Prosthetic Knee Selection for Individuals with Unilateral Transfemoral Amputation: A Clinical Practice Guideline

A disparity in prosthetic access for Ecuadorians with lower-limb amputation

BACKGROUND

Individuals with disabilities in low- and middle-income countries face barriers to rehabilitation services, including prosthetic care. Many countries, such as Ecuador, have adapted policies toward achieving universal health care coverage. For optimal functional outcomes, understanding the physical potential of prosthetic users is critical for appropriate prosthetic services.

OBJECTIVE

To determine the association between the functional level of Ecuadorians with lower-limb amputations and the functional level of their prosthetic componentry.

STUDY DESIGN

Retrospective study.

METHODS

A data set containing functional level (K-Level) of Ecuadorians with lower-limb amputations and the K-Level of their prosthesis was analyzed.

RESULTS

A diverse cohort of 164 participants with unilateral lower-limb amputation was recruited. Most participants were male (76.8%) with transfemoral amputations (56.1%) due to traumatic causes (51.2%). There was a small, positive, and statistically significant correlation between participants' functional levels and prosthetic componentry. Participants's functional levels were typically superior (median = 3) to their prostheses' functional abilities (median = 1), and 37.2% of participants did not have a prosthesis at the time of assessment.

CONCLUSIONS

These data indicated that participants whose physical ability exceeded basic ambulation lacked access to prostheses to match their functional abilities. The detailed disparity between physical potential and prosthetic access derived from the study's analysis supports investment into high functioning prosthetic componentry and further investigation into where gaps in care exist.

Lower limb prosthetic prescription

Lower limb amputations are the most common level of amputation. Mobilization of patients with lower limb amputations is an important rehabilitation goal. It is critical to prescribe the most appropriate prosthesis for the patient to achieve the rehabilitation goal in lower extremity amputations. Appropriate prosthesis prescription in lower extremity amputations is based on the selection of the correct prosthetic parts. The choice of prosthesis should be based on the patient's activity level and potential. The prosthesis decision should be made by a team, particularly with the participation of the patient.

[Objective measurement tools that predict success in the fitting of major unilateral lower limb amputations patients]

The profile of the patient who most frequently suffers lower limb amputations is usually an elderly patient with high comorbidity. Physiatrists need objective tools in the assessment of these patients that predict the results of prosthetic programs to increase patient safety and efficiency of prosthetic rehabilitation programs. Given the need to update scientific knowledge in this field, we have carried out a review of the literature with the aim of defining a proposal for tools that facilitate decision-making in the indication of prosthetic rehabilitation in these patients. A bibliographic search strategy has been carried out using the scientific databases PubMed, Web of Science, Scopus and Cochrane Library. The quality of the selected articles has been assessed according to the tools proposed by CASPe.

Transfemoral interface considerations: A clinical consensus practice guideline

BACKGROUND

Although there have been a number of studies exploring the impact and efficacy of transfemoral prosthetic components such as knee and foot mechanisms, the empirical evidence surrounding transfemoral prosthetic interface considerations is limited. This constitutes a substantial void for practicing clinicians seeking to apply best practices for patients who use transfemoral prostheses. Recent years have seen increased production and availability of clinical practice guidelines germane to prosthetic rehabilitation. In those areas where empirical evidence is lacking, consensus clinical opinions may constitute the highest level of evidence.

OBJECTIVE

A consensus exercise was performed to generate clinical practice recommendations in the areas of transfemoral interface considerations including socket variations and critical design features, suspension and interface considerations, alignment, heat retention and dermatologic considerations, female considerations, surgical considerations, and both regulatory and ethical considerations related to osseointegration.

METHODS

This began with the generation of postulate items through systematic and narrative literature reviews. A Delphi consensus exercise was performed among clinical experts in government hospital and private clinical practice settings, culminating in a series of clinical practice recommendations associated with the prosthesis-limb interface for individuals with transfemoral amputation.

RESULTS

The completed recommendations include guidance statements relative to socket variations and critical design features, female considerations, suspension and interface considerations, surgical variations and prescription considerations, rehabilitation team considerations and both regulatory and ethical considerations related to osseointegration.

CONCLUSIONS

The Delphi process facilitated the development of practice guidelines for transfemoral prosthetic interface considerations based on aggregated subject matter expertise.

Normalized kinematic walking symmetry data for individuals who use lower-limb prostheses: considerations for clinical practice and future research

Introduction

Individuals who use unilateral transtibial or transfemoral prostheses have negative secondary health effects associated with decreased kinematic (e.g., spatiotemporal and joint angle) walking symmetry between prosthetic and intact limbs. Research studies have quantified kinematic walking symmetry, but studies can be difficult to compare owing to the inclusion of small sample sizes and differences in participant demographics, biomechanical parameters, and mathematical analysis of symmetry. This review aims to normalize kinematic walking symmetry research data across studies by level of limb loss and prosthetic factors to inform considerations in clinical practice and future research.

Methods

A search was performed on March 18, 2020, in PubMed, Scopus, and Google Scholar to encompass kinematic walking symmetry literature from the year 2000. First, the most common participant demographics, kinematic parameters, and mathematical analysis of symmetry were identified across studies. Then, the most common mathematical analysis of symmetry was used to recalculate symmetry data across studies for the five most common kinematic parameters.

Results

Forty-four studies were included in this review. The most common participant demographics were younger adults with traumatic etiology who used componentry intended for higher activity levels. The most common kinematic parameters were step length, stance time, and sagittal plane ankle, knee, and hip range of motion. The most common mathematical analysis was a particular symmetry index equation.

Conclusions

Normalization of data showed that symmetry tended to decrease as level of limb loss became more proximal and to increase with prosthetic componentry intended for higher activity levels. However, most studies included 10 or fewer individuals who were active younger adults with traumatic etiologies.

Clinical Relevance

Data summarized in this review could be used as reference values for rehabilitation and payer justification. Specifically, these data can help guide expectations for magnitudes of walking symmetry throughout rehabilitation or to justify advanced prosthetic componentry for active younger adults under 65 years of age with traumatic etiologies to payers.

3D printed transtibial prosthetic sockets: A systematic review

The prosthetic socket, which transfers load from the residual limb to the prosthesis, is an integral part of the prosthesis. 3D printing has emerged as a potentially viable alternative to traditional fabrication for producing sockets that effectively transfer loads. We conducted a systematic review to better understand the current state of this newer fabrication method, with a focus on the structural integrity of 3D printed sockets and factors that can affect the strength of 3D printed sockets when tested using ISO 10328 standards. Literature searches were carried out in five databases (PubMed, Scopus, CINAHL, Web of Science and Google Scholar). Two reviewers independently performed the literature selection, quality assessment, and data extraction. A total of 1023 unique studies were screened in accordance with inclusion and exclusion criteria. Of 1023 studies, 12 studies met all inclusion criteria, with failure data for 15 3D-printed sockets and 26 standard laminated sockets. Within 3D printed sockets, the addition of composite materials such as carbon fiber particles and distal reinforcement using a compositing infill technique appears to improve socket strength. In light of the considerable amount of heterogeneity between studies in terms of materials and alignment used, the absolute values for failure could not be established for 3DS nor directly compared between 3DS and LCS. However, there is some evidence that the probability of a failure at a given load may be comparable between 3DS and LCS up to the P8 level. For all sockets, whether a laminated composite socket or a 3D printed socket, failure mainly occurred at the distal end of the socket or the pyramid attachment, which is consistent with the ISO testing protocol. Improving the strength of the 3D printed sockets through design modifications at the distal end and implementing emerging printing technologies could help to promote 3D printed sockets as a viable option, particularly when cost or access to care is limited.

Ambulation Control System Design for a Hybrid Knee Prosthesis

Prosthetic knees available to individuals with transfemoral amputation seek to restore functional ability to the user. Passive prosthetic knees are lightweight but can restore only limited, dissipative ambulation activities whereas active knees can provide energy to restore additional ambulation activities such as stair climbing and standing up from a chair. Semi-active prosthetic devices aim to only power a subset of activities and use passive components and control when that power is not necessary. Here, we outline an ambulation control system for a lightweight Hybrid Knee prosthesis that is powered for climbing stairs and passive for other ambulation activities (level-ground walking, walking on an incline, and stair descent). We include preliminary offline and online intent recognition system results for one able-bodied user and one individual with a transfemoral amputation demonstrating low error rates in predicting between active and passive control.

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.

Degree of Safety Against Falls Provided by 4 Different Prosthetic Knee Types in People With Transfemoral Amputation: A Retrospective Observational Study

OBJECTIVE

People with transfemoral amputation have balance and mobility problems and are at high risk of falling. An adequate prosthetic prescription is essential to maximize their functional levels and enhance their quality of life. This study aimed to evaluate the degree of safety against falls offered by different prosthetic knees.

METHODS

A retrospective study was conducted using data from a center for prosthetic fitting and rehabilitation. Eligible individuals were adults with unilateral transfemoral amputation or knee disarticulation. The prosthetic knee models were grouped into 4 categories: locked knees, articulating mechanical knees (AMKs), fluid-controlled knees (FK), and microprocessor-controlled knees (MPK). The outcome was the number of falls experienced during inpatient rehabilitation while wearing the prosthesis. Association analyses were performed with mixed-effect Poisson models. Propensity score weighting was used to adjust causal estimates for participant confounding factors.

RESULTS

Data on 1486 hospitalizations of 815 individuals were analyzed. Most hospitalizations (77.4%) were related to individuals with amputation due to trauma. After propensity score weighting, the knee category was significantly associated with falls. People with FK had the highest rate of falling (incidence rate = 2.81 falls per 1000 patient days, 95% CI = 1.96 to 4.02). FK significantly increased the risk of falling compared with MPK (incidence rate ratio [IRRFK-MPK] = 2.44, 95% CI = 1.20 to 4.96). No other comparison among knee categories was significant.

CONCLUSIONS

Fluid-controlled prosthetic knees expose inpatients with transfemoral amputation to higher incidence of falling than MPK during rehabilitation training.

IMPACT

These findings can guide clinicians in the selection of safe prostheses and reduction of falls in people with transfemoral amputation during inpatient rehabilitation.

Microprocessor knee technology reduces odds of incurring an injurious fall for individuals with diabetic/dysvascular amputation

Individuals with lower limb amputation have a high incidence of falls. An above-the-knee amputation and diabetes/vascular disease are both risk factors for falls. Microprocessor knee (MPK) technology may reduce falls in this population. The objective was to determine the association of MPKs and reduced injurious falls. A retrospective analysis of injurious falls within a large, national outcomes database was conducted. Inclusion was limited to adult K3 ambulators with unilateral, transfemoral or knee disarticulation amputation due to diabetes/vascular disease. There were 744 out of 881 individuals that did not receive an MPK. Results showed that 16.3% of non-MPK users experienced an injurious fall compared to 7.3% of MPK users (p=0.007). Not having an MPK resulted in significantly increased odds (unadjusted: OR: 2.47, 95% CI: 1.26 - 4.83, p=0.009; adjusted for confounders: OR: 2.52, 95% CI: 1.28 - 4.94, p=0.007) of incurring an injurious fall over a 6-month period. In conclusion, the current study found use of an MPK strongly associated with reduced injurious falls in a population of patients with amputation due to diabetes/vascular disease. The findings strongly support the use of MPK technology to mitigate fall risk, and in particular injurious falls requiring medical intervention.

Clinical Outcomes Comparing Two Prosthetic Knee Designs in Individuals with Unilateral Transfemoral Amputation in Turkey

BACKGROUND

Clinical outcome assessments provide important input for the rehabilitation of individuals with transfemoral amputation. Differences in prosthetic knee designs may influence clinical outcomes.

OBJECTIVES

The aim of this study was to compare functional mobility, balance, prosthetic satisfaction and quality of life in individuals with unilateral transfemoral amputation with microprocessor-controlled (MPK) and non-microprocessor knee designs (Non-MPK).

METHODOLOGY

The study included ten experienced MPK (Rheo Knee) users (Group 1) and ten experienced Non-MPK (Total Knee® 2000) users (Group 2). For mobility; the 6 Minute Walk Test (6MWT), for balance; the Berg Balance Scale (BBS), Single Leg Stand Test (SLST) and Four Square Step Test (FSST), for quality of life; the Nottingham Health Profile (NHP) and for prosthetic satisfaction; the Satisfaction with Prosthesis Questionnaire (SATPRO) were administered.

FINDINGS

6MWT results of the MPK group were significantly higher than Non-MPK group (p<0.05). In the MPK group a strong negative correlation was found between the FSST and the 6MWT (r=-0.661, p=0.038). No statistically significant differences were found between the groups (p>0.05) comparing balance, prosthesis satisfaction and quality of life values.

CONCLUSION

The findings will inform about the patient's prognosis and the expected clinical outcomes when prescribing an MPK or an Non-MPK. Individuals with unilateral transfemoral amputation covered longer distances using an MPK compared to Non-MPK.

Is lower limb salvage worthwhile after severe open tibial fractures in a developing country? An analysis of surgical outcomes, quality of life and cost implications

INTRODUCTION

Open tibial fractures are rare and difficult-to-treat injuries because of the involvement of bony, skin and neuromuscular injury along with co-morbidities. Often, during the management of very severe cases these injuries, the question arises, should we amputate or salvage the limb? This question has been explored previously in civilian and military contexts in the US and UK but remains unstudied in the alternative sociocultural and economic context of the developing world.

METHODS

We studied 78 adult patients with severe open tibial fracture that presented to our institution, a Level 1 trauma center in India, from February 2018 to June 2019. 20 patients underwent above-knee amputation (AKA), 16 underwent below-knee amputation (BKA), and 42 underwent limb salvage. We assessed injury severity using [our institution's] Open Injury Severity Score (GHOISS), which has separate sub-scores for bony injury, skin injury, neuromuscular injury and co-morbidities, and patients were only included with GHOISS > 13. We assessed functional outcome measures as well as economic costs as primary cost levied by our institution and other secondary costs.

RESULTS

Salvage (LEFS: mean=51, SF-12 PCS: mean=48, SF-12 MCS: mean=49) provided better outcomes to BKA (LEFS: mean=39, p=0.005, SF-12 PCS: mean=40, p=0.003, SF-12 MCS: mean=43, p=0.052) and AKA (LEFS: mean=31, p<0.001, SF-12 PCS: mean=34, p<0.001, SF-12 MCS: mean=43, p=0.043). Primary costs were higher for limb salvage (index: mean=$3100, total: mean=$4400) than both BKA (index: mean=$2500, p=0.012, total: mean=$2600, p<0.001) and AKA (index: mean=$2800, p=0.020, total: mean=$3200, p<0.001). Secondary costs were higher for limb salvage than both BKA and AKA (p<0.001). Patients who underwent salvage were more likely to return to work at 36 months post-injury compared to below-knee amputees (adjusted OR=0.11, p=0.010).

CONCLUSIONS

Limb salvage results in better functional outcomes compared with amputation at a higher upfront cost but a likely lower lifetime cost. Unlike other literature on the topic, amputation carries a heavy mental and physical toll in India, likely due to sociocultural differences and stigma. Amputation is a difficult decision for patients to accept and results in poorer outcomes; therefore, we believe that limbs should be aggressively salvaged in our developing country.

STUDY DESIGN

Therapeutic Level II Prospective Cohort Study.

A systematic review of health economic evaluations in orthotics and prosthetics: Part 1 - prosthetics

BACKGROUND

The extent to which current prosthetic health economic evaluations inform healthcare policy and investment decisions is unclear. To further the knowledge in this area, existing evidence gaps and method design issues must be identified, thereby informing the design of future research.

OBJECTIVES

The aim of this systematic review was to identify evidence gaps, critical method design and reporting issues and determine the extent to which the literature informs a wide range of policy and investment decisions.

STUDY DESIGN

Systematic review.

METHODS

A range of databases were searched using intervention- and health economic evaluation-related terms. Issues with methodological design and reporting were evaluated using the Consolidated Health Economic Checklist - Extended and the Checklist for Health Economic Evaluation Reporting Standards.

RESULTS

The existing health economic evaluation literature was narrowly focused on informing within-participant component decisions. There were common method design (e.g. time horizon too short) and reporting issues (e.g. competing intervention descriptions) that limit the extent to which this literature can inform policy and investment decisions.

CONCLUSION

There are opportunities to conduct a wider variety of health economic evaluations to support within- and across-sector policy and investment decisions. Changes to aspects of the method design and reporting are encouraged for future research in order to improve the rigour of the health economic evaluation evidence.

CLINICAL RELEVANCE

This systematic review will inform the clinical focus and method design of future prosthetic health economic evaluations. It will also guide readers and policy-makers in their interpretation of the current literature and their understanding of the extent to which the current literature can be used to inform policy and investment decisions.

Prosthetic management of unilateral transradial amputation and limb deficiency: Consensus clinical standards of care

INTRODUCTION

Upper limb research is currently lacking detailed clinical guidance on the provision of unilateral transradial prostheses. Clinical practice guidelines are meant to serve as assistance for the decision-making process, and Delphi surveys have been used with increasing frequency within orthotics and prosthetics to create these guidelines for clinical practice.

METHODS

A three round Delphi survey was used to gain consensus on clinical statements regarding unilateral transradial prostheses.

RESULTS

We achieved consensus (> 80% agreement) on a total of 40 statements by surveying 22 experts on upper limb prosthetics over three rounds of surveys. Response rate ranged from 81.8-86.4% with a total of 55 total statements under consideration throughout the duration of the survey. The 40 passing statements were arranged into nine guidelines for provision of prosthetic care in this population.

CONCLUSIONS

The Delphi technique allowed for the creation of a set of clinical practice guidelines for the unilateral transradial patient in the absence of conclusive empirical evidence.

Using a Simple Walking Model to Optimize Transfemoral Prostheses for Prosthetic Limb Stability-A Preliminary Study

The interaction between the prescribed prosthetic knee and foot is critical to the safety of transfemoral prosthesis users primarily during the stance phase of the gait, when knee buckling can result in a fall. Nonetheless, there is still a need for standardized approaches to quantify the effects of prosthetic component interactions and associated mechanical function on user gait biomechanics. A numerical model was defined to simulate sagittal plane prosthetic limb stance based on a single inverted pendulum and predict effects of prosthetic knee alignment and foot stiffness on knee moment to identify optimal solutions. Model validation against laboratory gait data suggests it is appropriate to preliminary simulate prosthetic gait during single-limb support, when prosthetic knee stability may be most at risk given reliance on the prosthetic limb and proximal anatomy, but only for knees with flexion smaller than 4°. Model predictions identify a solution space containing those combinations of knee alignment and foot stiffness (via roll-over shape radius) guaranteeing knee stability in early and mid- single-limb support, whilst facilitating knee break at the end of it. Specifically, a posterior to in-line knee alignment should be combined with low to medium ankle-foot stiffness, whereas anterior knee alignments and rigid feet should likely be avoided. Clinicians can use these solution spaces to optimize transfemoral prostheses including knees with little to no change in stance flexion, ensuring the safety of users. Model prediction can further inform in-vivo investigations on commercial device interactions, providing evidence for future Clinical Practice Guidelines on transfemoral prostheses design.

Effects of microprocessor-controlled prosthetic knees on self-reported mobility, quality of life, and psychological states in patients with transfemoral amputations

OBJECTIVE

This study aimed to determine the effects of the microprocessor-controlled prosthetic knee (MPK) joint on self-mobility, body perceptions, depression, and quality of life in patients with unilateral transfemoral amputations (TFAs).

METHODS

Thirty consecutive patients (28 males, mean age=38.5 years, age range=22-57) who had previously used non-MPKs and who were approved to use swing and stance phase-control MPKs were included in this 12-week clinical study. Before the MPK use and after the three-month follow-up, prosthetic use and locomotor capabilities were evaluated using the Houghton Scale and the Locomotor Capabilities Index (LCI-5), respectively. Body perception was assessed using the Amputee Body Image Scale (ABIS). The depressive symptoms and quality of life were evaluated using the Beck Depression Inventory (BDI) score and the 36-Item Short- Form Health Survey (SF-36), respectively.

RESULTS

After MPK use, statistically significant ameliorations were observed in all outcome measures. The basic and advanced LCI-5 increased from 26.7±2.2 and 24.8±5.2 to 27.6±1.2 (p=0.007) and 27±2.1 (p=0.004), respectively. Houghton scores improved from 9±1 to 10.3±0.8 (p=0.000). The ABIS and BDI scores decreased from 43.2±10.9 and 5.7±6.6 to 37.1±8.9 (p=0.000) and 3.8±4.5 (p=0.015), respectively. Also, the SF-36 physical function and vitality subscales increased from 71.2±24.0 and 75.5±14.6 to 85.6±16.6 (p=0.001) and 81.7±14.1 (p=0.015), respectively.

CONCLUSION

MPK use provides significant improvements in the locomotor capabilities, quality of life, and activities of daily living to patients with TFAs as well as improves their body image perceptions and depressive symptoms.

LEVEL OF EVIDENCE

Level III, Self controlled study.

A systematic review on design technology and application of polycentric prosthetic knee in amputee rehabilitation

The objective of this paper is to conduct a systematic review on design technology and clinical application of polycentric prosthetic knee joint in the rehabilitation of trans-femoral amputees. Relevant studies were identified using electronic database such as PubMed, EMBASE, SCOPUS and the Cochrane Controlled Trials Register (Rehabilitation and Related Therapies) up to February 2020. Screening of abstracts and application of inclusion and exclusion criteria were made. Design, modeling, material use, kinematic study, simulation technique and clinical application of polycentric knee models used in many developed and developing countries have been reviewed. Out of 516 potentially relevant studies, 43 articles were included. Specific variables on technical and clinical aspects were extracted and added to summary tables. The results reveal that polycentric knees have a variety of geometries but the methods for comparing their performances are rare. The data of structural analysis using different simulation techniques are validated with experimental results for determining model accuracy. Gait analysis using the polycentric knee components provides a valid tool to correlate with experimental results. There are well-designed studies on the technological development of polycentric knees, however, high-quality clinical researches are scarce. Conventional clinical knowledge had considerable gaps concerning the effects of polycentric knee and their mechanical characteristics on human functioning with a lower-limb prosthesis. Still, further research is needed to develop and implement standardized measures on prosthetic knee joints for their effective use, function, durability, and cost-effectiveness.

CLINICAL GAIT ANALYSIS OF SUBJECTS WITH TRANS-FEMORAL AMPUTATION USING POLYCENTRIC FOUR-BAR LINKAGE PROSTHETIC KNEE JOINT

Background: Adequate research is not reported so far to underline the influence of commonly used polycentric knee joints on gait performance of subjects with trans-femoral amputation. Objective: The intent of this investigation is to analyze prosthetic gait of unilateral traumatic trans-femoral amputees with polycentric four-bar linkage knee and compare it with normal subjects for evaluating any asymmetry in gait performance. Methods: Objective three-dimensional gait analysis of 15 subjects [mean (age): 36.4 (10.7) years] were performed in gait lab through force plate and optoelectronic devices to measure temporal-spatial parameters, kinematic and kinetic performances. Gait patterns of amputees were compared with those of 15 individuals with normal gait to analyze distinct functionalities of existing polycentric knee. Results: Asymmetry in gait was observed between amputees and normal subjects for all variables concerned ([Formula: see text]). Amputee gait was with significantly lesser velocity, cadence with shorter step and stride length. There was significantly less hip, knee and pelvic motions, however, pelvic obliquity and rotation did not show significant difference from the normal subjects. The vertical component of the ground reaction force differed significantly between prosthetic and intact limb [49.7 (8.5)% and 90.4 (7.4)% body weight] and also from normal subjects [107.5 (2.4)% body weight] during stance ([Formula: see text]). Interpretation and Conclusion: This difference may be attributed to nonproportionate loading of limbs and mechanical adaptations for counteracting deficiencies of prosthetic side. This study will help to explain gait asymmetry in trans-femoral amputees and to identify underlying mechanisms to enhance the quality of the existing design of prosthetic knee through optimizing design parameters and utilizing appropriate materials.

Obstacles to Prosthetic Care—Legal and Ethical Aspects of Access to Upper and Lower Limb Prosthetics in Germany and the Improvement of Prosthetic Care from a Social Perspective

Prosthetic technology for people with missing limbs has made great progress in recent decades. However, acceptance rates and user satisfaction are not only dependent on technical aspects, but also to a great extent on social and psychological factors. We propose that these factors should receive greater attention in order to improve prosthetic care and give recommendations how to incorporate the findings from social science in research and development (R&D) and in care practice. Limited access due to high costs of new prosthetic technology combined with rising costs in health care systems in general is a further issue we address. Our legal and ethical analysis of the reimbursement process in Germany shows that this issue requires further empirical investigation, a stakeholder dialogue and maybe even policy changes. Social science knowledge and participatory methods are of high relevance to answer questions about the benefit of prosthetics for users, based on individual needs and preferences, which should be at the core of debates on ethical resource allocation.

OASIS 1: Retrospective analysis of four different microprocessor knee types

INTRODUCTION

Microprocessor knee analyses to date have been primarily limited to microprocessor knees as a category rather than comparisons across different models. The purpose of the current analysis was to compare outcomes from four common knee models.

METHODS

A retrospective analysis of clinical outcomes was performed. Outcomes for functional mobility, quality of life, satisfaction with amputee status, and injurious falls were compared. Specific knee types represented were C-Leg (Ottobock), Orion (Blatchford), Plié (Freedom Innovations), and Rheo (Össur).

RESULTS

Outcomes from 602 individuals were included. No significant differences were noted for functional mobility (H = 2.91, p = 0.406) or satisfaction (H = 4.43, p = 0.219). For quality of life, differences existed for C-Leg versus Plié (p = 0.010). For injurious falls, C-Leg (χ2 (1,137) = 10.99, p < 0.001) and Orion (χ2 (1,119) = 4.34, p = 0.037) resulted in significantly reduced injurious falls compared to non-microprocessor knee users. C-Leg (H = 19.63, p < 0.001) and Plié (H = 14.04, p = 0.003) users saw declines with advanced aging.

CONCLUSIONS

Our data indicate relative parity among the 4 microprocessor knees with regard to functional mobility and satisfaction. In contrast to mobility, neither satisfaction nor quality of life values reflected declines with aging. Finally, when compared to non-microprocessor knees, significant differences were observed across the microprocessor knee types in relation to the reduction of injurious falls.Keywords: MPK, mobility, quality of life, falls, amputee, outcomes.