Search

Prosthetic manufacturers have marketed shock-absorbing pylons (SAPs) for attenuation of injurious loads from foot-ground contact. In this study, we compared a commonly prescribed SAP with a conventional rigid pylon, using a within-subject design (n = 15 unilateral transtibial amputees), to assess effect on gait mechanics, measure transmitted accelerations in situ, and determine functional outcomes using step counts and questionnaires. No differences were found across pylons for self-selected walking speed, prosthetic-side step length, prosthetic-side loading rate and decelerative peak of the vertical ground reaction force, peak pylon acceleration, step count per week, or questionnaire results that examined pylon performance and subjects' pain and fatigue levels. The only statistically significant finding was for the prosthetic-side knee angle at initial contact, where subjects displayed an average of 2.6 degrees more flexion with the rigid pylon than the SAP while walking at a controlled speed (p = 0.004); this result indicates that transtibial amputees are able to modulate the effective stiffness of their residual limb in response to changes in prosthetic component stiffness. The results from the laboratory, field, and subjective outcome measurements suggest that the SAP in this study is as effective as a rigid pylon for unilateral transtibial amputees. [ABSTRACT FROM AUTHOR]

Amputees lack movement and control mechanisms at the foot and ankle that result in different strategies for locomotion than nonamputees. The torsion adapter is a prosthetic device designed to minimize shear stress at the residual limb by facilitating rotation in the transverse plane. This study determined if the addition of a torsion adapter alters lower-limb joint rotation moments of transtibial amputees walking in a straight line and turning. Ten transtibial amputees wore either a torsion adapter or a rigid adapter for an acclimation period of 3 weeks in random order. Ten nonamputees were also included for comparison. Kinetics were collected as participants walked in a straight line and around a 1 m-radius circular path at their self-selected turning walking speed. When amputee participants wore the torsion adapter, they demonstrated decreased prosthetic-limb peak internal rotation moments at the inside limb knee and hip compared with when they wore the rigid adapter, which may facilitate changes in orientation by not actively resisting the turn. Nonamputees exhibited larger moments compared with the prosthetic limb for both the amputee participants wearing either the torsion or rigid adapters. No differences were found in the moments for the intact limb between torsion and rigid adapter conditions during turning and for both limbs during straight-line walking. [ABSTRACT FROM AUTHOR]

Prosthetic devices that can store and return energy during gait enhance the mobility and functionality of lower-limb amputees. The process of selecting and fitting such devices is complicated, partly because of confusing literature on the topic. Gait analysis methods for measuring energy characteristics are often incomplete, leading to inconsistencies in the energy classifications of different products. These inconsistencies are part of the reason for the lack of universally accurate terminology in the field. Inaccurate terminology perpetuates misunderstanding. In this paper, important prosthetic energy concepts and methods for measuring energy characteristics are reviewed. Then a technically accurate nomenclature and a method of functional classification are proposed. This review and proposed classification scheme should help to alleviate confusion and should facilitate enhancement of the design, selection, and fitting of prosthetic limbs for amputee patients. [ABSTRACT FROM AUTHOR]

Ninety-two (92) persons with lower-limb amputations who regularly used prostheses responded to a survey that included questions about preferred recreational activities. This article describes the variety of activities selected by these men and women aged 20 to 87 years. Of the activities that were of high importance, 74% to 88% could be performed. Those activities assigned moderate to low importance were less often reported as able to be performed. The activities that require high energy level were more problematic for performance. The diversity of identified activities (n= 166) underscores the value of learning about amputees' activity preferences when making prosthetic prescription decisions. [ABSTRACT FROM AUTHOR]

The condition in which ankle dorsiflexion is restricted is known as equinus contracture (EC). Equinus contracture is purported to be associated with a number of clinical conditions. However, there are no data to support or refute a clinician's ability to diagnose EC by clinical exam. We prospectively evaluated the maximum ankle dorsiflexion with the knee fully extended in 68 people (34 patients with isolated fore- or midfoot pain and 34 asymptomatic subjects) both by clinical exam and by a custom-designed ankle goniometer. We compared the likelihood of agreement of the clinical impression (equinus, no equinus) to the maximum ankle dorsiflexion measured with the instrument at two different numerical definitions of EC (< or =5 degrees and < or =10 degrees of maximum dorsiflexion). When all subjects were included and equinus defined as < or =5 degrees of ankle dorsiflexion, a clinician's ability to detect the equinus when it is truly present is 77.8%. If equinus is defined as < or =10 degrees, this ability increases to 97.2%. Alternatively, if equinus is not present, as defined by < or =5 degrees, then a clinician's ability to correctly diagnose no equinus is 93.8%. If equinus is defined to < or =10 degrees, this ability decreases to 68.8%. [ABSTRACT FROM AUTHOR]

Lower-limb amputees have identified comfort and mobility as the two most important characteristics of a prosthesis. While these in turn depend on a multitude of factors, they are strongly influenced by the biomechanical performance of the prosthesis and the loading it imparts to the residual limb. Recent years have seen improvements in several prosthetic components that are designed to improve patient comfort and mobility. In this paper, we discuss two of these: VSAP and prosthetic foot-ankle systems; specifically, their mechanical properties and impact on amputee gait are presented. [ABSTRACT FROM AUTHOR]

The C-Leg(R) (Otto Bock, Duderstadt, Germany) is a microprocessor-controlled prosthetic knee that may enhance amputee gait. This intrasubject randomized study compared the gait biomechanics of transfemoral amputees wearing the C-Leg with those wearing a common noncomputerized prosthesis, the Mauch SNS (Ossur, Reykjavik, Iceland). After subjects had a 3-month acclimation period with each prosthetic knee, typical gait biomechanical data were collected in a gait laboratory. At a controlled walking speed (CWS), peak swing phase knee-flexion angle decreased for the C-Leg group compared with the Mauch SNS group (55.2 degrees +/- 6.5 degrees vs 64.41 degrees +/- 5.8 degrees, respectively; p = 0.005); the C-Leg group was similar to control subjects' peak swing knee-flexion angle (56.0 degrees +/- 3.4 degrees). Stance knee-flexion moment increased for the C-Leg group compared with the Mauch SNS group (0.142 +/- 0.05 vs 0.067 +/- 0.07 N* m, respectively; p = 0.01), but remained significantly reduced compared with control subjects (0.477 +/- 0.1 N* m). Prosthetic limb step length at CWS was less for the C-Leg group compared with the Mauch SNS group (0.66 +/- 0.04 vs 0.70 +/- 0.06 m, respectively; p = 0.005), which resulted in increased symmetry between limbs for the C-Leg group. Subjects also walked faster with the C-Leg versus the Mauch SNS (1.30 +/- 0.1 vs 1.21 +/- 0.1 m/s, respectively; p = 0.004). The C-Leg prosthetic limb vertical ground reaction force decreased compared with the Mauch SNS (96.3 +/- 4.7 vs 100.3 +/- 7.5% body weight, respectively; p = 0.0092). [ABSTRACT FROM AUTHOR]

Microprocessor-controlled prosthetic knees are claimed to improve gait efficiency in transfemoral (TF) amputees.This hypothesis was tested in a prospective randomized crossover trial that compared the Mauch SNS knee and the C-Leg microprocessor-controlled knee in eight TF amputees. The subjects were given a 3-month acclimation period in each knee. Then, their net oxygen cost (mL/kg/m) was measured while they walked over ground at four speeds in random order: 0.8 m/s, 1.0 m/s, 1.3 m/s, and self-selected walking speed (SSWS). The C-Leg caused small reductions in net oxygen cost that were not statistically significant compared with the Mauch SNS at any of the walking speeds (p > 0.190). Subjects chose higher SSWSs with the C-Leg compared with the Mauch SNS (mean +/- standard deviation =1.31 +/- 0.12 m/s vs 1.21 +/- 0.10 m/s, respectively, p = 0.046) but did not incur higher oxygen costs (p = 0.270), which suggests greater efficiency only at their SSWS. [ABSTRACT FROM AUTHOR]

Twenty-four adults with phantom limb pain (PLP) and/or residual limb pain (RLP) participated in a double-blind crossover trial. Participants were randomly assigned to receive gabapentin or placebo and later crossed over to the other treatment, with a 5-week washout interval in which they did not receive medication. Gabapentin was titrated from 300 mg to the maximum dose of 3,600 mg. Measures of pain intensity, pain interference, depression, life satisfaction, and functioning were collected throughout the study. Analyses revealed no significant group differences in pre- to posttreatment change scores on any of the outcome measures. More than half of the participants reported a meaningful decrease in pain during the gabapentin phase compared with about one-fifth who reported a meaningful decrease in pain during the placebo phase. In this trial, gabapentin did not substantially affect pain. More research on the efficacy of gabapentin to treat chronic PLP and RLP is needed. [ABSTRACT FROM AUTHOR]

Postamputation management is an important determinant of recovery from amputation. However, consensus on the most effective postoperative management strategies for individuals undergoing transtibial amputation (TTA) is lacking. Dressings can include simple soft gauze dressings, thigh-high rigid cast dressings, shorter removable rigid dressings, and prefabricated pneumatic dressings. Postoperative prosthetic attachments can be added to all but simple soft dressings. These dressings address the need to cleanly cover a fresh surgical wound, but not all postoperative dressings are designed to facilitate the strategic goals of preventing knee contractures, reducing edema, protecting from external trauma, or facilitating early weight bearing. The type of dressing and management strategy often overlap and are certainly interrelated. Current protocols and decisions are based on local practice, skill, and intuition. The current available literature is challenging, and difficulties include variations in healing potential, in comorbidity, in surgical-level selection, in techniques and skill, in experience with postoperative strategies, and with poorly defined outcome criteria. This paper reviews the published literature and compares measures of safety, efficacy, and clinical outcomes of the various techniques. Analysis of 10 controlled studies supported only 4 of the 14 claims cited in uncontrolled, descriptive studies. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To assess trends in peripheral vascular procedures performed in Veterans Health Administration (VHA) facilities. METHODS: All discharges with peripheral vascular procedures recorded for 1989-1998 were analyzed. The VHA user population was used to calculate age-specific rates. Trends were evaluated using frequency tables and Poisson regression. RESULTS: The VHA had 55,916 discharges with peripheral vascular procedures performed almost exclusively in men. Indications included peripheral vascular disease (53.7%), gangrene (19.3%), surgical complications (13.3%), and ulcers and infection (9.6%). The VHA age-specific rates were higher than US population rates for persons 45 to 64 years, similar for those 65 to 74 years, and lower for those 75 years and older. The age-specific rates declined slightly over the 10 years of observation, with the greatest decline noted in men age 45 to 65. CONCLUSION: The VHA provides almost 8% of all US peripheral vascular procedures in males. The VHA age-specific rates differ from the US rates with a shift to younger patients. The rates decreased for all age groups between 1989-1998. [ABSTRACT FROM AUTHOR]

GOAL: We sought to describe the common demographic and comorbid conditions that affect survival following nontraumatic amputation. METHODS: Veterans Administration hospital discharge records for 1992 were linked with death records. The most proximal level during the first hospitalization in 1992 was used for analysis. Demographic information (age, race) and comorbid diagnosis (cardiovascular, cerebrovascular, and renal disease) were used for Kaplan-Meier curves to describe survival following amputation. MAIN OUTCOME MEASURE: Death. RESULTS: Mortality risk increased with advanced age, more proximal amputation level, and renal and cardiovascular disease, and decreased for African Americans. No increased risk for persons with diabetes was noted in the first year following amputation but the risk increased thereafter. A higher risk of mortality in the first year was noted for renal disease, cardiovascular disease, and proximal amputation level. CONCLUSION: Survival following lower-limb amputation is impaired by advancing age, cardiovascular and renal disease, and proximal amputation level. Also, a small survival advantage is seen for African Americans and those with diabetes. [ABSTRACT FROM AUTHOR]

Rigid plaster dressings and immediate postoperative prostheses (IPOP) in patients undergoing transtibial amputations have been reported to reduce pain and healing time, prevent knee flexion contractures, and expedite early ambulation compared to soft dressings. Yet, despite the reported benefits, surgical adoption of (conventional) rigid dressings and IPOP has been inconsistent. The purpose of this study was to determine the current postoperative transtibial amputation dressing practices in VA hospitals. A six-item questionnaire was sent to 134 surgeons at the 117 VA hospitals where transtibial amputations were performed in fiscal year 1999. Responses were received from 83% of the surgeons. During the 1999 study year, surgeons performing transtibial amputations used soft dressings on 67% of patients, conventional rigid dressings with no intent to apply a foot attachment on 14% of patients, removable rigid dressings on 14% of patients, and IPOP (almost exclusively without a foot) on 5% of patients. The application of a rigid dressing or IPOP did not correlate well with the total number of transtibial amputations performed by the surgeon, hospital bed size, or academic affiliation. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To assess trends in lower limb amputation performed in Veterans Health Administration (VHA) facilities. METHODS: All lower limb amputations recorded in the Patient Treatment File for 1989-1998 were analyzed using the hospital discharge as the unit of analysis. Age-specific rates were calculated using the VHA user-population as the denominator. Frequency tables and linear, logistic, and Poisson regression were used respectively to assess trends in amputation numbers, reoperation rates, and age-specific amputation rates. RESULTS: Between 1989-1998, there were 60,324 discharges with amputation in VHA facilities. Over 99.9% of these were in men and constitute 10 percent of all US male amputations. The major indications were diabetes (62.9%) and peripheral vascular disease alone (23.6%). The age-specific rates of major amputation in the VHA are higher than US rates of major amputation. VHA rates of major and minor amputation declined an average of 5% each year, while the number of diabetes-associated amputations remained the same. CONCLUSION: The number and age-specific rates of amputations decreased over 10 years despite an increase in the number of veterans using VHA care. [ABSTRACT FROM AUTHOR]

Objective: To develop a lower limb prosthesis (LLP) sophistication classification system that categorizes prosthetic component prescriptions into "basic," "intermediate," and "advanced" and assess its content validity, reliability, and accuracy., Design: Classification development and validation study., Setting: The Veterans Affairs (VA) Corporate Data Warehouse database and National Prosthetics Patient Database were used to identify patients undergoing their first amputation at the transtibial or transfemoral level due to diabetes or peripheral artery disease and to identify the associated codes for each LLP., Participants: An expert panel of 6 nationally recognized certified prosthetists, a national expert in VA prosthetics data and coding, a physical medicine and rehabilitation physician, and an epidemiologist developed an LLP classification system ( PROClass ) using 30 transfemoral and transtibial lower limb amputees., Main Outcome Measures: The expert panel reviewed 20 consecutive participants meeting study criteria for the development of the PROClass system and a subsequent 30 consecutive cases for assessing the inter- and intra-rater reliability and accuracy., Results: The interrater and intrarater reliability was almost perfect with Gwet's AC1 values ranging from .82 to .96 for both expert panel members and research assistants. The accuracy of the research assistant's classifications to the "criterion standard" was excellent with Gwet's AC1 values ranging between .75 and .92., Conclusions: PROClass is a pragmatic, reliable, and accurate prosthetic classification system with strong face validity that will enable the classification of prosthetic components used for large data set research aimed at evaluating important clinical questions such as the effects of sophistication on patient outcomes., (© 2023 The Authors.)

Introduction: The most suitable elevated vacuum (EV) pressure may differ for each individual prosthesis user depending on suspension needs, socket fit, prosthetic components, and health. Mechanical and physiological effects of EV were evaluated in an effort to determine the optimal vacuum pressure for three individuals., Methods: Instrumented EV sockets were created based on the participants' regular EV sockets. Inductive distance sensors were embedded into the wall of the socket at select locations to measure limb movement relative to the socket. Each participant conducted an activity protocol while limb movement, limb fluid volume, and user-reported comfort were measured at various socket vacuum pressure settings., Results: Increased socket vacuum pressure resulted in reduced limb-socket displacement for each participant; however, 81-93% of limb movement was eliminated by a vacuum pressure setting of 12 (approximately -9 inHg). Relative limb-socket displacement by sensor location varied for each participant, suggesting distinct differences related to socket fit or residual limb tissue content. The rate of limb fluid volume change and the change in socket comfort did not consistently differ with socket vacuum pressure, suggesting a more complex relationship unique to each individual., Conclusions: Practitioners may use individual responses to optimize socket vacuum pressure settings, balancing mechanical and physiological effects of EV for improved clinical outcomes., Competing Interests: Conflict of Interest: Authors state no conflicts of interest.

Background: Women Veterans with amputation are a group with unique needs whose numbers have grown over the last 5 years, accounting for nearly 3% of all Veterans with amputation in 2019. Although identified as a national priority by the Veterans Health Administration, the needs of this population have remained largely underrepresented in amputation research., Objective: To describe the experiences of women Veterans with lower extremity amputation (LEA) related to prosthetic care provision and devices., Design: National qualitative study using semi-structured individual interviews., Participants: Thirty women Veterans with LEA who had been prescribed a prosthesis at least 12 months prior., Approach: Inductive content analysis., Key Results: Four key themes emerged: (1) a sense of "feeling invisible" and lacking a connection with other women Veterans with amputation; (2) the desire for prosthetic devices that meet their biological and social needs; (3) the need for individualized assessment and a prosthetic limb prescription process that is tailored to women Veterans; the current process was often perceived as biased and either dismissive of women's concerns or failing to adequately solicit them; and (4) the desire for prosthetists who listen to and understand women's needs., Conclusions: Women Veterans with LEA articulated themes reminiscent of those previously reported by male Veterans with LEA, such as the importance of prostheses and the central role of the provider-patient relationship. However, they also articulated unique needs that could translate into specific strategies to improve prosthetic care, such as integrating formal opportunities for social support and peer interaction for women Veterans with LEA, advocating for administrative changes and research efforts to expand available prosthetic component options, and ensuring that clinical interactions are gender-sensitive and free of bias., (© 2022. The Author(s).)

Objective: The aim of this study was to determine the cumulative incidence of, and the risk factors associated with, contralateral amputation in patients with chronic limb threatening ischaemia (CLTI)., Methods: This was a retrospective cohort study of patients with incident unilateral transmetatarsal (TM), transtibial (TT), or transfemoral (TF) amputation secondary to CLTI, identified from the National Veterans Affairs Surgical Quality Improvement Program database (2004 - 2014). Thirteen potential pre-operative risk factors for contralateral amputation were considered. A competing risk analysis to estimate the cumulative incidence of contralateral amputation was performed using a Fine-Gray subdistribution hazard model. The effect of risk factors on contralateral amputation was estimated by computing subdistribution hazard ratios (sub-HR) with 95% confidence intervals (CI)., Results: From the database, 7 360 patients met the inclusion criteria. The contralateral amputation risk was 7.7% and was greatest in those who underwent a TF amputation (9.7%), followed by TT (7.4%) and TM amputation (6.6%) (p < .001). Among the 588 contralateral amputations, 50% were at the TF level, 34% at the TT level, and 16% at the TM level. The adjusted risk of contralateral amputation was greater in those who underwent an incident TF amputation or were Black or Hispanic. The factor that contributed to risk of contralateral amputation to the greatest extent was dialysis (sub-HR, 2.3; 95% CI 1.7 - 3.0; p < .001) while those who were obese (compared with underweight) were at lowest risk (0.67; 95% CI 0.46 - 0.97; p = .030)., Conclusion: The one year risk of contralateral amputation in patients with CLTI is related to incident amputation level, medical comorbidities, correlates with race/ethnicity, and body mass index at the time of the incident amputation. The identified risk factors are largely not modifiable; however, they can be used to help identify populations at elevated risk., (Copyright © 2022 European Society for Vascular Surgery. All rights reserved.)

Objective: Amputation level decision making in patients with chronic limb threatening ischaemia is challenging. Currently, evidence relies on published average population risks rather than individual patient risks. The result is significant variation in the distribution of amputation levels across health systems, geographical regions, and time. Clinical decision support has been shown to enhance decision making, especially complex decision making. The goal of this study was to translate the previously validated AMPREDICT prediction models by developing and testing the usability of the AMPREDICT Decision Support Tool (DST), a novel, web based, clinical DST that calculates individual one year post-operative risk of death, re-amputation, and probability of achieving independent mobility by amputation level., Methods: A mixed methods approach was used. Previously validated prediction models were translated into a web based DST with additional content and format developed by an expert panel. Tool usability was assessed using the Post-Study System Usability Questionnaire (PSSUQ; a 16 item scale with scores ranging from 1 to 7, where lower scores indicate greater usability) by 10 clinician end users from diverse specialties, sex, geography, and clinical experience. Think aloud, semi-structured, qualitative interviews evaluated the AMPREDICT DST's look and feel, user friendliness, readability, functionality, and potential implementation challenges., Results: The PSSUQ overall and subscale scores were favourable, with a mean overall total score of 1.57 (standard deviation [SD] 0.69) and a range from 1.00 to 3.21. The potential clinical utility of the DST included (1) assistance in counselling patients on amputation level decisions, (2) setting outcome expectations, and (3) use as a tool in the academic environment to facilitate understanding of factors that contribute to various outcome risks., Conclusion: After extensive iterative development and testing, the AMPREDICT DST was found to demonstrate strong usability characteristics and clinical relevance. Further evaluation will benefit from integration into an electronic health record with assessment of its impact on physician and patient shared amputation level decision making., (Copyright © 2021 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.)

Objective: The decision to undertake a major lower limb amputation can be complex. This review evaluates the performance of risk prediction tools in estimating mortality, morbidity, and other outcomes following amputation., Methods: A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The MEDLINE, Embase, and Cochrane databases were searched to identify studies reporting on risk prediction tools that predict outcomes following amputation. Outcome measures included the accuracy of the risk tool in predicting a range of post-operative complications, including mortality (both short and long term), peri-operative morbidity, need for re-amputation, and ambulation success. A narrative synthesis was performed in accordance with the Guidance on the Conduct of Narrative Synthesis In Systematic Reviews., Results: The search identified 518 database records. Twelve observational studies, evaluating 13 risk prediction tools in a total cohort of 61 099 amputations, were included. One study performed external validation of an existing risk prediction tool, while all other studies developed novel tools or modified pre-existing generic calculators. Two studies conducted external validation of the novel/modified tools. Nine tools provided risk estimations for mortality, two tools provided predictions for post-operative morbidity, two for likelihood of ambulation, and one for re-amputation to the same or higher level. Most mortality prediction tools demonstrated acceptable discrimination performance with C statistic values ranging from 0.65 to 0.81. Tools estimating the risk of post-operative complications (0.65 - 0.74) and necessity for re-amputation (0.72) also performed acceptably. The Blatchford Allman Russell tool demonstrated outstanding discrimination for predicting functional mobility outcomes post-amputation (0.94). Overall, most studies were at high risk of bias with poor external validity., Conclusion: This review identified several risk prediction tools that demonstrate acceptable to outstanding discrimination for objectively predicting an array of important post-operative outcomes. However, the methodological quality of some studies was poor, external validation studies are generally lacking, and there are no tools predicting other important outcomes, especially quality of life., Competing Interests: Conflicts of interest Daniel Norvell and Joseph Czerniecki were involved in the development of the AMPREDICT tools,(18)(,)(22)(,)(26) and Christopher Twine and Emma Thomas-Jones developed UKAmpRisk.(23) Ryan A. Preece, Nafi Dilaver, Cherry-Ann Waldron, Philip Pallmann, Emma Thomas-Jones, Brenig L. Gwilym, Christopher P. Twine, and David C. Bosanquet are currently part of the team running PERCEIVE.(33), (Copyright © 2021 European Society for Vascular Surgery. All rights reserved.)

Objective: To identify timing, incidence, and risk factors for ipsilateral re-amputation within 12 months of first dysvascular amputation and to determine specific subgroups of patients at each amputation level that are at increased risk., Methods: A retrospective cohort study evaluating 7187 patients with first unilateral transmetatarsal (TM), transtibial (TT), or transfemoral (TF) amputation secondary to diabetes and/or peripheral artery disease (PAD) were identified in the VA Surgical Quality Improvement Program database between 2004 and 2014. Re-amputation was defined as any subsequent ipsilateral soft tissue/bony revision or amputation to a higher level. Twenty-three potential pre-operative risk factors (and nine potential interactions) were identified. A backward stepwise Cox regression was used to identify risk factors. Incidence rates and hazard ratios (HR) with 95% confidence intervals (CI) were computed., Results: The median time to highest level of re-amputation in the first year was 33 (interquartile range, 13-73) days. Risk of requiring at least one re-amputation was 41% (TM), 25% (TT), and 9% (TF). Risk factors associated with requiring re-amputation included chronic obstructive pulmonary disease, elevated white blood cell count, abnormal ankle brachial index (ABI), history of revascularisation, and alcohol misuse. TM patients who had diabetes only (HR 1.9; 95% CI 1.4-2.5), diabetes with an abnormal ankle brachial index (ABI) score (HR 2.4; 95% CI 1.8-3.2), and kidney failure (HR 1.7; 95% CI 1.3-2.1) were at the greatest risk of re-amputation. TT amputees who were smokers were also at an increased risk (HR 1.4; 95% CI 1.2-1.6)., Conclusion: This research identified important risk factors for failure of primary healing and need for re-amputation at the TM and TT level. If considering a TM amputation, caution should be exercised in patients with diabetes, in particular those with an abnormal ABI and/or renal failure. At the TT level, caution should be exercised in those who smoke., (Copyright © 2020 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.)

Background: Previous studies investigating limb volume change with elevated vacuum have shown inconsistent results and have been limited by out-of-socket volume measurements and short, single-activity protocols., Objectives: To evaluate the effectiveness of elevated vacuum for managing limb fluid volume compared to suction suspension with an in-socket measurement modality during many hours of activity., Study Design: Fixed-order crossover design with a standardized out-of-laboratory activity protocol., Methods: Transtibial electronic elevated vacuum users participated in two sessions. Elevated vacuum was used during the first session, and suction suspension in the second. Participants completed a 5.5-h protocol consisting of multiple intervals of activity. In-socket residual limb fluid volume was continuously measured using a custom portable bioimpedance analyzer., Results: A total of 12 individuals participated. Overall rate of fluid volume change was not significantly different, though the rate of posterior fluid volume change during Cycle 3 was significantly lower with elevated vacuum. Although individual results varied, 11 participants experienced lower overall rates of fluid volume loss in at least one limb region using elevated vacuum., Conclusion: Elevated vacuum may be more effective as a volume management strategy after accumulation of activity. Individual variation suggests the potential to optimize the limb fluid volume benefits of elevated vacuum by reducing socket vacuum pressure for some users., Clinical Relevance: A better understanding of how elevated vacuum (EV) affects residual limb fluid volume will allow prosthetists to make more informed clinical decisions regarding accommodation strategies designed to improve daily socket fit.

Objective: To assess whether the risk of subsequent lower-limb amputations and death following an initial toe amputation among individuals with diabetes has changed over time and varies by demographic characteristics and geographic region., Research Design and Methods: Using Veterans Health Administration (VHA) electronic medical records from 1 October 2004 to 30 September 2016, we determined risk of subsequent ipsilateral minor and major amputation within 1 year after an initial toe/ray amputation among veterans with diabetes. To assess changes in the annual rate of subsequent amputation over time, we estimated age-adjusted incidence of minor and major subsequent ipsilateral amputation for each year, separately for African Americans (AAs) and whites. Geographic variation was assessed across VHA markets ( n = 89) using log-linear Poisson regression models adjusting for age and ethnoracial category., Results: Among 17,786 individuals who had an initial toe amputation, 34% had another amputation on the same limb within 1 year, including 10% who had a major ipsilateral amputation. Median time to subsequent ipsilateral amputation (minor or major) was 36 days. One-year risk of subsequent major amputation decreased over time, but risk of subsequent minor amputation did not. Risk of subsequent major ipsilateral amputation was higher in AAs than whites. After adjusting for age and ethnoracial category, 1-year risk of major subsequent amputation varied fivefold across VHA markets., Conclusions: Nearly one-third of individuals require reamputation following an initial toe amputation, although risks of subsequent major ipsilateral amputation have decreased over time. Nevertheless, risks remain particularly high for AAs and vary substantially geographically., (© 2020 by the American Diabetes Association.)

Background:: Low back pain is a common secondary disabling condition in the transfemoral amputee population. Transfemoral amputees are at risk of excessive lumbar lordosis; it has been suggested that increased lumbar lordosis may be associated with low back pain. However, the relationship between lumbar lordosis angle and low back pain has not yet been studied in this population., Objective:: To determine whether the extent of lumbar lordosis is associated with low back pain in transfemoral amputees., Study Design:: Case-control observational study., Methods:: Participants included eight transfemoral amputees without low back pain and nine transfemoral amputees with low back pain. Etiology of amputation was primarily trauma. All participants underwent lateral view radiographs of the lumbar spine, from which lumbar lordosis angle and sacral inclination angle were measured., Results:: Lumbar lordosis angle mean ± standard deviation was 46.1° ± 12.4° in participants with low back pain and 51.0° ± 12.6° in those without. Sacral inclination angle mean ± standard deviation was 38.3° ± 8.7° in participants with low back pain and 39.1° ± 7.5° in those without. There was no significant difference in lumbar lordosis angle or sacral inclination angle between participants with and without low back pain., Conclusion:: This study suggests that increased lumbar lordosis angle and sacral inclination angle are not significantly associated with low back pain in transfemoral amputees of a primarily traumatic etiology., Clinical Relevance: Low back pain (LBP) is a common, disabling condition in transfemoral amputees. In the clinical setting, increased lumbar lordosis is implicated in LBP. This study does not support an association between increased lumbar lordosis and LBP; further study is needed to understand the increased prevalence of LBP in this population.

Objective: The objective of this study was the development of AMPREDICT-Mobility, a tool to predict the probability of independence in either basic or advanced (iBASIC or iADVANCED) mobility 1 year after dysvascular major lower extremity amputation., Methods: Two prospective cohort studies during consecutive 4-year periods (2005-2009 and 2010-2014) were conducted at seven medical centers. Multiple demographic and biopsychosocial predictors were collected in the periamputation period among individuals undergoing their first major amputation because of complications of peripheral arterial disease or diabetes. The primary outcomes were iBASIC and iADVANCED mobility, as measured by the Locomotor Capabilities Index. Combined data from both studies were used for model development and internal validation. Backwards stepwise logistic regression was used to develop the final prediction models. The discrimination and calibration of each model were assessed. Internal validity of each model was assessed with bootstrap sampling., Results: Twelve-month follow-up was reached by 157 of 200 (79%) participants. Among these, 54 (34%) did not achieve iBASIC mobility, 103 (66%) achieved at least iBASIC mobility, and 51 (32%) also achieved iADVANCED mobility. Predictive factors associated with reduced odds of achieving iBASIC mobility were increasing age, chronic obstructive pulmonary disease, dialysis, diabetes, prior history of treatment for depression or anxiety, and very poor to fair self-rated health. Those who were white, were married, and had at least a high-school degree had a higher probability of achieving iBASIC mobility. The odds of achieving iBASIC mobility increased with increasing body mass index up to 30 kg/m 2 and decreased with increasing body mass index thereafter. The prediction model of iADVANCED mobility included the same predictors with the exception of diabetes, chronic obstructive pulmonary disease, and education level. Both models showed strong discrimination with C statistics of 0.85 and 0.82, respectively. The mean difference in predicted probabilities for those who did and did not achieve iBASIC and iADVANCED mobility was 33% and 29%, respectively. Tests for calibration and observed vs predicted plots suggested good fit for both models; however, the precision of the estimates of the predicted probabilities was modest. Internal validation through bootstrapping demonstrated some overoptimism of the original model development, with the optimism-adjusted C statistic for iBASIC and iADVANCED mobility being 0.74 and 0.71, respectively, and the discrimination slope 19% and 16%, respectively., Conclusions: AMPREDICT-Mobility is a user-friendly prediction tool that can inform the patient undergoing a dysvascular amputation and the patient's provider about the probability of independence in either basic or advanced mobility at each major lower extremity amputation level., (Copyright © 2016 Society for Vascular Surgery. All rights reserved.)

Background: Myoelectric control of upper extremity powered prostheses has been used clinically for many years, however this approach has not been fully developed for lower extremity prosthetic devices. With the advent of powered lower extremity prosthetic components, the potential role of myoelectric control systems is of increasing importance. An understanding of muscle activation patterns and their relationship to functional ambulation is a vital step in the future development of myoelectric control. Unusual knee muscle co-contractions have been reported in both limbs of trans-tibial amputees. It is currently unknown what differences exist in co-contraction between trans-tibial amputees and controls. This study compares the activation and co-contraction patterns of the ankle and knee musculature of trans-tibial amputees (intact and residual limbs), and able-bodied control subjects during three speeds of gait. It was hypothesized that residual limbs would have greater ankle muscle co-contraction than intact and able-bodied control limbs and that knee muscle co-contraction would be different among all limbs. Lastly it was hypothesized that the extent of muscle co-contraction would increase with walking speed., Methods: Nine unilateral traumatic trans-tibial amputees and five matched controls participated. Surface electromyography recorded activation from the Tibialis Anterior, Medial Gastrocnemius, Vastus Lateralis and Biceps Femoris of the residual, intact and control limbs. A series of filters were applied to the signal to obtain a linear envelope of the activation patterns. A co-contraction area (ratio of the integrated agonist and antagonist activity) was calculated during specific phases of gait., Results: Co-contraction of the ankle muscles was greater in the residual limb than in the intact and control limbs during all phases of gait. Knee muscle co-contraction was greater in the residual limb than in the control limb during all phases of gait., Conclusion: Co-contractions may represent a limb stiffening strategy to enhance stability during phases of initial foot-contact and single limb support. These strategies may be functionally necessary for amputee gait; however, the presence of co-contractions could confound future development of myoelectric controls and should thus be accounted for.

Adding active power to a prosthetic knee unit may improve function and reduce the potential for overuse injuries in persons with transfemoral amputation (TFA). Servicemembers who have sustained a TFA are often young and motivated to perform at high functional levels. The goal of this article is to compare the biomechanics of ramp and stair descent and ascent for participants using the C-Leg and the Power Knee (PK). Subjects were asked to ascend and descend an instrumented staircase and 12 degree ramp at their comfortable pace while equipped with retroreflective markers. Temporal-spatial and kinetic data were collected. Knee power generated by the nondisabled limb during stair ascent for subjects wearing the C-Leg was significantly greater than for those wearing the PK. Knee power generated by prosthetic knee units was significantly greater for subjects while wearing the PK. Although the PK reduced the power required from the nondisabled knee during stair climbing, it does not appear to be superior to the C-Leg for other tasks. Adding power to a prosthetic knee may reduce wear on the nondisabled limb; however, there are still limitations that require improvement.

Relatively little attention has been given to the use of well-established motor learning strategies to enable individuals with lower limb loss to effectively and safely learn to walk with their prostheses in the home and community. Traditionally, such outcomes have been pursued by focusing on the design and function of a patient's prosthesis, rather than on how he or she should learn to use it. The use of motor learning strategies may enhance physical rehabilitation outcomes among individuals with lower limb loss. This review explores these motor learning strategies and ways in which they can be applied to the physical rehabilitation of individuals with lower limb loss and highlights some of the challenges to their implementation, as well as unanswered research questions.

Providing a satisfactory, functional prosthesis following lower-limb amputation is a primary goal of rehabilitation. The objectives of this study were to describe the rate of successful prosthetic fitting over a 12 mo period; describe prosthetic use after amputation; and determine factors associated with greater prosthetic fitting, function, and satisfaction. The study design was a multicenter prospective cohort study of individuals undergoing their first major lower-limb amputation because of vascular disease and/or diabetes. At 4 mo, unsuccessful prosthetic fitting was significantly associated with depression, prior arterial reconstruction, diabetes, and pain in the residual limb. At 12 mo, 92% of all subjects were fit with a prosthetic limb and individuals with transfemoral amputation were significantly less likely to have a prosthesis fit. Age older than 55 yr, diagnosis of a major depressive episode, and history of renal dialysis were associated with fewer hours of prosthetic walking. Subjects who were older, had experienced a major depressive episode, and/or were diagnosed with chronic obstructive pulmonary disease had greater functional restriction. Thus, while most individuals achieve successful prosthetic fitting by 1 yr following a first major nontraumatic lower-limb amputation, a number of medical variables and psychosocial factors are associated with prosthetic fitting, utilization, and function.

Lower-limb amputees expend more energy to walk than non-amputees and have an elevated risk of secondary disabilities. Insufficient push-off by the prosthetic foot may be a contributing factor. We aimed to systematically study the effect of prosthetic foot mechanics on gait, to gain insight into fundamental prosthetic design principles. We varied a single parameter in isolation, the energy-storing spring in a prototype prosthetic foot, the controlled energy storage and return (CESR) foot, and observed the effect on gait. Subjects walked on the CESR foot with three different springs. We performed parallel studies on amputees and on non-amputees wearing prosthetic simulators. In both groups, spring characteristics similarly affected ankle and body center-of-mass (COM) mechanics and metabolic cost. Softer springs led to greater energy storage, energy return, and prosthetic limb COM push-off work. But metabolic energy expenditure was lowest with a spring of intermediate stiffness, suggesting biomechanical disadvantages to the softest spring despite its greater push-off. Disadvantages of the softest spring may include excessive heel displacements and COM collision losses. We also observed some differences in joint kinetics between amputees and non-amputees walking on the prototype foot. During prosthetic push-off, amputees exhibited reduced energy transfer from the prosthesis to the COM along with increased hip work, perhaps due to greater energy dissipation at the knee. Nevertheless, the results indicate that spring compliance can contribute to push-off, but with biomechanical trade-offs that limit the degree to which greater push-off might improve walking economy., (© 2011 IEEE)

Background: Information about longer-term functional outcomes following lower extremity amputation for peripheral vascular disease and diabetes remains limited. This study examined factors associated with mobility success during the first year following amputation., Methods: Prospective cohort study of 87 amputees experiencing a first major unilateral amputation surgery. Seventy-five (86%) participants completed 12-month follow-up interview., Results: Twenty-eight subjects (37%) achieved mobility success, defined as returning to or exceeding a baseline level of mobility on the locomotor capability index (LCI-5). Forty-three subjects (57%) were satisfied with their mobility. Individuals who were 65 years of age and older (risk difference [RD] = -0.52; 95% confidence interval [CI]: -0.75, -0.29), reported a current alcohol use disorder (RD = -0.37; 95% CI: -0.48, -0.26), had a history of hypertension (RD = -0.23; 95% CI: -0.43, -0.03) or treatment for anxiety or depression (RD = -0.39; 95% CI: -0.50, -0.28) were less likely to achieve mobility success. Mobility success was associated with mobility satisfaction (RD = 0.36; 95% CI: 0.20, 0.53) and satisfaction with life (RD = 0.28; 95% CI: 0.06, 0.50). Although higher absolute mobility at 12 months was also associated with mobility satisfaction and overall life satisfaction, 50% of individuals who achieved success with low to moderate 12-month mobility function reported they were satisfied with their mobility., Conclusion: Defining success after amputation in relation to an individual's specific mobility prior to the development of limb impairment which led to amputation provides a useful, patient-centered measure that takes other aspects of health, function, and impairment into account., (Published by Mosby, Inc.)