The role of microvascular free flaps in salvaging below-knee amputation stumps: a review of 22 cases

Twenty-two cases of traumatic below-knee amputation stumps with inadequate soft-tissue coverage salvaged with microvascular free flaps were reviewed retrospectively. All patients would have required an above-knee amputation for prosthesis fitting had microvascular free flaps not bee utilized. A total of 24 flaps were used in 22 patients; parascapular 11 (46%), foot filet six (25%), latissimus dorsi four (17%), lateral thigh, tensor fascia lata, and groin one (4%). Free flaps were performed immediately after injury in five (21%) cases, within the first week in two (8%), between 1 and 3 months in 12 (50%), and after 3 months in five (21%). Fifty per cent of the patients had significant other injuries. The patients had a total of 107 operations (mean, 4.9) related to their injury: 33 (mean, 1.5) of those operations were after the free flap, 27 (25%) of which were either performed because of a complication of the free flap or for revision of the free flap. Complications included partial necrosis in five (21%), neuroma in three (13%), hematoma in two (8%), donor site complication in two (8%), thrombosis requiring reoperation in one (4%), and flap failure in one (4%). Patient followup ranged from 12 to 116 months. All patients maintained a functional below-knee prosthetic level. The mean time to ambulation was 5.75 months, and was not significantly affected by flap complications. Most patients employed before their injury were employed after their injury. Despite a protracted course in these severe injured trauma patients, a functional below-knee amputation level was preserved in all cases utilizing microvascular free flaps.