Lower Limb Amputation Rates in Germany

Background and Objectives: The current epidemiology of lower limb amputations is unknown. Therefore, the purpose of this study was to determine (1) lower extremity amputation rates as a function of age, gender, and amputation level between 2015 and 2019, (2) main diagnoses indicating amputation, (3) revision rates after lower extremity amputation. Materials and Methods: Lower extremity amputation rates were quantified based on annual Operation and Procedure Classification System (OPS) and International Classifications of Disease (ICD)-10 codes from all German medical institutions between 2015 through 2019, provided by the Federal Statistical Office of Germany (Destatis). Results: In 2019, 62,016 performed amputations were registered in Germany. Out of these 16,452 procedures (26.5%) were major amputations and 45,564 patients (73.5%) underwent minor amputations. Compared to 2015, the incidence of major amputations decreased by 7.3% to 24.2/100,000 inhabitants, whereas the incidence of minor amputation increased by 11.8% to 67.1/100,000 inhabitants. Highest incidence was found for male patients aged 80–89 years. Patients were mainly diagnosed with peripheral arterial disease (50.7% for major and 35.7% for minor amputations) and diabetes mellitus (18.5% for major and 44.2% for minor amputations). Conclusions: Lower limb amputations remain a serious problem. Further efforts in terms of multidisciplinary team approaches and patient optimization strategies are required to reduce lower limb amputation rates.

Human Activity Recognition of Individuals with Lower Limb Amputation in Free-Living Conditions: A Pilot Study

This pilot study aimed to investigate the implementation of supervised classifiers and a neural network for the recognition of activities carried out by Individuals with Lower Limb Amputation (ILLAs), as well as individuals without gait impairment, in free living conditions. Eight individuals with no gait impairments and four ILLAs wore a thigh-based accelerometer and walked on an improvised route in the vicinity of their homes across a variety of terrains. Various machine learning classifiers were trained and tested for recognition of walking activities. Additional investigations were made regarding the detail of the activity label versus classifier accuracy and whether the classifiers were capable of being trained exclusively on non-impaired individuals’ data and could recognize physical activities carried out by ILLAs. At a basic level of label detail, Support Vector Machines (SVM) and Long-Short Term Memory (LSTM) networks were able to acquire 77–78% mean classification accuracy, which fell with increased label detail. Classifiers trained on individuals without gait impairment could not recognize activities carried out by ILLAs. This investigation presents the groundwork for a HAR system capable of recognizing a variety of walking activities, both for individuals with no gait impairments and ILLAs.

Association Between the ACE Insertion/Deletion Polymorphism and Risk of Lower-Limb Amputation in Patients With Long-Standing Type 1 Diabetes

<b>OBJECTIVE. </b>The <i>ACE</i> insertion/deletion (I/D) polymorphism has been widely studied in people with diabetes, albeit not regarding lower-limb amputation (LLA). We examined associations between this polymorphism, plasma ACE concentration and LLA in people with type 1 diabetes. <b></b> <p><b>RESEARCH DESIGN AND METHODS. </b><i>ACE </i>I/D genotype and plasma ACE were assessed in three prospective cohorts of participants with type 1 diabetes. LLA was defined as minor (below the ankle amputation consisting of at least 1-ray metatarsal resection) or major (transtibial or transfemoral) amputation. Linear, logistic and Cox regression models were computed to evaluate the likelihood of prevalent and incident LLA by <i>ACE</i> genotype (XD [ID or ID] versus II) and plasma ACE, after adjusting for confounders.<b></b></p> <p><b>RESULTS. </b>Among 1301 participants (male 54%, age 41±13 years), 90 (6.9%) participants had a baseline history of LLA. Baseline LLA was more prevalent in XD (7.4%) than in II genotype (4.5%): OR 2.17 (95%CI, 1.03–4.60). Incident LLA occurred in 53 individuals during 14-year follow-up. It was higher in XD <i>versus</i> II carriers: HR 3.26 (1.16–13.67). This association was driven by excess risk of minor, but not major, LLA. The D-allele was associated with increased prevalent LLA at the end of follow-up (OR 2.48 [1.33–4.65]). LLA was associated with higher ACE levels in II (449 [360–539] versus 354 [286–423] ng/ml), but not in XD carriers (512 [454–570] versus 537 [488–586]).</p> <p><b>CONCLUSIONS</b>. This is the first report of an independent association between <i>ACE</i> D-allele and excess LLA risk, mainly minor amputations, in patients with type 1 diabetes.</p>

Association Between the ACE Insertion/Deletion Polymorphism and Risk of Lower-Limb Amputation in Patients With Long-Standing Type 1 Diabetes

<b>OBJECTIVE. </b>The <i>ACE</i> insertion/deletion (I/D) polymorphism has been widely studied in people with diabetes, albeit not regarding lower-limb amputation (LLA). We examined associations between this polymorphism, plasma ACE concentration and LLA in people with type 1 diabetes. <b></b> <p><b>RESEARCH DESIGN AND METHODS. </b><i>ACE </i>I/D genotype and plasma ACE were assessed in three prospective cohorts of participants with type 1 diabetes. LLA was defined as minor (below the ankle amputation consisting of at least 1-ray metatarsal resection) or major (transtibial or transfemoral) amputation. Linear, logistic and Cox regression models were computed to evaluate the likelihood of prevalent and incident LLA by <i>ACE</i> genotype (XD [ID or ID] versus II) and plasma ACE, after adjusting for confounders.<b></b></p> <p><b>RESULTS. </b>Among 1301 participants (male 54%, age 41±13 years), 90 (6.9%) participants had a baseline history of LLA. Baseline LLA was more prevalent in XD (7.4%) than in II genotype (4.5%): OR 2.17 (95%CI, 1.03–4.60). Incident LLA occurred in 53 individuals during 14-year follow-up. It was higher in XD <i>versus</i> II carriers: HR 3.26 (1.16–13.67). This association was driven by excess risk of minor, but not major, LLA. The D-allele was associated with increased prevalent LLA at the end of follow-up (OR 2.48 [1.33–4.65]). LLA was associated with higher ACE levels in II (449 [360–539] versus 354 [286–423] ng/ml), but not in XD carriers (512 [454–570] versus 537 [488–586]).</p> <p><b>CONCLUSIONS</b>. This is the first report of an independent association between <i>ACE</i> D-allele and excess LLA risk, mainly minor amputations, in patients with type 1 diabetes.</p>