Comparative evaluation of transcutaneous oxygen tension and ankle-brachial index as predictors of reoperation following below-knee amputation.

OBJECTIVE: Decision-making regarding level of lower extremity amputation is sometimes challenging. Selecting an appropriate anatomic level for major amputation requires consideration of tradeoffs between postoperative function and risk of wound complications that may require additional operations, including debridement and/or conversion to above-knee amputation (AKA). We evaluated the utility of common, non-invasive diagnostic tests used in clinical practice to predict the need for reoperations among patients undergoing primary, elective, below knee-amputations (BKAs) by vascular surgeons. METHODS: Patients undergoing elective BKA over a 5-year period were identified using Current Procedural Terminology codes. Medical records were reviewed to characterize demographics, pre-amputation testing transcutaneous oxygen tension (TcPO2), and ankle-brachial index (ABI). The need for ipsilateral post-BKA reoperation (including BKA revision and/or conversion to AKA) regardless of indication was the primary outcome. Associations were evaluated using univariable and multivariable logistic regression models. Cutpoints for TcPO2 values associated with amputation reoperation were evaluated using receiver operating characteristic curves. RESULTS: We identified 175 BKAs, of which 46 (26.3%) required ipsilateral reoperation (18.9% BKA revisions and 14.3% conversions to AKA). The mean age was 63.3 ± 14.8 years. Most patients were male (65.1%) and White (72.0%). Mean pre-amputation calf TcPO2 was 40.0 ± 20.5 mmHg, and mean ABI was 0.64 ± 0.45. In univariable models, post-BKA reoperation was associated with calf TcPO2 (odds ratio [OR], 0.97; 95% confidence interval [CI], 0.94-0.99; P = .013) but not ABI (OR, 0.53; 95% CI, 0.19-1.46; P = .217). Univariable associations with reoperation were also identified for age (OR, 0.97; 95% CI, 0.94-0.990; P = .003) and diabetes (OR, 0.43; 95% CI, 0.21-0.87; P = .019). No associations with amputation revision were identified for gender, race, end-stage renal disease, or preoperative antibiotics. Calf TcPO2 remained associated with post-BKA reoperation in a multivariable model (OR, 0.97; 95% CI, 0.94-0.99; P = .022) adjusted for age (OR, 0.98; 95% CI, 0.94-1.01; P = .222) and diabetes (OR, 0.98; 95% CI, 0.94-1.01; P = .559). Receiver operating characteristic analysis suggested a TcPO2 ≥38 mmHg as an appropriate cut-point for assessing risk for BKA revision (area under the curve = 0.682; negative predictive value, 0.91). CONCLUSIONS: Reoperation after BKA is common, and reoperation risk was associated with pre-amputation TcPO2. For patients undergoing elective BKA, higher risk of reoperation should be discussed with patients with an ipsilateral TcPO2 <38 mmHg.

The impact of diabetes on mortality rates after lower extremity amputation.

OBJECTIVE: To assess the impact of diabetes, amputation level, sex and age on mortality rates after lower extremity amputation (LEA) in Belgium, and to assess temporal trends in one-year survival rates from 2009 to 2018. METHODS: Nationwide data on individuals who underwent minor and major LEA from 2009 to 2018 were collected. Kaplan-Meier survival curves were constructed. A Cox regression model with time-varying coefficients was used to estimate the likelihood of mortality after LEA in individuals with or without diabetes. Matched amputation-free individuals with or without diabetes were used for comparison. Time trends were analysed. RESULTS: Amputations 41,304 were performed: 13,247 major and 28,057 minor. Five-year mortality rates in individuals with diabetes were 52% and 69% after minor and major LEA, respectively (individuals without diabetes: 45% and 63%, respectively). In the first six postoperative months, no differences in mortality rates were found between individuals with or without diabetes. Later, hazard ratios (HRs) for mortality in individuals with diabetes (compared with no diabetes) after minor LEA ranged from 1.38 to 1.52, and after major LEA from 1.35 to 1.46 (all p ≤ 0.005). Among individuals without LEA, HRs for mortality in diabetes (versus no diabetes) were systematically higher compared to the HRs for mortality in diabetes (versus no diabetes) after minor and major LEA. One-year survival rates did not change for individuals with diabetes. CONCLUSIONS: In the first six postoperative months, mortality rates after LEA were not different between individuals with or without diabetes; later, diabetes was significantly associated with increased mortality. However, as HRs for mortality were higher in amputation-free individuals, diabetes impacts mortality less in the minor and major amputation groups relative to the comparison group of individuals without LEA.

The incidence of lower extremity amputation and its associated risk factors in patients with diabetic foot ulcers: A meta-analysis.

This study analysed the incidence of lower extremity amputation and its associated risk factors in patients with diabetic foot ulcers. This study systematically searched both Chinese and English databases, including CNKI, Wanfang, VIP, PubMed, EMBASE and Web of Science, to identify cohort studies related to lower extremity amputation and associated risk factors in patients with diabetic foot ulcers up to October 2023. The patients were stratified based on whether they underwent lower extremity amputation, and relevant data, including basic information, patient characteristics, complications, comorbidities and pertinent laboratory test data, were extracted from the included studies. The literature quality assessment in this study utilized the Newcastle-Ottawa Scale to screen for high-quality literature, resulting in the inclusion of 16 cohort studies, all of which were of at least moderate quality. Meta-analysis of outcome indicators was conducted using the Stata 14.0 software. The results indicate that the overall amputation rate of lower extremities in patients with diabetic foot ulcers is 31% (0.25, 0.38). Among the 16 variables evaluated, gender (male), smoking history, body mass index (BMI), hypertension, cardiovascular disease, kidney disease, white blood cell count, haemoglobin and albumin levels were found to be correlated with the occurrence of lower extremity amputation in patients with diabetic foot ulcers. However, no significant correlation was observed between age, diabetes type, duration of diabetes, stroke, glycosylated haemoglobin, creatinine and total cholesterol levels and lower extremity amputation in patients with diabetic foot ulcers. This meta-analysis indicates that the overall amputation rate in patients with diabetic foot ulcers is 31%. Factors such as gender (male), smoking history, high BMI, hypertension, cardiovascular disease, kidney disease, white blood cell count, haemoglobin and albumin levels are identified as significant risk factors for lower extremity amputation in diabetic foot ulcer patients. These findings suggest that attention should be focused on these risk factors in patients with diabetic foot ulcers to reduce the risk of lower extremity amputation. Therefore, preventive and intervention measures targeting these risk factors are of significant importance in clinical practice. (Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier [CRD42024497538]).

A systematic review and meta-analysis of general versus regional anesthesia for lower extremity amputation.

OBJECTIVE: Postoperative morbidity in patients undergoing lower extremity amputation (LEA) has remained high. Studies investigating the influence of the anesthetic modality on the postoperative outcomes have yielded conflicting results. The aim of our study was to assess the effects of regional anesthesia vs general anesthesia on postoperative complications for patients undergoing LEA. METHODS: We systematically searched PubMed, Embase, MEDLINE, Web of Science, and Google Scholar from 1990 to 2022 for studies investigating the effect of the anesthetic modality on the postoperative outcomes after LEA. Regional anesthesia (RA) included neuraxial anesthesia and peripheral nerve blocks. The outcomes included 30-day mortality, respiratory failure (unplanned postoperative intubation, failure to wean, mechanical ventilation >24 hours), surgical site infection, cardiac complications, urinary tract infection, renal failure, sepsis, venous thrombosis, pneumonia, and myocardial infarction. RESULTS: Of the 25 studies identified, we included 10 retrospective observational studies with 81,736 patients, of whom 69,754 (85.3%) had received general anesthesia (GA) and 11,980 (14.7%) had received RA. In the GA group, 50,468 patients were men (63.8%), and in the RA group, 7813 patients were men (62.3%). The results of the meta-analyses revealed that GA was associated with a higher rate of respiratory failure (odds ratio, 1.38; 95% confidence interval, 1.06-1.80; P = .02) and sepsis (odds ratio, 1.21; 95% confidence interval, 1.11-1.33; P < .0001) compared with RA. No differences were found in postoperative 30-day mortality, surgical site infection, cardiac complications, urinary tract infection, renal failure, venous thrombosis, pneumonia, and myocardial infarction between the GA and RA groups. CONCLUSIONS: The results of our meta-analysis have shown that GA could be associated with a higher rate of respiratory failure and sepsis compared with RA for LEA.

Residual osteomyelitis at the resection margin after conservative surgery is not associated with the recurrence of diabetic foot infection and may successfully be treated without postoperative antibiotic therapy.

AIMS: We hypothesize that microbiology- and pathology-confirmed positive bone margins after the resection of diabetes-related foot osteomyelitis are associated with worse outcomes. METHODS: We conducted a prospective study consisting of a cohort of 93 patients with diabetes-related foot osteomyelitis (histopathology confirmed) who underwent bone resection and where an additional bone biopsy was taken at the resection margin. The primary outcome was the recurrence of the infection. RESULTS: Pathology-confirmed positive margins were detected in 62 cases (66.7%), microbiology-confirmed positive margins were detected in 75 cases (80.6%) and recurrence was detected in 19 patients (20.4%). Chi-squared test failed to show the presence of an association between the recurrence of the infection with pathology-confirmed positive margins (p = 0.82), with microbiology-confirmed positive margins, (p = 0.34) and with the use of postoperative antibiotics (p = 0.70). Healing in patients with pathology-confirmed positive margins was achieved in a median of 12 weeks (95% CI 9.2-18) and those with pathology-confirmed negative margins in 14.9 weeks (95% CI 10.2-21.9), Log-rank test, p = 0.74. Thirty-four patients out of 61 available for follow-up (55.7%) with pathology-confirmed positive margins were treated without postoperative antibiotics. In that group, Chi-squared test failed to show the presence of an association between the recurrence of the infection with the use of postoperative antibiotics (p = 0.47). CONCLUSIONS: A positive margin was neither associated with the recurrence of the infection nor with the time to healing. More than half of patients with pathology-confirmed positive margins were treated without postoperative antibiotics and this approach was not associated with the recurrence of the infection.

Estimated glomerular filtration rate based on creatinine, cystatin C, ß-trace protein and ß2 microglobulin in patients undergoing nontraumatic lower extremity amputation.

AIMS: The study's aim is to compare current and new equations for estimating glomerular filtration rate (GFR) based on creatinine, cystatin C, ß-trace protein (BTP) and ß2 microglobulin (B2M) among patients undergoing major amputation. METHODS: This is a secondary analysis of data from a prospective cohort study investigating patients undergoing nontraumatic lower extremity amputation. Estimated GFR (eGFR) was calculated using equations based on creatinine (eGFRcre[2009] and eGFRcre[2021]), cystatin C (eGFRcys), the combination of creatinine and cystatin C (eGFRcomb[2012] and eGFRcomb[2021]) or a panel of all 4 filtration markers (eGFRpanel). Primary outcome was changed in eGFR across amputation according to each equation. Two case studies of prior amputation with GFR measured by 99mTc-DTPA clearance are described to illustrate the relative accuracies of each eGFR equation. RESULTS: Analysis of the primary outcome included 29 patients (median age 75 years, 31% female). Amputation was associated with a significant decrease in creatinine concentration (-0.09 mg/dL, P = 0.004), corresponding to a significant increase in eGFRcre[2009] (+6.1 mL/min, P = 0.006) and eGFRcre[2021] (+6.3 mL/min, P = 0.006). Change across amputation was not significant for cystatin C, BTP, B2M or equations incorporating these markers (all P > 0.05). In both case studies, eGFRcre[2021] yielded the largest positive bias, eGFRcys yielded the largest negative bias and eGFRcomb[2012] and eGFRcomb[2021] yielded the smallest absolute bias. CONCLUSION: Creatinine-based estimates were substantially higher than cystatin C-based estimates before amputation and significantly increased across amputation. Estimates combining creatinine and cystatin were stable across amputation, while the addition of BTP and B2M is unlikely to be clinically relevant.

Analysis of Lower Extremity Amputations from the SerbVasc Registry.

BACKGROUND: Peripheral arterial disease (PAD) and diabetes are the major causes of lower extremity amputations (LEAs) worldwide. Morbidity and mortality in patients with LEAs are high with an associated significant burden on the global health system. The aim of this article is to report the overall morbidity and mortality rates after major and minor LEAs from the Serbian Vascular Registry (SerbVasc), with an analysis of predictive factors that influenced adverse outcomes. MATERIALS AND METHODS: SerbVasc was created in 2019 as a part of the Vascunet collaboration that is aiming to include all vascular procedures from 21 hospitals in Serbia. Prevalence of diabetes among patients with LEAs, previous revascularization procedures, the degree and the type of foot infection and tissue loss, and overall morbidity and mortality rates were analyzed, with a special reference to mortality predictors. RESULTS: In the period from January 2020 to December 2022, data on 702 patients with LEAs were extracted from the SerbVasc registry, mean age of 69.06±10.63 years. Major LEAs were performed in 59%, while minor LEAs in 41% of patients. Diabetes was seen in 65.1% of the patients, with 44% of them being on insulin therapy. Before LEA, only 20.3% of patients had previous peripheral revascularization. Soft tissue infection, irreversible acute ischemia, and Fontaine III and IV grade ischemia were the most common causes of above-the-knee amputations while diabetic foot was the most common cause of transphalangeal and toe amputations. The infection rate was 3.7%, the re-amputation rate was 5.7%, and the overall mortality rate was 6.9%, with intrahospital mortality in patients with above-the-knee amputation of 11.1%. The most significant intrahospital mortality predictors were age >65 years (p<0.001), chronic kidney disease (CKD) (p<0.001), ischemic heart disease (IHD) (p=0.001), previous myocardial revascularization (p=0.017), emergency type of admission (p<0.001), not using aspirin (p=0.041), using previous anticoagulation therapy (p=0.003), and postoperative complications (p<0.001). CONCLUSIONS: The main predictors of increased mortality after LEAs from the SerbVasc registry are age >65 years, CKD, IHD, previous myocardial revascularization, emergency type of admission, not using aspirin, using previous anticoagulation therapy, and postoperative complications. Taking into account high mortality rates after LEAs and a small proportion of previous peripheral revascularization, the work should be done on early diagnosis and timely treatment of PAD hopefully leading to decreased number of LEAs and overall mortality. CLINICAL IMPACT: Mortality after lower limb amputation from the SerbVasc register is high. A small number of previously revascularized patients is of particular clinical importance, bearing in mind that the main reasons for above-the-knee amputations were irreversible ischemia, Fontaine III and Fontaine IV grade ischemia. Lack of diagnostics procedures and late recognition of patients with PAD, led to subsequent threating limb ischemia and increased amputation rates. The work should be done on early diagnosis and timely treatment of PAD in Serbia, hopefully leading to an increased number of PAD procedures, decreased number of LEAs, and lower overall mortality.

Lower Extremity Amputation Rates in People With Diabetes Mellitus: A Retrospective Population Based Cohort Study in Zwolle Region, The Netherlands.

OBJECTIVE: Lower extremity amputations are a major complication of diabetes mellitus (DM). In a previous Dutch study, the incident rate of major amputations was 89.2 per 100 000 person years. The primary aim of this study was to describe the lower extremity amputation rates in people with DM in the Zwolle region, where preventive and curative footcare is organised according to the guidelines of the International Working Group of the Diabetic Foot (IWGDF). The secondary aim was to evaluate outcomes and underlying characteristics of these people. METHODS: This was a retrospective regional population based cohort study. Data from all people with DM treated in primary and secondary care, living in the region Zwolle were collected. All amputations in the period 2017 to 2019 were analysed. Comparisons were made between those with and without an amputation. RESULTS: In the analysis 5 915 people with DM were included, with a mean age of 67.8 (IQR 57.9, 75.9) years. Of those people, 47% were women and the median HbA1c was 53 (IQR 47, 62) mmol/mol. Over the three year study period 68 amputations were performed in 59 people: 46 minor, 22 major. This translated into an average annual crude amputation incidence rate of non-traumatic major and minor amputations of 41.5 and 86.9 per 100 000 person years among people with diabetes. Compared with those not undergoing amputations, those who underwent an amputation were more often men, older, mainly had T2DM, were treated in secondary care, had higher diastolic blood pressure, worse diabetic footcare profile, longer DM duration and higher HbA1c. At the end of the follow up, 111 people died: 96 (1.6%) without and 15 (25.4%) with amputations (p < .001). CONCLUSIONS: This retrospective study provides detailed insight into the rate of amputations in Dutch people with diabetes in the region Zwolle. Compared with previous Dutch estimates, these data suggest a considerable decrease in the major amputation incidence rate.

Differences in Prosthetic Prescription Between Men and Women Veterans After Transtibial or Transfemoral Lower-Extremity Amputation: A Longitudinal Cohort Study (2005-2018).

OBJECTIVE: To evaluate whether prosthetic prescription differed by gender and the extent to which differences were mediated by measured factors. DESIGN: Retrospective longitudinal cohort study using data from Veterans Health Administration (VHA) administrative databases. SETTING: VHA patients throughout the United States. PARTICIPANTS: The sample included 20,889 men and 324 women who had an incident transtibial or transfemoral amputation between 2005 and 2018. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Time to prosthetic prescription (up to 1 year). We used parametric survival analysis (an accelerated failure time model) to assess gender differences. We estimated mediation effects of amputation level, pain comorbidity burden, medical comorbidities, depression, and marital status on time to prescription. RESULTS: In the 1 year after amputation, the proportion of women (54.3%) and men (55.7%) prescribed a prosthesis was similar. However, after we controlled for age, race, ethnicity, enrollment priority, VHA region, and service-connected disability, the time to prosthetic prescription was significantly faster among men compared with women (acceleration factor=0.73; 95% confidence interval, 0.61-0.87). The difference in time to prosthetic prescription between men and women was significantly mediated by amputation level (23%), pain comorbidity burden (-14%), and marital status (5%) but not medical comorbidities or depression. CONCLUSIONS: Although the proportion of patients with prosthetic prescription at 1-year postamputation was similar between men and women, women received prosthetic prescriptions more slowly than men, suggesting that more work is needed to understand barriers to timely prosthetic prescriptions among women, and how to intervene to reduce those barriers.

The relationship between lower extremity amputation and body mass index.

OBJECTIVES: Non-traumatic lower extremity amputation (LEA) is associated with significant morbidity and mortality. Diabetes mellitus (DM) and peripheral vascular disease (PVD) are associated with increased risk for LEA. As such, DM and PVD account for 54% of all LEA's, performed in the United States annually. As obesity is highly associated with both DM and PVD, our study sought to explore the relationship between LEA and obesity defined by BMI. METHODS: Using the National Inpatient Sample (NIS) database, a retrospective review of patients who underwent non-traumatic LEA (LEA) between 2008 and 2014 was performed. The International Classification of Diseases 9th edition (ICD-9) codes were utilized to determine the diagnoses, comorbidities, and procedures. Patient BMIs were classified as follows: Non-obese [BMI <30], Obesity class I [BMI 30-34.9], Obesity class II [BMI 35-39.9], and Obesity class III [BMI ≥40]. Predictors for LEA were compared between groups using chi-square test and binary logistic regression to identify possible underlying factors associated with LEA. We also conducted a multivariate analysis to measure the effect of multiple variables on LEA. RESULTS: We identified 16,259 patients with non-traumatic LEA and a mean age of 59.9 years. Rate of amputation in females was lower than males at 0.35% vs 0.87% respectively (p < 0.001). Of patients that underwent amputation there was a V-shape trend based on BMI, with 30.4% in non-obese patients, 18.2% in obesity class I, 17.3% in obesity class II, and 34.1% in obesity class III. The incidence of diabetes increased with obesity class, while the incidence of PVD decreased. Interestingly, of those with DM there was an inverse relationship between amputation rate and BMI class, with LEA rates in non-obese versus obesity class III patients were 1.63% vs 0.98% respectively (p < 0.001). Similarly, patients who had both diabetes and PVD showed a downward trend in LEA rate as obesity class increased; non-obese patients had a LEA rate of 8.01%, while obesity class III had 4.65% (p < 0.001). Patients in higher income bracket have lower odds of LEA (OR 0.77, p < 0.001) compared to the lowest income patients. Also, patients with comorbidities such as PVD (OR 10.78), diabetes (OR 5.02), renal failure (OR 1.41), and hypertension (OR 1.36) had higher odds to get an LEA (p < 0.001). Individuals with obesity class III are almost at half the odds (OR 0.52) to get an LEA compared to non-obese (p < 0.001). CONCLUSIONS: Higher BMI and female gender are protective factors against lower extremity amputation. Factors that predisposing to LEA include lower household income and certain comorbidities such as PVD, diabetes, renal failure, and hypertension. These findings warrant further research to identify patients at high risk for LEA and help develop management guidelines for targeted populations.

Considerable gaps and differences in rehabilitation after major lower extremity amputations across regions and municipalities in Denmark - A national survey.

INTRODUCTION: Equal access to healthcare is a fundamental principle in the fully tax-financed Danish healthcare system. This study reveals whether this system lives up to the principle of equal access when it comes to the rehabilitation of patients who have major lower extremity amputations. METHODS: With the aim of exploring possible inequality in rehabilitation for patients having major lower extremity amputation in Denmark, a nationwide electronic survey was conducted in the autumn of 2020, which included all hospitals and municipalities in Denmark. RESULTS: Eighty six percent of hospitals (n = 19) and 97% (n = 95) of municipalities responded. Of the 32% (n = 6) of hospitals and 78% (n = 74) of municipalities that provided prosthesis rehabilitation, the majority (hospitals 50% /municipalities 91%) provided prostheses for <10 patients in 2019, and 36% reported having competencies at only a general level among physiotherapists performing prosthetic training. Psychosocial rehabilitation modalities were lacking overall. CONCLUSIONS: This national study documents pronounced geographic inequality in access to qualified rehabilitation services for the relatively few patients undergoing lower extremity amputations in Denmark. The decentralised organisation of amputation rehabilitation makes it difficult to build and maintain specialist competencies among healthcare professionals. Inconsistent availability of psychosocial rehabilitation modalities of all kinds found in this study points to a need for action particularly among patients not in prosthetic rehabilitation where palliative needs should also be considered.

Effect of diabetic foot ulcers and other risk factors on the prevalence of lower extremity amputation: A meta-analysis.

A meta-analysis study was conducted to measure the consequence of diabetic foot ulcers (DFUs) and other risk factors (RFs) on the prevalence of lower extremity amputation (LEA). A comprehensive literature inspection till February 2023 was applied and 2765 interrelated studies were reviewed. Of the 32 chosen studies enclosed, 9934 subjects were in the chosen studies' starting point, and 2906 of them were with LEA. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were used to compute the value of the effect of DFUs and other RFs on the prevalence of LEA by the continuous and dichotomous approaches and a fixed or random effect model. Male gender (OR, 1.30; 95% CI, 1.17-1.44, P < .001), smoking (OR, 1.24; 95% CI, 1.01-1.53, P = .04), previous foot ulcer (OR, 2.69; 95% CI, 1.93-3.74, P < .001), osteomyelitis (OR, 3.87; 95% CI, 2.28-6.57, P < .001), gangrene (OR, 14.45; 95% CI, 7.03-29.72, P < .001), hypertension (OR, 1.17; 95% CI, 1.03-1.33, P = .01), and white blood cells count (WBCC) (MD, 2.05; 95% CI, 1.37-2.74, P < .001) were significantly shown to be an RF in LEA in subjects with DFUs. Age (MD, 0.81; 95% CI, -0.75 to 2.37, P = .31), body mass index (MD, -0.55; 95% CI, -1.15 to 0.05, P = .07), diabetes mellitus type (OR, 0.99; 95% CI, 0.63-1.56, P = .96), and glycated haemoglobin (MD, 0.33; 95% CI, -0.15 to 0.81, P = .17) were not shown to be an RF in LEA in subjects with DFUs. Male gender, smoking, previous foot ulcer, osteomyelitis, gangrene, hypertension, and WBCC were significantly shown to be an RF in LEA in subjects with DFUs. However, age and diabetes mellitus type were not shown to be RF in LEA in subjects with DFUs. However, caused of the small sample sizes of several chosen studies for this meta-analysis, care must be exercised when dealing with its values.

Diabetic foot in primary and tertiary (DEFINITE) Care: A health services innovation in coordination of diabetic foot ulcer (DFU) Care within a healthcare cluster - 18-month results from an observational population health cohort study.

Diabetic Foot in Primary and Tertiary (DEFINITE) Care is an inter-institutional and multi-disciplinary team (MDT) health systems innovation programme at a healthcare cluster in Singapore. We aim to achieve coordinated MDT care across primary and tertiary care for patients with diabetic foot ulcers (DFU), within our public healthcare cluster - an integrated network of seven primary care polyclinics and two acute care tertiary hospitals (1700-bed and 800-bed) with a total catchment population of 2.2 million residents. Results from prospective DEFINITE Care is referenced against a retrospective 2013-2017 cohort, which was previously published. Cardiovascular profile of the study population is compared against the same population's profile in the preceding 12 months. Between June 2020 and December 2021, there were 3475 unique patients with DFU with mean age at 65.9 years, 61.2% male, mean baseline HbA1c at 8.3% with mean diabetes duration at 13.3 years, mean diabetes complication severity index (DCSI) at 5.6 and mean Charlson Comorbidity Index (CCI) at 6.8. In the 12-months preceding enrolment to DEFINITE Care, 35.5% had surgical foot debridement, 21.2% had minor lower extremity amputation (LEA), 7.5% had major LEA whilst 16.8% had revascularisation procedures. At 18-months after the implementation of DEFINITE Care programme, the absolute minor and major amputation rates were 8.7% (n = 302) and 5.1% (n = 176), respectively, equating to a minor and major LEA per 100000 population at 13.7 and 8.0, respectively. This represents an 80% reduction in minor amputation rates (P < .001) and a 35% reduction in major amputation rates (P = .005) when referenced against a retrospective 2013-2017 cohort, which had minor and major LEA per 100000 population at 68.9 and 12.4, respectively. As compared to the preceding 12 months, there was also a significant improvement in cardiovascular profile (glycemic and lipid control) within the DEFINITE population, with improved mean HbAc1 (7.9% from 8.4%, P < .001), low-density lipoprotein (LDL) levels (2.1 mmol/L from 2.2, P < .001), total cholesterol (3.9 mmol/L from 4.1, P < .001) and triglycerides levels (1.6 mmol/L from 1.8, P = .002). Multivariate analysis revealed a history of minor amputation in the preceding 12 months to be an independent predictor for major and minor amputation within the study period of 18 months (Hazard Ratio 3.4 and 1.8, respectively, P < .001). In conclusion, within DEFINITE care, 18-month data showed a significant reduction of minor and major LEA rates, with improved medical optimisation and cardiovascular profile within the study population.

Risk factor analysis for diabetic foot ulcer-related amputation including Controlling Nutritional Status score and neutrophil-to-lymphocyte ratio.

Diabetic foot ulcer often leads to amputation, and both nutritional status and immune function have been associated with this process. We aimed to investigate the risk factors of diabetic ulcer-related amputation including the Controlling Nutritional Status score and neutrophil-to-lymphocyte ratio biomarker. We evaluated data from hospital in patients with diabetic foot ulcer, performing univariate and multivariate analyses to screen for high-risk factors and Kaplan-Meier analysis to correlate high-risk factors with amputation-free survival. Overall, 389 patients underwent 247 amputations over the follow-up period. After correction to relevant variables, we identified five independent risk factors for diabetic ulcer-related amputation: ulcer severity, ulcer site, peripheral arterial disease, neutrophil-to-lymphocyte ratio and nutritional status. Amputation-free survival was lower for the moderate-to-severe versus mild cases, for the plantar forefoot versus hindfoot location, for the concomitant peripheral artery disease versus without and in the high versus low neutrophil-to-lymphocyte ratio (all p < 0.01). The results showed that ulcer severity (p < 0.01), ulcer site (p < 0.01), peripheral artery disease (p < 0.01), neutrophil-to-lymphocyte ratio (p < 0.01) and Controlling Nutritional Status score (p < 0.05) were independent risk factors for amputation in diabetic foot ulcer patients and have predictive values for diabetic foot ulcer progression to amputation.

Demographics and Etiology for Lower Extremity Amputations-Experiences of an University Orthopaedic Center in Germany.

Background and Objectives: Currently, the worldwide incidence of major amputations in the general population is decreasing whereas the incidence of minor amputations is increasing. The purpose of our study was to analyze whether this trend is reflected among orthopaedic patients treated with lower extremity amputation in our orthopaedic university institution. Materials and Methods: We conducted a single-center retrospective study and included patients referred to our orthopaedic department for lower extremity amputation (LEA) between January 2007 and December 2019. Acquired data were the year of amputation, age, sex, level of amputation and cause of amputation. T test and Chi² test were performed to compare age and amputation rates between males and females; significance was defined as p < 0.05. Linear regression and multivariate logistic regression models were used to test time trends and to calculate probabilities for LEA. Results: A total of 114 amputations of the lower extremity were performed, of which 60.5% were major amputations. The number of major amputations increased over time with a rate of 0.6 amputation/year. Men were significantly more often affected by LEA than women. Age of LEA for men was significantly below the age of LEA for women (men: 54.8 ± 2.8 years, women: 64.9 ± 3.2 years, p = 0.021). Main causes leading to LEA were tumors (28.9%) and implant-associated complications (25.4%). Implant-associated complications and age raised the probability for major amputation, whereas malformation, angiopathies and infections were more likely to cause a minor amputation. Conclusions: Among patients in our orthopaedic institution, etiology of amputations of the lower extremity is multifactorial and differs from other surgical specialties. The number of major amputations has increased continuously over the past years. Age and sex, as well as diagnosis, influence the type and level of amputation.

Risk factors for reamputation in patients with diabetic foot: A case-control study.

BACKGROUND: Reamputation as a complication of diabetic foot ulcers presents a high economic burden and represents a therapeutic failure. It is paramount to identify as early as possible patients in whom a minor amputation may not be the best option. The purpose of this investigation was to do a case-controlled study to determine risk factors associated with re-amputation in patients with DFU (diabetic foot ulcers) at two University Hospitals. METHODS: Multicentric, observational, retrospective, case-control study from clinical records of 2 university hospitals. Our study included 420 patients, with 171 cases (re-amputations), and 249 controls. We performed a multivariate logistic regression analysis and time-to-event survival analysis to identify re-amputation risk factors. RESULTS: Statistically significant risk factors were artery history of tobacco use (p = 0.001); male sex (p = 0.048); arterial occlusion in Doppler ultrasound (p = 0.001); percentage of stenosis in arterial ultrasound >50 % (p = 0.053); requirement of vascular intervention (p = 0.01); and microvascular involvement in photoplethysmography (p = 0.033). The most parsimonious regression model suggests that history of tobacco use, male sex, arterial occlusion in ultrasound, and percentage of stenosis in arterial ultrasound >50 % remained statistically significant. The survival analysis identified earlier amputations in patients with larger occlusion in arterial ultrasound, high leukocyte count, and elevated ESR. CONCLUSION: Direct and surrogate outcomes in patients with diabetic foot ulcers identify vascular involvement as an important risk factor for reamputation. LEVEL OF EVIDENCE: III.

Epidemiology and Outcome of Nontraumatic Lower Limb Amputations.

Background: In order to create a solid evidence base for the development of improved management methods, this study was performed to describe the epidemiology and outcome of nontraumatic lower limb amputations (LLAs). Methods: This descriptive case series was conducted over a period of 4 years. It included all patients of both sexes and all ages who underwent LLAs for nontraumatic indications. Results: There were a total of 217 patients with 136 (62.67%) men and 81(37.32%) women. The age range was 7 to 71 years, with a mean of 54.25 ± 11.49 years. The most common indication for amputation (41.47%) was diabetic foot gangrene. The most common level of amputation (48.29%) was below knee amputation. Conclusion: Patients with diabetic foot gangrene, malignant tumors, and chronic neuropathic ulcers with osteomyelitis constituted the bulk of the amputees. Diabetes mellitus, obesity, and hypertension were the commonest comorbidities identified among them. Public awareness and education would ensure prompt and early health seeking at the appropriate time and help to prevent the need for major amputations in many instances. The amputees' improved reintegration into society and ability to become contributing members of society would be ensured by the provision of vigorous rehabilitation.

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

OBJECTIVE: 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 1 year. We tested a novel wound imaging system to predict amputation wound healing at initial evaluation. METHODS: 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. RESULTS: 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 30 days. The machine learning algorithm had 91% sensitivity and 86% specificity for prediction of non-healing amputation sites (area under curve, 0.89). CONCLUSIONS: 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.

Factors influencing lower extremity amputation outcomes in people with active foot ulceration in regional Australia: A retrospective cohort study.

Australia has the second highest rate of non-traumatic lower extremity amputation (LEA) globally. Australia's large geographical size is one of the biggest challenges facing limb preservation services and may be contributing to LEA. The aim of this study was to determine what factors contribute to the likelihood of LEA in people with active foot ulceration in regional Australia. This retrospective cohort study audited patients with active foot ulceration in a multidisciplinary high risk foot service (HRFS) in regional Australia. Neurological, vascular and wound characteristics were systematically extracted, along with demographic information. Participants were followed for at least 12 months until healing or LEA occurred. Correlations between LEA and clinical and demographic characteristics were assessed using the Pearson's product moment correlation coefficient and chi squared test for independence. Significant variables (p < 0.05) were included in the model. Direct logistic regression assessed the independent contribution of significantly correlated variables on the likelihood of LEA. Of note, 1876 records were hand screened with 476 participants (25%) meeting the inclusion criteria. Geographical distance from the HRFS, toe systolic pressure (TSP), diabetes and infection were all significantly correlated with LEA and included in the logistic regression model. TSP decrease of 1 mmHg (OR 1.02, 95% CI 1.01-1.03), increased geographical distance (1 km) from HRFS (OR 1.006, 95% CI 1.001-1.01) infection (OR 2.08, 95% CI 1.06-4.07) and presence of diabetes (OR 3.77, 95% CI 1.12-12.65) were all significantly associated with increased likelihood of LEA. HRFS should account for the disparity in outcomes between patients living in close proximity to their service, compared to those in rural areas. Optimal management of diabetes, vascular perfusion and control of infection may also contribute to preventing LEA in people with active foot ulceration.

National Rates of Lower Extremity Amputation in People With and Without Diabetes in a Multi-Ethnic Asian Population: a Ten Year Study in Singapore.

OBJECTIVE: Population level data from Asia on amputation rates in people with and without diabetes are extremely limited. Hence it is unclear how the rising diabetes prevalence in Asia has affected the amputation burden. The present study examined national amputation rates in people with and without diabetes in Singapore from 2008 to 2017 in the context of increasing diabetes prevalence and health system changes. METHODS: This was a retrospective observational study using national population data for ages 16 - 100 years obtained from the Ministry of Health Singapore administrative datasets. Age sex standardised major and toe/ray amputation rates per 100 000 people with diabetes and per 100 000 people without diabetes were calculated. Rates were calculated overall and in each ethnic group (Chinese, Malay, Indian, Others), with trends over time calculated using joinpoint trend analysis. In addition, age specific rates, relative risk (RR) of amputation in diabetics compared with non-diabetics and proportion of amputations in the population attributable to diabetes were also calculated. RESULTS: Between 2008 and 2017, the database included 3.6 million unique individuals, of whom 75% were Chinese, 8.6% Malay, 7.9% Indian, and 8.4% Others. Of those, 413 486 (11%) had diabetes. Major amputation rates in people with diabetes remained stable (2008: 99.5/100 000; 2017: 95.0/100 000 people with diabetes, p = .91) as did toe/ray amputation rates. Rates in people without diabetes were substantially lower, with major amputation rates decreasing significantly (2008: 3.0/100 000; 2017: 2.1/100 000 people without diabetes, 3% annual reduction, p = .048). Diabetes related amputation rates were highest in Malays and lowest in Chinese. Diabetes related major amputation rates declined significantly among Chinese (3.1% annual reduction, p < .038). While the RR for amputations in diabetes remained stable, the proportion of major amputations attributable to diabetes increased from 63.6% in 2008 to 81.7% in 2017 (3% annual increase, p = .003). CONCLUSION: Diabetes related major and toe/ray amputation rates have remained stable but relatively high in Singapore compared with other countries, and the proportion of amputations attributable to diabetes has increased over time. More research is needed to understand the aetiopathological, sociocultural, and health system factors that may underlie the continued high rates of diabetes related amputations in this population.