All anesthesia providers must take extra care with patients with amputations to avoid positioning injuries. Be aware that limbs that have sustained partial amputation have undergone subtle but very real changes in musculoskeletal structure, skin integrity, and somatic and autonomic innervation.

The joints proximal to an amputation are often affected on both the contralateral and ipsilateral sides. For example, because of increased weight bearing in the contralateral leg, it is very common after lower-limb amputation for the contralateral hip to develop significant osteoarthritis. This is true even for patients who use a prosthesis. On the ipsilateral side in above-knee amputations, a hip flexure contracture results from immobility (more time sitting) and a hip abduction contracture from loss of the insertions of the adductors to the distal femur. On the ipsilateral side in below-knee amputations, a knee flexion contracture develops as a result of impaired mobility and loss of quadriceps extension strength. This is very common even in relatively young and active patients and will predispose a patient to injury in any position involving extension at the knee, such as the simple supine position. A pad below the distal thigh allows mild knee flexion and protects the integrity of the skin at the end of the stump.

In all types of amputation, there can be subcutaneous fibrosis at the amputation site that puts the overlying skin at risk because of increased tension and decreased blood flow. In many patients with amputations, the underlying medical reason for the amputation (diabetes or vascular disease) may mean that the skin of the residual limb is at high risk for skin breakdown independent of amputation. Even in patients whose limb loss was due to trauma, there is a higher risk of skin breakdown because of concomitant skin disorders such as contact dermatitis and verrucous hyperplasia. Patients who show skin breakdown or ulceration on a residual limb should be positioned so that there is minimal chance of further pressure injuries. Perturbations in both the somatic and autonomic nervous systems can cause patients who have had amputations to experience a variety of hypersensivity and chronic pain syndromes, including causalgia and phantom limb pain. Positioning injuries therefore can also cause an acute-on-chronic pain syndrome that can be especially distressing to the patient.