Transmetatarsal Amputation Outcomes When Utilized to Address Foot Gangrene and Infection: A Retrospective Chart Review

Healing rates and outcomes following closed transmetatarsal amputations: A systematic review and random effects meta-analysis of proportions

Transmetatarsal amputation (TMA) is a common surgical procedure for addressing severe forefoot pathologies, such as peripheral vascular disease and diabetic foot infections. Variability in research methodologies and findings within the existing literature has hindered a comprehensive understanding of healing rates and complications following TMA. This meta-analysis and systematic review aims to consolidate available evidence, synthesising data from multiple studies to assess healing rates and complications associated with closed TMA procedures. Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, a systematic search of Medline, Embase, and Cochrane databases was conducted for articles published from January 1st, 1988, to June 1st, 2023. Inclusion criteria comprised studies reporting healing rates in non-traumatic transmetatarsal amputation patients with more than 10 participants, excluding open TMAs. Two independent reviewers selected relevant studies, with disagreements resolved through discussion. Data extracted from eligible studies included patient demographics, healing rates, complications, and study quality. Among 22 studies encompassing 1569 transmetatarsal amputations, the pooled healing rate was 67.3%. Major amputation rates ranged from 0% to 55.6%, with a random-effects pooled rate of 23.9%. Revision rates varied from 0% to 36.4%, resulting in a pooled rate of 14.8%. 30-day mortality ranged from 0% to 9%, with a fixed-effects pooled rate of 2.6%. Post-operative infection rates ranged from 3.0% to 30.7%, yielding a random-effects pooled rate of 16.7%. Dehiscence rates ranged from 1.7% to 60.0%, resulting in a random-effects pooled rate of 28.8%. Future studies should aim for standardised reporting and assess the physiological and treatment factors influencing healing and complications.

A Preliminary Look at the Macrovascular System for Transmetatarsal Amputation Success

OBJECTIVE

Transmetatarsal amputation (TMA) is a commonly used level of amputation that preserves most of the foot's function and independence. However, many TMAs fail, and patients go onto higher amputations. The primary endpoint of this study is to determine if source artery occlusions are correlated with TMA flap failure.

METHODS

A total of 82 patients with TMAs were retrospectively reviewed for healing rates between 2009 and 2019 at a single center. Forty-five of the patients had an angiogram, which was analyzed for source artery and overall TMA failure. Of the initial 82 patients, a cohort of 12 had documentation of specific flap failure and an angiogram performed. This cohort of 12 patients was used for correlation of flap failure with source artery occlusion.

RESULTS

Overall, the TMA healing rate was 45.28%. No correlation was noted between a specific source artery occlusion and overall TMA failure. However, a moderate positive correlation was seen with dorsalis pedis artery and peroneal artery occlusions and dorsal flap failure. No correlation was seen with the posterior tibial artery and plantar flap failure. A moderate negative correlation was seen with peroneal artery occlusion and plantar flap failure.

CONCLUSIONS

The authors concluded that retrograde flow through the angiosome principle is what allowed for successful outcomes in TMAs. Physicians are urged to carefully plan, dissect, and preserve these vessels to help prevent TMA flap failure, especially in patients with vascular risk or disease.

Etiology, Epidemiology, and Disparities in the Burden of Diabetic Foot Ulcers

Diabetic foot ulcers (DFU) are a major source of preventable morbidity in adults with diabetes. Consequences of foot ulcers include decline in functional status, infection, hospitalization, lower-extremity amputation, and death. The lifetime risk of foot ulcer is 19% to 34%, and this number is rising with increased longevity and medical complexity of people with diabetes. Morbidity following incident ulceration is high, with recurrence rates of 65% at 3-5 years, lifetime lower-extremity amputation incidence of 20%, and 5-year mortality of 50-70%. New data suggest overall amputation incidence has increased by as much as 50% in some regions over the past several years after a long period of decline, especially in young and racial and ethnic minority populations. DFU are a common and highly morbid complication of diabetes. The pathway to ulceration, involving loss of sensation, ischemia, and minor trauma, is well established. Amputation and mortality after DFU represent late-stage complications and are strongly linked to poor diabetes management. Current efforts to improve care of patients with DFU have not resulted in consistently lower amputation rates, with evidence of widening disparities and implications for equity in diabetes care. Prevention and early detection of DFU through guideline-directed multidisciplinary care is critical to decrease the morbidity and disparities associated with DFU. This review describes the epidemiology, presentation, and sequelae of DFU, summarizes current evidence-based recommendations for screening and prevention, and highlights disparities in care and outcomes.

The Effect of Remnant Metatarsal Parabola Structure on Transmetatarsal Amputation Primary Healing and Durability

Although generally considered to be both a durable and functional procedure for limb preservation, the transmetatarsal amputation (TMA) has high rates of complication, failure, revisional operation, and progression to more proximal amputation. The objective of this investigation was to determine the effect of remnant metatarsal parabola structure on healing outcomes following TMA. A retrospective chart review was performed of subjects undergoing a complete TMA with primary closure. We considered 4 patterns of remnant metatarsal parabola structure. TMA pattern type 1 was a normal parabola with the remnant second metatarsal extending furthest distally and slightly longer than the remnant first and third metatarsals with a gradual lateral taper. TMA pattern type 2 was the first metatarsal remnant extending furthest distally with a gradual lateral taper. TMA pattern type 3 was a relatively long fifth metatarsal remnant without the presence of a gradual lateral taper. And TMA pattern type 4 was a relatively short first metatarsal remnant with a relatively long second metatarsal with a gradual lateral taper. Seventy-three transmetatarsal amputations in 73 subjects met selection criteria. Thirty-nine (53.4%) amputations healed primarily at 90 days. No statistically significant differences were observed between groups with respect to the 90-day primary healing rate (p = .571) or 1-year ambulation rate without wound recurrence or reoperation (p = .811). These results might indicate that the remnant metatarsal structure does not have an effect on transmetatarsal amputation outcome. It is our hope that these results add to the body of knowledge and lead to further investigations into outcomes of limb preservation surgical interventions.

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.

Functional and Patient-reported Outcomes following Transmetatarsal Amputation in High-risk Limb Salvage Patients

Background

Transmetatarsal amputation (TMA) is performed in patients with nonhealing wounds of the forefoot. Compared with below-knee amputations, healing after TMA is less reliable, and often leads to subsequent higher-level amputation. The aim of this study was to evaluate the functional and patient-reported outcomes of TMA.

Methods

A retrospective review of patients who underwent TMA from 2013 to 2021 at our limb-salvage center was conducted. Primary outcomes included postoperative complications, secondary proximal lower extremity amputation, ambulatory status, and mortality. Univariate and multivariate analyses were performed to evaluate independent risk factors for higher-level amputation after TMA. Patient-reported outcome measures for functionality and pain were also obtained.

Results

A total of 146 patients were identified. TMA success was achieved in 105 patients (72%), and 41 patients (28%) required higher-level amputation (Lisfranc: 31.7%, Chopart: 22.0%, below-knee amputations: 43.9%). There was a higher incidence of postoperative infection in patients who subsequently required proximal amputation (39.0 versus 9.5%, P < 0.001). At mean follow-up duration of 23.2 months (range, 0.7-97.6 months), limb salvage was achieved in 128 patients (87.7%) and 83% of patients (n = 121) were ambulatory. Patient-reported outcomes for functionality corresponded to a mean maximal function of 58.9%. Pain survey revealed that TMA failure patients had a significantly higher pain rating compared with TMA success patients (P = 0.016).

Conclusions

TMA healing remains variable, and many patients will eventually require a secondary proximal amputation. Multi-institutional studies are warranted to identify perioperative risk factors for higher-level amputation and to further evaluate patient-reported outcomes.