Functional foot salvage after extensive plantar excision and amputations proximal to the standard transmetatarsal...

It is generally accepted that when necrosis extends proximal to the transmetatarsal level a viable and functional foot can no longer be preserved and a major (above- or below-knee) amputation must be performed. However, with continuing advances in operations for limb salvage we felt the need to reexamine this concept.

In 1983 we initiated a prospective study to evaluate the role of extended foot amputations. All ambulatory patients with necrosis extending proximal to the transmetatarsal level (but not involving the whole foot) were included in the study. Among the 21 patients studied amputations ranged from open guillotine transmetatarsal amputation to removal of the medial or lateral three fifths of the foot. Five of these patients had adequate pedal circulation by clinical and laboratory criteria. The remaining 16 required vascular reconstruction to improve pedal flow.

Eighteen (86%) of 21 patients had complete healing of the foot amputations and were ambulatory at the time of discharge from the hospital. Two patients required early above- or below-knee amputations. Three additional patients sustained limb loss in the follow-up period. The cumulative graft patency rate was 94% at 12 months. The cumulative limb salvage rate at 24 months was 84%. The operative mortality rate was 1 (5%) of 21.

Our experience in a small number of patients suggests that functional foot salvage is possible even when necrosis or gangrene extends proximal to the transmetatarsal level.