One of the major challenges that surgeons face with a limb-threatening injury is the decision to perform a primary amputation or limb salvage. The only absolute indication for amputation is irreversible ischemia in the traumatized limb, a diagnosis that is usually difficult to establish in the trauma resuscitation room. Although unattractive as a therapeutic option, amputation should not be viewed as a failure or destructive surgery, but rather as a lifesaving and reconstructive alternative. Some studies on long-term functional outcomes of amputation versus limb salvage have shown similar functional outcomes and self-rated disability among both patient groups at a 7-year follow-up, with a high level of disability in both groups [5–7].

Many factors must be taken into account when deciding to amputate or salvage. First, each treatment has its distinct short- and long-term risks. Limb salvage, for example, is associated with a longer rehabilitation time, greater costs, higher rates of rehospitalization, additional surgeries, and complications, such as osteomyelitis, sepsis, failure of wound healing, and rhabdomyolysis [6]. Second, a realistic assessment of functional expectations at the conclusion of treatment is critical. Finally, the performance of the salvaged limb versus that of a prosthetic limb as well as the financial, physiological, and psychosocial burden that the patient will face with each treatment option must be discussed. The significance of these factors will vary between patients; thus, the decision-making process must be individualized. Most patients and families are shaken by the acute situation and certainly emotionally disturbed and unable to think clearly. It is essential to educate the patient and their family so they can adequately make informed decisions. Most people are appalled by the idea of an amputation and the resulting disfigurement; however, this is partly due to the lack of awareness of recent advances in amputation surgery and prosthetic design that offer results paralleling the advances in limb salvage surgery [1]. Situations where patients are unconscious and no family is available may cause challenging dilemmas. Close collaboration and communication of the surgical subspecialty teams under the oversight of the trauma surgeon is of paramount importance in these situations. Regardless of the approach, the primary goal should always be to return the patient as closely as possible to their preinjury functional level.

Although each situation is clearly unique and an individualized plan should be developed, there are certain risk factors that make primary amputation a more appropriate treatment (Table 63.2). Another tool to help with decision making is the mangled extremity severity score (MESS, Table 63.3), which takes into account the level of energy that caused the injury, presence of shock or ischemia, and patient’s age. Studies indicate that a MESS of six or less is consistent with a salvageable limb, while a score of seven or more is close to 100 % predictive of amputation [8, 9]. Prospective reliability of the MESS score is not sufficient to permit a firm decision for amputation and should not replace experience and good judgment.

The next challenge is usually determining the most distal level for amputation with a reasonable chance of healing. You must consider the trade-offs between an increased function with a more distal level of amputation and a decreased rate of complications with a more proximal level of amputation. The optimal level of amputation is one that will provide a stump length that allows a controlling lever arm for the prosthesis, has a vascular supply sufficient for healing, and has an adequate quantity of protective soft tissue coverage for weight bearing [1, 10]. The patient’s general medical condition, overall well-being, and rehabilitation potential must be evaluated in this balance. A vascular surgery consultation can aid with this decision. When in doubt and in a relatively stable patient with no other life-threatening injuries, a more conservative initial amputation can be attempted with a plan to revise it later if necessary.

You must handle all soft tissues gently in order to keep tissues viable for a healthy and highly functional amputation stump. A desirable soft tissue envelope distributes the load to the underlying bone and dissipates the forces applied during weight bearing. The use of thick myofasciocutaneous flaps will lead to an optimal soft tissue envelope. Do not dissect tissue planes between the muscle and subcutaneous tissue, as this may further devascularize the compromised tissues and lead to skin flap necrosis [1, 10, 11]. The goal is to achieve a mobile, nonadherent muscle mass and a full-thickness, skin and soft tissue envelope that can withstand the direct pressures of weight-bearing and shearing forces that occur within a prosthetic. A sufficient muscle mass between the skin and bone will allow the bone to piston within the envelope. If standard flaps are not possible, you may use atypical skin flaps in order to salvage residual limb length [1, 10, 11]. The location of the scar is usually not important as long as the scar is not adherent to the underlying bone, as this can make prosthetic fitting extremely difficult and will most likely break down after prolonged prosthetic use [1, 10].

To create a viable muscle flap, divide the muscles at least 5 cm distal to the intended bone resection, with either a number 10 scalpel or electrocautery. Ligate any bleeding muscular vessels with 2-0 absorbable sutures. A hematoma under the muscle flaps can be detrimental as it may lead to infection and stump breakdown resulting in prolonged healing time and delays in rehabilitation. Stabilize the muscle by myodesis at their normal physiological length, as this will provide a stronger insertion, help maximize strength and function of the residual limb, and minimize atrophy. However, if this is not possible, myoplasty will suffice. Ensure that all muscle repairs are performed at normal resting muscle tensions with the limb in a neutral position to prevent iatrogenic joint flexion contractures.

To minimize blood loss, elevate and wrap the limb with an elastic bandage prior to the amputation, and apply a pneumatic tourniquet in order to exsanguinate it. Isolate and double ligate arteries with 2-0 silk suture ligatures. Veins can be effectively ligated with surgical clips, electrocautery, or 2-0 silk sutures. Remember to deflate the tourniquet prior to closure to check for small bleeders and ensure hemostasis. Most cases warrant a postoperative drain placed deep to the fascia for 48–72 h to prevent fluid collections and hematomas that frequently get infected [1].