Healing of Transmetatarsal Amputation in the Diabetic Patient: Is Angiography Predictive?

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.

Open revascularization approach is associated with healing and ambulation after transmetatarsal amputation in patients with chronic limb threatening ischemia

BACKGROUND

Transmetatarsal amputation (TMA) allows for maintenance of ambulatory function for patients with significant forefoot tissue loss. Effective revascularization is key to optimizing limb salvage for patients with chronic limb threatening ischemia (CLTI). We hypothesized that CLTI patients requiring TMA will have better healing and functional outcomes with open bypass than with endovascular revascularization.

METHODS

Consecutive TMAs performed at three affiliated centers between 2008 and 2020 were retrospectively reviewed. The baseline characteristics, including WIfI (wound, ischemia, foot infection) stage, noninvasive vascular studies, healing, and ambulatory outcomes, were collected. Catheter-based angiographic images were evaluated using the GLASS (global limb anatomic staging system). The primary outcomes were TMA healing and community ambulation. The secondary outcomes were TMA that had healed at study end, any ambulatory function postoperatively, major amputation, and mortality. Descriptive statistics and univariate, multivariable, and Kaplan-Meier analyses were performed.

RESULTS

A total of 346 TMAs had been performed in 318 patients, 209 of whom had had peripheral artery disease (PAD). The median follow-up was 2.5 years. Patients with PAD had had significantly lower rates of healing compared with those without PAD (64% vs 77%; P = .007). Revascularization was performed in 185 limbs, with 102 treated endovascularly and 83 with open surgery. The patients who had undergone endovascular surgery were significantly less likely to have had the TMA healed at any point (55% vs 76%; P = .003) and less likely to have remained healed at study end (49% vs 66%; P = .02). Patients with GLASS stage 3 anatomy were significantly more likely to have healed after open surgery (75% vs 45%; P = .003). Long-term ambulation data were available for 72% of the revascularized patients. Endovascular surgery was associated with a lower likelihood of community ambulation after TMA (34% vs 57%; P = .002). On multivariable analysis, open surgery was significantly associated with TMA healing (odds ratio, 2.8; P = .007) and ambulation (odds ratio, 2.9; P = .001).

CONCLUSIONS

For patients with CLTI and significant tissue loss requiring TMA, an initial open approach to revascularization was associated with improved healing and higher rates of ambulation compared with endovascular interventions. The metabolic requirement for healing of a TMA in patients with CLTI might be better met by open revascularization.

Transmetatarsal amputations in patients with diabetes mellitus: A contemporary analysis from an academic tertiary referral centre in a developing community

Transmetatarsal amputation (TMA) involves the surgical removal of the distal portion of metatarsals in the foot. It aims to maintain weight-bearing and independent ambulation while eliminating the risk of spreading soft tissue infection or gangrene. This study aimed to explore the risk factors and surgical outcomes of TMA in patients with diabetes at an academic tertiary referral center in Jordan. Medical records of all patients with diabetes mellitus who underwent TMA at King Abdullah University Hospital, Jordan, between January 2017 and January 2019 were retrieved. Patient characteristics along with clinical and laboratory findings were analyzed retrospectively. Pearson’s chi-square test of association, Student’s t-test, and multivariate regression analysis were used to identify and assess the relationships between patient findings and TMA outcome. The study cohort comprised 81 patients with diabetes who underwent TMA. Of these, 41 (50.6%) patients achieved complete healing. Most of the patients were insulin-dependent (85.2%). Approximately half of the patients (45.7%) had severe ankle-brachial index (ABI). Thirty patients (37.1%) had previous revascularization attempts. The presence of peripheral arterial disease (P<0.05) exclusively predicted poor outcomes among the associated comorbidities. Indications for TMA included infection, ischemia, or both. The presence of severe ABI (≤0.4, P<0.01) and a previous revascularization attempt (P<0.05) were associated with unfavorable outcomes of TMA. Multivariate analysis that included all demographic, clinical, and laboratory variables in the model revealed that insulin-dependent diabetes, low albumin level (< 33 g/L), high C-reactive protein level (> 150 mg/L), and low score of Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC, <6) were the main factors associated with poor TMA outcomes. TMA is an effective technique for the management of diabetic foot infection or ischemic necrosis. However, attention should be paid to certain important factors such as insulin dependence, serum albumin level, and LRINEC score, which may influence the patient’s outcome.

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.

Avoiding the Deep Plantar Arterial Arch in Transmetatarsal Amputations: A Cadaver Study

BACKGROUND

The deep plantar arterial arch (DPAA) is formed by an anastomosis between the deep plantar artery and the lateral plantar artery. The potential risk of injury to the DPAA is concerning when performing transmetatarsal amputations, and care must be taken to preserve the anatomy. We sought to determine the positional anatomy of the DPAA based on anatomical landmarks that could be easily identified and palpated during transmetatarsal amputation.

METHODS

In an effort to improve our understanding of the positional relationship of the DPAA to the distal metatarsal parabola, dissections were performed on 45 cadaveric feet to measure the location of the DPAA with respect to the distal metatarsal epiphyses. Images of the dissected specimens were digitally acquired and saved for measurement using in-house-written software. The mean, SD, SEM, and 95% confidence interval were calculated for all of the measurement parameters and are reported on pooled data and by sex. An independent-samples t test was used to assess for sex differences. Interrater reliability of the measurements was estimated using the intraclass correlation coefficient.

RESULTS

The origin of the DPAA was located a mean ± SD of 35.6 ± 3.9 mm (95% confidence interval, 34.5-36.8 mm) proximal to the perpendicular line connecting the first and fifth metatarsal heads. The average interrater reliability across all of the measurements was 0.921.

CONCLUSIONS

This study provides the positional relationship of the DPAA with respect to the distal metatarsal parabola. This method is easily reproducible and may assist the foot and ankle surgeon with surgical planning and approach when performing partial pedal amputation.

Predictive Factors and Amputation Level for Reamputation in Patients With Diabetic Foot: A Retrospective Case-Control Study

The aim of this study was to assess the rate and level of reamputation in patients who had a previous amputation from diabetic foot. We retrospectively analyzed patients who underwent amputation and reamputation due to diabetic foot in our clinic between 2011 and 2019. Fifty-nine were evaluated as the healed group after the first amputation and 55 were evaluated as the reamputation group. Given 55 patients who needed reamputation: there were 13 finger or ray, 23 transmetatarsal or syme, 18 transtibial, and 1 transfemoral in the first operation. We found the reamputation rate was 65.4% in distal amputations. When serum parameters were examined before the first amputation in each group, there was no statistically significant difference in white blood cells, neutrophils, lymphocytes, platelets, sedimentation, C-reactive protein, total protein, hematocrit, urea, creatinine, and HgA1c values. There was, however, a significant difference between groups in albumin levels. When comorbidities were assessed for smoking, hypertension, duration of diabetes, and number of debridements after the first surgery, a significant difference between groups was found. When peripheral artery disease and chronic renal failure were examined, no significant difference was observed. In our study, it was observed that the rate of reamputation was higher in distal level amputations for diabetic foot patients. Accordingly, albumin values, smoking, hypertension, duration of diabetes, number of debridements after surgery, were seen as risk factors for reamputation patients.

Analysis of Early Lower Extremity Re-amputation

BACKGROUND

Data is scarce regarding the need for early re-amputation to a higher anatomic level. This study seeks to define outcomes and risk factors for re-amputation.

METHODS

Patients undergoing primary major lower extremity amputation were identified within the 2012-2016 ACS-NSQIP database. Demographics, outcomes, and peri-operative characteristics were compared, and multivariable logistic regression model was used to determine association with early re-amputation.

RESULTS

Over a four-year period, 8306 below knee amputations and 6367 above knee amputations were identified. Thirty-day re-amputation occurred in 262 patients (1.8%) and was associated with increased length of stay (12.9 vs. 7.3 days, p<0.001), higher rates of readmission (64.9% vs. 13.6%, p<0.001), and overall complications (69.5% vs. 39.3%, p<0.01). On multivariable analysis, advanced age (OR 1.02, CI 1.01-1.03), smoking (OR 1.75, CI 1.32-2.33), dialysis dependence (OR 1.67, CI 1.23-2.26), preoperative septic shock (OR 2.53, CI 1.29-4.97), and bleeding disorders (OR 1.72, CI 1.34-2.22) were associated with early re-amputation.

CONCLUSIONS

Thirty-day re-amputation rates are low, but are associated with significant morbidity, prolonged hospitalization, and frequent readmissions.

Lower extremity reamputation in people with diabetes: a systematic review and meta-analysis

In this study, we determined the reamputation-free survival to both limbs and to the contralateral limb only following an index amputation of any-level and assessed whether reamputation rates have changed over time. We completed a systematic search using PubMed and screened a total of 205 articles for data on reamputation rates. We reported qualitative characteristics of 56 studies that included data on reamputation rates and completed a meta-analysis on 22 of the studies which enrolled exclusively participants with diabetes. The random-effects meta-analysis fit a parametric survival distribution to the data for reamputations to both limbs and to the contralateral limb only. We assessed whether there was a temporal trend in the reamputation rate using the Mann-Kendall test. Incidence rates were high for reamputation to both limbs and to the contralateral limb only. At 1 year, the reamputation rate for all contralateral and ipsilateral reamputations was found to be 19% (IQR=5.1%-31.6%), and at 5 years, it was found to be 37.1% (IQR=27.0%-47.2%). The contralateral reamputation rate at 5 years was found to be 20.5% (IQR=13.3%-27.2%). We found no evidence of a trend in the reamputation rates over more than two decades of literature analyzed. The incidence of lower extremity reamputation is high among patients with diabetes who have undergone initial amputations secondary to diabetes, and rates of reamputation have not changed over at least two decades.

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

A transmetatarsal amputation (TMA) is a widely utilized procedure to address foot gangrene and infection. Although a common procedure, so too are the associated complications. The purpose of this review was to evaluate TMA healing and to explore if there were associated variables correlating with healed vs. failed to heal TMA sites. To do so, the Medical Department Orthopaedics Division Electronic Database, West Virginia University, College of Medicine was retrospectively searched to identify all cases of TMAs (CPT code 28805) during the period of January 2011 through June 2019, and those variables that might impact TMA healing. Then both univariate and multivariable logistic regression analyses were performed to investigate the associations between these variables and TMA healing, and sensitivity analyses were also conducted to determine if the results resisted the influence of one unmeasured confounder. There were 39 patients (41 procedures) who would undergo a TMA. The mean average patient age was 53 (range 29-73) years old. The median postoperative follow-up period was 617 (range 199-3632) days. TMA mortality data revealed 0 deaths at 30 days, 2 (5.1%) at 1 year, 8 (20.5%) at 5 years. In our study, 29 (70.7%) of the TMAs would achieve primary healing at a median of 31 (range 16-253) days. When comparing the TMA healed group to the failed to heal group the following independent variables were considered: diabetes mellitus, HgA1c >8%, neuropathy, peripheral arterial disease, chronic kidney disease, active smoking status, previous surgery, and a clean margin metatarsal bone pathology specimen positive for osteomyelitis. Of the aforementioned, only neuropathy (odds ratio [OR] = 0.056, 95% confidence interval [CI] = 0-0.501, p = .0062) and positive bone margin (OR = 0.144, 95% CI = 0.022-0.835, p = .0385) were found to be significant in univariate logistic regression analysis. In multivariable logistic regression analyses where the potential confounders age, gender, and body mass index were accounted for, of the 8 independent variables of interest, only neuropathy (OR = 0.037, 95% CI = 0-0.497, p = .0036) remained significantly associated with the healing status. Neuropathy was present in 17 (58.6%) of the healed TMAs and in 12 (100%) of the failed to heal TMAs. However, the positive bone margin failed to reach statistical significance (OR = 0.079, 95% CI = 0-1.39, p = .1331). Results from another multivariable logistic regression model where a quadratic term for age was added revealed that positive bone specimen correlated with the TMA healing status with significance (OR = 0.051, 95% CI = 0.001- 0.560, p = .0404). A positive clean margin bone specimen was found in 3 (10.3%) of the healed TMAs and in 4 (44.4%) of the failed to heal TMAs. The sensitivity analysis where current ulceration was used as an unmeasured confounder indicated that the results regarding the association between neuropathy or positive bone margin and TMA healing, though inconclusive, resisted the influence of this unmeasured confounder. Hopefully these findings will be a beneficial addition to the current TMA literature and as such, further assist with informed surgical decision making.

Risks and Risk Factors for Ipsilateral Re-Amputation in the First Year Following First Major Unilateral Dysvascular Amputation

OBJECTIVE

To identify timing, incidence, and risk factors for ipsilateral re-amputation within 12 months of first dysvascular amputation and to determine specific subgroups of patients at each amputation level that are at increased risk.

METHODS

A retrospective cohort study evaluating 7187 patients with first unilateral transmetatarsal (TM), transtibial (TT), or transfemoral (TF) amputation secondary to diabetes and/or peripheral artery disease (PAD) were identified in the VA Surgical Quality Improvement Program database between 2004 and 2014. Re-amputation was defined as any subsequent ipsilateral soft tissue/bony revision or amputation to a higher level. Twenty-three potential pre-operative risk factors (and nine potential interactions) were identified. A backward stepwise Cox regression was used to identify risk factors. Incidence rates and hazard ratios (HR) with 95% confidence intervals (CI) were computed.

RESULTS

The median time to highest level of re-amputation in the first year was 33 (interquartile range, 13-73) days. Risk of requiring at least one re-amputation was 41% (TM), 25% (TT), and 9% (TF). Risk factors associated with requiring re-amputation included chronic obstructive pulmonary disease, elevated white blood cell count, abnormal ankle brachial index (ABI), history of revascularisation, and alcohol misuse. TM patients who had diabetes only (HR 1.9; 95% CI 1.4-2.5), diabetes with an abnormal ankle brachial index (ABI) score (HR 2.4; 95% CI 1.8-3.2), and kidney failure (HR 1.7; 95% CI 1.3-2.1) were at the greatest risk of re-amputation. TT amputees who were smokers were also at an increased risk (HR 1.4; 95% CI 1.2-1.6).

CONCLUSION

This research identified important risk factors for failure of primary healing and need for re-amputation at the TM and TT level. If considering a TM amputation, caution should be exercised in patients with diabetes, in particular those with an abnormal ABI and/or renal failure. At the TT level, caution should be exercised in those who smoke.

Present-day analysis of early failure after forefoot amputation

BACKGROUND

Forefoot transmetatarsal amputation is performed commonly to achieve limb salvage, but transmetatarsal amputations have a high rate of failure, requiring more proximal amputations. Few contemporary studies have examined the incidence of major amputation (transtibial or transfemoral) after transmetatarsal amputation. The goal of this study is to determine risk factors and outcomes for a more proximal amputation after forefoot amputation.

METHODS

We queried the 2012 to 2016 database of the American College of Surgeons National Quality Improvement Program for patients undergoing a complete transmetatarsal amputation with wound closure by Current Procedural Terminology code. Patients requiring early (within 30 days) more proximal amputation after transmetatarsal amputation were compared with those who did not need further amputation. Characteristics of patients requiring more proximal amputation were examined, and a multivariable logistic regression model was created to identity risk factors for early more proximal amputation.

RESULTS

In the study, 1,582 transmetatarsal amputation were identified. Most patients were male (70%), white (59%), and diabetic (74%), with a median age of 63 years. More proximal amputation occurred in 4.2% of patients within the first 30 days postoperatively. This early failure was associated with greater hospital stays postoperatively (10 days vs 7 days), more wound complications (29% vs 11%), pneumonia (8% vs 2%), stroke (3% vs 0.1%), and overall complications (50% vs 28%; P ≤ .025 each). Although there was no difference in 30-day mortality (P = .27), there was a marked increase in unplanned readmission (59% vs 14%; P < .0001) for those undergoing reamputation. On multivariable analysis, preoperative systemic inflammatory response, sepsis, or septic shock (odds ratio 2.1; 95% confidence interval, 1.2-3.6) were independent predictors of more proximal amputation.

CONCLUSION

Early below-knee or above-knee amputation early after transmetatarsal amputation leads to increased morbidity. Because patients with preoperative sepsis may be at increased risk of failure after transmetatarsal amputation, the level of amputation should be considered carefully in these patients.

Outcome of Ray Resection as Definitive Treatment in Forefoot Infection or Ischemia: A Cohort Study

Ray resection is frequently performed in cases of infection or ischemia, but the literature is scarce concerning its outcome as a definitive treatment. In this retrospective cohort study, we reviewed our cohort with transmetatarsal ray resection with a mean follow-up of 36.3 months. Reulcerations, transfer ulcers, and reamputations were determined. Risk factor analysis for revision surgery was conducted. Among 185 patients, 71 (38.4%) had revision surgery within a mean of 1.4 ± 2.6 years (range 2 days to 12.9 years), 22 (11.9%) had major amputations, 49 (26.5%) had minor amputations, 11 (5.9%) had same-ray reulceration, 40 (21.6%) had transfer ulceration, and 2 (1.1%) had both reulceration and transfer ulceration. Occurrence of a postoperative ulcer was statistically significantly associated with revision surgery (p < .01). In conclusion, metatarsal ray resection is a reasonable treatment option in cases of forefoot ischemia or infection to prevent major amputation but fails in 11.9%, and reulceration is associated with further revisions, making ulcer prevention paramount.

Transmetatarsal amputation: A 12 year retrospective case review of outcomes

BACKGROUND

Diabetic foot pathology has rapidly increased, presenting a vast economic burden with severe implications for patients. Establishing effective limb salvage techniques such as transmetatarsal amputation is essential to offer viable alternatives to major limb amputation in severe foot infection, where outcomes are variable and mortality rates high.

METHODS

A retrospective review of outcomes was performed on patients who underwent TMA at a single United Kingdom hospital between 2005-2017. Healing rate and time to healing, mortality, duration of hospital admission and incidence of revision surgery was evaluated. Forty-seven patients had 54 TMA's by the Podiatric Surgery team. Data was assessed for Mean (SD) and Median. The impact of co-morbidities was considered and the perioperative and surgical management reviewed to identify techniques which may improve outcomes.

RESULTS

A 78% healing rate was achieved. Six patients (11%) died before healing. The aremaining 11% did not heal and resulted in major limb amputation. No further surgery to the same foot was required after the TMA healed. A Median healing time of 83 days was identified and the Median duration of hospital admission was 24 days. Adjunctive wound care products may to have a positive impact on these factors. Five-year mortality was 43%, and demonstrated an association with renal and/or vascular pathology. All patients had diabetes, with many also having Peripheral Vascular Disease (PVD). Almost all TMA's failing to heal had PVD. The presence and severity of renal disease also seemed to have a negative impact on wound healing.

CONCLUSION

Positive healing and mortality rates with low need for revision surgery support TMA to be an effective alternative to major limb amputation. Adjunctive agents may have a positive impact on wound healing and length of hospital admission. Skilled surgical technique and Multidisciplinary work is essential for positive long-term outcomes and cost-effective care.

Predictors of Major Adverse Limb Events after Open Forefoot Amputation in Patients with Chronic Limb-Threatening Ischemia

BACKGROUND

Management of patients with chronic limb-threatening ischemia (CLTI) and extensive foot necrosis presents a challenge for limb salvage. Our study evaluates preoperative risk factors that contributed to durability and efficacy of limb salvage after open transmetatarsal amputation (TMA) in patients with critical limb-threatening ischemia.

METHODS

We abstracted data from patients who underwent open TMA at Los Angeles County-University of Southern California Medical Center and Keck Hospital of University of Southern California from 2009 to 2018. Multivariable logistic regression analysis, adjusting for preoperative risk factors, was used to examine predictors of major adverse limb events (MALE). The aim was to evaluate outcomes following open TMA with MALE as the primary outcome. Our hypotheses were that outcomes would be worse for patients with foot infections and renal failure.

RESULTS

Forty-three open TMAs were done in 39 patients during the study period. The cohort had a mean age of 63 ± 11.6 years, 89% had a history of diabetes, 95% hypertension (HTN), 54% had end-stage renal disease (ESRD), and 26% were current smokers. MALE occurred in 39% of the cohort. Sex, race, indication, HTN, smoking status, and history of prior ipsilateral revascularization or minor amputations were not associated with MALE (P > 0.05). Multivariate logistic regression found ESRD to be an independent predictor of MALE (odds ratio 7.43, 95% confidence interval 1.12-49.17, P = 0.038) after adjusting for clinically significant covariates.

CONCLUSIONS

Open TMA provides acceptable rates of limb salvage for complex patients with CLTI. ESRD is an independent risk factor for MALE following open TMA in these patients. Vigilant follow-up is essential for this morbid patient population given poorer outcomes after forefoot amputation.

Revision After Total Transmetatarsal Amputation

Total transmetatarsal amputation (TMA) can be an option for foot salvage in gangrene, sepsis, or infected necrosis. However, the literature concerning predictive outcome factors and bacterial sampling is scarce. To identify potential associations between revision surgery and underlying bacteria or other preoperative selection criteria, we reviewed all patients with TMA who were treated at our institution. We compared the patients with remissions with surgical revisions. Among 96 adult patients with TMA (105 amputations), 42 required a revision surgery (40%), 18 had a further minor proximal surgical reamputation (17%) and 18 had a major proximal surgical reamputation (14%). In group comparisons, a previous infection with Staphylococcus aureus was protective with a lower revision risk (4/26 with revision surgery vs 22/26 without revisions; p = .03). This was the opposite for postoperative persistent soft tissue or bone infections (p < .01) and delayed wound healing (p < .01), which were positively associated with a revision risk. The American Society of Anesthesiologists Score, sex, age, body mass index, diabetes, polyneuropathy, chronic renal failure, dialysis, peripheral arterial disease, smoking status, and antibiotic regimen did not influence this revision risk. These results must be interpreted cautiously because no multiple variable calculations could be conducted as a result of the paucity of cases and confounding could not be evaluated sufficiently. TMA is an option to prevent major amputations, but it may be associated with a subsequent revision risk of 40% in adult patients. In our cohort study, persistent postamputation infection and delayed wound healing were associated with revision. However, no preoperative selection criteria were found that lead to revision surgery except for an infection with Staphylococcus aureus, which protected against revision surgery.

Clinical Outcomes of Transmetatarsal Amputation in Patients with Diabetic Foot Ulcers Treated without Revascularization

INTRODUCTION

Most studies on outcomes of transmetatarsal amputation (TMA) have been for patients who underwent revascularization. This study was performed to evaluate the outcomes of TMA in diabetic patients without revascularization.

METHODS

One hundred two diabetic patients who were not candidates for revascularization underwent TMA and received a multidisciplinary treatment. These patients were followed up for a mean period of 38 months to observe the outcomes, including wound healing, above-the-ankle amputation and death. The associations between variables and the outcomes were analyzed by Cox regression analysis.

RESULTS

By the end of the follow-up, 97 patients with full data were analyzed. Sixty-three (64.9%) patients had wounds healed completely after a median interval of 8 months, 16 (16.5%) patients underwent above-the-ankle amputation, and 26 (26.8%) died. Cox regression analysis showed that patients with higher ABI (RR = 3.097, 95% CI: 1.587-6.043) and serum albumin (RR = 2.755, 95% CI: 1.335-5.687) exhibited a higher probability of wound healing.

CONCLUSIONS

Diabetic patients who were not candidates for revascularization who underwent TMA could achieve a satisfactory wound healing rate with a multidisciplinary treatment. ABI and serum albumin were significant predictors of wound healing.

Anatomic Limitations of the Transmetatarsal Amputation With Consideration of the Deep Plantar Perforating Branch of the Dorsalis Pedis Artery

The transmetatarsal amputation is considered a durable procedure with respect to limb salvage when managing the consequences of diabetic foot disease. The success of the procedure is, in part, determined by the preoperative appreciation of arterial and functional status. The objectives of the present investigation were to determine the length of the remaining first metatarsal required during transmetatarsal amputation to preserve the anastomotic connection of the deep plantar perforating artery and subsequent "vascular arch" of the foot and the insertion of the tibialis anterior tendon. The primary outcome measure of our investigation was a measurement of the distance between the first metatarsal-medial cuneiform articulation and the distal extent of the deep plantar perforating artery in 85 embalmed lower limbs. As a secondary outcome measure, the insertion of the tibialis anterior tendon was evaluated relative to the deep plantar perforating artery. The most distal extent of the deep plantar perforating artery was observed at a mean ± standard deviation of 15.62 ± 3.74 (range 6.0 to 28.28) mm from the first metatarsal-medial cuneiform articulation. Most (89.41%) of the arteries were found within 20 mm of the first metatarsal-medial cuneiform articulation. The insertion of the tibialis anterior tendon was found to be proximal to the deep plantar perforating artery in all specimens (100.0%). In conclusion, 2.0 cm of remnant first metatarsal might represent an anatomic definition of how "short" a transmetatarsal amputation can safely be performed in most patients when considering the vascular and biomechanical anatomy.

Review of Transmetatarsal Amputations in the Management of Peripheral Arterial Disease in an Asian Population

Objective: To evaluate outcomes after transmetatarsal amputation (TMA) in peripheral arterial disease (PAD) limb salvage in an Asian population and identify risk factors associated with TMA failure. Methodology: A retrospective review of 147 patients with PAD, who had undergone TMA between 2008 and 2014, was carried out. Univariate and multivariate analysis were used to identify predictors of TMA failure. Kaplan-Meier survival analysis was used to calculate major amputation and all-cause mortality rates. Results: The mean age was 66 years. 92% were diabetic patients and 78% had preceded angioplasty. 56% of TMAs were healed via secondary intention, 8% required subsequent split-thickness skin graft closure, 24% required further debridement while 37% had wounds, which failed to heal and required below-knee amputations (BKA). Multivariate analysis showed that diabetes is the only independent predictor of TMA failure (odds ratio (OR) 7.11, p=0.064). Patients with TMA failure were at increased risk of developing nosocomial infections (p=0.025) and faced a higher risk of 30-day re-admission rate (p=0.002). Conclusion: The success rate for PAD limb salvage TMA was 63% and diabetes was an independent predictor of TMA failure. Patients with TMA failure were at increased risks of nosocomial infections, and 30-day re-admissions; hence the risks and benefits of TMA for diabetic foot limb salvage must be individualized for each patient.

Outcomes after foot surgery in people with a diabetic foot ulcer and a 12-month follow-up

OBJECTIVE

The aim of this study was to retrospectively measure the outcomes of foot-sparing surgery at one year follow-up for patients with diabetic foot ulcers (DFUs). We assessed wound healing and the need for further surgery in relation to the variables that influence healing.

METHOD

Data were retrospectively collected by reviewing the electronic files of patients attending the Wound Expert Clinic (WEC). Outcomes of surgical debridement, toe, ray and transmetatarsal amputations were assessed.

RESULTS

A total of 129 cases in 121 patients were identified for inclusion. The results demonstrated that complete wound healing was reached in 52% (61/117) of the patients within 12 months. The need for additional surgery or for major amputation was 56% (n=72/129) and 30% (n=39/129) respectively. The need for an additional procedure was particularly high after surgical debridement (75%, 33/44) and transmetatarsal amputation (64%, 7/11). Risk factors for non-healing or for a major amputation were: infection (p=0.01), ischaemia (p=0.01), a history of peripheral arterial occlusive disease (p<0.01) and smoking (p=0.01). Additional findings were that not all patients underwent vascular assessment and in half of the patients there was a delay in undergoing revascularisation.

CONCLUSION

The results of the study reveal some areas for improvement including timely revascularisation and performance of multiple debridement procedures if needed in order to save a limb.

An Approach to Transmetatarsal Amputation to Encourage Immediate Weightbearing in Diabetic Patients

Transmetatarsal amputation remains the standard treatment for the unsalvageable diabetic forefoot; however, this operation is often complicated by wound dehiscence, ulceration, and the need for additional surgery and tendon balancing. The technique described in the present report provides an uncomplicated suturing method for closure of a standard transmetatarsal amputation. A drill hole is created through the first, second, and fourth metatarsals, which facilitates added stability to the plantar flap of the residual metatarsals. The patients are encouraged to begin protected weightbearing as early as the first postoperative day. The security of the flap promotes immediate weightbearing, which could result in fewer postoperative complications of transmetatarsal amputations. Early weightbearing will not only encourage tendon rebalancing, but also could improve angiogenesis through capillary ingrowth.

The care of transmetatarsal amputation in diabetic foot gangrene

Diabetic foot ulcerations may determine minor or major amputation, with a high impact on patients' life expectation and quality of life and on economic burden. Among minor amputations, transmetatarsal amputation (TMA) appears to be the most effective in terms of limb salvage rates and in maintaining foot and ankle biomechanics. In spite of this, TMA needs particular pre- and postoperative management in order to avoid the frequent failure rates. A systematic review was undertaken of studies concerning TMA and its care in diabetic foot gangrene. Studies were identified by searching the MEDLINE, Scopus and Science Direct databases until 13 January 2016. All studies were assessed using the Downs and Black quality checklist. Of the 348 records found, 86 matched our inclusion criteria. After reading the full-text articles, we decided to exclude 35 manuscripts because of the following reasons: (1) no innovative or important content, (2) no multivariable analysis, (3) insufficient data, (4) no clear potential biases or strategies to solve them, (5) no clear endpoints and (6) inconsistent or arbitrary conclusions. The final set included 51 articles. In the current literature, there are less data about TMA, indication for the selection of patients, outcomes and complications. Generally, the judgment of an experienced physician is one of the best indicators of subsequent healing. Ankle brachial indices, toe pressures, laser Doppler skin perfusion pressures, angiography and Doppler assessment of foot vasculature may help physicians in this decision. In any case, despite the presumed lower healing rate, it is reasonable to pursue a TMA in a patient with a higher likelihood of continued ambulation. Furthermore, tailored wound closure, adjuvant local treatments and the choice of the most appropriate antibiotic therapy, when infection occurs, are pivotal elements for the success of TMA procedures. TMA is a valuable option for diabetic foot gangrene that can prevent major limb loss and minimise loss of function, thus improving the quality of life for diabetic patients.

Reoperation and Reamputation After Transmetatarsal Amputation: A Systematic Review and Meta-Analysis

Transmetatarsal amputations have generally been accepted as a relatively more definitive amputation compared with other lesser ray resections. However, many investigators have reported a high occurrence of more proximal amputation after transmetatarsal amputation. A systematic review was performed to evaluate the occurrence of reamputation and reoperation after transmetatarsal amputations. A search of the Medline, CINAHL, and Cochrane Central databases yielded 159 abstracts. After review, 24 reports were included in the study. A total of 391 (26.9%) reoperations were identified after 1453 transmetatarsal amputations. Any level reamputation occurred in 152 (29.7%) of 365 transmetatarsal amputations and major amputation occurred in 380 (33.2%) of 1146 transmetatarsal amputations. Using a random effects model, the reoperation rate was estimated at 24.43% (95% confidence interval 11.64% to 37.21%), the reamputation rate was estimated at 28.37% (95% confidence interval 19.56% to 37.19%), and the major amputation rate was estimated at 30.16% (95% confidence interval 23.86% to 36.47%). These findings raise questions about the conventional wisdom of performing primary transmetatarsal amputation in lieu of other minor amputations, such as partial first ray amputation, and suggest that the choice between transmetatarsal amputation and other minor amputations might be a decision that depends on very patient-specific factors.

Predictors for the Healing of Transmetatarsal Amputations: Retrospective Study of 91 Amputations

This retrospective study reviewed 80 consecutive patients (mean age 62 years; range 21–91 years) who underwent 91 transmetatarsal amputations (TMAs) between 1995 and 2003. The mean follow-up was 12 ± 1.36 months. Sixty-two TMAs healed initially (group 1), whereas 29 TMAs did not heal by 3 months (group 2). At the final examination, in groups 1 and 2, 63 of 91 (69%) limbs were healed. Of the 28 limbs that did not heal, 25 of 28 (89%) required further proximal amputation. Initial healing correlated significantly with the ability to ambulate ( p < .0001) and overall limb salvage ( p < .0001). In group 1, 20 of 27 (74%) limbs that were revascularized healed ( p = .0336). Nonhealing amputations were associated with end-stage renal disease (13 of 19; 68%) ( p = .0209) and leukocytosis (13 of 19; 68%) ( p = .0052).

Partial foot amputation in patients with diabetic foot ulcers

BACKGROUND

Transtibial amputations (TTA) are performed for recalcitrant or infected ulcers of the midfoot, hindfoot, or ankle. This procedure results in decreased ambulatory status caused by increased oxygen demands and energy expenditure. Partial foot amputations have the advantage of being an end-bearing limb and require less work to walk, theoretically suggesting improved functional outcome. The purpose of this research was to examine the longevity, outcome, and mortality of partial foot amputations as an alternative to TTA.

METHODS

Retrospective chart review identified diabetic patients with transmetatarsal, Chopart's, and calcanectomy amputations for osteomyelitis or nonhealing ulcers. A control group consisted of diabetic patients who underwent TTA. A comparison between groups examined mortality, proximal ipsilateral reamputation, and a validated ambulatory functional outcome measure.

RESULTS

Eighteen TTA patients were enrolled. The 5-year mortality rate was 0.45, one patient required reamputation, and the mean postoperative ambulatory score was 2.8. Twenty-one transmetatarsal patients were enrolled. The 5-year mortality rate was 0.30, two patients required reamputation, and the mean postoperative ambulatory score was 4.3. Ten Chopart's amputation patients were enrolled. The 5-year mortality rate was 0.36, six patients required reamputation, and the mean postoperative ambulatory score was 4.3. Seventeen partial calcanectomy patients were enrolled. The 5-year mortality rate was 0.69, six patients required reamputation, and the mean postoperative ambulatory score was 4.3. Sixteen total calcanectomy patients were enrolled. The 5-year mortality rate was 0.59, five patients required reamputation, and the mean postoperative ambulatory score was 3.3.

CONCLUSION

TTA is associated with high morbidity and mortality, which suggests that the advantage of partial foot amputations should be investigated. Only transmetatarsal amputations at 1 and 3 years were statistically lower for mortality than TTA. Partial foot amputations at the other levels failed to show statistically improved survivorship. Transmetatarsal and Chopart's amputations had high ambulatory levels and the longest durability, which suggests that these amputations may provide some ambulatory advantage.

Peripheral arterial disease in diabetic patients with renal insufficiency: a review

Peripheral arterial disease is common among diabetic patients with renal insufficiency, and most of the diabetic patients with end-stage renal disease (ESRD) have peripheral arterial disease. Ischaemia is probably overrepresented as an etiological factor for a diabetic foot ulcer in this group of patients compared with other diabetic patients. ESRD is a strong risk factor for both ulceration and amputation in diabetic patients. It increases the risk of nonhealing of ulcers and major amputation with an OR of 2.5-3. Renal disease is a more important predictor of poor outcome after revascularizations than commonly expected. Preoperative vascular imaging is also affected by a number of limitations, mostly related to side effects of contrast agents poorly eliminated because of kidney dysfunction. Patients with renal failure have high perioperative morbidity and mortality. Persistent ischaemia, extensive infection, forefoot and heel gangrene, poor run-off, poor cardiac function, and the length of dialysis-dependent renal failure all affect the outcome adversely. Despite dismal overall outcome, recent data indicate that by proper selection, favourable results can be obtained even in ESRD patients, with the majority of studies reporting 1-year limb salvage rates of 65-75% after revascularization among survivors. High 1-year mortality of 38% reported in a recent review has to be taken into consideration, though. The preferential use of endovascular-first approach is attractive in this vulnerable multimorbid group of patients, but the evidence for endovascular treatment is very scarce. The need for complete revascularization of the foot may be even more important than in other patients with ischaemic ulcerated diabetic foot because there are a number of factors counteracting healing in these patients. Typically, half of the patients are reported to lose their legs despite open bypass. To control tissue damage and improve chances of ulcer healing, one should understand that early referral to vascular consultation is necessary.

A modified transmetatarsal amputation

The incidence of the diabetic foot is increasing worldwide. Because evidence has shown that transmetatarsal amputation is associated with fewer failures in amputations of the diabetic foot with or without peripheral arterial disease, improving its management and surgical technique is a mission for the surgeon. Conventional transmetatarsal amputation has held firm, however, for more than 150 years. With a new concept for the transmetatarsal amputation method aimed at a better outcome, we propose a modified procedure for preserving the soft tissue between the metatarsal bones (the vasculature complex with the muscles, periostea, and vessels) and applying it to the distal bone stumps. The purpose of this method is to secure a functional foot by preserving the longitudinal arch. The new method was applied to 11 patients with diabetes mellitus or peripheral arterial disease, or both. All wounds closed successfully. Of the 11 patients, 8 were still alive with no complications. Of these 8 patients, 6 were able to ambulate with a custom-made shoe and 2 used a wheelchair, just as preoperatively. Of the 3 patients who died, 1 died a natural death, 1 died of sepsis, and 1 of cerebral infarction. We believe that the modified transmetatarsal amputation that we have described in this report is a potential breakthrough in the care of patients with forefoot gangrene and may gain acceptance over time.

Assessing the long-term outcomes of minor lower limb amputations: a 5-year study

Our aim was to assess the long-term outcome for minor forefoot amputations. A retrospective study of 126 patients who had such amputations between 1999 and 2004 was performed. Patients were divided into 2 groups, diabetic (group A: 79 patients) and nondiabetic (group B: 47 patients). Angiograms were requested in 45 patients in group A compared with 31 patients in group B (P = ·77). In group A, 11 patients underwent further ipsilateral amputations compared with 30 patients in group B (P = ·02.). The 2 groups were equally likely to have vascular reconstruction (35% vs 37%). The overall 5-year mortality was 27%, with 58% of deaths occurring within the first year. This study shows that foot amputees have high mortality and reintervention rates. Adequate utilization of vascular services, extra vigilance in the prevention of complications, and risk factor modifications are required to improve postoperative outcomes.

[Minor amputations for diabetic foot syndrome]

Minor amputations are frequently performed for neuroischemic or neuropathic lesions of the diabetic foot. Depending on the definition used, minor amputations can range from toe to Syme amputations. Minor amputations are often combined with necrosectomy and débridement. For early and optimal rehabilitation, as much vital tissue as possible should be conserved, especially considering the skeletal structures of the foot (borderline amputation). Minor amputations are of utmost importance for the prevention of ascending infections and reduce the duration of clinical and outpatient treatment. Minor amputations should be performed only by experienced surgeons and only if arterial perfusion is sufficient. They should be as tissue-conserving as possible and structured interdisciplinary postoperative care is mandatory. Metabolic control should be optimized. Controversial opinions exist with respect to the use of tourniquets, conservation or resection of cartilage and sesamoid bones, open amputation or primary closure of the wound, interdigital spacer function of toes, aseptic proximal transection of tendons, postoperative wound care, negative-pressure wound treatment and antibiotic therapy. In view of these controversies the most important minor amputation techniques are described and discussed.

Preoperative Doppler assessment for transmetatarsal amputation

A thorough preoperative vascular evaluation should be performed before the initiation of any lower extremity surgical intervention, but particularly in situations of diabetic foot reconstruction with compromised blood flow. The intended emphasis of this brief report is to provide the foot and ankle surgeon with an appreciation for the clinical vascular anatomy of the transmetatarsal amputation through a handheld Doppler examination.

Transmetatarsal amputation: assessment of current selection criteria

BACKGROUND

Transmetatarsal amputation (TMA) is an operation designed to remove a limited area of irremediable tissue ischemia and/or infection and preserve limb function. Patients are selected for TMA based on degree of tissue loss/infection, adequacy of tissue perfusion at the transmetatarsal level, current ambulatory status, and estimation of the likelihood of postprocedure ambulation. The purpose of this study was to assess the validity of these selection criteria.

METHODS

An institutional review board-approved retrospective review was conducted of all patients undergoing TMA from January 1, 1997, until January 1, 2006. Information was collected on patient demographics, medical comorbidity, and clinical and surgical variables. Outcome measures included the proportion of patients requiring amputation revision to a more proximal level and ambulatory status at last follow-up.

RESULTS

Fifty-two TMAs were performed. In 35 procedures, the skin was left open, and in 17 TMA was closed primarily. Primary indications for the procedure were vascular insufficiency or infection in 50 of 52 patients, whereas 2 patients required amputation for malignancy. The majority (46/52, 89%) of patients were diabetic. After the index TMA, 85 additional operations were required. Only 9 patients (18%) underwent a single operation. Revision of the TMA to a more proximal level was required in 29 of 52 (56%) patients, resulting in 4 Syme, 20 transtibial, and 5 transfemoral amputations. Non-insulin-dependent diabetes was associated with an increased likelihood of revision to a more proximal amputation (odds ratio [OR] = 5.4; 95% confidence interval [CI], 1.2-24). At the time of last follow-up (median 18 months), 37 of 50 (74%) patients were ambulatory (83% for TMAs and 67% for more proximal amputations, P = 0.18). Prior vascular procedures were associated with a significantly decreased likelihood of ambulation (OR = 14; 95% CI, 1.9-103).

CONCLUSIONS

Although most patients retain the ability to ambulate after TMA, multiple operations should be anticipated in the majority of patients and revision of a TMA to a more proximal level may be required. These data suggest that current selection criteria for TMA may be inadequate.

Transmetatarsal Amputation: Predictors of Healing

The objective of this study is to determine the predictors of healing after transmetatarsal amputations (TMA) and factors leading to a higher level of amputation. A total of 33 TMA was performed in 31 patients during the 5 years between January 2000 and Jul 2005. All patients were men between the ages of 44 and 82 years (mean, 68 years). The mean follow-up period was 36 months (range, 1–65 months). Twelve (40%) TMA required a subsequent higher level of amputation. Seventeen (57%) TMA were successful. The average time until further proximal amputation after TMA was 3.5 months. Risk factors for subsequent higher amputation by univariate analysis included infrapopliteal arterial occlusion (P < 0.05), tobacco smoking greater than 20 years (P < 0.05), and further TMA debridement (P < 0.05). Upon multivariate analysis, only patients undergoing further TMA debridement were at risk for TMA failure (P = 0.01). The difference in ankle-to-brachial pressure ratio (ABI) between the higher amputation group (ABI = 0.51) and the successful TMA group (ABI = 0.54) was not significant. There were no perioperative deaths after TMA. Five (18%) deaths occurred at a mean of 8.2 months after the TMA. In patients who are walking preoperatively, aggressive TMA is warranted in an attempt to maintain ambulation, recognizing that requirement for further debridement, smoking history, and infrapopliteal occlusion may be predictors of nonhealing and subsequent higher amputation.