A Novel Approach to Limb Salvage: Healing Transmetatarsal Amputations without a Viable Plantar Flap.

Background: The lack of a viable plantar flap in patients undergoing transmetatarsal amputation has been considered an indication for below-knee amputation (BKA). In an effort to reduce limb loss in this patient population, we sought to review our experience with transmetatarsal amputation salvage in patients with an open, guillotine transmetatarsal amputation. We hypothesized that performing a transmetatarsal amputation without a viable flap would extend time of independent ambulation and improve limb salvage.

Methods: This is a retrospective review of 27 consecutive patients who did not have a viable plantar flap and who underwent an open, guillotine transmetatarsal amputation. Patients presented with a nonviable plantar flap due to either extensive tissue loss on initial presentation, or secondary transmetatarsal amputation (TMA) flap necrosis. Patients initially underwent an open, guillotine TMA for control of infection and debridement of nonviable tissue. To achieve best results, during procedure, the metatarsals were resected to be as flush with soft tissue as possible. Once infection was resolved and all nonviable tissue debrided, negative pressure wound therapy (NPWT) was applied to the open wound. NPWT was continued until a base of granulation tissue covered the previously exposed bone. Wound closure was obtained by either the application of a split-thickness skin graft (STSG) or through continued NPWT allowing the wound to heal by secondary intention.

Results: Between January 2016 and December 2018, there were 27 open TMAs performed in 27 patients. Two patients did not granulate sufficiently and underwent BKA. Fourteen patients underwent STSG for closure, whereas 11 patients continued with NPWT. In the STSG group, 12 (86%) of the patients are healed, with a median time to complete healing of 75 days (range 28-330 days); the remaining 2 are ambulatory and undergoing continued wound care. In the 11 patients who did not receive STSG, 7 (64%) are healed with a median time to heal of 165 days. Of the remaining 4 patients in this group, 3 are ambulatory and still undergoing wound care, one was lost to follow-up. Overall, 19 patients (70%) have completely healed with a median time to heal of 82 days.

Conclusions: Limb salvage in patients with a nonviable plantar flap for TMA is possible and should be a considered procedure. This technique has the potential to improve functional outcomes and limb salvage in patients who might otherwise undergo BKA.