Prosthesis satisfaction in lower limb amputees: A systematic review of associated factors and questionnaires

Transfemoral Osseointegration in Association With Total Hip Replacement: Observational Cohort Study of Patients With Follow-Up Exceeding 2 Years

Background

Some amputees with transfemoral osseointegration (TFOI) have ipsilateral hip arthritis which can be addressed with total hip arthroplasty (THA). This study reported the medium-term outcomes of THA in association with TFOI (THA + TFOI).

Methods

Retrospective review was performed for eight patients with THA + TFOI performed at least 2 years prior. Primary outcomes include complications prompting surgical intervention. Secondary outcomes include changes in mobility (K-level, 6-minute walk test [6MWT], timed up and go) and patient-reported measures (hip pain, daily prosthesis wear hours, Questionnaire for Persons with a Transfemoral Amputation, and Short Form 36 [SF36]).

Results

One patient died after 11 months (cancer); he was included to maximally report complications but excluded from mobility and reported outcomes. Three patients required subsequent surgeries: Two had skin refashioning, and the other underwent hip debridement of the replaced joint with subsequent removal of the TFOI. No perioperative complications, fractures, or arthroplasty explantations occurred. All patients reported complete hip pain relief. Of 6 patients reporting prosthesis wear time, 2 (33%) wore their prosthetic leg at least 4 hours daily before, vs all (100%) who did afterward (P = .061). K-levels improved in all responding patients. All 5 wheelchair-bound patients achieved and maintained ambulation. The Questionnaire for Persons with a Transfemoral Amputation and Short Form 36 did not significantly change.

Conclusions

THA + TFOI does not appear to pose an inevitable risk for prosthetic hip infection and may improve mobility and enhance quality of life (QOL) for transfemoral amputees with concurrent arthritic hip pain who are dissatisfied with their outcome following traditional socket prosthesis rehabilitation.

Intuitive and versatile bionic legs: a perspective on volitional control

Active lower limb prostheses show large potential to offer energetic, balance, and versatility improvements to users when compared to passive and semi-active devices. Still, their control remains a major development challenge, with many different approaches existing. This perspective aims at illustrating a future leg prosthesis control approach to improve the everyday life of prosthesis users, while providing a research road map for getting there. Reviewing research on the needs and challenges faced by prosthesis users, we argue for the development of versatile control architectures for lower limb prosthetic devices that grant the wearer full volitional control at all times. To this end, existing control approaches for active lower limb prostheses are divided based on their consideration of volitional user input. The presented methods are discussed in regard to their suitability for universal everyday control involving user volition. Novel combinations of established methods are proposed. This involves the combination of feed-forward motor control signals with simulated feedback loops in prosthesis control, as well as online optimization techniques to individualize the system parameters. To provide more context, developments related to volitional control design are touched on.

The nonsalvageable tibia: amputation and prosthetics

Mangled extremities are a challenging problem for the orthopaedic surgeon. The decision for salvage versus amputation is multifactorial. Several work groups have attempted to create scoring systems to guide treatment, but each case must be regarded individually. As surgical technique and prosthetics continue to improve, amputations should be seen as a viable reconstructive option, rather than failure. This article reviews scoring systems for the mangled extremity, outcomes on salvage versus amputation, amputation surgical technique, and prosthetic options.

A systematic review of the psychometric properties of Quebec user evaluation of satisfaction with assistive technology (QUEST)

PURPOSE

The aim of this systematic review was to evaluate the psychometric properties of the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST).

MATERIALS AND METHODS

Searches were conducted in August 2021 on four electronic databases: MEDLINE, CINAHL, Scopus, and Web of Science. Eligible papers included cross-sectional validation studies evaluating the psychometric properties of all QUEST versions. Cronbach's alpha, intraclass correlation coefficient, and comparison tools were reported. Study quality and risk of bias were assessed using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist.

RESULTS

Nineteen studies were included in this systematic review. Results showed that the QUEST and QUEST 2.0 were available in 10 languages, and most validation studies analysed this tool in patients using mobility devices in various clinical conditions. One article analysed the child version (QUEST 2.1) in English. The most analysed psychometric property was Cronbach's alpha for internal consistency in 14 out of 19 studies, with values ranging between 0.74 and 0.79. Overall, 17 out of 19 studies were of adequate quality, though responsiveness was never studied.

CONCLUSION

Our systematic review showed that the QUEST and its subsequent versions are reliable and valid measurement instruments to evaluate satisfaction in patients with different disabilities using various assistive technologies. This study provides useful information on the instrument's psychometric properties in different populations and cultures.

Development and alpha testing of a patient shared decision aid for prosthesis design for new lower limb prosthesis users

BACKGROUND

After lower limb amputation, several prosthesis design options exist. However, prosthesis design decisions do not always reflect a prosthesis user's needs, values, and preferences.

OBJECTIVE

To develop a patient decision aid (PDA) prototype for prosthetists and new prosthesis users facing prosthesis design decisions after lower limb amputation, and to assess its usability, accuracy, and comprehensibility.

STUDY DESIGN

Exploratory mixed methods.

METHODS

PDA development was informed by a qualitative needs assessment and guided by the International Patient Decision Aid Standards. The PDA was evaluated by steering groups of experienced prosthesis users and prosthetic professionals (prosthetists and researchers) to test usability, accuracy, and comprehensibility through focus groups, individual interviews, and rating on a Likert scale ranging from 1 to 10.

RESULTS

The resulting PDA included 6 sections: (1) Amputation and Early Recovery, (2) Communication, (3) Values, (4) Prosthesis Design, (5) Preferences, and (6) Prosthetic Journey. Usability, accuracy, and comprehensibility were rated as 9.2, 9.6, and 9.6, respectively, by prosthetic professionals, and 9.4, 9.6, and 9.6, respectively, by prosthesis users.

DISCUSSION

The PDA incorporated guidance by relevant stakeholders and was rated favorably, emphasizing a need for shared decision-making support in prosthesis design. One challenge was determining the amount of information in the PDA, highlighting the diversity in end users' informational needs. Future iterations of the PDA should undergo beta testing in clinical settings.

CONCLUSIONS

A standardized, iterative method was used to develop a PDA for new lower limb prosthesis users and prosthetists when considering prosthesis design decisions. The PDA was considered useable, accurate, and comprehensible.

Reliability and validity of the Turkish version of the Prosthesis Embodiment Scale for Lower Limb Amputees

BACKGROUND

Prosthetic embodiment is the perception of the prosthesis as a part of the body, and it is important for acceptance and adequate and effective use of the prosthesis.

OBJECTIVE

The aim of this study was to investigate the validity and reliability of the Turkish version of the Prosthesis Embodiment Scale for Lower Limb Amputees.

METHODS

This cross-sectional study included a total of 88 lower limb amputees. Internal consistency was evaluated using Cronbach α coefficient. The test-retest reliability of the scale, which was reapplied after 7-10 d, was evaluated using intraclass correlation coefficient. Principal component analysis with Varimax rotation was used to analyze the factor structure. Spearman correlation coefficient with Trinity Amputation and Prosthesis Experience Scale subscales was calculated for concurrent validity.

RESULTS

The mean age of the participants was 45.13 ± 15.05 years, and 76.1% were male. Internal consistency (Cronbach α = 0.905) and test-retest reliability (intraclass correlation coefficient = 0.822) were high. 76.1% of the total variance could be explained by the 3 dimensions. Significant correlation was found with the Trinity Amputation and Prosthesis Experience Scale subscales (r = 0.542 for psychosocial adjustment subscale, r = -0.452 for activity restriction subscale, r = 0.490 for prosthesis satisfaction subscale, p < 0.001).

CONCLUSIONS

The results of this study showed that the Turkish version of the Prosthesis Embodiment Scale for Lower Limb Amputees is a valid and reliable tool that can be used to evaluate prosthetic rehabilitation outcomes.

Gender differences in prosthesis-related outcomes among veterans: Results of a national survey of U.S. veterans

BACKGROUND

Women with lower extremity amputations (LEAs) tend to have poorer prosthesis-related outcomes than men, although the literature is sparse. To our knowledge, there are no prior studies examining prosthesis-related outcomes of women veterans with LEAs.

OBJECTIVE

To examine gender differences (overall and by type of amputation) among veterans who underwent LEAs between 2005 and 2018, received care at the Veterans Health Administration (VHA) prior to undergoing amputation, and were prescribed a prosthesis. It was hypothesized that compared to men, women would report lower satisfaction with prosthetic services, poorer prosthesis fit, lower prosthesis satisfaction, less prosthesis use, and worse self-reported mobility. Furthermore, it was hypothesized that gender differences in outcomes would be more pronounced among individuals with transfemoral than among those with transtibial amputations.

DESIGN

Cross-sectional survey. Linear regressions were used to assess overall gender differences in outcomes and gender differences based on type of amputation in a national sample of veterans.

SETTING

VHA medical centers.

PARTICIPANTS

The sample consisted of 449 veterans who self-identified their gender (women = 165, men = 284) with transtibial (n = 236), transfemoral (n = 135), and bilateral LEAs (n = 68) including all amputation etiologies.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The Orthotics and Prosthetics User's Survey, Trinity Amputation and Prosthesis Experiences Scale, and Prosthetic Limb Users Survey of Mobility-Short Form were used to assess satisfaction with prosthetic services, prosthesis fit, prosthesis satisfaction, prosthesis use, and self-reported mobility.

RESULTS

Women had poorer self-reported mobility than men (d = -0.26, 95% confidence interval -0.49 to -0.02, p < .05); this difference was small. There were no statistically significant gender differences in satisfaction with prosthetic services, prosthesis fit, prosthesis satisfaction, daily hours of prosthesis use, or by amputation type.

CONCLUSIONS

Contrary to the hypothesis, prosthesis-related outcomes were similar between men and women with LEAs. Minimal differences may in part be due to receiving care from the VHA's integrated Amputation System of Care.

Development of an evidence-based diagnostic algorithm for infection in patients with transcutaneous osseointegration following amputation

Introduction: Transcutaneous osseointegration following amputation (TOFA) confers better mobility and quality of life for most patients versus socket prosthesis rehabilitation. Peri-TOFA infection remains the most frequent complication and lacks an evidence-based diagnostic algorithm. This study's objective was to investigate preoperative factors associated with positive intraoperative cultures among patients suspected of having peri-TOFA infection in order to create an evidence-based diagnostic algorithm. Methods: We conducted a retrospective study of 83 surgeries (70 patients) performed to manage suspected lower-extremity peri-TOFA infection at a specialty orthopedic practice and tertiary referral hospital in a major urban center. The diagnosis of infection was defined as positive intraoperative cultures. Preoperative patient history (fevers, subjective pain, increased drainage), physician examination findings (local cellulitis, purulent discharge, implant looseness), and laboratory data (white blood cell count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and external swab culture) were evaluated for association with subsequent positive intraoperative cultures using regression and area under receiver-operator curve (AUC) modeling. Results: Peri-implant limb pain (highly correlated with infection), ESR > 30 (highly correlated against infection), positive preoperative swab (moderately correlated with infection), gross implant motion (moderately correlated against infection), and erythema or cellulitis of the transcutaneous region (mildly correlated with infection) were variables included in the best AUC model, which achieved an 85 % positive predictive value. Other clinical findings and laboratory values (notably CRP and WBC) were non-predictive of infection. Conclusions: This seminal investigation to develop a preoperative diagnostic algorithm for peri-TOFA infection suggests that the clinical examination remains paramount. Further evaluation of a wider spectrum of clinical, laboratory, and imaging data, consistently and routinely collected with prospective data techniques in larger cohorts of patients, is necessary to create a robust predictive algorithm.

A pneumatic reconfigurable socket for transtibial amputees

Many transtibial amputees rate the fit between their residual limb and prosthetic socket as the most critical factor in satisfaction with using their prosthesis. This study aims to address the issue of prosthetic socket fit by reconfiguring the socket shape at the interface of the residual limb and socket. The proposed reconfigurable socket shifts pressure from sensitive areas and compensates for residual limb volume fluctuations, the most important factors in determining a good socket fit. Computed tomography scan images are employed to create the phantom limb of an amputee and to manufacture the reconfigurable socket. The performance of the reconfigurable socket was evaluated both experimentally and numerically using finite element modelling. The study showed that the reconfigurable socket can reduce interface pressure at targeted areas by up to 61%.

Advances in prosthetic technology: a perspective on ethical considerations for development and clinical translation

Technological advancements of prostheses in recent years, such as haptic feedback, active power, and machine learning for prosthetic control, have opened new doors for improved functioning, satisfaction, and overall quality of life. However, little attention has been paid to ethical considerations surrounding the development and translation of prosthetic technologies into clinical practice. This article, based on current literature, presents perspectives surrounding ethical considerations from the authors' multidisciplinary views as prosthetists (HG, AM, CLM, MGF), as well as combined research experience working directly with people using prostheses (AM, CLM, MGF), wearable technologies for rehabilitation (MGF, BN), machine learning and artificial intelligence (BN, KKQ), and ethics of advanced technologies (KKQ). The target audience for this article includes developers, manufacturers, and researchers of prosthetic devices and related technology. We present several ethical considerations for current advances in prosthetic technology, as well as topics for future research, that may inform product and policy decisions and positively influence the lives of those who can benefit from advances in prosthetic technology.

Toward the Development of User-Centered Neurointegrated Lower Limb Prostheses

The last few years witnessed radical improvements in lower-limb prostheses. Researchers have presented innovative solutions to overcome the limits of the first generation of prostheses, refining specific aspects which could be implemented in future prostheses designs. Each aspect of lower-limb prostheses has been upgraded, but despite these advances, a number of deficiencies remain and the most capable limb prostheses fall far short of the capabilities of the healthy limb. This article describes the current state of prosthesis technology; identifies a number of deficiencies across the spectrum of lower limb prosthetic components with respect to users' needs; and discusses research opportunities in design and control that would substantially improve functionality concerning each deficiency. In doing so, the authors present a roadmap of patients related issues that should be addressed in order to fulfill the vision of a next-generation, neurally-integrated, highly-functional lower limb prosthesis.

User perspectives of digital manufacturing for lower-limb prosthetic sockets

BACKGROUND

There is growing interest to use digital technology (DT) for manufacturing lower-limb prosthetic sockets to improve efficiency and clinical outcomes. However, little is known about how lower-limb prosthesis users perceive DTs, such as 3D scanning and 3D printing.

OBJECTIVES

This study aimed to provide an understanding of perceptions and experiences with DT for prosthetic socket manufacturing from the perspective of prosthesis users.

STUDY DESIGN

A qualitative descriptive research study.

METHODS

Nine lower-limb prosthesis users (mean age 56; 5 female; 4 male) participated in one-on-one semistructured telephone interviews. Inductive thematic analysis was performed to identify a codebook and emerging themes from the interview transcripts.

RESULTS

Two major themes were identified: (1) expectations and prioritization of 3D printed socket usability and (2) facilitators and barriers to uptake of DT among patients.

CONCLUSION

DT methods were found to be acceptable and feasible from a patient perspective, although technological advancements are still required, and real-time communication about the process may be vital for ensuring patient engagement. Consideration of these findings may improve patient satisfaction to emerging prosthesis treatment plans and ultimately support widespread adoption of DT as an additional tool for fabricating prosthetic sockets.

Evaluating Feasibility and Durability of the Aero Prosthetic Liner in Transtibial Prosthetic Users

BACKGROUND

The choice of prosthetic socket interface material significantly affects user comfort and satisfaction. The Affordable Ethylene-Vinyl Acetate Roll-On (AERO) liner was created with the aim of improving functionality and streamlining the wearing process for users.

OBJECTIVE

The purpose of this study was to comprehensively assess user satisfaction, comfort, and durability of the AERO liner and compare it with the common soft Pe-Lite liner.

METHODOLOGY

Fourteen individuals with transtibial amputation participated in this three-month randomized crossover trial study. The Prosthesis Evaluation Questionnaire (PEQ), Expanded Socket Comfort Score (ESCS), and liner thickness measurements were used to comprehensively compare the AERO and Pe-Lite liner.

FINDINGS

The AERO liner demonstrated notable improvements in prosthetic comfort and functionality over Pe-Lite liner. After three months use, there was a significant reduction in reported frustration with the AERO liner (p=0.023, r=0.604) in the PEQ subscale. Specific aspects, such as walking with the prosthesis (p=0.030, r=0.601) and odor perception (p=0.024, d=0.579), favored the use of the AERO liner. The expanded socket comfort score (ESCS) revealed significant superiority for the AERO liner "at best" (p=0.04) and "on average" (p=0.02) after one and three months, respectively. Liner thickness analysis showed significant reductions at the mid-patellar tendon location for the AERO liner at one (0.57±0.48) and three months (0.90±0.69, p=0.01) and in the posterior region after three months (0.63±0.64, p=0.05).

CONCLUSION

Our study highlights the potential advantages of the AERO liner in enhancing comfort and satisfaction. Yet, durability and thinning of the liner when compared to Pe-Lite may be a concern which may eventually affect socket fit. These findings contribute to ongoing efforts to optimize prosthetic interventions and improve the quality of life of individuals with lower limb prosthesis in resource-limited environments.

Depression and Anxiety Symptoms Among Lebanese Lower Limb Traumatic Amputees: Association with Education, Employment, Adjustment to Amputation and Prosthesis Satisfaction

ObjectiveTo examine and compare the association between the presence of depression and anxiety symptoms and different sociodemographic and clinical factors including the adjustment to amputation and prosthesis satisfaction among Lebanese individuals with lower limb amputation (LLA). Method: This cross-sectional study was conducted between December 2022 and May 2023 among 72 participants with LLA. Participants completed a questionnaire that included sociodemographic and clinical variables, the revised Trinity Amputation and Prosthesis Experience Scale (TAPES-R), and the Hopkins Symptom Checklist (HSCL-25). Result: Using the HSCL depression and anxiety cut-off, 25% of participants were categorized as having depression symptoms, with unemployment being significantly associated (p-value < .05) with depression. Similarly, 25% were classified as having anxiety symptoms, with both lower education and unemployment (p-value < .05) significantly linked to anxiety. TAPES-R subscales scores exhibited significant differences between non-depressed and depressed, as well as non-anxious and anxious participants (p-value < .05). Correlation analysis demonstrated significant relationship between HSCL scales and TAPES-R subscales; lower scores in adjustment to amputation and prosthesis satisfaction were moderately associated with increased rates of depression (r ranging between -0.331 and -0.500, p-values < .005) and increased rates of anxiety symptoms (r ranging between -0.362 and -0.441, p-values < .002). In addition, higher scores in activity limitation were moderately correlated to increased rates of depression and anxiety (r = 0.438 for anxiety and 0.490 for depression; p < .001). Conclusion: Mental health symptoms are associated with educational level, employment status, and adjustment to amputation and prosthesis satisfaction in Lebanese individuals with LLA. These findings should be considered to achieve optimal prosthetic rehabilitation.

Development of a prosthetic fit and alignment assessment (ProFit) in persons with post-traumatic transtibial amputation

BACKGROUND

There are no standards for reliably measuring the quality of prosthetic fit and alignment which is important for evaluation and improvement of clinical care for patients with transtibial amputation.

OBJECTIVES

The purpose of this study was to develop an instrument to quantitatively assess prosthetic fit and alignment in patients with transtibial amputation.

STUDY DESIGN

Prospective cohort study.

METHODS

The fit and alignment assessment (ProFit) included 39 items for assessments of skin quality, stance and gait, and radiographic characteristics that could be feasibly captured in clinic using photographs, video, and radiographs. Data were collected on adults aged 18-60 years treated with transtibial amputation and followed up for 18 months at 1 of 27 US hospitals. One hundred thirteen assessments were conducted by 6 prosthetists using an online platform. Items demonstrating reliability and face validity were included in the ProFit score for subsequent validation testing. Validation measures included 18-month patient-reported function (Short Musculoskeletal Function Assessment ), tests of physical performance, patient-reported pain (Brief Pain Inventory ), satisfaction with prosthesis (Orthotics Prosthetics Users Survey), prosthesis use, and walking activity.

RESULTS

The ProFit score included 10 of 39 items that demonstrated high inter-rater reliability and face validity. A higher ProFit score correlated with worse function on all domains of the Short Musculoskeletal Function Assessment except arm and hand and with worse performance on the 4-Square Step Test, Shuttle Run, and Illinois Agility Test. ProFit scores did not correlate with the Brief Pain Inventory, Orthotics Prosthetics Users Survey, prosthesis use, or walking activity.

CONCLUSIONS

The ProFit score can be used by researchers and clinicians to measure the quality of socket fit and prosthetic alignment. Future prospective validation is necessary to verify the promising results observed in ProFit development and establish clinical utility.

Soft robotics-inspired sensing system for detecting downward movement and pistoning in prosthetic sockets: A proof-of-concept study

BACKGROUND

Vertical displacement of the residual limb within transtibial prosthetic socket, often known as "pistoning" or downward movement, may lead to skin breakdowns and ulcers. Downward movement is particularly difficult to self-manage for diabetic individuals living with amputation because of diminished sensation in the residual limb from peripheral neuropathy. Therefore, a customizable sensor at the distal end that can alert the users when high-risk downward movement and pistoning occurs is urgently needed.

OBJECTIVES

Presented herein for the first time is a lightweight, inexpensive sensing system inspired by soft robotics that can detect the occurrence and severity of downward movement at the distal end.

METHODS

The sensing system consists of a multilayered torus-shaped balloon, allowing easy integration with pin-lock socket systems. The design allows sensing of vertical displacement without imparting high reaction forces back onto the distal end. A benchtop compression tester was used to characterize system performance. Systematic and parametric benchtop tests were conducted to examine the sensor's physical characteristics. Long-term (24-h) stability of the sensor was also recorded.

RESULTS

Compared with water, air was determined to be a better medium with a higher linear full-scale span (FSS) because of its compressible nature. Repeatable 0.5-mm vertical displacements yielded a linear (>0.99 R2) FSS of 4.5 mm and a sensitivity of 0.8 kPa/mm. The sensing system is highly precise, with as low as 1% FSS total error band and average hysteresis of 2.84% of FSS. Over 24 h, a 4% FSS drift was observed.

CONCLUSION

Sensing system characteristics, coupled with low-cost, customizable fabrication, indicates promising performance for daily use to notify and alert transtibial prosthetic users of downward movement and/or pistoning.

Exploring meaningful outcome domains of recovery following lower limb amputation and prosthetic rehabilitation: the patient's perspective

PURPOSE

There is currently no consensus regarding what outcome domains to measure following lower limb prosthetic rehabilitation. Prosthetic users have a unique insight into important outcome domains, little is currently known about their critical viewpoint.

MATERIALS AND METHODS

A total of 37 participants who underwent lower limb amputation in the last five years were recruited from UK limb fitting centres and social media. Data were collected using focus groups and interviews and analysed using reflexive thematic analysis.

RESULTS

Five themes were identified. 1) The ability to participate in important activities, 2) how participants were able to undertake these activities, i.e., independently, with ease, safely and with minimal equipment. 3) A comfortable, easy-to-use prosthesis, 4) the importance of managing pain and finally, 5) adjusting and accepting their new normal. These five themes, or outcome domains, did not exist in isolation, but appeared to interact with each other, contributing to, or inhibiting the participant's holistic sense of recovery.

CONCLUSIONS

Understanding important outcome domains that define what recovery means to people following amputation can help to inform domain consensus, as well as direct the focus of rehabilitation. Domain consensus would guide the selection of measurement tools that evaluate prosthetic interventions in a meaningful way.IMPLICATIONS FOR REHABILITATIONThere is currently no consensus around which outcome domains should be measured following prosthetic rehabilitation.Outcome domains of importance from a patient's perspective focus on participation in important activities, prosthesis comfort, pain management, and acceptance of their new normal.Identifying these domains can help direct the focus of rehabilitation as well as inform outcome measurement practice.The interrelated nature of these domains suggests the need for a physical and psychosocial multi-domain approach to outcome measurement in prosthetic rehabilitation, with patient priorities at its centre.

Improving Sit/Stand Loading Symmetry and Timing Through Unified Variable Impedance Control of a Powered Knee-Ankle Prosthesis

Individuals using passive prostheses typically rely heavily on their biological limb to complete sitting and standing tasks, leading to slower completion times and increased rates of osteoarthritis and lower back pain. Powered prostheses can address these challenges, but have control methods that divide sit-stand transitions into discrete phases, limiting user synchronization across the motion and requiring long manual tuning times. This paper extends our preliminary work using a thigh-based phase variable to parameterize optimized data-driven impedance parameter trajectories for sitting, standing, and walking, with only two classification modes. We decouple the stand-to-sit and sit-to-stand equilibrium angles through a knee velocity-dependent scaling term, reducing the model fitting error by approximately half compared to our previous results. We then experimentally validate the controller with three individuals with above-knee amputation performing sitting and standing transitions to/from three different chair heights. We show that our controller implemented on a powered knee-ankle prosthesis produced biomimetic joint mechanics, resulting in significantly reduced sit/stand loading symmetry and time to complete a 5x sit-to-stand task compared to participants' passive prostheses. Integration with a previously developed walking controller also allowed sit/walk transitions between different chair heights. The controller's biomimetic assistance may reduce the overreliance on the biological limb caused by inadequate passive prostheses, helping improve mobility for people with above-knee amputations.

Prosthetic device and service satisfaction, quality of life, and functional performance in lower limb prosthesis clients

OBJECTIVE

The aim of this study was to characterize the relationship between prosthetic device and service satisfaction, health-related quality of life (HRQOL), and functional movement in a diverse population of lower limb prosthesis users.

METHODS

An online survey was conducted on individuals with lower limb amputation between September and October 2021. Sample validated questionnaires assessing demographic and clinical features, satisfaction, functional outcomes, and quality of life were analyzed using path analysis.

RESULTS

Participants were 1736 individuals with lower limb amputation. Overall, 44% of participants reported dissatisfaction with prosthetic device, whereas 37% were dissatisfied with prosthetic service. Low functional mobility was reported by 58% of participants and 61% reported low HRQOL. Lower extremity functional status (β = 0.55), HRQOL (β = 0.08), Activities-specific Balance Scale (β = 0.22), and modified fall efficacy scale (β = -0.07) are significantly associated with prosthetic device satisfaction (P < 0.0005, R2 = 0.47). Satisfaction with provider service was significantly associated with lower extremity functional status (β = 0.44) and balance confidence (β = 0.18) (P < 0.0005, R2 = 0.34).

CONCLUSION AND CLINICAL RELEVANCE

Civilians, veterans, and service members reported low functional mobility, low quality of life, and moderate levels of dissatisfaction with their lower extremity prosthetic device and provider service. Improvements in mobility, balance, quality of life, and fall efficacy may enhance device satisfaction. Functional mobility and balance improvements may increase ratings of provider service. This study provides feedback that may improve clinical decisions on lower limb prosthesis patient care.

Moisture mitigation using a vented liner and a vented socket system for individuals with transfemoral amputation

Sweating and heat buildup at the skin-liner interface is a major challenge for persons with limb loss. Liners made of heat-non-conducting materials may cause sweating of the residual limb and may result in liners slipping off the skin surface especially on a warm day or during high activity, causing skin breakdown and affecting limb health. To address this, we evaluated the efficacy of the vented liner-socket system (VS, Össur) compared to Seal-In silicone liner and non-vented socket (nVS, Össur) in reducing relative humidity (RH) during increased sweat. Nine individuals with limb loss using nVS were randomized to VS or nVS and asked for activity in a 20-min treadmill walk. RH was significantly attenuated (p = 0.0002) and perceived sweating, as reported by prosthesis users, improved (p = 0.028) with VS, patient-reported comprehensive lower limb amputee socket survey (CLASS) outcomes to determine the suspension, stability, and comfort were not significantly different between VS and nVS. There are limited rigorous scientific studies that clearly provide evidence-based guidelines to the prosthetist in the selection of liners from numerous available options. The present study is innovative in clearly establishing objective measures for assessing humidity and temperatures at the skin-liner interface while performing activity. As shown by the measured data and perceived sweat scores provided by the subjects based on their daily experience, this study provided clear evidence establishing relative humidity at the skin-liner interface is reduced with the use of a vented liner-socket system when compared to a similar non-vented system.

A Scientometric Analysis and Visualization of Prosthetic Foot Research Work: 2000 to 2022

This study aims to highlight recent research work on topics around prosthetic feet through a scientometric analysis and historical review. The most cited publications from the Clarivate Analytics Web of Science Core Collection database were identified and analyzed from 1 January 2000 to 31 October 2022. Original articles, reviews with full manuscripts, conference proceedings, early access documents, and meeting abstracts were included. A scientometric visualization analysis of the bibliometric information related to the publications, including the countries, institutions, journals, references, and keywords, was conducted. A total of 1827 publications met the search criteria in this study. The related publications grouped by year show an overall trend of increase during the two decades from 2000 to 2022. The United States is ranked first in terms of overall influence in this field (n = 774). The Northwestern University has published the most papers on prosthetic feet (n = 84). Prosthetics and Orthotics International has published the largest number of studies on prosthetic feet (n = 151). During recent years, a number of studies with citation bursts and burst keywords (e.g., diabetes, gait, pain, and sensor) have provided clues on the hotspots of prosthetic feet and prosthetic foot trends. The findings of this study are based on a comprehensive analysis of the literature and highlight the research topics on prosthetic feet that have been primarily explored. The data provide guidance to clinicians and researchers to further studies in this field.

Model Predictions that Consider Individualized Gait Patterns and Patient Mobility Level for the Use of Passive Hip-Flexion Exosuits by Persons with Unilateral Transfemoral Amputation

The muscular remodeling that occurs during a transfemoral amputation surgery and subsequent long-term use of mechanically-passive prostheses have significant impacts on the mobility and gait pattern of the patient. At toe-off and during the subsequent swing phase, this behavior is characterized by increased hip flexion moment and power provided by the biological limb. In other patient populations (e.g., individuals with multiple sclerosis) passive tension-generating assistive elements have been shown to restore altered hip flexion mechanics at toe off. We hypothesized that an exosuit of the same basic architecture could be well applied to individuals with transfemoral amputation. In this paper, we simulate the effects of such a device for 18 patients of K2 and K3 Medicare functional classification levels. The device consists of two parallel elastic bands. Our approach considers the wrapping and geometric behavior of these elements over the residual limb in full-body patient-specific kinematic simulations of level ground walking. A nonlinear least squares problem was solved via the Levenberg-Marquardt method to find the band properties that best match (in order to offset) the intrinsic power delivery of the muscles during the swing phase. We found higher mobility patients (K3) often require a stiffer device, which leads to a greater error in the kinetic match between the biological limb and exosuit. In contrast, this method appears to be effective for K2 patients, which suggests that a different means of parameter selection or power delivery (e.g., active devices) may be necessary for higher mobility levels.

A framework for understanding prosthetic embodiment for the plastic surgeon

Plastic surgeons play a critical role in the management of amputations and are uniquely positioned to improve the lives and functional abilities of patients with limb loss. The embodiment of a prosthesis describes how effectively it replaces a missing limb and is an important aspect of patient care. Despite its importance, the current prosthetics literature lacks a formal definition of embodiment, and descriptions are often vague or incomplete. In this narrative review, we assess the current literature on prosthetic embodiment to explore the main mechanisms of embodiment and how each allows a prosthesis to interface with the human body. In doing so, we provide a comprehensive, holistic framework for understanding this concept.

Approach for Non-Intrusive Detection of the Fit of Orthopaedic Devices Based on Vibrational Data

The soft tissues of residual limb amputees are subject to large volume fluctuations over the course of a day. Volume fluctuations in residual limbs can lead to local pressure marks, causing discomfort, pain and rejection of prostheses. Existing methods for measuring interface stress encounter several limitations. A major problem is that the measurement instrumentation is applied in the sensitive interface between the prosthesis and residual limb. This paper presents the principle investigation of a non-intrusive technique to evaluate the fit of orthopaedic prosthesis sockets in transfemoral amputees based on experimentally obtained vibrational data. The proposed approach is based on changes in the dynamical behaviour detectable at the outer surface of prostheses; thus, the described interface is not affected. Based on the experimental investigations shown and the derived results, it can be concluded that structural dynamic measurements are a promising non-intrusive technique to evaluate the fit of orthopaedic prosthesis sockets in transfemoral amputee patients. The obtained resonance frequency changes of 2% are a good indicator of successful applicabilityas these changes can be detected without the need for complex measurement devices.

A Modified Version of the Forgotten Joint Score-12 in Lower Limb Amputees: Validity and Reliability Study

Adaptation to prosthesis is important for occupation, quality of life, and participation in social life, so it needs to be evaluated. The aim of this study was to determine the validity and reliability of the Forgotten Joint Score-12 (FJS-12) in lower limb amputees. The FJS-12 was applied to 80 amputees. Criterion-referenced validity was assessed using the activity restriction subparameter of Trinity Amputation and Prosthesis Experience Scale (TAPES). The internal consistency of the FJS-12 was high (Cronbach's α = .943). A statistically significant very good negative correlation was determined between the FJS-12 and the activity restriction subparameter of TAPES (r = -.641; p < .001). The results of this study showed that FJS-12 is a valid and reliable measurement tool that can be used to assess the adaptation to prosthesis in amputees. Evaluation of prosthesis awareness in daily living activities of amputees is important in terms of establishing occupational therapy and rehabilitation programs.

Numerical Analysis of a Transtibial Prosthesis Socket Using 3D-Printed Bio-Based PLA

Lower-limb prosthesis design and manufacturing still rely mostly on the workshop process of trial-and-error using expensive unrecyclable composite materials, resulting in time-consuming, material-wasting, and, ultimately, expensive prostheses. Therefore, we investigated the possibility of utilizing Fused Deposition Modeling 3D-printing technology with inexpensive bio-based and bio-degradable Polylactic Acid (PLA) material for prosthesis socket development and manufacturing. The safety and stability of the proposed 3D-printed PLA socket were analyzed using a recently developed generic transtibial numeric model, with boundary conditions of donning and newly developed realistic gait cycle phases of a heel strike and forefoot loading according to ISO 10328. The material properties of the 3D-printed PLA were determined using uniaxial tensile and compression tests on transverse and longitudinal samples. Numerical simulations with all boundary conditions were performed for the 3D-printed PLA and traditional polystyrene check and definitive composite socket. The results showed that the 3D-printed PLA socket withstands the occurring von-Mises stresses of 5.4 MPa and 10.8 MPa under heel strike and push-off gait conditions, respectively. Furthermore, the maximum deformations observed in the 3D-printed PLA socket of 0.74 mm and 2.66 mm were similar to the check socket deformations of 0.67 mm and 2.52 mm during heel strike and push-off, respectively, hence providing the same stability for the amputees. We have shown that an inexpensive, bio-based, and bio-degradable PLA material can be considered for manufacturing the lower-limb prosthesis, resulting in an environmentally friendly and inexpensive solution.

Understanding decision-making in prosthetic rehabilitation by prosthetists and people with lower limb amputation: a qualitative study

PURPOSE

Little has been published about the process of decision-making between prosthetists and people with lower limb amputation (LLA). The purpose of this study is to identify decisions and factors influencing decision-making in prosthetic rehabilitation from the perspectives of prosthetists and prosthesis users, to identify barriers and opportunities for shared decision-making (SDM).

METHODS

Qualitative semi-structured individual interviews were conducted with 13 prosthetists and 14 prosthesis users from three clinics in three states of the Rocky Mountain and Southwest regions of the United States. Transcripts were analyzed using thematic analysis.

RESULTS

Four main themes were identified: perceived decision points, importance of relationship, balancing competing priorities, and experience. Contrasts between perceptions of prosthetists and prosthesis users were related to prosthesis design decisions, and the purpose of communication (e.g., goals for a prosthesis vs. goals informing prosthesis design). Both prosthetists and prosthesis users described balancing priorities that contribute to prosthetic rehabilitation decisions, and the role of experience for informing realistic expectations and preferences necessary for participating in decision-making.

CONCLUSION

Opportunities for improving SDM between prosthetists and prosthesis users include (1) clarifying key rehabilitation decisions, (2) identifying the purpose of initial communications, (3) support for balancing priorities, and (4) utilizing experience to achieve informed preferences.IMPLICATIONS FOR REHABILITATIONMany people with lower limb amputation experience poor physical function and psychosocial outcomes, which may be further compounded by under informed prosthesis-user expectations for function with a prosthesis.Shared decision-making offers an opportunity for improving realistic prosthesis-user expectations, reducing healthcare costs, and improving prosthesis-user satisfaction and adherence to care plans.Opportunities for improving shared decision-making between prosthetists and prosthesis-users include (1) clarifying key rehabilitation decisions, (2) identifying the purpose of initial communications, (3) support for balancing priorities, and (4) utilizing experience to achieve informed preferences.

User-relevant factors influencing the prosthesis use of persons with a transfemoral amputation or knee-disarticulation: A meta-synthesis of qualitative literature and focus group results

OBJECTIVE

Persons with a transfemoral amputation or knee-disarticulation are heavily reliant on an adequate set of components for their prosthesis. To improve the process of adjusting the specific prosthetic properties to the expectations of the prosthesis users, it is of importance to first identify which factors have an influence on prosthesis use. Therefore, we aimed to identify factors that influence prosthesis use in adults with a transfemoral amputation or knee-disarticulation.

METHODS

A qualitative meta-synthesis was conducted by searching five databases (last update January 20th 2022). Studies were considered eligible if they contained qualitative data about adult persons with a transfemoral amputation or knee-disarticulation with experience in using a prosthesis and focused on the users' opinions. All eligible studies were independently screened by two reviewers. The results sections of the included studies were entered in Atlas.ti software (v8) and coded using the framework approach. The quality of the included studies was assessed using the Critical Appraisal Skills Program (CASP) qualitative research checklist. Results of the meta-synthesis were validated with prosthesis users (n = 8) in a focus group.

RESULTS

Out of 5757 articles, 14 studies were included. An overview of seven themes ('prosthesis related'; 'rehabilitation, costs and prosthetist'; 'mental'; 'physical'; 'social'; 'activities and participation' and 'walking') containing 84 factors was created. Ten factors were added during the focus group, resulting in an overview of 94 factors that may influence the prosthesis use of lower-limb prosthesis users. Participants would like more user-involvement from the rehabilitation team. The development of a patient decision aid could help this process in the future.

CONCLUSION

The large number of factors demonstrates that there is a great variety between prosthesis users and the factors that influence their prosthesis use. Therefore, it is important to take individual preferences into account for the selection of a new prosthesis.

Effects of Implementing a Self-Care Program for Adults With Lower Limb Prostheses

An artificial replacement for a lost limb or portion of a limb, known as a prosthesis, is a tool that can assist a person to regain their independence. The aim of this project was to evaluate the effect of a self-care program for adults with lower limb prostheses. We used a quasi-experimental research design. We conducted our study at the Physical Medicine and Rehabilitation and Rheumatology Center affiliated with the Armed Forces, located in the Al-Geza Governorate of Egypt using a purposeful sample of 81 adults with lower limb prostheses. We used two tools for data collection: a structured interviewing questionnaire and the Trinity Amputation and Prosthesis Experience Scales (TAPES). The mean age of adults with lower limb prosthesis in our study was 38.91 years (10.53). A total of 64.2% of the study participants (n = 51) were men. We found that before the self-care program, 22.2% of the participants (n = 18) had a satisfactory level of knowledge about self-care, which increased to 88.9% (n = 72) after the program. Before the self-care program, the number of participants with adequate practice levels was 13.6% (n = 11), which increased to 100.0% (n = 81) after the program. We concluded that implementing the self-care program provided a significant improvement in the attendee's total satisfactory knowledge (χ2[79,81] = 72.90, p < .000) and adequate practice levels (p < .001).

A qualitative study on stakeholder perceptions of digital prosthetic socket fabrication for transtibial amputations

BACKGROUND

Digital residual limb shape capture (three-dimensional [3D] scanning), computer-assisted design (CAD), and computer-assisted manufacturing with 3D printing technology show promise for a completely digital process of fabricating prosthetic sockets for patients with limb loss. The effectiveness and quality of digitally designed 3D-printed lower extremity prosthetic sockets is understudied, and there is lack of data on the patient and prosthetist experiences with this digital workflow.

OBJECTIVE

To obtain stakeholder feedback on the feasibility and acceptability of using a completely digital prosthetic fabrication process consisting of 3D scanning, CAD, and 3D printing in a rehabilitation setting for adults with transtibial limb amputations.

STUDY DESIGN

Qualitative design.

METHODS

Study participants with a transtibial-level amputation were fit with a prosthetic socket fabricated using digital shape capture with a 3D scanner, CAD, and 3D printing in addition to a traditionally handcasted manually fabricated socket. Participants tried on and evaluated both sockets. Semistructured interviews took place after the fitting appointments. A focus group was conducted with prosthetists to obtain their feedback. Audio data were transcribed verbatim, and an inductive content analysis was undertaken.

RESULTS

Eleven patient participants and 3 prosthetists identified 4 main themes: 1) openness and enthusiasm for digital prosthetic fabrication; 2) relative advantages of digital fabrication vs. traditional socket fabrication; 3) readiness of the technology used for adoption in practice; and 4) digital prosthetic workflow and 3D printing implementation considerations.

CONCLUSIONS

Patients and prosthetists were enthusiastic about digital prosthetic socket fabrication and saw potential advantages over traditional methods. Both patients and prosthetists had concerns about the durability, safety, and aesthetics of the 3D printed sockets in this study. Further studies are needed to optimize digital prosthetic fabrication with 3D printing in prosthetic practice.

A review of user needs to drive the development of lower limb prostheses

Background

The development of bionic legs has seen substantial improvements in the past years but people with lower-limb amputation still suffer from impairments in mobility (e.g., altered balance and gait control) due to significant limitations of the contemporary prostheses. Approaching the problem from a human-centered perspective by focusing on user-specific needs can allow identifying critical improvements that can increase the quality of life. While there are several reviews of user needs regarding upper limb prostheses, a comprehensive summary of such needs for those affected by lower limb loss does not exist.

Methods

We have conducted a systematic review of the literature to extract important needs of the users of lower-limb prostheses. The review included 56 articles in which a need (desire, wish) was reported explicitly by the recruited people with lower limb amputation (N = 8149).

Results

An exhaustive list of user needs was collected and subdivided into functional, psychological, cognitive, ergonomics, and other domain. Where appropriate, we have also briefly discussed the developments in prosthetic devices that are related to or could have an impact on those needs. In summary, the users would like to lead an independent life and reintegrate into society by coming back to work and participating in social and leisure activities. Efficient, versatile, and stable gait, but also support to other activities (e.g., sit to stand), contribute to safety and confidence, while appearance and comfort are important for the body image. However, the relation between specific needs, objective measures of performance, and overall satisfaction and quality of life is still an open question.

Conclusions

Identifying user needs is a critical step for the development of new generation lower limb prostheses that aim to improve the quality of life of their users. However, this is not a simple task, as the needs interact with each other and depend on multiple factors (e.g., mobility level, age, gender), while evolving in time with the use of the device. Hence, novel assessment methods are required that can evaluate the impact of the system from a holistic perspective, capturing objective outcomes but also overall user experience and satisfaction in the relevant environment (daily life).

'It's more than just a running leg': a qualitative study of running-specific prosthesis use by children and youth with lower limb absence

PURPOSE

The purpose of this study was to investigate the use of running-specific prostheses (RSPs) by children with lower limb absence (LLA) along with the benefits and challenges of RSPs.

MATERIALS AND METHODS

In this descriptive qualitative study, eight children (ages 8-20 years) and their parents participated in semi-structured interviews. The interviews were audio-recorded and transcribed. Coded data were the foundation for central theme development.

RESULTS

Three main themes were generated. "Run faster, jump higher, do more" (the benefits of RSP use), "Every leg serves its purpose" (comparing functionality between daily use prostheses and RSPs), and "A lot more to think about" (additional considerations with RSP use).

CONCLUSIONS

RSPs have a positive impact in promoting children's engagement in sports and physical activities. While some children used their RSP primarily for running, others wore it for a broader range of physical activities. Issues with balance and discomfort caused by leg length discrepancies and/or ill-fitting sockets limited daily wear time. Limitations related to current RSP designs and clinical implementation should be addressed to optimize the functional potential of children with unilateral or bilateral LLA.Implications for rehabilitationRunning-specific prostheses (RSPs) positively impacted children's ability to participate in some sports with peers promoting their physical and social well-being.The main issues that children faced were discomfort, difficulty balancing, and inability to use RSPs for certain sports, while parents' issues focused on supporting prosthesis use and transport, and adjustments of different prostheses to keep up with their child's growth.Clinicians should be aware of the challenges of RSP use to best support children and their families.Designers should focus on addressing limitations with current RSPs to facilitate the diverse needs of pediatric users.

Air microfluidics-enabled soft robotic transtibial prosthesis socket liner toward dynamic management of residual limb contact pressure and volume fluctuation

Residual limb volume fluctuation and the resulting contact pressures are some of the key factors leading to skin ulcerations, suboptimal prosthetic functioning, pain, and diminishing quality of life of transtibial amputees. Self-management of socket fit is complicated by peripheral neuropathy, reducing the perception of pressure and pain in the residual limb. We introduce a novel proof-of-concept for a transtibial prosthetic socket liner with the potential to dynamically adjust the fit between the limb and socket. The core of the technology is a small air microfluidic chip (10 cm³ and 10 g) with 10 on-chip valves that enable sequential pressurizing of 10 actuators in custom sizes to match the pressures required by the residual limb's unique anatomy. The microfluidic chip largely reduced the number of electromechanical solenoid valves needed for sequential control of 10 actuators (2 instead of 10 valves), resulting in the reduction of the required power, size, mass, and cost of the control box toward an affordable and wearable prosthetic socket. Proof-of-concept testing demonstrated that the applied pressures can be varied in the desired sequence and to redistribute pressure. Future work will focus on integrating the system with biofidelic prosthetic sockets and residual limb models to investigate the ability to redistribute pressure away from pressure-sensitive regions (e.g., fibular head) to pressure tolerant areas. Overall, the dynamic prosthesis socket liner is very encouraging for creating a dynamic socket fit system that can be seamlessly integrated with existing socket fabrication methods for managing residual limb volume fluctuations and contact pressure.

Scoping review to evaluate existing measurement parameters and clinical outcomes of transtibial prosthetic alignment and socket fit

INTRODUCTION

Fit and alignment are observable objectives of the prosthesis rendering process for individuals with lower limb amputation. Nevertheless, there is a dearth of validated measures to directly assess the quality of this clinical procedure.

OBJECTIVES

The objectives of this scoping review are to evaluate existing measurement parameters and clinical outcomes used in investigations of transtibial socket fit or prosthetic alignment and to identify gaps in the literature regarding tools for evaluation of prosthetic fitting.

STUDY DESIGN

Scoping literature review.

METHODS

A comprehensive search was conducted in the following databases: MEDLINE (through PubMed), Embase (through Elsevier), Scopus (through Elsevier), and Engineering Village (through Elsevier), resulting in 6107 studies to be screened.

RESULTS

Sixty-three studies were included in the review. When measuring fit, studies most frequently reported on patient-reported comfort (n = 22) and socket size compared with the residual limb volume (n = 9). Alignment was most frequently measured by the prosthetists' judgment and/or use of an alignment jig (n = 34). The measurement parameters used to determine alignment or fit varied greatly among the included studies.

CONCLUSION

This review demonstrated that most measures of socket fit rely on a patient's self-report and may vary with biopsychosocial factors unrelated to the socket fitting process. Meanwhile, alignment is determined mostly by the prosthetist's judgment, paired with objective measurements, such as alignment jigs and gait analysis. Efforts to standardize and validate measures of these parameters of prosthetic fitting are vital to improving clinical practice and reporting outcomes.

Impacts of Microprocessor-Controlled Versus Non-microprocessor-Controlled Prosthetic Knee Joints Among Transfemoral Amputees on Functional Outcomes: A Comparative Study

INTRODUCTION

Selecting a prosthetic knee mechanism is an important part of transfemoral (TF) amputee rehabilitation. Prosthetic knee joint selection depends on the users' gait and their energy consumption. This study compares the feedback of transfemoral prosthesis users based on the prosthetic knee design self-reporting responses using the Prosthetic Evaluation Questionnaire (PEQ) outcome measure.

OBJECTIVE

This study aims to assess the impact of using a microprocessor-controlled prosthetic knee (MCPK) compared with a non-microprocessor-controlled prosthetic knee (NMCPK); feedback on the amputee usage can improve the clinical decision for proper prosthetic knee joint selection.

METHODS

This is a cross-sectional study with a total of 76 adult unilateral transfemoral amputees classified into two groups. The participants in the first group (38) used the MCPK (Genium, Otto Bock, Minneapolis, MN, USA), and the participants in the second group (38) used the NMCPK (hydraulic and total knee joints). Enrolment was based on a sequence of appointments where all participants answered the PEQ, with different subscale questions including utility (UT), sounds (SO), appearance (AP), residual limb health (RL), frustration (FR), perceived response (PR), social burden (SB), ambulation (AM), and quality of life (QoL). PEQ was filled out during the follow-up appointments at the prosthetic clinic through a visual analog scale (VAS). All data entered into a database were analyzed.

RESULT

The MCPK participants have significantly improved utility, appearance, ambulation, and total PEQ score, the same results as the male participants. Middle-adulthood (25-40 years) MCPK participants have a significant p-value in the score of utility, frustration, ambulation, and total PEQ score compared to early-adulthood (18-24 years) and late-adulthood (41-60 years) participants. Also, there was a significant improvement in the p-value in ambulation scores in participants using MCPK with amputations caused by diseases compared to amputations caused by trauma and congenital cause.

CONCLUSION

Transfemoral amputee prosthesis utility, natural gait, and ambulation improved when using MCPK compared to when using NMCPK during prosthetic rehabilitation.

Biomechanical evaluation over level ground walking of user-specific prosthetic feet designed using the lower leg trajectory error framework

The walking pattern and comfort of a person with lower limb amputation are determined by the prosthetic foot’s diverse set of mechanical characteristics. However, most design methodologies are iterative and focus on individual parameters, preventing a holistic design of prosthetic feet for a user’s body size and walking preferences. Here we refined and evaluated the lower leg trajectory error (LLTE) framework, a novel quantitative and predictive design methodology that optimizes the mechanical function of a user’s prosthesis to encourage gait dynamics that match their body size and desired walking pattern. Five people with unilateral below-knee amputation walked over-ground at self-selected speeds using an LLTE-optimized foot made of Nylon 6/6, their daily-use foot, and a standardized commercial energy storage and return (ESR) foot. Using the LLTE feet, target able-bodied kinematics and kinetics were replicated to within 5.2% and 13.9%, respectively, 13.5% closer than with the commercial ESR foot. Additionally, energy return and center of mass propulsion work were 46% and 34% greater compared to the other two prostheses, which could lead to reduced walking effort. Similarly, peak limb loading and flexion moment on the intact leg were reduced by an average of 13.1%, lowering risk of long-term injuries. LLTE-feet were preferred over the commercial ESR foot across all users and preferred over the daily-use feet by two participants. These results suggest that the LLTE framework could be used to design customized, high performance ESR prostheses using low-cost Nylon 6/6 material. More studies with large sample size are warranted for further verification.

Psychometric evaluation of the Arabic version of the Quebec user evaluation of satisfaction with assistive technology (A-QUEST 2.0) in prosthesis users

BACKGROUND

The evaluation of patient satisfaction and perceptions plays a vital role in determining the quality of prosthesis users' devices and the competency of healthcare services.

AIM

To evaluate the psychometric properties of the Arabic Quebec User Evaluation of Satisfaction with Assistive Technology (A-QUEST 2.0) with prosthetics users.

DESIGN

A methodological study.

SETTING

Saudi Arabia, Turkey.

POPULATION

A convenience sample of outpatient prosthesis users (N.=183).

METHODS

The A-QUEST 2.0 includes two subscales respectively evaluating the user's satisfaction with the device and the services provided. The data for each subscale were investigated using Rasch analysis to evaluate the item fit, reliability indices, item difficulty, local item dependency, and differential item functioning (DIF).

RESULTS

Both subscales met the Rasch criteria for the functioning of rating scale categories. All items showed an acceptable fit to the Rasch model. The person separation indices for the Device and Services subscales were 2.21 (Cronbach's α=0.90) and 1.72 (Cronbach's α=0.85), respectively. Therefore, the two subscales are sensitive enough to distinguish between at least three different levels of satisfaction. The unidimensionality of each subscale was confirmed, and none of the items displayed differential item functioning across age, gender, location of amputation, country, and duration of use.

CONCLUSIONS

Overall, the findings indicate the psychometric evaluation of A-QUEST 2.0 is effective with prosthesis users across different clinical contexts and cultures. Thus, the A-QUEST 2.0 allows for a comprehensive understanding of users' perceptions of prosthesis characteristics, particularly among subjects with lower limb amputations caused by traumatic injuries.

CLINICAL REHABILITATION IMPACT

Our paper provides clinicians dealing with Arabic patients a validated outcome measure for satisfaction with prosthesis. Besides providing information in the development of new products and service delivery. Further studies are necessary to improve the measure's metric quality in different contexts and for different prosthesis devices.

Prosthesis satisfaction and quality of life in US service members with combat-related major lower-limb amputation

BACKGROUND

Military amputee patient care programs offer extensive services, including advanced prosthetic devices, to restore function and improve quality of life (QOL) among veterans and service members with combat-related limb loss, but research on satisfaction with these devices is limited.

OBJECTIVE

To assess prosthesis satisfaction and QOL in US service members and veterans with combat-related major lower-limb amputation.

STUDY DESIGN

Cross-sectional study.

METHODS

Eighty-six participants with combat-related major lower-limb amputation completed the Orthotics and Prosthetics Users' Survey (OPUS) Satisfaction with Device scale and Quality of Well-Being Scale, Self-Administered, for the Wounded Warrior Recovery Project.

RESULTS

Most participants (62%-88%) responded Agree or Strongly Agree to OPUS Satisfaction with Device items on the fit, weight, comfort, ease of donning, appearance, and durability of their prosthesis. By contrast, the majority of participants (55%-79%) responded Disagree or Strongly Disagree to items on clothes being free of wear and tear, skin free of abrasions and irritations, and the affordability of their prosthesis. In linear regression analysis, total OPUS Satisfaction with Device score was positively associated with Quality of Well-Being Scale, Self-Administered score (β = 0.0058; P = 0.004).

CONCLUSIONS

Findings indicate the majority of participants were satisfied with the overall functionality of their prosthesis, but dissatisfied with the effect of their prosthesis on clothing and skin, as well as expenses related to their prosthesis. Additionally, prosthesis satisfaction was positively associated with QOL.

Limb Salvage Surgery in Osteosarcoma of the Femur Using Liquid-Nitrogen-Frozen Free Femur Autograft in a Developing Country

Introduction

Limb salvage is a technically demanding and capital intensive procedure. In low-income countries, amputation followed by prosthesis use is widely used for the treatment of limb malignancies. This is associated with considerable morbidity and frequent non-adherence to prosthetic use. Therefore, we are reporting a case of osteosarcoma of the femur treated by the use of pre-operative chemotherapy, followed by frozen free femur autograft and intramedullary nailing, with excellent radiologic and functional results at 1 year of follow-up, in a developing country.

Case Report

A 16-year-old female presented with the left thigh swelling and pain for 3 months. X-ray of the left femur showed an osteosclerotic tumor in the medial aspect of the middle third of the left femur, diagnosed as osteogenic sarcoma on biopsy. Pre-operative chemotherapy was given. En bloc resection of the tumor was done. The cleaned femur shaft was frozen in liquid nitrogen, reimplanted, and stabilized with an intramedullary nail. One year after surgery, the femur osteotomy sites are fully united and the patient is fully ambulant, without evidence of metastasis or recurrence.

Conclusion

This case describes the successful use of a free frozen autograft of the femur in a 16-year-old girl with osteosarcoma of the left femur, done in a developing country, Kenya. It demonstrates the feasibility of limb salvage using this technique in low-income countries.

Viscoelastic Polyurethane Foams for Use as Auxiliary Materials in Orthopedics

One of the essential factors in prostheses is their fitting. To assemble a prosthesis with the residual limb, so-called liners are used. Liners used currently are criticized by users for their lack of comfort, causing excessive sweating and skin irritation. The objective of the work was to develop viscoelastic polyurethane foams for use in limb prostheses. As part of the work, foams were produced with different isocyanate indexes (0.6–0.9) and water content (1, 2 and 3 php). The produced foams were characterized by scanning electron microscopy, computer microtomography, infrared spectroscopy, thermogravimetry and differential scanning calorimetry. Measurements also included apparent density, recovery time, rebound elasticity, permanent deformation, compressive stress value and sweat absorption. The results were discussed in the context of modifying the foam recipe. The performance properties of the foams, such as recovery time, hardness, resilience and sweat absorption, indicate that foams that will be suitable for prosthetic applications are foams with a water content of 2 php produced with an isocyanate index of 0.8 and 0.9.

Survey of transfemoral amputee experience and priorities for the user-centered design of powered robotic transfemoral prostheses

BACKGROUND

Transfemoral amputees experience a complex host of physical, psychological, and social challenges, compounded by the functional limitations of current transfemoral prostheses. However, the specific relationships between human factors and prosthesis design and performance characteristics have not yet been adequately investigated. The present study aims to address this knowledge gap.

METHODS

A comprehensive single-cohort survey of 114 unilateral transfemoral amputees addressed a broad range of demographic and clinical characteristics, functional autonomy, satisfaction and attitudes towards their current prostheses, and design priorities for an ideal transfemoral prosthesis, including the possibility of active assistance from a robotic knee unit. The survey was custom-developed based on several standard questionnaires used to assess motor abilities and autonomy in activities of daily living, prosthesis satisfaction, and quality of life in lower-limb amputees. Survey data were analyzed to compare the experience (including autonomy and satisfaction) and design priorities of users of transfemoral prostheses with versus without microprocessor-controlled knee units (MPKs and NMPKs, respectively), with a subsequent analyses of cross-category correlation, principal component analysis (PCA), cost-sensitivity segmentation, and unsupervised K-means clustering applied within the most cost-sensitive participants, to identify functional groupings of users with respect to their design priorities.

RESULTS

The cohort featured predominantly younger (< 50 years) traumatic male amputees with respect to the general transfemoral amputee population, with pronounced differences in age distribution and amputation etiology (traumatic vs. non-traumatic) between MPK and NMPK groups. These differences were further reflected in user experience, with MPK users reporting significantly greater overall functional autonomy, satisfaction, and sense of prosthesis ownership than those with NMPKs, in conjunction with a decreased incidence of instability and falls. Across all participants, the leading functional priorities for an ideal transfemoral prosthesis were overall stability, adaptability to variable walking velocity, and lifestyle-related functionality, while the highest-prioritized general characteristics were reliability, comfort, and weight, with highly variable prioritization of cost according to reimbursement status. PCA and user clustering analyses revealed the possibility for functionally relevant groupings of prosthesis features and users, based on their differential prioritization of these features-with implications towards prosthesis design tradeoffs.

CONCLUSIONS

This study's findings support the understanding that when appropriately prescribed according to patient characteristics and needs in the context of a proactive rehabilitation program, advanced transfemoral prostheses promote patient mobility, autonomy, and overall health. Survey data indicate overall stability, modularity, and versatility as key design priorities for the continued development of transfemoral prosthesis technology. Finally, observed associations between prosthesis type, user experience, and attitudes concerning prosthesis ownership suggest both that prosthesis characteristics influence device acceptance and functional outcomes, and that psychosocial factors should be specifically and proactively addressed during the rehabilitation process.

A Focus Group- and Patient-Driven Study to Understand Patients' and Health Care Providers' Perspectives on Services for People with Amputation

Purpose: This study investigates patients' and health care providers' perspectives on the services provided for people with amputation in Saskatoon. Method: We used a qualitative approach, following the Delphi method. A patient-oriented research team designed five questions and presented them to two focus groups. The discussions focused on what worked well in the health care system and what could be improved, what could be improved in the community, future research, and ways to improve specific knowledge translation regarding care of people with amputation to therapists. Results: The two focus groups consisted of 48 panellists, all community members and health care professionals. The themes that emerged included positive experiences with prosthetic care and the individual people responsible for amputee care and improvements needed to streamline the pathways of care, community support, education, and research into all aspects of amputation. Conclusions: Amputation is not just a one-time medical procedure; people with amputation need lifelong support from health care providers and the community. Clear pathways of care, access to immediate support, amputee-specific education for health care providers, better patient education, increased physical therapy, and enhanced resources and care were identified as areas in need of improvement. This study will, we hope, form the basis of future research to continually improve the quality of care and support for people living with amputation.

Patient-reported benefits of bone-anchored transfemoral prostheses as assessed by MedTech20: A general outcome measure for medical products

BACKGROUND

The medical community demands evidence for the benefits of medical devices such as bone-anchored prostheses (BAPs). MedTech20  is a novel instrument aiming to address general benefits of medical devices.

OBJECTIVE

To describe general patient-reported benefits of BAPs measured with MedTech20.

STUDY DESIGN

This is a cross-sectional descriptive survey.

METHODS

Patients treated in Sweden who had used a BAP for >1 year were mailed the MedTech20  Questionnaire. Responses to each attribute were described, and the MedTech20   Index (0-1), in which a higher figure represents larger benefits from the product, was calculated. Index values were compared based on demographic variables (sex, unilateral or bilateral transfemoral amputation (TFA), and those having experienced any complication of implant parts or the prosthetic connection device).

RESULTS

The response rate was 72%. The 62 participants (41 men and 21 women; mean age 57 years) had 11 ± 6.9 mean years of BAP experience. Single attributes stated as highly relevant and with high benefit for BAPs included perceived reliability, perceived safety, sense of control of the disability, facilitation of movement outside home, no discomfort at use, and ease of use. Attributes with less relevance included aid to remember tasks, reduction of barriers to a good sleep, and reduced sense of compromised integrity. The MedTech20  Index was 0.655 ± 0.188 and was not statistically significantly different based on any of the demographic variables.

CONCLUSIONS

By using a general measure on attributes of medical devices, this study provides new insights strengthening the evidence regarding the benefits that BAPs provide for patients with TFA who had difficulties with socket-suspended prostheses.

A Scoping Review of Pressure Measurements in Prosthetic Sockets of Transfemoral Amputees during Ambulation: Key Considerations for Sensor Design

Sensor systems to measure pressure at the stump–socket interface of transfemoral amputees are receiving increasing attention as they allow monitoring to evaluate patient comfort and socket fit. However, transfemoral amputees have many unique characteristics, and it is unclear whether existing research on sensor systems take these sufficiently into account or if it is conducted in ways likely to lead to substantial breakthroughs. This investigation addresses these concerns through a scoping review to profile research regarding sensors in transfemoral sockets with the aim of advancing and improving prosthetic socket design, comfort and fit for transfemoral amputees. Publications found from searching four scientific databases were screened, and 17 papers were found relating to the aim of this review. After quality assessment, 12 articles were finally selected for analysis. Three main contributions are provided: a de facto methodology for experimental studies on the implications of intra-socket pressure sensor use for transfemoral amputees; the suggestion that associated sensor design breakthroughs would be more likely if pressure sensors were developed in close combination with other types of sensors and in closer cooperation with those in possession of an in-depth domain knowledge in prosthetics; and that this research would be facilitated by increased interdisciplinary cooperation and open research data generation.

Compression and tension behavior of the prosthetic foam materials polyurethane, EVA, Pelite™ and a combination of polyurethane and EVA: a preliminary study

Materials with low-strength and low-impedance properties, such as elastomers and polymeric foams are major contributors to prosthetic liner design. Polyethylene-Light (Pelite™) is a foam liner that is the most frequently used in prosthetics but it does not cater to all amputees' limb and skin conditions. The study aims to investigate the newly modified Foam Liner, a combination of two different types of foams (EVA + PU + EVA) as the newly modified Foam Liner in terms of compressive and tensile properties in comparison to Pelite™, polyurethane (PU) foam, and ethylene-vinyl acetate (EVA) foam. Universal testing machine (AGS-X, Shimadzu, Kyoto, Japan) has been used to measure the tensile and compressive stress. Pelite™ had the highest compressive stress at 566.63 kPa and tensile stress at 1145 kPa. Foam Liner fell between EVA and Pelite™ with 551.83 kPa at compression and 715.40 kPa at tension. PU foam had the lowest compressive stress at 2.80 kPa and tensile stress at 33.93 kPa. Foam Liner has intermediate compressive elasticity but has high tensile elasticity compared to EVA and Pelite™. Pelite™ remains the highest in compressive and tensile stiffness. Although it is good for amputees with bony prominence, constant pressure might result in skin breakdown or ulcer. Foam Liner would be the best for amputees with soft tissues on the residual limbs to accommodate movement.

Investigation of Orthopedic Prosthesis Socket Management after Transfemoral Amputation by Expert Survey

Prosthesis treatment requires the close interaction of different actors. In fitting prostheses to patients, special attention is given to the manufacturing of the socket. The continuous development of the technologies involved in the fitting and optimization of prostheses is shown in the literature. The assessment of orthopedic technicians and their influence in the process is thus far largely unexplored. Ten orthopedic technicians were interviewed about the socket fitting process after transfemoral amputation. The research goal was to clarify the socket treatment process with regards to the German context. The results showed that the orthopedic technicians focussing on the patient during the fitting process. This study underlines the importance of interaction and empathy. Volume fluctuations are decisive within the treatment process and are interactively influenced by various factors. Furthermore, the research emphasizes the need for appropriate assistive technologies and the potential for the further development of existing systems.

CHECKLIST USE FOR ASSESSMENT OF SATISFACTION WITH TRANS-TIBIAL PROSTHESES

Objective

To assess satisfaction of prosthesis users with their prostheses, and the problems they experience with the residual limb, using a checklist, in order to evaluate potential benefits of checklist use and to summarize issues and problems with the prosthesis and/or residual limb presented by prosthesis users.

Design

Cross-sectional study.

Subjects

Participants were adult trans-tibial prosthesis users (n = 82) and certified prosthetist orthotist (n = 19) experienced in fitting lower-limb prostheses.

Methods

Prosthesis users reported their reasons for consultation and factors concerning prosthesis (dis)satisfaction and residual limb problems, using a checklist. Checklist use was evaluated by certified prosthetist orthotists and prosthesis users and the significance of evaluation scores was determined.

Results

Checklist use identified 126 issues/problems, most of which concerned prosthesis fit (33%) and pressure points on the residual limb skin (26%). Evaluation scores were significantly higher than neutral regarding the checklist helping the certified prosthetist orthotist to gather more information and to make clear with which issues the prosthesis user was dissatisfied. Prosthesis users reported that checklist use made them feel more understood by the certified prosthetist orthotist.

Conclusion

Checklist use in the assessment of trans-tibial prostheses is beneficial in identifying factors related to dissatisfaction, and improves the quality of certified prosthetist orthotists’ consultation. The implementation of checklist use is, however, challenging.

The comprehensive lower limb amputee socket survey: Reliability and validity of the persian version

BACKGROUND

The Comprehensive Lower limb Amputee Socket Survey (CLASS) is a self-reported measure developed to assess prosthetic socket fit in individuals with lower limb amputation.

OBJECTIVE

To assess the reliability and validity of the Persian version of the CLASS.

STUDY DESIGN

Cross-sectional and repeated-measures.

METHODS

We evaluated the translation and back translation of the CLASS and made the required changes according to expert committee feedback. Then, we recruited 124 participants with unilateral lower limb amputation (89.5% men). Internal consistency was analyzed with Cronbach's alpha and test-retest reliability using intra-class correlation coefficients. Convergent construct validity was assessed by comparing the CLASS scores with the Persian version of the Trinity Amputation and Prosthesis Experience Scales (TAPES) scores. In addition, known groups construct validity was assessed by comparing CLASS scores between groups with different causes and levels of amputation.

RESULTS

Cronbach's alpha coefficient represented a very good internal consistency for all domains of the Persian CLASS (ranged from 0.86 to 0.92). The intra-class correlation coefficient for test-retest reliability for the Persian CLASS was good to excellent (ranged from 0.73 to 0.97). There was a significant correlation between the subscales of the Persian CLASS and satisfaction subscales of the Persian TAPES (p < 0.001). There was significant difference between comfort subscale of the Persian CLASS scores by level of amputation.

CONCLUSION

The Persian CLASS is a reliable and valid measure for evaluating prosthetic socket fit.

A Conceptual Blueprint for Making Neuromusculoskeletal Models Clinically Useful

The ultimate goal of most neuromusculoskeletal modeling research is to improve the treatment of movement impairments. However, even though neuromusculoskeletal models have become more realistic anatomically, physiologically, and neurologically over the past 25 years, they have yet to make a positive impact on the design of clinical treatments for movement impairments. Such impairments are caused by common conditions such as stroke, osteoarthritis, Parkinson’s disease, spinal cord injury, cerebral palsy, limb amputation, and even cancer. The lack of clinical impact is somewhat surprising given that comparable computational technology has transformed the design of airplanes, automobiles, and other commercial products over the same time period. This paper provides the author’s personal perspective for how neuromusculoskeletal models can become clinically useful. First, the paper motivates the potential value of neuromusculoskeletal models for clinical treatment design. Next, it highlights five challenges to achieving clinical utility and provides suggestions for how to overcome them. After that, it describes clinical, technical, collaboration, and practical needs that must be addressed for neuromusculoskeletal models to fulfill their clinical potential, along with recommendations for meeting them. Finally, it discusses how more complex modeling and experimental methods could enhance neuromusculoskeletal model fidelity, personalization, and utilization. The author hopes that these ideas will provide a conceptual blueprint that will help the neuromusculoskeletal modeling research community work toward clinical utility.