Higher Level Of Amputation Research Articles

The risk factors in diabetic foot ulcers and predictive value of prognosis of wound tissue vascular endothelium growth factor

Diabetic foot ulcer (DFU) is a leading cause of high-level amputation in DM patients, with a low wound healing rate and a high incidence of infection. Vascular endothelial growth factor (VEGF) plays an important role in diabetes mellitus (DM) related complications. This study aims to explore the VEGF expression and its predictive value for prognosis in DFU, in order to provide basis for the prevention of DFU related adverse events. We analyzed 502 patients, with 328 in healing group and 174 in non-healing/recurrent group. The general clinical data and laboratory indicators of patients were compared through Spearman correlation analysis, ROC analysis and logistic regression analysis. Finally, the independent risk factors for adverse prognosis in DFU patients were confirmed. Spearman analysis reveals a positive correlation between the DFU healing rate and ABI, VEGF in wound tissue, and positive rate of VEGF expression, and a negative correlation with DM duration, FPG, HbA1c, TC, Scr, BUN, and serum VEGF. Further logistic regression analysis finds that the DM duration, FPG, HbA1c, ABI, serum VEGF, VEGF in wound tissue, and positive rate of VEGF expression are the independent risk factors for adverse prognosis in DFU (p < 0.05). DM duration, FPG, HbA1c, ABI, serum VEGF, VEGF in wound tissue, and positive rate of VEGF expression are the independent risk factors for prognosis in DFU patients. Patients with these risk factors should be screened in time, which is of great significance to prevent DFU related adverse events and improve outcomes.

Postoperative Casting of Below-Knee Amputation Reduces StumpComplications

Against the technological advances in limb salvage, below-the-knee amputation (BKA) remains a common procedure. Although most elective BKA is classified as clean operation, the reported stump complication rate is much higher than predicted. Postoperative casting (PC) may reduce the number of these complications. The aim of this study was to compare the efficacy of elastic bandage with knee immobilizer (EBKI) and PC in BKA stump complications. Retrospective cohort comparison design identified patients who underwent BKA between 2000 and 2023 for non-correctable critical limb ischemia (CLI), or excessive tissue loss secondary to CLI, infection, severe neuropathy, or the combination of these and stratified them into 2 cohorts based on their postoperative stump dressing: EBKI and PC. BKAs that were done for trauma or neoplastic processes were excluded. The primary outcome measures: wound healing in 6weeks and length of stay (LOS). stump injury, infection, dehiscence, necrosis, number of higher-level amputations, knee contracture, and post-BKA mobility with Special Interest Group of Amputee Medicine score. One hundred sixteen patients with 122 limbs (52 EBKI and 70 PC) were found who met inclusion criteria and analyzed. The groups were comparable in demographics and comorbidities and preoperative variables, including mobility. The primary wound healing at 6weeks was higher (P=0.007); wound dehiscence (P=0.01) and LOS (P=0.006) was lower in the PC group compared to EBKI group. The PC group achieved higher Special Interest Group of Amputee Medicine mobility score and lower number of contractures developed compared to the EBKI group. Applying and maintaining PC to the BKA stump during the first month of healing reduced the incidence of stump complications, shortened the LOS, and improved postrehabilitation mobility results. We found no effect of PC on postoperative infections, stump necrosis, and higher-level amputations.

Major Lower Limb Amputation for Chronic Limb-Threatening Ischemia Is Associated with Poor Long-Term Survival: 4-Year Follow-Up of a Single-Center Experience.

Objective: Despite advances in medicine, 30% of patients with chronic limb-threatening ischemia (CLTI) require major lower limb amputation (MLLA). The long-term outcome of this cohort is poorly described. Methods: In all, 154 patients undergoing MLLA for CLTI during 2018-2020 were analyzed for short-term and long-term outcomes and prosthesis use. Results: In total, 106 below-knee amputations and 48 above-knee amputations were followed up for a mean duration of 50 months (37-78). The mean age of the cohort was 63 years. The majority were male (60%) with multiple comorbidities, including diabetes (83.8%), hypertension (49.4%), ischemic heart disease (20%), and smoking (32.5%). An equal proportion underwent MLLA as primary (45%) or secondary (55%). 30-day mortality was 6%. The mean length of in-hospital stay was 18 days (3-56). Overall survival rates at 1st, 2nd, and 4th year were 73%, 64%, and 35%, respectively. On a multivariate regression analysis, a higher level of amputation had a significant impact on mortality (p = 0.015). 54% of amputees had a prosthetic limb. However, the primary use of prosthesis was for cosmesis, with only 12% mobile independently. Conclusions: MLLA for CLTI is associated with poor early and long-term survival. Prosthesis use and mobility are extremely poor in the Sri Lankan context.

Impact of diabetes on medical costs in the pre- and postoperative year of lower extremity amputations in Belgium

AimsTo compare the medical costs of individuals undergoing lower extremity amputation (LEA) in Belgium with those of amputation-free individuals. MethodsBelgian citizens undergoing LEAs in 2014 were identified. The median costs per capita in euros for the 12 months preceding and following minor and major LEAs were compared with those of matched amputation-free individuals. ResultsA total of 3324 Belgian citizens underwent LEAs (2295 minor, 1029 major), 2130 of them had diabetes. The comparison group included 31,716 individuals. Amputation was associated with high medical costs (individuals with diabetes: major LEA €49,735, minor LEA €24,243, no LEA €2,877 in the year preceding amputation; €45,740, €21,445 and €2,284, respectively, in the post-amputation year). Significantly higher costs were observed in the individuals with (versus without) diabetes in all groups. This difference diminished with higher amputation levels. Individuals undergoing multiple LEAs generated higher costs (individuals with diabetes: €39,313–€89,563 when LEAs preceded index amputation; €46,629–€92,877 when LEAs followed index amputation). Individuals dying in the year after a major LEA generated remarkably lower costs. ConclusionsLEA-related medical costs were high. Diabetes significantly impacted costs, but differences in costs diminished with higher amputation levels. Individuals with multiple amputations generated the highest costs.

Проблеми діагностики та лікування турнікетного синдрому при вогнепальних пораненнях верхніх і нижніх кінцівок

The article presents topical issues of diagnostic monitoring of changes in vascular status when using a tourniquet during a combat injury, diagnosis of tourniquet syndrome. An alternative diagnostic approach in the form of additional use of multifocal express muscle biopsy and dynamic digital thermography has been demonstrated. Purpose - to conduct an analysis of the problematic issues of diagnosis and treatment of tourniquet syndrome in gunshot wounds of the limbs in order to reduce the number of organizational and technical errors in wounds of the limbs where a tourniquet was used. Materials and methods. In the 16 months since the beginning of Russia’s full-scale aggression against Ukraine, 28 wounded people with tourniquet limb syndrome were treated in the Military Medical Clinical Center of the Northern Region (MMCC of the Northern Region). All the wounded were male, the average age was 34.2±0.6 years. The analysis of the following indicators was carried out: the timing of applying a tourniquet before arrival at ROLE 2, the localization of the tourniquet, the amount of surgical intervention at ROLE 2, the length of stay at ROLE 2, the amount of pre-operative examination in the MMCC of the NR, the amount of surgical interventions in the conditions of the MMCC of the NR, the number of cases of acute kidney injury, the need for renal replacement therapy, the average bed-day on ROLE 3, the level of mortality. Classical general clinical studies were carried out in combination with thermographic and histological research. Results. In terms of localization, in gunshot wounds with tourniquet syndrome, wounds of the lower extremities prevail 28 (82.4%) over the upper extremities 6 (17.6%). There were 12 (35.3%) cases of gunshot fractures in tourniquet syndrome. All (28 patients) injured people arrived with tourniquets on their limbs. The terms of applying a tourniquet before hospitalization on ROLE 3 - from 3 hours 10 minutes to 11 hours 25 minutes, on average - 5 hours 35 minutes ±20 minutes. In 5 (14.7%) cases, there were attempts to remove the tourniquet when it was applied for more than 3 hours at the ROLE 1 level. In 6 (21.4%) of the wounded, there were 2 tourniquets on one anatomical and functional site, which led to amputation on proximal level. The average length of stay at ROLE 2 with tourniquet syndrome was 60±10 hours. All wounded (28 patients) with tourniquet syndrome underwent 34 amputations. 16 (57.1%) wounded with tourniquet syndrome had acute kidney injury and were on prolonged renal replacement therapy. This category of wounded had a tourniquet syndrome at the level of the thigh. Polyfocal express muscle biopsy and dynamic digital thermography were used to diagnose tourniquet syndrome. Conclusions. Improving the training of combat medics will lead to a decrease in the number of organizational and technical errors in limb injuries where a tourniquet is used. A tourniquet applied for a long time leads to a high level of limb amputation in case of irreversible changes in the muscles. There is a need for further development of objective methods for the diagnosis of tourniquet syndrome. The proposed additional methods of diagnosis in the form of polyfocal express biopsy and thermography make it possible to objectify the extent of damage due to standing of the tourniquet. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

Predicting Prosthetic Mobility at Discharge From Rehabilitation Following Major Amputation in Vascular Surgery

This study aimed to construct a decision aid to estimate the likelihood of independence with a prosthesis following rehabilitation for limb loss secondary to advanced ischaemia (acute or chronic limb threatening ischaemia) or diabetic foot disease (DFD). A secondary aim was to determine whether prosthetic independence is a surrogate marker of long term survival. A retrospective cohort study of a prospectively maintained database of unilateral amputations due to ischaemia or DFD entering rehabilitation between 2007 and 2020 was performed. Predictors of independent prosthetic mobility (IPM) were used in construction of the IPM prediction model, which underwent bootstrap internal and criterion validation through correlation with predictors of other measures of function: Timed Up and Go (TUG) and two minute walk test. Kaplan-Meier and Cox regression analyses were performed to address the secondary aim. Of the 771 patients included, only 49.9% of amputees achieved IPM. Independent negative predictors of IPM were age > 75 years, female sex, higher amputation level, active malignancy, cerebrovascular disease, end stage renal disease, and cognitive impairment. The model yielded high discrimination (C statistic 0.778), and internal validation was demonstrated with bootstrapping (C statistic 0.778), confirming no over optimism. There was a strong correlation between IPM, TUG, and two minute distance and their predictors, confirming strong criterion validity. The IPM group had a median survival of 93.7 (80.7, 105) months, whereas the non-IPM group fared worse with a median survival of 56.6 (48.5, 66.7) months (p < .001). An internally validated decision aid for estimating the likelihood of independence with a prosthesis after major amputation was constructed. A strong association between female sex and poorer prosthetic mobility was observed. Prosthetic function was shown to be a surrogate marker of long term survival. Future research will involve external validation studies to confirm the generalisability of the decision aid in clinical practice.

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.

Investigating the joint application of negative pressure wound treatment and tissue therapy for chronic wounds in patients with diabetes.

This study aimed to investigate the effectiveness of combined negative pressure wound therapy (NPWT) and human amniotic membrane in patients with chronic wounds associated with diabetes. A total of five patients with type 2 diabetes, including ischemic and mixed forms of diabetic foot syndrome, presenting with ischemic wounds of the lower extremities were included in this study. Patients with uncorrected limb ischemia were excluded. The treatment protocol included diabetes compensation (treatment with fractional insulin therapy), anticoagulant, metabolic therapy and angiotropic therapy, physical treatment methods, osteoporosis therapy with calcium preparations, and wound-specific interventions. The primary treatment approach involved the application of a vacuum bandage to the transplanted human amniotic membrane, which improved the adaptation of the flap to the wound surface, allowed the removal of excess wound exudate, and stimulated angiogenesis and reparative properties. The combined approach of NPWT and biotherapy was a safe and effective cure for diabetic wounds, promoting faster wound healing, reducing the need for autodermoplasty, and possibly reducing the necessity for high-level amputations.

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

Chronic lower extremity wounds affect up to 13% of the US population. Transmetatarsal amputation (TMA) is frequently performed in patients with chronic forefoot wounds. TMA allows limb salvage and preserves functional gait, without need for prosthesis. Traditionally, when tension-free primary closure is not possible, a higher-level amputation is performed. This is the first series to evaluate the outcomes of local and free flap coverage of TMA stumps in patients with chronic foot wounds. A retrospective cohort of patients who underwent TMA with flap coverage from 2015 through 2021 was reviewed. Primary outcomes included flap success, early postoperative complications, and long-term outcomes (limb salvage and ambulatory status). Patient-reported outcome measures using the Lower Extremity Functional Scale (LEFS) were also collected. Fifty patients underwent 51 flap reconstructions (26 local, 25 free flap) after TMA. Average age and body mass index were 58.5 years and 29.8 kg/m 2 , respectively. Comorbidities included diabetes [ n = 43 (86%)] and peripheral vascular disease [ n = 37 (74%)]. Flap success rate was 100%. At a mean follow-up of 24.8 months (range, 0.7 to 95.7 months), the limb salvage rate was 86.3% ( n = 44). Forty-four patients (88%) were ambulatory. The LEFS survey was completed by 24 surviving patients (54.5%). Mean LEFS score was 46.6 ± 13.9, correlating with 58.2% ± 17.4% of maximal function. Local and free flap reconstruction after TMA are viable methods of soft-tissue coverage for limb salvage. Applying plastic surgery flap techniques for TMA stump coverage allows for preservation of increased foot length and ambulation without a prosthesis. Therapeutic, IV.

Comparing Patient and Provider Priorities Around Amputation Level Outcomes Using Multiple Criteria Decision Analysis

Patients with chronic limb threatening ischemia may require a transmetatarsal amputation (TMA) or a transtibial amputation. When making an amputation-level decision, these patients face a tradeoff-a TMA preserves more limb and may provide better mobility but has a lower probability of primary wound healing and may therefore result in additional same or higher level amputation surgeries with an associated negative impact on function. Understanding differences in how patients and providers prioritize these tradeoffs and other outcomes may enhance shared decision-making. Compare patient priorities with provider perceptions of patient priorities using Multiple Criteria Decision Analysis (MCDA). The MCDA Analytic Hierarchy Process was chosen due to its low cognitive burden and ease of implementation. We included 5 criteria (outcomes): ability to walk, healing after amputation surgery, rehabilitation program intensity, limb length, and ease of use of prosthetic/orthotic device. A national sample of dysvascular lower-limb amputees and providers were recruited from the Veterans Health Administration with the MCDA administered online to providers and telephonically to patients. Twenty-six dysvascular amputees and 38 providers participated. Fifty percent of patients had undergone a TMA; 50%, a transtibial amputation. When compared to providers, patients placed higher value on TMA (72% vs. 63%). Patient versus provider priorities were ability to walk (47% vs. 42%), healing (18% vs. 28%), ease of prosthesis use (17% vs. 13%), limb length (11% vs. 13%), and then rehabilitation intensity (7% vs. 6%). Our sample may not generalize to other populations. Provider perceptions aligned with patient values on amputation level but varied around the importance of each outcome. These findings illuminate some differences between patients' values and provider perceptions of patient values, suggesting a role for shared decision-making. Embedding this MCDA framework into a future decision aid may facilitate these discussions.

Association Between Combat-Related Traumatic Injury and Skeletal Health: Bone Mineral Density Loss Is Localized and Correlates With Altered Loading in Amputees: the Armed Services Trauma Rehabilitation Outcome (ADVANCE) Study.

The association between combat-related traumatic injury (CRTI) and bone health is uncertain. A disproportionate number of lower limb amputees from the Iraq and Afghanistan conflicts are diagnosed with osteopenia/osteoporosis, increasing lifetime risk of fragility fracture and challenging traditional osteoporosis treatment paradigms. The aim of this study is to test the hypotheses that CRTI results in a systemic reduction in bone mineral density (BMD) and that active traumatic lower limb amputees have localized BMD reduction, which is more prominent with higher level amputations. This is a cross-sectional analysis of the first phase of a cohort study comprising 575 male adult UK military personnel with CRTI (UK-Afghanistan War 2003 to 2014; including 153 lower limb amputees) who were frequency-matched to 562 uninjured men by age, service, rank, regiment, deployment period, and role-in-theatre. BMD was assessed using dual-energy X-ray absorptiometry (DXA) scanning of the hips and lumbar spine. Femoral neck BMD was lower in the CRTI than the uninjured group (T-score -0.08 versus -0.42 p=.000). Subgroup analysis revealed this reduction was significant only at the femoral neck of the amputated limb of amputees (p=0.000), where the reduction was greater for above knee amputees than below knee amputees (p < 0.001). There were no differences in spine BMD or activity levels between amputees and controls. Changes in bone health in CRTI appear to be mechanically driven rather than systemic and are only evident in those with lower limb amputation. This may arise from altered joint and muscle loading creating a reduced mechanical stimulus to the femur resulting in localized unloading osteopenia. This suggests that interventions to stimulate bone may provide an effective management strategy. © 2023 Crown copyright and The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). This article is published with the permission of the Controller of HMSO and the King's Printer for Scotland.

A Comparative Analysis of Functional and Patient-Reported Outcomes Following Lisfranc and Chopart Amputations in High-Risk Limb Salvage Patients

Midfoot amputations provide an opportunity for limb salvage through preservation of a weightbearing limb. However, the longevity of midfoot amputations is threatened by restrictions in surface area and risks of skin breakdown. To better inform decisions surrounding the level of amputation, we sought to compare outcomes of high-risk individuals who underwent Lisfranc or Chopart amputations. A single-center retrospective cohort study was performed from November 2013 to September 2022 of adult patients who underwent Lisfranc or Chopart amputations. Patients were stratified into cohorts based on the amputation type. Outcomes included postoperative rates of re-amputation, functional status, mortality and patient-reported outcome measures in the form of Lower Extremity Functional Scale scores. Sixty-six patients were identified; of which, 45 underwent Lisfranc amputation, and 21 underwent Chopart amputation. Median Charlson Comorbidity Index was 7, signifying a substantial comorbidity burden. By median follow-up of 14 (Interquartile range: 28) months, 31 patients (36%) progressed to higher-level amputation, and most patients were ambulatory (n=38, 58%). Overall rates of re-amputation, ambulatory status, and mortality were comparable between groups. Re-amputation to another midfoot amputation was more common among the Lisfranc cohort (n=16, 36% vs n=1, 5%), whereas re-amputation to BKA was more prevalent among the Chopart cohort (Chopart: n=7, 33% vs Lisfranc: n=7, 16%; p=.011). Average Lower Extremity Functional Scale scores were similar between groups and corresponded to a maximal function of 48%. Lisfranc and Chopart amputations have the potential to be efficacious limb salvage options in high-risk patient populations in conjunction with intraoperative biomechanical optimization and optimal preoperative patient selection.

Factors affecting successful prosthetic use after hemipelvectomy and hip disarticulation amputations: Five-year experience from a tertiary prosthetic rehabilitation center.

Rehabilitation after hip disarticulation and hemipelvectomy amputations can be challenging, and many opt to forego prosthetic limb use. There is limited evidence on characteristics that result in successful prosthetic use; therefore, our study aimed to identify these to help guide patient expectations. A retrospective review was performed on patients seen at a UK tertiary prosthetic center in the past 5 years with hip disarticulation or hemipelvectomy amputations. Details and etiology of amputation, length between assessment and delivery of prosthesis, goals, reasons for abandonment, and outcomes were recorded. Successful prosthetic use was defined as the use of a prosthesis at least 3 times a week. Characteristics were compared using odds ratios and Fisher exact test. Twenty-seven patient notes were analyzed: 42% female, 58% male, and age range 14-90. Thirty percent had a hemipelvectomy, and 70% had a hip disarticulation. Neoplasia accounted for 78% of etiologies followed by trauma 15% and infected endoprosthesis 7%. Sixty-seven percent trialed a walking prosthesis; 33% of these stopped eventually. There were no statistically significant findings of factors increasing odds of successful prosthetic use. However, age significantly increased the odds of being given a trial of a prosthesis. Although younger patients are more likely to be given the opportunity to trial a walking prosthesis, age does not seem to affect the overall outcome alone. In cases of neoplasia, there is often a delayed start to rehabilitation and prosthetic use, which may affect eventual success. Further studies are required to define the optimum characteristics for successful prosthetic use at higher amputation levels.

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

Category: Diabetes; Midfoot/Forefoot; Trauma; Other Introduction/Purpose: The level of amputation in patients with severe lower extremity pathology often presents a challenge. Surgeons are often confronted with deciding between a transmetatarsal amputation (TMA) or below-knee amputation (BKA). Certainly, in cases where patients are candidates for a TMA, the decision might seem rather straightforward. However, the literature has demonstrated that minor foot amputations, like TMAs, often have high rates of revision and often necessitate a higher level of amputation. This study compared revision rates, need for higher level of amputation, post-operative ambulatory rates, and the demographics between patients undergoing either TMA or BKA. Methods: This was a retrospective analysis of patients who underwent BKA or TMA and received follow-up care at a single academic medical center from January of 2013 to May of 2021. Demographic and medical historical data was collected and compared between patients undergoing BKA or TMA. A binary logistic regression model was used to evaluate independent predictors for necessitation of revision surgery and/or higher levels of amputation between the two groups. Secondary outcomes included hospital length of stay, as well as ambulatory and wound status at last patient follow-up. Statistical significance was defined as p&lt;.05. Results: A total of 367 patients underwent either BKA (n=293) or TMA (n=74). On binary logistic regression, significant independent predictors of needing surgical revision were undergoing TMA (OR 2.29, CI 1.23-4.27, p=.009) and peripheral arterial disease (PAD) (OR 2.28, CI 1.12-4.6, p=.023). Similarly, significant independent predictors of needing higher level amputation were undergoing TMA (OR 4.4, CI 2.01-9.63, p&lt;.001) and presence of PAD (OR 6.18, CI 2.12- 17.98, p&lt;.001). Secondary outcomes showed that more TMA patients were ambulatory (56.8%) on last follow-up compared to BKA patients (30.9%). Hospital length of stay was significantly greater in the BKA group (17.3 +- 21.2) vs the TMA group (13.6 +- 10.9) (p=.04). There was no significant difference between BKA and TMA groups with respect to healed incisions at last follow-up (58.3% and 51.4% respectively). Conclusion: This study found transmetatarsal amputations to have a higher risk of re-operation and need for revision amputation compared to below-knee amputations. Transmetatarsal amputations had a higher chance of returning patients to independent ambulation. These findings are consistent with the literature suggesting higher reoperation rates in minor foot amputations. Patients with peripheral arterial disease are at a higher risk of revision surgery and higher-level amputation with both operations warranting further vascular work-up for patients with severe PAD and absent pulses.

Transmetatarsal Amputations: Outcomes of Primary Healing versus Secondary Healing.

Transmetatarsal amputations are limb salvage surgical procedures that preserve limb length and functional ankle joints. Indications for transmetatarsal amputations include forefoot trauma, infection, and ischemia. Prior research demonstrates patients who undergo transmetatarsal amputations have a lower 2-year mortality rate compared to those who undergo more proximal amputations. The aim of this study was to determine whether primary closure of a transmetatarsal amputation is a superior treatment compared to secondary healing of a transmetatarsal amputation for forefoot abnormality of infection, gangrene, or chronic ulceration. A retrospective chart review was performed on patients aged 18 years or older requiring a transmetatarsal amputation because of forefoot abnormality between September of 2011 and December of 2019. Foot and ankle surgeons performed transmetatarsal amputations. Outcome variables measured included healing time of transmetatarsal amputation site, recurrent infection, recurrent gangrene, and the need for revision surgery or higher level amputations. Of the original 112 patients, 76 met the inclusion criteria; 47 of these had primary closure of transmetatarsal amputation and 29 of these had an open transmetatarsal amputation performed. Primarily closed transmetatarsal amputations resulted in a significantly greater overall healing rate of 78.8% (37 of 47) compared to open transmetatarsal amputations, with a healing rate of 37.9% (11 of 29) (P < .01). Closed transmetatarsal amputations were statistically significantly less likely than open transmetatarsal amputations to have recurrent gangrene, require revision pedal operations, or progress to higher level amputations. Our research demonstrated that primary closure of transmetatarsal amputations is a superior treatment compared with secondary healing of transmetatarsal amputations in specific cases of infection, dry gangrene, or chronically nonhealing ulcerations.

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.

3. MOTOR CONTROL OF INDIVIDUAL DIGITS OF A ROBOTIC HAND USING ONLY SIGNALS RECORDED FROM THE PERIPHERAL NERVES

PURPOSE: Despite advances in artificial sensory feedback and EMG-based motor control, robotic hand “dexterity” remains elusive due to the inability to provide reliable individual digit motor control. We previously demonstrated functionally-relevant tactile and proprioceptive sensory feedback using fascicle-specific targeting of longitudinal intrafascicular electrodes (FAST-LIFE interfaces) implanted in the residual nerves of the amputated upper limb. Here we describe advances in motor control obtained by combining FAST-LIFE interfacing with peripheral nerve-specific motor control technology developed by our group. METHODS: Oversight by the UTSW IRB. 6 patient trials were performed, duration 3 - 15 months. Amputation level: 3 partial hand (FAST-LIFE interfaces in motor/sensory fascicles of ulnar nerve); 3 transradial (FAST-LIFE interfaces in motor/sensory fascicles of median + ulnar nerves). RESULTS: We demonstrated individual digit control of a robotic hand prosthesis using: 1) FAST-LIFE interfacing, 2) hardware for recording peripheral nerve signals, 3) machine learning decoding of motor intent, and 4) portable controllers for individual digit actuation. Details of decoding accuracy, task matching trials, and individual digit control will be discussed. The study culminated in a “take-home” trial. CONCLUSION: Individual digit control of a robotic hand prosthesis can be accomplished using only signals derived from FAST-LIFE implants placed in the residual nerves of the amputated upper limb. Our novel motor control strategy holds promise for robotic hand control in higher level amputations, where conventional EMG sensors are ineffective due to total absence of the forearm muscles.

The Effect of Socioeconomic Status On Amputation Outcomes And Limb Salvage Interventions

INTRODUCTION AND OBJECTIVES Disadvantaged patients have historically undergone higher level amputations without prior limb salvage interventions when compared with other populations. We sought to determine if racial and socioeconomic status is associated with decreased access to vascular care, less attempts of primary revascularization and higher level amputations. METHODS The Vascular Quality Initiative was queried from 2012-2020 for patients with below-knee and above-knee amputations (AKA). Outcomes based on race and distressed community index (DCI) as a marker of socioeconomic status were investigated. Baseline characteristics, prior revascularization on the ipsilateral limb and amputation outcomes were compared between races and the five DCI groups (prosperous, comfortable, mid-tier, at-risk, distressed) using Pearson chi and student t-test. RESULTS The cohort consisted of 14,816 cases of amputations. As seen in table I, when comparing DCI groups, the AKA rate was highest in the distressed group while prior revascularization was lowest (p<0.001). Thirty-day and one-year mortality were equal among the groups as well as the postoperative complication rate. Ambulation at long term follow up progressively decreased through the groups from 60.5% in the prosperous group to 49.6% in the distressed group (p<0.001). When comparing races (table II) the black group had a higher rate of AKA and a lower rate of primary revascularization when compared to the white group. The black group also had the lowest rate of ambulation at follow up. CONCLUSIONS Lower socioeconomic status and minority race is associated with a higher rate of AKA, a lower rate of primary revascularization and a low chance at future ambulation nationwide. Disadvantaged patients have historically undergone higher level amputations without prior limb salvage interventions when compared with other populations. We sought to determine if racial and socioeconomic status is associated with decreased access to vascular care, less attempts of primary revascularization and higher level amputations. The Vascular Quality Initiative was queried from 2012-2020 for patients with below-knee and above-knee amputations (AKA). Outcomes based on race and distressed community index (DCI) as a marker of socioeconomic status were investigated. Baseline characteristics, prior revascularization on the ipsilateral limb and amputation outcomes were compared between races and the five DCI groups (prosperous, comfortable, mid-tier, at-risk, distressed) using Pearson chi and student t-test. The cohort consisted of 14,816 cases of amputations. As seen in table I, when comparing DCI groups, the AKA rate was highest in the distressed group while prior revascularization was lowest (p<0.001). Thirty-day and one-year mortality were equal among the groups as well as the postoperative complication rate. Ambulation at long term follow up progressively decreased through the groups from 60.5% in the prosperous group to 49.6% in the distressed group (p<0.001). When comparing races (table II) the black group had a higher rate of AKA and a lower rate of primary revascularization when compared to the white group. The black group also had the lowest rate of ambulation at follow up. Lower socioeconomic status and minority race is associated with a higher rate of AKA, a lower rate of primary revascularization and a low chance at future ambulation nationwide.

Machine learning analysis of multispectral imaging and clinical risk factors to predict amputation wound healing.

Prediction of amputation wound healing is challenging due to the multifactorial nature of critical limb ischemia and lack of objective assessment tools. Up to one-third of amputations require revision to a more proximal level within 1year. We tested a novel wound imaging system to predict amputation wound healing at initial evaluation. Patients planned to undergo amputation due to critical limb ischemia were prospectively enrolled. Clinicians evaluated the patients in traditional fashion, and all clinical decisions for amputation level were determined by the clinician's judgement. Multispectral images of the lower extremity were obtained preoperatively using a novel wound imaging system. Clinicians were blinded to the machine analysis. A standardized wound healing assessment was performed on postoperative day 30 by physical exam to determine whether the amputation site achieved complete healing. If operative revision or higher level of amputation was required, this was undertaken based solely upon the provider's clinical judgement. A machine learning algorithm combining the multispectral imaging data with patient clinical risk factors was trained and tested using cross-validation to measure the wound imaging system's accuracy of predicting amputation wound healing. A total of 22 patients undergoing 25 amputations (10 toe, five transmetatarsal, eight below-knee, and two above-knee amputations) were enrolled. Eleven amputations (44%) were non-healing after 30days. The machine learning algorithm had 91% sensitivity and 86% specificity for prediction of non-healing amputation sites (area under curve, 0.89). This pilot study suggests that a machine learning algorithm combining multispectral wound imaging with patient clinical risk factors may improve prediction of amputation wound healing and therefore decrease the need for reoperation and incidence of delayed healing. We propose that this, in turn, may offer significant cost savings to the patient and health system in addition to decreasing length of stay for patients.