Delayed healing, marginal necrosis of the incision, and frank wound dehiscence represent the most frequent early complications of amputations, with approximately 60% of early residuum complications requiring surgery and up to 42% of all patients requiring revision surgery.^7,8 Likewise, some form of delayed wound healing may affect up to 40% of patients with transtibial amputation.^9,10 The reasons for delayed wound healing are numerous. In patients with dysvascular disease or diabetes, decreased tissue perfusion is frequently responsible. Selection of the appropriate amputation level and healing potential may be determined with
transcutaneous partial pressure of oxygen measurements (values greater than 20 to 30 mm Hg are ideal), an ankle-brachial index (a value greater than 0.5 is ideal), and a clinical evaluation.¹¹ It should be noted that ankle-brachial index values may be falsely elevated in some patients with dysvascular disease and noncompressible, calcified vessels. Diligent attention to appropriate presurgical perfusion restoration and optimization, even when amputation is required or inevitable, as well as meticulous level selection, perisurgical multidisciplinary care, and surgical technique may dramatically reduce wound healing complications rates.¹² In patients with traumatic injuries, infection, or cancer, it is critical to ensure that only overtly viable tissue flaps are retained and to avoid unnecessary fasciocutaneous flap dissection and stripping. When in doubt, flap viability should be assessed by gross appearance and visible capillary bleeding with the tourniquet deflated and/or demonstrated by means of staged débridement or revision and closure procedures. Fasciocutaneous or myofasciocutaneous flaps also may be assessed intrasurgically with fluorescent, near-infrared, laser-assisted indocyanine green angiography.¹³ Although so-called flaps of opportunity (rather than the generally named and described flaps referenced throughout most of this text) may be used by necessity in these patient populations, well-vascularized, described flaps are advocated whenever practicable without substantively affecting residual limb length or amputation level. Incisional negative pressure wound therapy has been demonstrated in a randomized trial to improve the outcomes of orthopaedic fracture wounds at risk and represents a useful adjunct measure after amputation closure.¹⁴

Current nutritional status and, when practicable, presurgical optimization of such status may be critical in improving healing rates and preventing early complications. Serum albumin levels greater than 3.5 g/dL as well as total lymphocyte counts greater than 1,500 mm³ have been correlated with improved lower limb amputation healing potential.^15,16 For more detailed nutritional assessment, prealbumin levels greater than 20 g/dL serve as a general marker of adequate protein intake.

Delayed healing, in the absence of wound necrosis or overt dehiscence, should be managed with prolonged suture retention, compressive dressing and edema control (ideally an elastic shrinker stocking), close monitoring, and nutritional optimization. Margin necrosis may result from suboptimal surgical technique and may (sometimes) be avoided by using careful tissue handling and tension-free, layered closure with diligent skin edge eversion. Minor edge necrosis or focal wound dehiscence often is managed nonsurgically, with diligent local wound care and close monitoring. Although complete healing and epithelialization is not an absolute prerequisite for initial prosthetic fitting and early wear, adequate time for myodesis and deep tissue healing, as well as documented serial improvement of wounds both before and after fitting, are required. For more extensive edge necrosis, a decision must be made regarding the probable depth of necrosis and the nutritional status and healing potential of the patient, as well as the mobility of adjacent tissues to determine the feasibility of wound excision and delayed primary closure. McCullough¹⁷ recommended excision of the necrotic areas if they extended more than 12 mm from the incision line. Often, this is achievable with concurrent revision closure under minimal tension, without substantive flap elevation and dissection creating risk of additional necrosis, if adequate time has elapsed since the index procedure such that postsurgical edema has largely resolved.

When simple excision and closure are not feasible, simple débridement and healing by secondary intention may be pursued for patients with superficial necrosis and adequate bone coverage. Patients with overt acute or progressive wound dehiscence, particularly caused by trauma (eg, falls onto the residual limb), should be managed with thorough débridement and revision closure if no evidence of deep infection or necrosis exists. More extensive, full-thickness necrosis, with or without dehiscence, frequently requires proximal revision of the amputation (Figure 1). In patients without vascular pathology (those with trauma or tumor) for whom such a revision would require extensive residual limb shortening or loss of a joint level, candidacy for free tissue transfer should be assessed by consulting with a microsurgical specialist.

Wound infections remain common after major limb amputation and are a concern after amputations for diabetes-related and dysvascular foot and limb infections. Infection rates ranging from 13% to 34% also have been reported in several recent studies of trauma-related amputations.^2,3,4 Infection management starts with prevention. Infection risk may ostensibly be minimized by débriding all nonviable tissue, meticulous flap
handling, appropriate amputation-level selection, sound sterile technique, staged closures when indicated, perisurgical antibiotic administration, smoking cessation, and nutritional optimization, in addition to tight glucose management for patients with diabetes. For patients undergoing chemotherapy or those with HIV infection, an absolute neutrophil count greater than 1,000 cells/mL and rising (ie, the absence of neutropenia) should be achieved presurgically whenever possible.

Postsurgical fluid collections are common after amputations but are not necessarily an indication for either drainage or débridement. In a series of generally older patients, Singh et al¹⁸ found a 27% rate of early residual limb fluid collections, with most resolving within 30 days. In a separate study of combat-related trauma amputations, Polfer et al¹⁹ reported a 55% rate of early fluid collections; after 3 months, the rate of early fluid collections decreased to 11%. In the absence of clinical indicators of infection, such as erythema, fever, and wound drainage, fluid collections within residual limbs were neither indicative nor predictive of infection.¹⁹

Established infections within residual limbs are initially managed similar to any other musculoskeletal infection. Superficial infections (such as cellulitis without copious or purulent wound drainage) should be managed with antibiotics and close observation. As a rule, deep infections require formal surgical débridement. In the absence of physiologic instability or sepsis in a patient, broad-spectrum antibiotics should not be used presurgically; they should be administered only after deep tissue cultures are obtained in an otherwise sterile environment. Wound swabs or bedside cultures have no proven utility and frequently demonstrate polymicrobial growth and skin flora contamination. Antibiotic coverage is subsequently narrowed postsurgically based on culture speciation and sensitivities, often in consultation with an infectious disease specialist.

Most patients with deep infections should be treated in a staged fashion. At least one second-look procedure should be performed 24 to 72 hours after the initial thorough surgical débridement to ensure that all residual tissue remains viable and all gross evidence of infection has been eradicated. Despite the absence of controlled studies, antibiotic-impregnated polymethyl methacrylate beads and negative pressure wound therapy with reticulated open-cell foam are useful adjuncts to wound management and infection control between débridement procedures.²⁰ Provisional anchorage of soft tissues (fascia, myodesis) over antibiotic beads or negative pressure wound therapy sponges with colored monofilament suture between procedures may prevent soft-tissue retraction and facilitate residual limb length and level retention when revision closure is eventually attempted. After all gross infection has been controlled and residual limb wound stability demonstrated, amputation revision and closure over drains is performed, with a period of continued postsurgical antibiotic administration. One study demonstrated that topical antibiotic powder application at the time of wound closure may be effective to prevent and/or treat infections for both primary closure and revision procedures.²¹ Residual limb shortening is sometimes required to achieve robust, tension-free closure after a deep infection, but this is generally modest and may be minimized or avoided entirely by adhering to the recommendations previously described. In patients with severe necrotizing soft-tissue infections or massive tissue necrosis, proximal amputation revision may be required.

Joint contractures can substantially affect and limit prosthetic fit, use, and function. Contractures that are present presurgically should be assessed and accounted for during surgical decision making, amputation-level selection, and presurgical patient and family counseling. Mild contractures are generally well tolerated and, in some patients, may be improved with focused therapy and nonsurgical management if they do not worsen postsurgically. In select patients, moderate trauma-related contractures may be addressed and improved surgically by lysing adhesions with or without adjacent muscleplasty (eg, quadricepsplasty) and manipulation under anesthesia. Such cases are best addressed in a staged fashion, before (in the elective setting) or after amputation, because the additive pain of concurrent procedures and the inability to tolerate socket use to facilitate joint rehabilitation postsurgically often precludes concurrent residual limb and joint rehabilitation. Severe contractures or overt joint ankylosis should prompt a reevaluation of the planned amputation levels. For example, a patient who is older than 70 years and has severe knee flexion or extension contractures will not optimally benefit from transtibial amputation, and knee disarticulation or transfemoral amputation should be strongly considered.

In patients with normal or nearly normal presurgical range of motion of the proximal joints, contractures are best managed with diligent prevention. Partial foot amputations require careful, balanced tendon reconstructions and should frequently include Achilles tendon lengthening or release intraoperatively. Virtually all other amputation levels simply require dedicated daily therapy for all proximal joints, most notably the knee and elbow. Range of motion and stretching exercise programs are started immediately after the procedure, and patients are encouraged to perform maximal range of motion exercises on their own several times per day between therapy sessions. Both formal and independent therapy are facilitated by good postsurgical pain control and the liberal use of peripheral nerve and epidural catheters. To avoid resting hip and knee flexion, pillows should not be used under a transfemoral residual limb or behind the knee of a patient with a transtibial amputation, even though many patients find resting hip and knee flexion most comfortable for these respective levels. For transfemoral amputations, mandatory flat supine and prone lying for a few hours a day is useful.

Some centers use bracing treatment, splinting, or casting postsurgically, particularly for transtibial amputations. Despite good intentions, however, such interventions create the risk
of additional potential complications because decubitus ulcers or eschars may form, even with diligent attention to padding, cutouts, and other precautions (Figure 2). In the absence of immediate postsurgical prosthetic placement at an experienced center, splint or cast placement is typically not necessary in a compliant, motivated patient.

The advantages of formal myodesis creation include restoration of physiologic resting muscle tension and greater residual limb control, improved soft-tissue anchorage, and preventing instability, prosthesis shifting, deep bursa formation, and superficial ulceration. Although adductor magnus myodesis, as popularized by Gottschalk,²² is perhaps most critical for patient function, the author of this chapter advocates myodesis or tenodesis for all transosseous amputation levels and many disarticulations.

Myodesis failure rarely occurs in an attritional, chronic fashion. Most cases are acute or related to trauma or prosthesis use and are noted by the patient (Figure 3). Partial tears of a myodesis—without muscle detachment and retraction or soft-tissue instability—verified by both the physical examination and advanced imaging (ultrasonography or MRI), often are managed nonsurgically with a period of rest from prosthesis use and subsequent resumption and rehabilitation. Complete failures in high-functioning patients are best managed with early surgery, before muscle retraction, tendon atrophy, and scarring preclude anatomic myodesis repair.⁴