Free Tissue Transfer after Open Transmetatarsal Amputation in Diabetic Patients

Abstract

Background Transmetatarsal amputation (TMA) preserves functional gait while avoiding the need for prosthesis. However, when primary closure is not possible after amputation, higher level amputation is recommended. We hypothesize that reconstruction of the amputation stump using free tissue transfer when closure is not possible can achieve similar benefits as primarily closed TMAs. Methods Twenty-eight TMAs with free flap reconstruction were retrospectively reviewed in 27 diabetic patients with a median age of 61.5 years from 2004 to 2018. The primary outcome was limb salvage rate, with additional evaluation of flap survival, ambulatory status, time until ambulation, and further amputation rate. In addition, subgroup analysis was performed based on the microanastomosis type. Results Flap survival was 93% (26 of 28 flaps) and limb salvage rate of 93% (25 of 27 limbs) was achieved. One patient underwent a second free flap reconstruction. In the two failed cases, higher level amputation was required. Thirteen flaps had partial loss or other complications which were salvaged with secondary intension or skin grafts. Median time until ambulation was 14 days following reconstruction (range: 9–20 days). Patients were followed-up for a median of 344 days (range: 142–594 days). Also, 88% of patients reported good ambulatory function, with a median ambulation score of 4 out of 5 at follow-up. There was no significant difference between the subgroups based on the microanastomosis type. Conclusion TMA with free flap reconstruction is an effective method for diabetic limb salvage, yielding good functional outcomes and healing results.

The Use of Flap Techniques to Preserve Limb Length in Patients with Transmetatarsal Amputations

“…However, despite revascularization, blood flow to the flap may remain suboptimal, and may contribute to recalcitrant infection, recurrent ulceration, partial flap necrosis, or dehiscence. 20,38 This may explain why 17.6% of our study population eventually required a higher-level amputation at 2 years, with infection being the most common indication for proximal amputation. Despite this high rate of long-term limb loss, preservation of prosthetic-free ambulation in this population should be attempted.…”

“…This supports the notion that adequate healing is possible with flap coverage in patients with comorbidities who undergo TMA. 20 During débridement and TMA, it is important to preserve all viable tissue that can be used for wound closure. Local flaps consist of tissue that is rotated about a pivot point, transposed, or advanced (V-Y) to an adjacent defect with exposed bone, joint, or tendon.…”

“…This supports the notion that adequate healing is possible with flap coverage in patients with comorbidities who undergo TMA. 20…”

“…35 To our knowledge, only two small case series have previously reported outcomes after free flap coverage of TMA stumps. 19,20 Hahn et al 19 reported no complications in 16 patients who underwent FTT to the TMA site. Lumley et al 20 evaluated patients with diabetes who underwent FTT after TMA and reported a 93% flap survival and 93% limb salvage rate, which is comparable to this study’s outcomes (Table 6).…”

“…However, there is a paucity of literature reporting the utility of these techniques after TMA. Only two small case series 19,20 have described patients who underwent TMA with free flap coverage. The purpose of this study was to evaluate surgical and functional outcomes after TMA with both local and free flap coverage in patients with comorbidities who have chronic forefoot wounds.…”