Present-day analysis of early failure after forefoot amputation

Success of transmetatarsal amputation for limb salvage in patients with peripheral artery disease

Limb salvage is a difficult path for patients to travel as there is no guarantee of the outcome, often the major factor is perfusion. For patients who underwent transmetatarsal amputation (TMA), success rate is crucial as the next option is most likely a major amputation. We performed a 10 years (2010-2020) retrospective review of patients that underwent a TMA and had an angiogram or computed tomography angiography (CTA) perioperatively at the Dallas VA Medical Center. Failure after TMA was defined as a patient requiring a proximal amputation within 1 year. There were 125 TMAs performed between 2010 and 2020 at the institution. Forty-four (35.2%) patients had an angiogram/CTA peri-operative and met the inclusion criteria. Seventeen subjects (38.6%) had a higher level of amputation. Of the 17 failures, 2 (11.8%) patients had no patent vessel runoff to the foot, 9 (52.9%) had one vessel, 4 (23.5%) had two vessels, and 2 (11.8%) had three vessels runoff. One vessel runoff to the foot yielded a high rate of poor outcomes (56.3%) defined as a higher level of amputation. Two or more vessels runoff to the foot had over 75% success of limb salvage with a TMA.

Transmetatarsal Amputation Results in Higher Frequency of Revision Surgery and Higher Ambulation Rates Than Below-Knee Amputation

Background:

Selecting the level of amputation for patients with severe foot pathology can be challenging. The surgeon is sometimes confronted with an option between transmetatarsal amputation (TMA) and below-knee amputation (BKA). Recent studies have suggested that minor foot amputations have high revision rates and need for higher level of amputation. This study sought to compare the revision rates, need for higher level of amputation, postoperative ambulatory rate, and the demographic factors between these 2 operations.

Methods:

We retrospectively reviewed the records of patients undergoing either BKA or TMA at a single academic institution during an 8-year period. Demographic characteristics and medical history were collected and included in a binary logistic regression model to evaluate for independent predictors of needing revision surgery or needing higher-level amputation. Secondary outcomes included ambulatory status and wound status at last follow-up.

Results:

There was a total of 367 patients who underwent either BKA (n=293) or TMA (n=74). On binary logistic regression, the only significant independent predictor of needing revision surgery was undergoing TMA (odds ratio [OR] 2.30, CI 1.199-4.146, P = .011). The presence of PAD trended toward significance (OR 2.12, CI 0.99-4.493, P = .051). Similarly, significant independent predictors of needing higher level amputation were undergoing TMA (OR 4.117, CI 1.9-8.9, P < .001) and presence of PAD (OR 4.85, CI 1.59-14.85, P = .006). More TMA patients were ambulatory (56.8%) on last follow-up compared with BKA patients (30.9%).

Conclusion:

Transmetatarsal amputation has a higher risk of reoperation and need for revision amputation compared with below-knee amputation. Transmetatarsal amputation has a higher chance of returning patients to independent ambulation. Patients with peripheral arterial disease are at a higher risk of revision surgery and higher-level amputation with both operations.

Level of Evidence:

Level III, retrospective case review.

Are Transmetatarsal Amputations a Durable Limb Salvage Option? A Single-Institution Descriptive Analysis

In limb and life-threatening diabetic foot infections, transmetatarsal amputations are often indicated as a limb salvage procedure. The aim of this study is to analyze the long-term durability of initially successful transmetatarsal amputations in the diabetic population. We defined a successful transmetatarsal amputation as one which had clinical healing 1 year after surgery. A retrospective review of transmetatarsal amputations completed at our institution over an 11-year period was performed. We identified 83 amputations that met inclusion criteria. The mean follow-up was 4 years. The mean time to surgical healing was 109.8 days. After successfully healing the transmetatarsal amputation the long-term outcomes were analyzed. Re-ulcerations occurred in 44% of the transmetatarsal amputations a mean of 15 months after surgical healing. Patients who re-ulcerated were noted to be significantly younger (p value 0.02) with a significantly higher preprocedure hemoglobin A1c (p value < .001). Additional procedures after successful healing included 13 (15.66%) revision surgeries and 12 (14.46%) more proximal amputations. While transmetatarsal amputations remain a viable and durable limb preserving surgery, all patients who have undergone a transmetatarsal amputation should be monitored lifelong as they remain at risk for re-ulceration and more proximal amputation.