Numerous factors play a crucial role in the healing and function of postamputation wounds. The level of amputation is a key determinant influencing both functional outcomes and the healing process. Achieving a balance between preserving function and removing damaged tissue is essential. A study investigating cardiac function and oxygen consumption in 25 patients with peripheral vascular disease found higher-level amputations resulted in decreased walking speed and cadence, along with increased oxygen consumption per meter walked.30
Selecting the appropriate amputation level is vital to optimize functional outcomes without compromising wound healing. Successful prosthetic limb fitting depends largely on the length of the residual stump to support the body load and suspend the prosthesis. For long bone amputations, maintaining at least 12-cm clearance above the knee joint in transfemoral amputees and 10-cm below the knee joint in transtibial amputees is critical for maximizing functional outcomes.31
Surgical technique also is paramount. The goal is to minimize the risk for pressure ulcers by avoiding bony spurs and muscle imbalances. Shaping the muscle and residual limb is essential for proper prosthesis fitting. Attention to neurovascular structures, such as burying nerve ends to prevent neuropathic pain during prosthesis wear, is crucial.32 In extremity amputations, surgeons often resort to free flap transfer techniques for stump reconstruction. In a study of 31 patients with severe lower extremity injuries undergoing various amputations, the use of latissimus dorsi myocutaneous flaps, alone or in combination with serratus anterior muscle flaps, resulted in fewer instances of deep ulceration and allowed for earlier prosthesis wear.33
Addressing Barriers to Wound Healing
Multiple barriers to successful wound healing are encountered in the amputee population. Amputations from trauma have a less-controlled initiation, which carries with it a higher risk for infection, poor wound healing, and other complications.
Infection—Infection often is one of the first hurdles encountered in postamputation wound healing. Critical first steps in infection prevention include thorough cleaning of soiled traumatic wounds and appropriate tissue debridement coupled with scrupulous sterile technique and postoperative monitoring for signs and symptoms of infection.
In a retrospective study of 223 combat-related major lower extremity amputations (initial and revision) between 2009 and 2015, the use of intrawound antibiotic powder at the time of closure demonstrated a 13% absolute risk reduction in deep infection rates, which was particularly notable in revision amputations, with a number needed to treat of 8 for initial amputations and 4 for revision amputations on previously infected limbs.34 Intra-operative antibiotic powder may represent a cheap and easy consideration for this special population of amputees. Postamputation antibiotic prophylaxis for infection prevention is an area of controversy. For nontraumatic infections, data suggest antibiotic prophylaxis may not decrease infection rates in these patients.35,36
Interestingly, a study by Azarbal et al37 aimed to investigate the correlation between nasal methicillin-resistant Staphylococcus aureus (MRSA) colonization and other patient factors with wound occurrence following major lower extremity amputation. The study found MRSA colonization was associated with higher rates of overall wound occurrence as well as wound occurrence due to wound infection. These data suggest nasal MRSA eradication may improve postoperative wound outcomes after major lower extremity amputation.37