An enhancement of the Genium™ microprocessor-controlled knee improves safety and different aspects of the perceived prosthetic experience for unilateral and bilateral users.

Introduction: Bilateral microprocessor-controlled prosthetic knee (MPK) users have unique needs in traversing environmental barriers compared to unilateral users. An enhancement to the Genium™/Genium X3™ MPK which included an updated ruleset, hydraulics, and new bilateral parameter presets was made to improve safety while stumbling and the smoothness of gait for all users while also improving the experience of bilateral users. The purpose of the study was to evaluate the effectiveness of the enhancements in a sample with unilateral and bilateral amputation. Methods: A convenience sample of MPK users was recruited from two sites in the USA in two phases. Assessments included the L-Test of Functional Mobility, Activity-specific Balance Confidence Scale, Prosthetic Limb User Survey of Mobility, a study-specific questionnaire, and the Comparative Activities of Daily Living (ADL) Questionnaire. Statistical significance of extracted data was tested with the Wilcoxon Rank-Sum Test for independent data and Wilcoxon Signed-Rank for paired data with an a priori significance level of p < 0.05. Unilateral subjects were age-matched to the group of bilateral subjects for between-groups and within-groups analyses. Results: Twenty-six subjects (n = 26) were enrolled. Stumble frequency reduced 85% from 16.0 ± 39.7 to 2.4 ± 2.3 (p = 0.008) between baseline and final assessment overall. The bilateral group reported 50% (p = 0.009) and 57% (p = 0.009) greater relative improvement in patient-reported ease and safety, respectively, of completing ADLs compared to the unilateral group. The unilateral group reported residual limb pain and low back pain reduced from 2.3 to 1.4 (p = 0.020) and 3.8 to 1.8 (p = 0.027), respectively, whereas the bilateral group did not. Discussion: Substantial reductions in stumbles, residual limb pain, and back pain were shown overall. These reductions were driven by the unilateral group who also showed improvements in comfort, exertion, and concentration while walking. The enhancements to the knee likely reduced some gait asymmetry for unilateral users. Improvements in patient-reported ease and safety of completing ADLs were shown overall and were driven by the bilateral group. This study shows further improvement in patient experience is achievable through innovation in MPK technology even for patients who appear to be functioning well.

The role of exercise testing in predicting successful ambulation with a lower extremity prosthesis: a systematic literature review and clinical practice guideline.

BACKGROUND: Growing discontent with the k-level system for functional classification of patients with limb loss and movement of healthcare toward evidence-based practice has resulted in the need for alternative forms of functional classification and development of clinical practice guidelines to improve access to quality prosthetic interventions. The purpose of this project was to develop and present a clinical practice recommendation for exercise testing in prosthetic patient care based on the results and synthesis of a systematic literature review. METHODS: Database searches of PubMed, Google Scholar, Web of Science, and Cochrane were conducted and articles reviewed. Of the potential 1386 articles 10 met the criteria for inclusion. These articles were assessed using the critical appraisal tool of the United Kingdom National Service Framework for Long-Term Conditions. Of the 10 included articles eight were of high, one of medium, and one of low, quality. Data from these articles were synthesized into 6 empirical evidence statements, all qualifying for research grade A. These statements were used to develop the proposed clinical practice guideline. RESULTS: While the results of this systematic review were not able to support the direct connection between cardiorespiratory performance and K-levels, the literature did support the ability of exercise testing results to predict successful prosthetic ambulation in some demographics. Both continuous maximum-intensity single lower extremity ergometer propelled by a sound limb and intermittent submaximal upper extremity ergometer protocols were found to be viable evaluation tools of cardiorespiratory fitness and function in the target population. CONCLUSION: The ability to sustain an exercise intensity of ≥50% of a predicted VO2max value in single leg cycle ergometry testing and achievement of a sustained workload of 30 W in upper extremity ergometry testing were found to be the strongest correlates to successful ambulation with a prosthesis. VO2 values were found to increase in amputee subjects following a 6-week exercise program. These synthesized results of the systematic literature review regarding exercise testing in patients with loss of a lower extremity were used to develop and a present a clinical treatment pathway.

Outcomes Associated With the Intrepid Dynamic Exoskeletal Orthosis (IDEO): A Systematic Review of the Literature.

High-energy lower extremity trauma is a consequence of modern war and it is unclear if limb amputation or limb salvage enables greater recovery. To improve function in the injured extremity, a passive dynamic ankle-foot orthosis, the Intrepid Dynamic Exoskeletal Orthosis (IDEO), was introduced with specialized return to run (RTR) therapy program. Recent research suggests, these interventions may improve function and return to duty rates. This systematic literature review sought to rate available evidence and formulate empirical evidence statements (EESs), regarding outcomes associated with IDEO utilization. PubMed, CINAHL, and Google Scholar were systematically searched for pertinent articles. Articles were screened and rated. EESs were formulated based upon data and conclusions from included studies. Twelve studies were identified and rated. Subjects (n = 487, 6 females, mean age 29.4 year) were studied following limb trauma and salvage. All included studies had high external validity, whereas internal validity was mixed because of reporting issues. Moderate evidence supported development of four EESs regarding IDEO use with specialized therapy. Following high-energy lower extremity trauma and limb salvage, use of IDEO with RTR therapy can enable return to duty, return to recreation and physical activity, and decrease pain in some high-functioning patients. In higher functioning patients following limb salvage or trauma, IDEO use improved agility, power and speed, compared with no-brace or conventional bracing alternatives.

The dead spot phenomenon in prosthetic gait: Quantified with an analysis of center of pressure progression and its velocity in the sagittal plane.

BACKGROUND: The "dead spot" phenomenon in prosthetics is a disruption in forward progression observed in the rearfoot of passive prosthetic foot-ankle systems which results in a compensatory and inefficient gait pattern by amputees. A metric to quantify the dead spot as a kinetic event has not yet been introduced. The present study implements a three-part metric to evaluate the dead spot in terms of time, magnitude, and total area using center of pressure velocity and a novel threshold value calculation. METHODS: The metrics are implemented for proof of efficacy using a convenient sample of four amputees (2 transtibial, 2 transfemoral) who walked in a 3D motion capture system with integrated force plates over five foot conditions. FINDINGS: "Continuous-lever" feet designs showed the most favorable metric results between subjects (p<0.05) and in an ad hoc analysis compared to an ideal foot condition within subjects (p>0.05). Ten of 18 (55.6%) foot conditions found to be similar to the ideal were continuous-lever feet. Lack of significant similarity between the feet and ideal conditions (1 of 18, 5.6%) were found in transfemoral subjects. INTERPRETATION: The metric calculations were able to show statistical difference among foot conditions between subjects. One foot (continuous-lever, glass composite) had no detectable dead spot in the transtibial subjects. The lack of significant findings in transfemoral subjects indicates a different coefficient in threshold calculations may be more appropriate for these subjects versus transtibial subjects. Further research with larger sample is needed to determine clinically significant findings among feet and between transtibial and transfemoral subjects.

ECONOMIC EVALUATIONS OF INTERVENTIONS FOR TRANSTIBIAL AMPUTEES: A SCOPING REVIEW OF COMPARATIVE STUDIES.

Transtibial amputation (TTA) is life-altering emotionally, functionally, and economically. The economic impact to all stakeholders is largely unknown, as is the cost-effectiveness of prosthetic intervention. This scoping report's purpose was to determine if there is sufficient evidence to conduct a formal systematic review or meta-analysis in any particular prosthetic intervention area and to determine if any evidence statements could be synthesized relative to economic evaluation of interventions provided to patients with TTA. The scoping review revealed six articles representing three topical areas of transtibial care: Care Models, Prosthetic Treatment, and Prosthetic Sockets. All six articles were cost-identification or cost-consequence design and included a total of 704 subjects. Presently, it can be concluded with moderate confidence that specific weight-bearing and total-contact sockets for transtibial amputees are functionally and economically equivalent in the short term when costs, delivery time, and all stakeholder perspectives are considered. Long-term socket outcomes are relatively unexplored. Further primary research is needed beyond this to determine cost-effectiveness for other areas of transtibial prosthetic care although clinical outcomes are somewhat established through systematic review and meta-analysis in other areas of care. Conversely, evaluation of narrative economic reports relative to transtibial care may be sufficient to warrant further analysis. Guidance from the profession may also be useful in devising a strategy for how to assure economic analyses are a routine element of future prosthetic science.

Gait Training Interventions for Lower Extremity Amputees: A Systematic Literature Review.

Lower extremity (LE) amputation patients who use prostheses have gait asymmetries and altered limb loading and movement strategies when ambulating. Subsequent secondary conditions are believed to be associated with gait deviations and lead to long-term complications that impact function and quality of life as a result. The purpose of this study was to systematically review the literature to determine the strength of evidence supporting gait training interventions and to formulate evidence statements to guide practice and research related to therapeutic gait training for lower extremity amputees. A systematic review of three databases was conducted followed by evaluation of evidence and synthesis of empirical evidence statements (EES). Eighteen manuscripts were included in the review, which covered two areas of gait training interventions: 1) overground and 2) treadmill-based. Eight EESs were synthesized. Four addressed overground gait training, one covered treadmill training, and three statements addressed both forms of therapy. Due to the gait asymmetries, altered biomechanics, and related secondary consequences associated with LE amputation, gait training interventions are needed along with study of their efficacy. Overground training with verbal or other auditory, manual, and psychological awareness interventions was found to be effective at improving gait. Similarly, treadmill-based training was found to be effective: 1) as a supplement to overground training; 2) independently when augmented with visual feedback and/or body weight support; or 3) as part of a home exercise plan. Gait training approaches studied improved multiple areas of gait, including sagittal and coronal biomechanics, spatiotemporal measures, and distance walked.

INTERVENTIONS TO MANAGE RESIDUAL LIMB ULCERATION DUE TO PROSTHETIC USE IN INDIVIDUALS WITH LOWER EXTREMITY AMPUTATION: A SYSTEMATIC REVIEW OF THE LITERATURE.

Patients with lower extremity amputation (LEA) experience 65% more dermatologic issues than non-amputees, and skin problems are experienced by ≈75% of LEA patients who use prostheses. Continuously referring LEA patients to a dermatologist for every stump related skin condition may be impractical. Thus, physical rehabilitation professionals should be prepared to recognize and manage common non-emergent skin conditions in this population. The purpose of this study was to determine the quantity, quality, and strength of available evidence supporting treatment methods for prosthesis-related residual limb (RL) ulcers. Systematic literature review with evidence grading and synthesis of empirical evidence statements (EES) was employed. Three EESs were formulated describing ulcer etiology, conditions in which prosthetic continuance is practical, circumstances likely requiring prosthetic discontinuance, and the consideration of additional medical or surgical interventions. Continued prosthetic use is a viable option to manage minor or early-stage ulcerated residual limbs in compliant patients lacking multiple comorbidities. Prosthetic discontinuance is also a viable method of residual limb ulcer healing and may be favored in the presence of severe acute ulcerations, chronic heavy smoking, intractable pain, rapid volume and weight change, history of chronic ulceration, systemic infections, or advanced dysvascular etiology. Surgery or other interventions may also be necessary in such cases to achieve restored prosthetic ambulation. A short bout of prosthetic discontinuance with a staged re-introduction plan is another viable option that may be warranted in patients with ulceration due to poor RL volume management. High-quality prospective research with larger samples is needed to determine the most appropriate course of treatment when a person with LEA develops an RL ulcer that is associated with prosthetic use.

EFFECTS OF THE GENIUM MICROPROCESSOR KNEE SYSTEM ON KNEE MOMENT SYMMETRY DURING HILL WALKING.

Use of the Genium microprocessor knee (MPK) system reportedly improves knee kinematics during walking and other functional tasks compared to other MPK systems. This improved kinematic pattern was observed when walking on different hill conditions and at different speeds. Given the improved kinematics associated with hill walking while using the Genium, a similar improvement in the symmetry of knee kinetics is also feasible. The purpose of this study was to determine if Genium MPK use would reduce the degree of asymmetry (DoA) of peak stance knee flexion moment compared to the C-Leg MPK in transfemoral amputation (TFA) patients. This study used a randomized experimental crossover of TFA patients using Genium and C-Leg MPKs (n = 20). Biomechanical gait analysis by 3D motion tracking with floor mounted force plates of TFA patients ambulating at different speeds on 5° ramps was completed. Knee moment DoA was significantly different between MPK conditions in the slow and fast uphill as well as the slow and self-selected downhill conditions. In a sample of high-functioning TFA patients, Genium knee system accommodation and use improved knee moment symmetry in slow speed walking up and down a five degree ramp compared with C-Leg. Additionally, the Genium improved knee moment symmetry when walking downhill at comfortable speed. These results likely have application in other patients who could benefit from more consistent knee function, such as older patients and others who have slower walking speeds.

THE EFFECT OF TRANSFEMORAL INTERFACE DESIGN ON GAIT SPEED AND RISK OF FALLS.

Falls and diminished walking capacity are impairments common in persons with transfemoral amputation (TFA). Reducing falls and optimizing walking capacity through such means as achieving a more normal gait speed and community ambulation should be considered when formulating the prosthetic prescription. Because walking capacity and balance confidence are compromised with TFA, these outcomes should be considered when evaluating interfaces for transfemoral prosthetic users. The purpose of this study was to compare the effect of TFA interface design on walking capacity and balance confidence A retrospective cohort design was utilized involving unilateral TFA patients who used ischial ramus containment (IRC) and High-Fidelity (HiFi) interfaces (independent variables). Dependent variables included the Activity-specific Balance Scale (ABC) and the two-minute walk test (2MWT). Complete records were available for 13 patients (n = 13). The age range was 26 to 58 years. Three patients functioned at the K4 activity level, whereas all others functioned at the K3 level. Mean ABC scores were significantly different (p ≤ 0.05) at 77.2 (±16.8; 35.6 to 96.9) for IRC and 90.7 (±5.7; 77.5 to 98.7) for HiFi. The mean distance walked on the 2MWT was 91.8 m (±22.0, 58.3 to 124.7) for IRC compared to 110.4 m (±28.7; 64.7 to 171.1) for the HiFi socket (p ≤ 0.05). Alternative transfemoral interface design, such as the HiFi socket, can improve walking capacity and balance confidence in higher-functioning TFA patients.

COMPARATIVE EFFECTIVENESS OF AN ADJUSTABLE TRANSFEMORAL PROSTHETIC INTERFACE ACCOMMODATING VOLUME FLUCTUATION: CASE STUDY.

The socket-limb interface is vital for functionality and provides stability and mobility for the amputee. Volume fluctuation can lead to compromised fit and function. Current socket technology does not accommodate for volume fluctuation. An adjustable interface may improve function and comfort by filling this technology gap. The purpose of this study was to compare the effectiveness of the standard of care (SOC) ischial ramus containment to an adjustable transfemoral prosthetic interface socket in the accommodation of volume fluctuation. A prospective experimental case study using repeated measures of subjective and performance outcome measures between socket conditions was employed. In the baseline volume condition, the adjustable socket improved subjective and performance measures 19% to 37% over SOC, whereas the two-minute walk test demonstrated equivalence. In the volume loss condition, the adjustable socket improved all subjective and performance measures 22% to 93%. All aggregated data improved 16% to 50% compared with the SOC. In simulated volume gain, the SOC socket failed, while the subject was able to complete the protocol using the adjustable socket. In this case study, the SOC socket was inferior to the comparative adjustable transfemoral amputation interface in subjective and performance outcomes. There is a lack of clinical trials and evidence comparing socket functional outcomes related to volume fluctuation.

RADIOGRAPHIC ASSESSMENT OF EXTREMITY OSSEOINTEGRATION FOR THE AMPUTEE.

Osseointegration (OI) is a bone-anchoring procedure that allows the direct skeletal attachment of a prosthesis through the use of an implant. Transcutaneous OI implants are similar to subcutaneous intramedullary joint implants with some exceptions. Particularly, OI implants are inserted at the distal aspect of the femur, while intramedullary implants are inserted at the proximal aspect of the femur. In this report, an additional adaptation of the radiographic zonal analysis used for intramedullary implants, known as Gruen zones, is introduced to include OI implants of extremity prosthetics. Radiographic zonal analyses and interpretations are proposed. Gruen zones are used for intramedullary implants, which are generally inserted from the proximal aspect of the bone. OI extremity implants are inserted from the distal end of the bone. Therefore, the zonal analysis is inverted. A radiographic zonal analysis has been introduced by the Osseointegration Group of Australia (OGA). This analysis is needed specifically for the clinical evaluation of extremity OI, as significant changes to the bone and OI implant have been reported and need to be clinically described. A classification technique is necessary for establishing treatment guidelines for the extremity osseointegrated implant. The OGA Zonal analysis addresses this need by adapting a common reference standard to osseointegration of the extremity amputee.

PSYCHOMETRIC EVALUATION OF THE HILL ASSESSMENT INDEX (HAI) AND STAIR ASSESSMENT INDEX (SAI) IN HIGH-FUNCTIONING TRANSFEMORAL AMPUTEES.

The hill assessment index (HAI) and stair assessment index (SAI) were developed to objectively evaluate ramp and stair gait. This study's purpose was to determine the validity and reliability of these tests in a sample of persons with unilateral transfemoral amputation (TFA) using microprocessor prosthetic knee systems. All subjects were fit with a microprocessor knee system. After accommodation, subjects performed three trials ascending and descending a 5° ramp and a flight of stairs while being recorded on video. Sensitivity and specificity for the HAI was calculated against degree of asymmetry in step length using Dartfish video analysis software. Reliability was assessed using intraclass correlational coefficients calculated using Spearman's Rho (rs). A priori significance level was set at p ≤ 0.05. Twenty (n = 20) individuals with TFA completed the study protocol. Sensitivity and specificity of the HAI were calculated at 88.0% and 75.0% during ascending conditions and 94.0% and 67.0% during descending conditions, respectively. Significant correlations for the HAI included rs = 0.87 and rs = 0.73 within raters uphill and downhill, respectively. Corresponding coefficients of rs = 0.80 and rs = 0.67 were calculated between raters. For the SAI, significant correlations included rs = 1.00 for both comparisons within raters and in the comparison between raters in the ascending condition. A correlation of rs = 0.89 was calculated for the between-rater comparison in the descending condition. The HAI showed moderate to excellent sensitivity and specificity but good to adequate reliability. The SAI showed excellent to good reliability.