amputations


The loss of one or both upper extremities is a devastating event. Loss of prehensile function and sensation are currently not adequately replaced by modern prosthetic technology. Prosthetic acceptance rates are frequently discussed as an outcome measure, although there is little high-quality evidence in the literature, and what is available is now dated.


Rejection rates in upper extremity amputations are frequently reported to be 21% to 38%, with larger studies typically reporting more than 30% rejection. When excluding cosmetic prostheses, the rates are probably higher. High rejection rates have been loosely associated with poor training, delayed prosthetic fitting, and proximal amputations. A 1995 survey of upper extremity amputations cited limited usefulness, increased weight, and residual limb socket discomfort as primary reasons for prosthesis rejection. Factors associated with increased prosthetic acceptance include loss of the dominant extremity, absence of pain in the residual limb, and early prosthetic fitting within 30 days of amputation.


It is generally accepted that prosthetic acceptance rates are directly correlated with level of amputation, with increasing utilization for progressively more distal levels of amputations, and this correlates with higher functional scores. The transradial amputation level also has the highest reported acceptance rates, which range from 80% to 94%. This is followed by transhumeral amputation, ranging from 43% to 83%. As expected, shoulder disarticulation is associated with the lowest reported prosthetic acceptance rates. Increased prosthetic weight and complexity, decreased prosthetic functionality, and difficulty with prosthetic suspension easily explain decreasing prosthetic acceptance rates with higher levels of amputation and illustrate the willingness of many patients to function with only one upper limb rather than use a burdensome prosthetic device. Two unique situations warrant mention. In those with bilateral upper extremity amputations, at least one limb will use a prosthesis. In patients with an ipsilateral brachial plexus injury, prosthetics will almost universally be rejected.


Most people who have undergone an upper extremity amputation are able to return to work, although one half to two thirds will change their occupation to accommodate for the loss of the limb. Patients with a transradial amputation have the highest rates of return to work. In the military population, fewer are able to return to an active duty status, with a range of 14% to 16.5% overall return-to-duty rate noted during the most recent conflicts.


Pain Management in the Upper Extremity Amputation


Chronic pain is a frequent complication of traumatic upper extremity amputations. The prevalence of pain in the residual limb after upper extremity amputation is reported in 7% to 49% of patients. Phantom limb pain is reported in 30% to 79% of upper extremity amputees, with most authors reporting greater than 50% prevalence. Despite this, chronic pain has not been shown to significantly impact functional prosthetic wear or return to employment as one might expect.


Acute pain management requires a multidisciplinary approach and early consultation with pain management specialists to facilitate timely rehabilitation and limit or prevent chronic pain complications. Phantom limb pain is common after traumatic upper extremity amputation. Although upper extremity data are not available currently, Hanley and colleagues demonstrated that postoperative pain and acute pain predict chronic pain in lower extremity amputations. Aggressive pain management with a multimodal pharmacologic approach; use of adjuncts such as injection therapy; and complementary and alternate approaches such as desensitization programs, biofeedback, relaxation techniques, acupuncture, and hypnosis optimize outcomes in amputation patients. Evidence, predominating in the lower extremity amputation literature, also supports use of perioperative epidural and perineural analgesia with indwelling catheters to reduce chronic and phantom limb pain but recommends that this treatment begin early at least 24 hours before amputation.


In addition to phantom limb pain, pain caused by neuromas is a frequent source of upper extremity limb pain and a frequent reason for amputation reoperation. This underscores the requirement for careful management of nerves during amputation surgery. Although gentle traction neurectomy is recommended to ensure that eventual neuromas are proximal to the incision line and the distal myodesis, careful exposure of nerves and using the technique of burying the nerve end in muscle may be required.


It is common for upper extremity amputees to experience pain in other locations, with back pain; neck pain; and most important, pain in the contralateral, uninjured extremity. This has been reported in rates higher than seen in the general U.S. population. This can lead to significant morbidity and lost workdays, and highlights the importance of educating new patients with amputations about overuse injuries.


Additional complications in upper extremity amputations include infection, myodesis failure, joint contractures, and heterotopic ossification (HO). In the combat-related upper extremity amputation population, infection is the most frequent indication for reoperation, with Tintle and colleagues reporting an incidence of 51% in their series of upper extremity amputations requiring reoperation. A high incidence of symptomatic HO was also reported, with painful neuromas, joint contractures, and scar revisions making up the remaining indications for reoperation ( Fig. 72-9 ).




Figure 72-9


Heterotopic ossification is common with traumatic amputations from combat injuries. It is common for symptomatic or functionally limiting heterotopic ossification to require surgical excision.




Lower Extremity Amputations


Transpelvic Amputation (Hemipelvectomy, Hip Disarticulation)


The first consideration in transpelvic amputation must be preservation of life because this surgery is generally performed emergently as a lifesaving measure secondary to trauma or life-threatening infection. The critical first step is to achieve proximal control of the arterial blood supply and limitation of often ongoing hemorrhage. This may involve entering the retroperitoneal space if injured vessels have retracted into the pelvis. After control of arterial and venous bleeding is achieved, all nonviable or infected tissue must be removed, and all viable tissue should be retained for consideration of reconstruction. Preferred, classic, gluteal artery and muscle-based flaps are often not intact in a posttraumatic setting; retention of atypical flaps and other viable tissues, including the quadriceps apron or adductor musculature for posterior degloving injuries, is critical for future wound closure. At this point, most patients are critically ill, and wounds are frequently marginally or grossly contaminated; therefore, as is the case for virtually all trauma-related amputations, primary wound closure is not recommended. Negative-pressure wound therapy is a valuable adjunct for both primary wound management and to achieve secondary wound contracture before delayed revision or reconstruction.


Patients who undergo amputation at the transpelvic or hip disarticulation levels are unlikely to be functional prosthetic users. Secondary wound management should include the creation of a bony platform and overlying soft tissue envelope with the goal of achieving chair sitting in a custom seating system. With this goal in mind, some motivated patients, particularly those with sound contralateral lower extremities, will be able to ambulate “sitting” in a custom prosthetic socket or by using crutches and no prosthesis.


Transfemoral Amputation


Unlike the dysvascular population, unilateral posttraumatic transfemoral amputees have a reasonable potential to walk, run, or climb with a prosthesis. Although the metabolic cost of walking is substantial in bilateral lower extremity amputees, surgery should be performed with the expectation and goal of functional prosthetic use in mind. Load transfer (i.e., weight bearing) in transfemoral amputation is usually accomplished by a total surface-bearing socket. The terminal end of the amputation stump is unloaded, and weight bearing is achieved by an intimate fit of the prosthesis ( Fig. 72-10 ).




Figure 72-10


Load transfer (weight bearing) with lower extremity amputation. A, Direct load transfer (end bearing) in knee or Syme ankle disarticulation amputation. The increased surface area of the distal metaphysis allows dissipation of loading pressures over the large surface area of the articular surface of the distal femur in knee disarticulation and distal tibia in Syme ankle disarticulation. Impact at heel strike is further dampened by the mechanical characteristics of the metaphyseal bone and cushioned end pad of gastrocnemius muscle (in knee disarticulation) or heel pad (in Syme ankle disarticulation). B, Indirect load transfer used with transosseous amputation levels through the femur or tibia. The femur is adducted in transfemoral levels, and the tibia is flexed 7 to 10 degrees to allow distribution of weight-bearing loads over the entire surface area of the bony platform (i.e., total surface bearing), thus avoiding concentration of forces on the small surface area of the terminal bony stump which is composed of mechanically stiff cortical bone.

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Jun 11, 2019 | Posted by in ORTHOPEDIC | Comments Off on Amputations in Trauma
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