Medicare Functional Classification Level Research Articles

Prosthetic outcomes after amputation and the impact of mobility level on survival

ObjectiveLower extremity amputation continues to be necessary in a significant number of patients with peripheral vascular disease. The 5-year survival following lower limb loss is markedly reduced. Many of these patients are never fitted with a prosthesis, and there is a dearth of knowledge regarding the barriers to prosthetic attainment. The goal of this study was to identify the risk factors for not receiving a prosthesis and the effect of mobility level on survival following major amputation. MethodsThis was a retrospective analysis of all patients that underwent lower extremity amputation by surgeons in our practice from January 1, 2010, to December 31, 2019. Abstracted data included: age, sex, race, body mass index, comorbidities, American Society of Anesthesiologists score, statin use, level of amputation, stump revision, fitting for prosthesis, type of prosthesis, and the United States’ Medicare Functional Classification Level, also called K level. Survival was determined using a combination of sources, including the Social Security Death Master File, searches of multiple genealogic registries, and general internet searches. Multivariable logistic regression was used to determine risk factors associated with prosthesis attainment. Multivariable Cox proportional hazard regression with time-dependent covariates was performed to assess risk factors associated with 5-year mortality. ResultsA total of 464 patients were included in this study. The mean age was 65 years, and mean body mass index was 27 kg/m2. The majority of patients were male (68%), White (56%), diabetic (62%), and hypertensive (76%), and underwent below-the-knee amputation (69%). Prosthetic attainment occurred in 185 (40%). On multivariable analysis, age >81 years and current tobacco use were associated with no prosthetic fitting. Overall 5-year survival was 41.9% (95% confidence interval [CI], 37.6%-46.6%) (below-the-knee amputation, 47.7% [95% CI, 42.5%-53.5%]; above-the-knee amputation, 28.7% [95% CI, 22.1%-37.2%]). On multivariable analysis, age >60 years, congestive heart failure, above-the-knee amputation, and no prosthetic attainment were associated with decreased survival. Increasing K level was incrementally associated with improved survival. ConclusionsThis study has identified several patient factors associated with prosthetic attainment, as well as multiple factors predictive of reduced survival after amputation. Being referred for prosthetic fitting was associated with improved survival not explained by patient characteristics and comorbidities. The Medicare Functional Classification Level K level predicts survival. More research is needed to determine the barriers to prosthetic attainment and if improving a patients K level will improve survival.

Biomechanical effects of an articulating prosthetic toe joint during stair navigation for individuals with unilateral, below-knee limb loss

Stair navigation is an essential and demanding form of locomotion. During stair ascent and descent, persons with lower limb loss exhibit gait characteristics which may increase their risk of falls and joint degeneration of the intact limb. To reduce deviations from typically-able-bodied gait and overloading of the intact limb for this population, one potential intervention involves modifying passive prosthetic feet by incorporating a flexible toe joint that simulates the biological metatarsophalangeal joint. In this study, we aimed to assess the user preferences and biomechanical effects of a flexible prosthetic toe joint during stair ascent and descent for persons with unilateral lower-limb loss. Nine participants with unilateral lower-limb loss were recruited (Male; Medicare Functional Classification Level: eight K4, one K3; age: 41 ± 11 years; mass: 95 ± 13 kg; height: 1.84 ± 0.05 m; mean ± SD). No significant changes in lower-limb joint mechanics were identified. Five of nine participants preferred the unmodified prosthesis with a standard carbon fiber keel for both stair ascent and descent. Varied user preferences and inconsistent changes in lower-limb joint parameters between participants highlight the importance of subject-specific analyses and individualized device prescription.

The German Version of the Satisfaction with Prosthesis Questionnaire: Translation, Adaptation, Reliability, and Validity in Adults with Major Lower-Limb Amputation

ABSTRACT Introduction The aim of this study was to translate and cross-culturally adapt the Satisfaction with Prosthesis Questionnaire (SAT-PRO) into German and to evaluate its validity and reliability. Materials and Methods The 2-fold forward and backward translations were carried out according to the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) guidelines. Subsequently, the German version of the SAT-PRO was administered to 68 patients with major lower-limb amputation (LLA) fitted with a prosthesis. The internal consistency, floor and ceiling effects, item-to-total correlation, and test-retest reliability were determined. In addition, the standard error of the mean (SEM) and minimal detectable change (MDC) were calculated. Convergent construct validity was assessed by correlation to a Numerical Rating Scale for Satisfaction Level (NRS-SAT), the 36-Item Short-Form Health Survey (SF-36), the Rivermead Mobility Index (RMI), and the Medicare Functional Classification Level (K-Levels). Descriptive subgroup analysis included levels of amputation (transtibial vs. transfemoral persons with amputations) and user type (long-term vs. subacute users). Results The mean SAT-PRO total score was 32.27 ± 6.89 (77.6%). Internal consistency was high (Cronbach α = 0.88), and reproducibility demonstrated excellent findings with an intraclass correlation coefficient (ICC2,1) of 0.90 (95% confidence interval [CI], 0.84–0.94). Floor or ceiling effects were not detected. Convergent construct validity indicated a strong correlation to the NRS-SAT (r = 0.89), K-Levels (r = 0.66), and RMI (r = 0.52, all with P < 0.001). Moderate to high correlations were shown to all eight domains of the SF-36 (in a range of r = 0.55 [physical function] to r = 0.39 [mental health], all with P < 0.001). MDC was 2.32 (MDC% = 3.4%). Conclusions The translation according to ISPOR guidelines and cross-cultural adaptation of the SAT-PRO into German were successfully conducted in the pilot study. The psychometric testing showed high reliability and validity of the German version of the SAT-PRO. Hence, it can be used as an outcome measure to assess a patient's satisfaction with prosthesis in a German-speaking population. Clinical Relevance Statement The SAT-PRO can make an important contribution to the treatment of patients with major LLA. The use of objective measurement parameters and guideline-based translation should be applied to increase the validity and comparability of the data.

Minimal clinically important difference in walking velocity, gait profile score and two minute walk test for individuals with lower limb amputation.

Individuals with lower limb amputation are routinely assessed with a variety outcome measures, however there is a lack of published data to indicate minimal clinically important differences (MCID) for many of these outcome measures. Three such important gait-specific outcome measures include walking velocity, gait profile score (GPS) and the two minute walk test (2MWT). Determine the MCIDs for walking velocity, GPS and 2MWT for individuals with lower limb amputation. Walking velocity and GPS (n = 60), and 2MWT (n = 119) data for individuals with unilateral transfemoral or knee disarticulation were identified retrospectively from a database held at the study centre. An anchor-based method was used with Medicare functional classification level (MFCL) acting as the impairment-related criterion, and a least-squares linear regression approach was used to calculate the gradient required for a change between MFCL levels. An increase of 0.21 m/s (95 % CI: 0.13,0.29) for walking velocity, a reduction of 1.7° (95 % CI: -2.449,-1.097) for GPS and an increase of 37.2 m (95 % CI: 28.8,45.5) for 2MWT were found to correspond to an increase in MFCL of one level. Walking velocity, GPS and 2MWT correlated with MFCL with R2 values of 0.333, 0.322 and 0.398 respectively (p < 0.00001). The authors propose that 0.21 m/s for walking velocity, 1.7° for GPS and 37.2 m for 2MWT be used as MCID values for individuals with lower limb amputation. The results of this study can be used to help both researchers and clinicians to objectively evaluate if interventions for individuals with lower limb amputation are effective.

Using a microprocessor knee (C-Leg) with appropriate foot transitioned individuals with dysvascular transfemoral amputations to higher performance levels: a longitudinal randomized clinical trial

BackgroundIndividuals with transfemoral amputations who are considered to be limited community ambulators are classified as Medicare functional classification (MFCL) level K2. These individuals are usually prescribed a non-microprocessor controlled knee (NMPK) with an appropriate foot for simple walking functions. However, existing research suggests that these individuals can benefit from using a microprocessor controlled knee (MPK) and appropriate foot for their ambulation, but cannot obtain one due to insurance policy restrictions. With a steady increase in older adults with amputations due to vascular conditions, it is critical to evaluate whether advanced prostheses can provide better safety and performance capabilities to maintain and improve quality of life in individuals who are predominantly designated MFCL level K2. To decipher this we conducted a 13 month longitudinal clinical trial to determine the benefits of using a C-Leg and 1M10 foot in individuals at K2 level with transfemoral amputation due to vascular disease. This longitudinal clinical trial incorporated recommendations prescribed by the lower limb prosthesis workgroup to design a study that can add evidence to improve reimbursement policy through clinical outcomes using an MPK in K2 level individuals with transfemoral amputation who were using an NMPK for everyday use.MethodsTen individuals (mean age: 63 ± 9 years) with unilateral transfemoral amputation due to vascular conditions designated as MFCL K2 participated in this longitudinal crossover randomized clinical trial. Baseline outcomes were collected with their current prosthesis. Participants were then randomized to one of two groups, either an intervention with the MPK with a standardized 1M10 foot or their predicate NMPK with a standardized 1M10 foot. On completion of the first intervention, participants crossed over to the next group to complete the study. Each intervention lasted for 6 months (3 months of acclimation and 3 months of take-home trial to monitor home use). At the end of each intervention, clinical outcomes and self-reported outcomes were collected to compare with their baseline performance. A generalized linear model ANOVA was used to compare the performance of each intervention with respect to their own baseline.ResultsStatistically significant and clinically meaningful improvements were observed in gait performance, safety, and participant-reported measures when using the MPK C-Leg + 1M10 foot. Most participants were able to achieve higher clinical scores in gait speed, balance, self-reported mobility, and fall safety, while using the MPK + 1M10 combination. The improvement in scores were within range of scores achieved by individuals with K3 functional level as reported in previous studies.ConclusionsIndividuals with transfemoral amputation from dysvascular conditions designated MFCL level K2 benefited from using an MPK + appropriate foot. The inference and evidence from this longitudinal clinical trial will add to the knowledgebase related to reimbursement policy-making.Trial registration This study is registered on clinical trials.gov with the study title “Functional outcomes in dysvascular transfemoral amputees” and the associated ClinicalTrials.gov Identifier: NCT01537211. The trial was retroactively registered on February 7, 2012 after the first participant was enrolled.

Performance-based outcome measures are associated with cadence variability during community ambulation among individuals with a transtibial amputation.

In the United States, Medicare Functional Classification Level (K-level) guidelines require demonstration of cadence variability to justify higher-level prosthetic componentry prescription; however, clinical assessment of cadence variability is subjective. Currently, no clinical outcome measures are associated with cadence variability during community ambulation. Evaluate whether physical performance, i.e. 10-meter Walk Test (10mWT)-based walking speeds, L-Test, and Figure-of-8 Walk Test scores, is associated with community-based cadence variability among individuals with a transtibial amputation. Cross-sectional. Forty-nine participants, aged 18-85 years, with a unilateral transtibial amputation were included. Linear regression models were conducted to determine whether physical performance was associated with cadence variability (a unitless calculation from FitBit® OneTM minute-by-minute step counts), while controlling for sex, age, and time since amputation (p ⩽ .013). Beyond covariates, self-selected gait speed explained the greatest amount of variance in cadence variability (19.2%, p < .001). Other outcome measures explained smaller, but significant, amounts of the variance (11.1-17.1%, p = .001-.008). For each 0.1 m/s-increase in self-selected and fast gait speeds, or each 1-s decrease in L-Test and F8WT time, community-based cadence variability increased by 1.76, 1.07, 0.39, and 0.79, respectively (p < .013). In clinical settings, faster self-selected gait speed best predicted increased cadence variability during community ambulation. The 10-meter Walk Test may be prioritized during prosthetic evaluations to provide objective self-selected walking speed data, which informs the assessment of cadence variability potential outside of clinical settings.

Validity of the Comprehensive High-Level Activity Mobility Predictor in a heterogeneous population with lower extremity amputations.

Lower extremity amputee outcome measures assess basic mobility. The Comprehensive High-Level Activity Mobility Predictor was developed to assess high-level mobility. Validity evidence was collected in military men with traumatic lower extremity amputations. This study examines its validity in a broader population. Cross-sectional. Forty-five lower extremity amputees (Medicare Functional Classification Level K3 or K4) completed the 2-min walk test, Amputee Mobility Predictor with Prosthesis, and Comprehensive High-Level Activity Mobility Predictor. The Comprehensive High-Level Activity Mobility Predictor correlated with the Amputee Mobility Predictor with Prosthesis (r = 0.77, p < 0.01) and the 2-min walk test (r = 0.65, p < 0.01). The Comprehensive High-Level Activity Mobility Predictor differentiated between K-levels, age groups, etiology of amputation, and amputation level (p < 0.005). No ceiling effect was observed (range: 2.5-29/40). This study provides convergent and discriminative validity evidence for Comprehensive High-Level Activity Mobility Predictor use in a more heterogeneous population than previously published, suggesting that clinicians should feel confident to use it as an outcome measure for individuals with amputations who are capable of more than level-ground walking. Clinically, the Comprehensive High-Level Activity Mobility Predictor has validity evidence for use in a more heterogeneous population than originally demonstrated, including civilians, women, people over age 40 years, and non-traumatic etiologies. The Comprehensive High-Level Activity Mobility Predictor may be more useful than standard outcome measures for high-level mobility.

Establishing K-levels and prescribing transtibial prostheses using six-minute walk test and one-leg standing test on prosthesis: a retrospective audit.

Rehabilitation programs after amputation often include fitting a prosthesis, but prescriptions vary under similar circumstances. The US Medicare Functional Classification Level (K-level) is a scale for describing functional abilities of persons after lower-limb amputation (from 0 = no ability or potential to ambulate, to 4 = prosthetic demands of a child/active adult/athlete). Different outcome measures are used to assess K-level, including six-minute walk test (6MWT). We attempted to predict the assigned K-level of unilateral transtibial prosthesis users from their results of 6MWT and one-leg standing test on prosthesis (OLSTP). Outpatients who had been rehabilitated and fitted with transtibial prosthesis at the University Rehabilitation Institute in Ljubljana in 2014 were included in a retrospective audit. The data were analysed using receiver-operating-characteristics curves, linear discriminant analysis, classification trees and ordinal logistic regression. Among the 120 patients (aged 39-90, mean 67 years; 79% men), eight belonged to K1 level, 94 to K2, and 18 to K3 or K4; 61 could not stand on the prosthesis, eight stood on it for 1 s, and 51 stood on it for 2 s or more. With a simple classification rule based only on 6MWT (130 m threshold for K2/K3/K4 vs. K1, 340 m for K3/K4 vs. K1/K2), we observed sensitivity and specificity close to 90%. The more sophisticated statistical approaches yielded substantially similar and comparably accurate results. 6MWT and OLST could therefore be used as predictors for transtibial prosthesis prescription in clinical practice.

Economic Benefits of Microprocessor Controlled Prosthetic Knees: A Modeling Study

ABSTRACT Background Advanced prosthetic knees allow for more dynamic movements and improved quality of life, but payers have recently started questioning their value. To answer this question, the differential clinical outcomes and cost of microprocessor-controlled knees (MPK) compared to non-microprocessor controlled knees (NMPK) were assessed. Methods We conducted a literature review of the clinical and economic impacts of prosthetic knees, convened technical expert panel meetings, and implemented a simulation model over a 10-year time period for unilateral transfemoral Medicare amputees with a Medicare Functional Classification Level of 3 and 4 using estimates from the published literature and expert input. The results are summarized as an incremental cost effectiveness ratio (ICER) from a societal perspective, i.e., the incremental cost of MPK compared to NMPK for each quality-adjusted life-year gained. All costs were adjusted to 2016 U.S. dollars and discounted using a 3 percent rate to the present time. Results The results demonstrated that compared to NMPK over a 10-year time period: for every 100 persons, MPK results in 82 fewer major injurious falls, 62 fewer minor injurious falls, 16 fewer incidences of osteoarthritis, and 11 lives saved; on a per person per year basis, MPK reduces direct healthcare cost by $3,676 and indirect cost by $909, but increases device acquisition and repair cost by $6,287 and total cost by $1,702; on a per person basis, MPK is associated with an incremental total cost of $10,604 and increases the number of life years by 0.11 and quality adjusted life years by 0.91. MPK has an ICER ratio of $11,606 per quality adjusted life year, and the economic benefits of MPK are robust in various sensitivity analyses. Conclusions Advanced prosthetics for transfemoral amputees, specifically MPKs, are associated with improved clinical benefits compared to non-MPKs. The economic benefits of MPKs are similar to or even greater than those of other medical technologies currently reimbursed by U.S. payers.

Bimodal ankle-foot prosthesis for enhanced standing stability.

Previous work suggests that to restore postural stability for individuals with lower-limb amputation, ankle-foot prostheses should be designed with a flat effective rocker shape for standing. However, most commercially available ankle-foot prostheses are designed with a curved effective rocker shape for walking. To address the demands of both standing and walking, we designed a novel bimodal ankle-foot prosthesis that can accommodate both functional modes using a rigid foot plate and an ankle that can lock and unlock. The primary objective of this study was to determine if the bimodal ankle-foot system could improve various aspects of standing balance (static, dynamic, and functional) and mobility in a group of Veterans with lower-limb amputation (n = 18). Standing balance was assessed while subjects completed a series of tests on a NeuroCom Clinical Research System (NeuroCom, a Division of Natus, Clackamas, OR), including a Sensory Organization Test, a Limits of Stability Test, and a modified Motor Control Test. Few statistically significant differences were observed between the locked and unlocked ankle conditions while subjects completed these tests. However, in the absence of visual feedback, the locked bimodal ankle appeared to improve static balance in a group of experienced lower-limb prosthesis users whose PLUS-M mobility rating was higher than approximately 73% of the sample population used to develop the PLUS-M survey. Given the statistically significant increase in mean equilibrium scores between the unlocked and locked conditions (p = 0.004), future testing of this system should focus on new amputees and lower mobility users (e.g., Medicare Functional Classification Level K1 and K2 prosthesis users). Furthermore, commercial implementation of the bimodal ankle-foot system should include a robust control system that can automatically switch between modes based on the user’s activity.

Economic benefits of microprocessor controlled prosthetic knees: a modeling study

BackgroundAdvanced prosthetic knees allow for more dynamic movements and improved quality of life, but payers have recently started questioning their value. To answer this question, the differential clinical outcomes and cost of microprocessor-controlled knees (MPK) compared to non-microprocessor controlled knees (NMPK) were assessed.MethodsWe conducted a literature review of the clinical and economic impacts of prosthetic knees, convened technical expert panel meetings, and implemented a simulation model over a 10-year time period for unilateral transfemoral Medicare amputees with a Medicare Functional Classification Level of 3 and 4 using estimates from the published literature and expert input. The results are summarized as an incremental cost effectiveness ratio (ICER) from a societal perspective, i.e., the incremental cost of MPK compared to NMPK for each quality-adjusted life-year gained. All costs were adjusted to 2016 U.S. dollars and discounted using a 3% rate to the present time.ResultsThe results demonstrated that compared to NMPK over a 10-year time period: for every 100 persons, MPK results in 82 fewer major injurious falls, 62 fewer minor injurious falls, 16 fewer incidences of osteoarthritis, and 11 lives saved; on a per person per year basis, MPK reduces direct healthcare cost by $3676 and indirect cost by $909, but increases device acquisition and repair cost by $6287 and total cost by $1702; on a per person basis, MPK is associated with an incremental total cost of $10,604 and increases the number of life years by 0.11 and quality adjusted life years by 0.91. MPK has an ICER ratio of $11,606 per quality adjusted life year, and the economic benefits of MPK are robust in various sensitivity analyses.ConclusionsAdvanced prosthetics for transfemoral amputees, specifically MPKs, are associated with improved clinical benefits compared to non-MPKs. The economic benefits of MPKs are similar to or even greater than those of other medical technologies currently reimbursed by U.S. payers.

Outcomes and evaluation in lower limb amputees

Assessment is part of our professional practices. Moreover, the arrival of several new microprocessor prosthetic knee and bionic prosthetic feet requires lower limb amputee assessment particularly to help rehab professionals to prescribe devices considering the amputee life project. Amputee evaluation, wearing or not a lower limb prosthesis, is organised according 3 axes: prosthesis assessment (technology), amputee assessment (deficiency, satisfaction) and the “amputee-prosthesis” couple assessment in terms of capability and disability. The aim of the study was to realize a review of the literature over the last 10 years to define the significant outcomes in lower limb amputees. Medline, Reedoc, Scopus were interviewed between January 2006 and September 2016 with the following words: lower limb amputee, lower limb amputation, survey, questionnaire, evaluation, assessment, outcome and their equivalent in French. Only studies in English and in French were selected. Self-reports and clinical tests assessing mobility and balance were included. Instrumental objective measures (biomechanics, kinematics, and energetics) realized with motion capture optoelectronic systems or with wearable systems were not retained. More than 52 different outcomes (either generic or specific) were found. These outcomes covered a wide range of assessment such as mobility, balance, satisfaction, coping strategy, quality of life or body image. Questionnaires and clinical tests were listed from the most to the less used. The clinical test AMP-Pro (amputee mobility predictor) evaluates the predicted mobility of amputee with and without a prosthesis. By differentiating Medicare Functional Classification Level, this test is already used for feet prescription in the USA. Several specific self-reports are available in French as Amputee Body Image Scale (ABIS), Trinity Amputation Prosthetics Profil Evaluation Scale (TAPES) or Special Interest Group in Amputee Medicine mobility grades (SIGAM). In lower limb amputees, many specific or generic outcomes could be used either in clinical purpose–help for rehab professionals to prescribe devices, follow-up–or in clinical research–cohort follow-up, devices evaluation by the couple “amputee-prosthesis” assessment–. Minimum detectable change for the dedicated population as well as psychometric properties like ceiling or floor effect must be considered for their “good use”. Moreover, questionnaires are increasingly available in French.

The importance of orthoses on activities of daily living in patients with unilateral lower limb amputations.

The role of the selected prothesis on activities of daily living (ADL). To evaluate the impact of prothesis on ADL in patients with lower-limb amputations. The data of 500 patients with unilateral lower limb amputation were recorded. The activity level was defined based on the Medicare Functional Classification Level. Old and new prescribed prosthesis were recorded. Nottingham Extended Activities of daily living activities Daily Living Scale was used to evaluate ADL. Amputation levels were transfemoral (TF) in 268 (53.6%), transtibial (TT) in 178 (35.6%), knee disarticulation (KD) in 54 (10.8%). In patients with TF and KD amputation active vacuum system, pin modular system, hydraulic system and mechanical modular prosthesis were replaced with the swing stance phase microprocessor-controlled prostheses. In patients with TT amputation pin modular system, hydraulic system and mechanical modular prosthesis were converted to active vacuum system prostheses. Prescribed new prosthesis has caused a statistically significant increase in all amputation levels in ADL of patients (p≤ 0.05). We observed that there was significant improvement in ADL when conventional prostheses replaced with advanced technology prostheses in unilateral lower extremity amputation patients.

CONCURRENT VALIDITY OF THE CONTINUOUS SCALE-PHYSICAL FUNCTIONAL PEFORMANCE-10 (CS-PFP-10) TEST IN TRANSFEMORAL AMPUTEES.

The Continuous Scale-Physical Functional Performance-10 (CS-PFP-10) test consists of 10 standardized daily living tasks that evaluate overall physical functional performance and performance in five individual functional domains: upper body strength (UBS), upper body flexibility (UBF), lower body strength (LBS), balance and coordination (BAL), and endurance (END). This study sought to determine the concurrent validity of the CS-PFP-10 test and its functional domains that involve the lower extremities (LBS, BAL, or END) in comparison to measures that have established validity for use in persons with transfemoral amputation (TFA). Ten TFA patients functioning at K3 or higher (Medicare Functional Classification Level) completed the study. Participants were assessed performing the CS-PFP-10, Amputee Mobility Predictor (AMP), 75 m self-selected walking speed (75 m SSWS) test, timed down stair walking (DN stair time), and the limits of stability (LOS) balance test. Concurrent validity was assessed using correlation analysis. The AMP, 75 m SSWS, LOS, and the DN stair time tests were strongly correlated (r = ± 0.76 to 0.86) with their paired CS-PFP-10 domain score (LBS, BAL, or END) and CS-PFP-10 total score. These findings indicate that the lower limb and balance domains of the CS-PFP-10 are valid measures to assess the physical functional performance of TFA patients.

Construct Validity of the Prosthetic Limb Users Survey of Mobility (PLUS-M) in Adults With Lower Limb Amputation

ObjectiveTo assess construct validity of the Prosthetic Limb Users Survey of Mobility (PLUS-M), a self-report mobility measure for people with lower limb amputation (LLA). DesignCross-sectional study. SettingPrivate prosthetic clinics (n=37). ParticipantsCurrent lower limb prosthesis users (N=199; mean age ± SD, 55.4±14.3y; 71.4% men) were assessed before receiving a replacement prosthesis, prosthetic socket, and/or prosthetic knee. InterventionsNot applicable. Main Outcome MeasuresConvergent construct validity was examined using correlations between participants' PLUS-M T-scores and measures of physical function, mobility, and balance, including the Amputee Mobility Predictor (AMP), timed Up and Go (TUG), Patient-Reported Outcomes Measurement Information System–Physical Function (PROMIS-PF), Prosthesis Evaluation Questionnaire–Mobility Subscale (PEQ-MS), and Activities-specific Balance Confidence (ABC) Scale. Known-groups construct validity was evaluated by comparing differences in PLUS-M T-scores among participants grouped by Medicare Functional Classification Level (MFCL). ResultsPLUS-M T-scores demonstrated a moderate positive relationship with AMP scores (ρ=.54, P<.001) and a moderate negative relationship with TUG times (ρ=−.56, P<.001). The PLUS-M also showed a strong positive relationship with PEQ-MS scores (ρ=.78, P<.001), ABC Scale scores (ρ=.81, P<.001), and PROMIS-PF T-scores (ρ=.81, P<.001). Significant differences (P<.05) in PLUS-M T-scores were found among groups of people classified by different MFCLs. ConclusionsStudy results support the validity of the PLUS-M as a self-report measure of prosthetic mobility. Correlations between PLUS-M and measures of physical function, mobility, and balance indicate convergent construct validity. Similarly, significant differences in PLUS-M T-scores across MFCL groups provide evidence of known-groups construct validity. In summary, evidence indicates that PLUS-M has good construct validity among people with LLA.

Real-World Walking Performance of Individuals with Lower-Limb Amputation Classified as Medicare Functional Classification Level 2 and 3

Introduction Lower-limb prostheses are prescribed based on each patient's individual needs. However, there is no standardized method to identify a patient's needs, which results in difficulty and variability in making prosthetic recommendations. Using measures of real-world walking performance in conjunction with clinical measures and the clinician's expertise may be an ideal way to ensure that patients receive the optimal prosthetic treatment. Currently, there is only limited understanding of the relationship among in-clinic performance-based measures, real-world walking performance, and K-level. Therefore, the purpose of this study was to investigate outcomes of in-clinic performance-based evaluations and real-world walking performance measures for individuals with unilateral lower-limb amputation classified as K2 and K3. Materials and Methods Twenty-seven individuals with unilateral lower-limb amputation classified as K2 or K3 functional levels underwent a clinical assessment visit that included a 10-m walk test and a 6-minute walk test. After the assessment, the individuals were equipped with an activity monitor, which they wore for a 7-day observation period. From these data, participants' self-selected walking speed, total distance walked in 6 minutes, total number of steps taken during the observation period, total number of active minutes during the observation period, and percentage of time spent in low-, moderate-, and high-intensity activity during the observation period were calculated. Results Individuals classified as K2 had, on average, a significantly slower self-selected walking speed, significantly shorter distance walked in 6 minutes, significantly lower total step count, and a significantly fewer number of active minutes when compared with those classified as K3. Although not significant, trends in activity intensity were seen with individuals classified as K2, spending a larger percentage of time in low-intensity activity and less percentage of time in high-intensity activity when compared with those classified as K3. Conclusions This study quantified real-world walking performance, in conjunction with in-clinic performance-based data, for individuals classified as K2 and K3 and showed significant differences between the 2 groups. This study is a step forward toward developing an objective and standardized method to classify an individual's functional ability and make prosthetic recommendations.

Survey of U.S. Practitioners on the Validity of the Medicare Functional Classification Level System and Utility of Clinical Outcome Measures for Aiding K-Level Assignment

ObjectiveTo characterize the opinion of the prosthetic clinical care community on the Medicare Functional Classification Level (K-level) assignment process to classify the mobility and rehabilitation potential of persons with lower-limb loss, including limitations and practicalities involved with the integration of outcome measures (OMs) into the clinical practice framework for K-level assignment. DesignSurvey. SettingEnglish online questionnaire with built-in logic. ParticipantsVolunteer sample of prosthetics practitioners (N=236). Data were analyzed only for U.S. practitioners (n=213). InterventionsNot applicable. Main Outcome MeasuresSubjective responses to 19 multiple choice, Likert scale, and open-ended questions. ResultsForty-seven percent of respondents indicated that they were the sole determinant in the K-level assignment process, while 43% indicated that it was a collaborative process with other health care professionals. Sixty-nine percent of respondents reported using standardized OMs to assist in K-level assignment, and most did not agree that commonly reported barriers to implementation (eg, lack of time and training) were relevant. Sixty-seven percent of respondents did not believe the K-level system can accurately assign a level of rehabilitation potential, with 75% agreeing that incorporating OMs into clinical practice would enhance objectivity of the K-level assignment process. ConclusionsThe results suggest that most prosthetics practitioners are involved in the K-level assignment at some level, and most agreed that there are considerable limitations with this system. To address these issues, many practitioners are using OMs to assess various aspects of patient mobility and rehabilitation potential, and minimize the subjectivity of the assignment process.

The benefits of using a vacuum-assisted socket system to improve balance and gait in elderly transtibial amputees.

Lower limb amputation leads to impaired balance, ambulation, and transfers. Proper fit of the prosthesis is a determining factor for successful ambulation. Vacuum-assisted socket systems extract air from the socket, which decreases pistoning and probability of soft-tissue injuries and increases proprioception and socket comfort. To investigate the effect of vacuum-assisted socket system on transtibial amputees' performance-based and perceived balance, transfers, and gait. Quasi-experimental before-and-after study. Subjects were initially assessed using their prosthesis with the regular socket and re-evaluated 4 weeks after fitting including the vacuum-assisted socket system. We evaluated the mobility grade using Medicare Functional Classification Level, Berg Balance Scale, Four Square Step Test, Timed Up and Go Test, the 6-Min Walk Test, the Locomotor Capabilities Index, Satisfaction with Prosthesis (SAT-PRO questionnaire), and Houghton Scale. A total of 16 unilateral transtibial dysvascular amputees, mean age 65.12 (standard deviation = 10.15) years. Using the vacuum-assisted socket system, the patients significantly improved in balance, gait, and transfers: scores of the Berg Balance Scale increased from 45.75 (standard deviation = 6.91) to 49.06 (standard deviation = 5.62) (p < 0.01), Four Square Step Test decreased from 18.18 (standard deviation = 3.84) s to 14.97 (3.9) s (p < 0.01), Timed Up and Go Test decreased from 14.3 (standard deviation = 3.29) s to 11.56 (2.46) s (p < 0.01). The distance walked in the 6-Min Walk Test increased from 288.53 (standard deviation = 59.57) m to 321.38 (standard deviation = 72.81) m (p < 0.01). Vacuum-assisted socket systems are useful for improving balance, gait, and transfers in over-50-year-old dysvascular transtibial amputees. This study gives more insight into the use of vacuum-assisted socket systems to improve elderly transtibial dysvascular amputees' functionality and decrease their risk of falls. The use of an additional distal valve in the socket should be considered in patients with a lower activity level.

Benefits of microprocessor-controlled prosthetic knees to limited community ambulators: systematic review.

The benefits of microprocessor-controlled prosthetic knees (MPKs) have been well established in community ambulators (Medicare Functional Classification Level [MFCL]-3) with a transfemoral amputation (TFA). A systematic review of the literature was performed to analyze whether limited community ambulators (MFCL-2) may also benefit from using an MPK in safety, performance-based function and mobility, and perceived function and satisfaction. We searched 10 scientific databases for clinical trials with MPKs and identified six publications with 57 subjects with TFA and MFCL-2 mobility grade. Using the criteria of a Cochrane Review on prosthetic components, we rated methodological quality moderate in four publications and low in two publications. MPK use may significantly reduce uncontrolled falls by up to 80% as well as significantly improve indicators of fall risk. Performance-based outcome measures suggest that persons with MFCL-2 mobility grade may be able to walk about 14% to 25% faster on level ground, be around 20% quicker on uneven surfaces, and descend a slope almost 30% faster when using an MPK. The results of this systematic review suggest that trial fittings may be used to determine whether or not individuals with TFA and MFCL-2 mobility grade benefit from MPK use. Criteria for patient selection and assessment of trial fitting success or failure are proposed.

Lower Limb Prosthetic Prescription in Jordan = الوصفة الطبية للطرف الاصطناعي السفلي في الأردن

Objective: This study examine if the criteria of prescribing prosthetic components in Jordan is based on the amputee’s level of activity or other variables (e.g. gender). Findings could help in standardizing the approach used when prescribing lower limb prosthetic components and could help in identifying the agreement, if present, on the criteria used when prescribing prosthetic components. Methods: The prosthetic components prescribed for 112 lower limb amputees (trans-femoral amputation, knee disarticulation, trans-tibial amputation, and syme amputation) from different rehabilitation centres in Amman/Jordan were recorded. For each amputee, the research team filled a form containing the amputees’ information and prescribed prosthetic components as well as the Medicare Functional Classification Level (MFCL) mobility scale, which intends to evaluate the amputee’s level of activity. Results: A relationship between the level of activity and prosthetic components prescription was not found. The study shows that an agreement could not be found in the prescription criteria for any of the investigated prosthetic components. The lack of guidelines that indicate the criteria for prescribing each prosthetic component could be the sole reason for these findings. Conclusions: The study raises the necessity to develop clinical guidelines that make prosthetic components prescription not only scientific evidence but also consistent between prescribers from different backgrounds. Given that prosthetic components keep developing and increase in alternatives, such clinical guidelines can be of vital importance.