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Background and Objectives: Medical registries evolved from a basic epidemiological data set to further applications allowing deriving decision making. Revision rates after non-traumatic amputation are high and dramatically impact the following rehabilitation of the amputee. Risk scores for revision surgery after non-traumatic lower limb amputation are still missing. The main objective was to create an amputation registry allowing us to determine risk factors for revision surgery after non-traumatic lower-limb amputation and to develop a score for an early detection and decision-making tool for the therapeutic course of patients at risk for non-traumatic lower limb amputation and/or revision surgery. Materials and Methods : Retrospective data analysis was of patients with major amputations lower limbs in a four-year interval at a University Hospital of maximum care. Medical records of 164 patients analysed demographics, comorbidities, and amputation-related factors. Descriptive statistics analysed demographics, prevalence of amputation level and comorbidities of non-traumatic lower limb amputees with and without revision surgery. Correlation analysis identified parameters determining revision surgery. Results: In 4 years, 199 major amputations were performed; 88% were amputated for non-traumatic reasons. A total of 27% of the non-traumatic cohort needed revision surgery. Peripheral vascular disease (PVD) (72%), atherosclerosis (69%), diabetes (42%), arterial hypertension (38%), overweight (BMI > 25), initial gangrene (47%), sepsis (19%), age > 68.2 years and nicotine abuse (17%) were set as relevant within this study and given a non-traumatic amputation score. Correlation analysis revealed delayed wound healing (confidence interval: 64.1% (47.18%; 78.8%)), a hospital length of stay before amputation of longer than 32 days (confidence interval: 32.3 (23.2; 41.3)), and a BKA amputation level (confidence interval: 74.4% (58%; 87%)) as risk factors for revision surgery after non-traumatic amputation. A combined score including all parameters was drafted to identify non-traumatic amputees at risk for revision surgery. Conclusions : Our results describe novel scoring systems for risk assessment for non-traumatic amputations and for revision surgery at non-traumatic amputations. It may be used after further prospective evaluation as an early-warning system for amputated limbs at risk of revision.

Background: It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements., Research Question: How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane?, Methods: Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed., Results: In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC., Significance: The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: Microprocessor-controlled knees are generally prescribed and reimbursed for active amputees. Recent studies suggested that this technology could be useful for amputees with moderate activity level. We compared the efficiency of a microprocessor-controlled knee (MPK, Kenevo, Otto Bock) and non-MPKs (NMPKs) in these indications., Methods: A multi-centric randomized crossover trial was conducted in 16 hospitals from 3 European countries. Participants were randomized to an MPK-NMPK sequence, testing the MPK for 3 months and the NMPK for 1 month, or to an NMPK-MPK sequence, testing the NMPK for 1 month and the MPK for 3 months. Dynamic balance, the main criteria, was assessed with the Timed-Up and Go test (TUG), functional mobility with the Locomotor Capability Index (LCI-5), quality of life with the Medical Outcomes Study Short Form 36 v2 (SF-36v2) and satisfaction with the Quebec User Evaluation of Satisfaction with Assistive Technology 2.0. The occurrence of falls was monitored during the last month of trial. Analysis was by intent-to-treat and per-protocol (PP)., Results: We recruited 35 individuals with transfemoral amputation or knee disarticulation (27 males; mean age 65.6years [SD 10.1]). On PP analysis, dynamic balance and functional mobility were improved with the MPK, as shown by a reduced median TUG time (from 21.4s [Q1-Q3 19.3-26.6] to 17.9s [15.4-22.7], P=0.001) and higher mean global LCI-5 (from 40.4 [SD 7.6] to 42.8 [6.2], P=0.02). Median global satisfaction score increased (from 3.9 [Q1-Q3 3.8-4.4] to 4.7 [4.1-4.9], P=0.001) and quality of life was improved for the mental component summary of the SF-36v2 (median score from 53.3 [Q1-Q3 47.8-60.7] to 60.2 [51.6-62.6], P=0.03) and physical component summary but not significantly (mean score from 44.1 [SD 6.3] to 46.3 [7.0], P=0.08). Monitoring of adverse events including falls revealed no differences between both assessed devices., Conclusion: This study enhances the level of evidence to argue equal opportunity for all individuals with transfemoral amputation or knee disarticulation, regardless of their mobility grade, to be provided with appropriate prostheses., (Copyright © 2018 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

The fixed neutral position of conventional prosthetic feet causes difficulties for transtibial amputees (TTAs) when walking on ramps. New microprocessor-controlled prosthetic ankles such as the Proprio-Foot (Ossur) aim to reduce these difficulties by modifying the prosthetic ankle angle according to the gait condition. The purpose of the present investigation was to assess the biomechanical effects of adaptation of the prosthetic ankle on ramp ambulation in TTAs. Sixteen TTAs and 16 controls underwent a conventional 3D gait analysis while walking up and down a ramp. TTAs walked with the prosthetic foot set to a neutral mode angle and set to the adapted mode. Norm distance, sagittal kinematics and kinetics were calculated for comparisons between TTAs and controls. During ramp ascent, the dorsiflexion brought about by the adapted prosthetic ankle reduced the increased knee extension noted on the TTAs' involved side and the increased plantarflexion on their sound side. During ramp descent, the plantarflexion of the adapted mode increased the adaptation mechanisms observed in TTAs. These findings suggest that the adapted mode leads to more physiologic kinematics and kinetics in the lower limbs in TTAs during ramp ascent but not during ramp descent. However, in the adapted mode, patients reported feeling safer during ramp descent, thus indicating that there might be other safety related measures such as toe-clearance or coefficient of friction influencing this perception., (Copyright 2010 Elsevier B.V. All rights reserved.)

Conventional prosthetic feet cannot adapt to specific conditions such as walking on stairs or ramps. Amputees are therefore forced to compensate their prosthetic deficits by modifying the kinematics and kinetics of their lower limbs. The Proprio-Foot (Ossur) intends to reduce these compensation mechanisms by automatically increasing dorsiflexion during stair ambulation thanks to an adaptive microprocessor-controlled ankle. The present investigation proposes to analyze the biomechanical effects of the dorsiflexion adaptation in transtibial (TT) amputees during stair ambulation. Sixteen TT amputees and sixteen healthy controls underwent conventional 3D gait analysis. Kinematics and kinetics of the lower limbs were compared during stair ascent and descent performed by patients with the prosthetic foot set to a neutral ankle angle and with an adapted dorsiflexion ankle angle of 4 degrees . Norm distance as well as minimum and maximal values of sagittal kinematics and kinetics were calculated for comparisons between patients and control subjects. For both stair ascent and descent, an improvement of the knee kinematics and kinetics could particularly be noticed on the involved side with an increase of the knee flexion and an increase of the knee moment during stance. Therefore, despite its additional weight compared to a conventional prosthetic ankle, the Proprio-Foot should be beneficial to active TT amputees whose knee musculature strength does not constitute a handicap.

Abstract: Background: The technological advances that have been made in developing highly functional prostheses are promising for very active patients but we do not yet know whether they cause an increase in biomechanical load along with possibly negative consequences for pressure conditions in the socket. Therefore, this study monitored the socket pressure at specific locations of the stump when using a microprocessor-controlled adaptive prosthetic ankle under different walking conditions. Methods: Twelve unilateral transtibial amputees between 43 and 59years of age were provided with the Proprio-Foot™ (Össur) and underwent an instrumented 3D gait analysis in level, stair, and incline walking, including synchronous data capturing of socket pressure. Peak pressures and pressure time integrals (PTI) at three different locations were compared for five walking conditions with and without using the device’s ankle adaptation mode. Findings: Highest peak pressures of 2.4kPa/kg were found for incline ascent at the calf muscle as compared to 2.1kPa/kg in level walking with large inter-individual variance. In stair ascent a strong correlation was found between maximum knee moment and socket pressure. The most significant pressure changes relative to level walking were seen in ramp descent anteriorly towards the stump end, with PTI values being almost twice as high as those in level walking. Adapting the angle of the prosthesis on stairs and ramps modified the pressure data such that they were closer to those in level walking. Interpretation: Pressure at the stump depends on the knee moments involved in each walking condition. Adapting the prosthetic ankle angle is a valuable means of modifying joint kinetics and thereby the pressure distribution at the stump. However, large inter-individual differences in local pressures underline the importance of individual socket fitting. [Copyright &y& Elsevier]