Comparative responsiveness of locomotor tests and questionnaires used to follow early recovery after total knee arthroplasty

Comparing Functional Recovery Between Total and Unicompartmental Knee Arthroplasty: A Prospective Health Kit Study

BACKGROUND

Both total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) have demonstrated excellent clinical outcomes for end-stage osteoarthritis. Although UKA has been shown to have lower survivorship, many patients are interested in a partial knee arthroplasty due to the perception of "better" function and a "quicker" recovery. The purpose of this study was to objectively compare and understand functional recovery between TKA and UKA through the utilization of cutting-edge technological health metrics.

METHODS

Over a 2-year period, 185 patients undergoing TKA or UKA (152 versus 33, respectively) were prospectively followed for 1 year postoperatively. Smart devices were worn by these patients to track their daily steps, steadiness, standing time, 6-minute walk test, and gait speed, and were averaged weekly at multiple time points ranging from immediately preoperatively to 1 year postoperatively. Propensity matching scores were conducted in a 1:3 UKA to TKA ratio, resulting in a final cohort of 120 patients undergoing TKA or UKA (87 versus 33). Additionally, EuroQol 5 dimension survey and Knee Injury and Osteoarthritis Outcome scores were compared between groups.

RESULTS

At 6 weeks postoperatively, the mean gait speed was quicker for patients who underwent a UKA in comparison to those who underwent a TKA (0.97 versus 0.89 meters/second, P = 0.02). Furthermore, the average steadiness at 6 weeks postoperatively was better in the UKA group when compared to the TKA cohort (0.60 versus 0.40 (0 to 1 scale), P = 0.03). No further differences were demonstrated between groups at the 6-week time point. No data or reported outcomes varied between the UKA and TKA cohorts at both 6-month and 1-year postoperative time points.

CONCLUSIONS

This prospective study compared UKA and TKA through the incorporation of real-time objective technological data. Although steadiness and gait speed were better in the UKA group at the 6-week follow-up, no differences existed beyond this time point. This study demonstrates that both UKA and TKA had the same recovery and functionality in regards to gait speed, daily step counts, standing time, steadiness, and the 6-minute walking test at 6-month and 1-year follow-up.

Differences in functional recovery after unilateral versus bilateral total knee arthroplasty

BACKGROUND

Understanding functional changes between unilateral and simultaneous bilateral total knee arthroplasty (TKA) patients remains limited. The purpose of this study was to investigate the differences in recovery times between unilateral and bilateral TKA.

METHODS

We retrospectively recruited patients who met the eligibility criteria. All patients engaged in a standard rehabilitation program and completed both self-reported questionnaires and performance-based physical function tests preoperatively, at 6 and 12 weeks postoperatively.

RESULTS

A total of 838 patients were included in this study. Those who underwent bilateral TKA (n = 281) were younger than those opting for unilateral TKA (n = 557), with no significant differences in baseline health status observed between the two groups. Both groups showed continuous improvements in pain, function, and performance-based physical functions from preoperatively to 12 weeks postoperatively. Notably, stiffness did not significantly improve from the preoperative to 6 weeks postoperatively and the stair-climbing test (SCT) showed delayed recovery, with deterioration at 6 weeks but subsequent improvement at 12 weeks in bilateral TKA group. Similarly, the recovery rate in the 6-min walking test (6MWT) was initially slow for the bilateral TKA group during the first 6 weeks, but later accelerated. Significant interactions between time and group were observed in the timed-up-and-go test, 6MWT, and SCT.

CONCLUSION

Patients who underwent bilateral TKA showed distinct recovery patterns, suggesting the need for tailored rehabilitation approaches compared those who underwent unilateral surgery. These findings underscore the need to provide patients with information about potential differences in recovery patterns based on their chosen surgical approach prior to surgery.

Performance-Based Outcome Measures After Hip or Knee Arthroplasty: A Systematic Review and Content Analysis Using the International Classification of Functioning, Disability and Health (ICF)

RATIONAL

One of the important considerations to select the appropriate outcome measures is determining if the tool is relevant to patients. Despite the availability of various performance-based tests to objectively assess function, it is unknown which performance-based tests best capture important aspects of function after hip or knee arthroplasty.

AIMS AND OBJECTIVES

Our systematic review aimed to identify the existing performance-based tests used in hip or knee arthroplasty and link the activity component of each test to the modified International Classification of Functioning, Disability and Health (ICF) core set for osteoarthritis (OA).

METHOD

We searched four databases from inception until April 2024. A performance-based test was included if an individual performs one or more activities, evaluated by an assessor and resulted in a numerical value. Two reviewers independently screened and extracted data and assessed the included performance-based tests.

RESULTS

From 449 studies included in this review, we identified 28 performance-based tests which covered 15 categories of OA core set activity and participation. The categories of d4500:walking short distances, d4104:standing and d4103:sitting were the most frequently used, employed in 14, 10 and 10 performance-based tests, respectively. However, 34 categories of activity and participation were not found in any performance-based tests. A-test ('A' like Activity or Assessment) had the widest coverage covering 10 out of 49 core set categories. Four performance tests covered four activity and participation categories, one covered three categories, 10 covered two categories and 12 covered one category.

CONCLUSION

Our ICF-based content analysis revealed that the existing performance-based tests covered certain OA core set activity and participation categories, but overlooked multiple categories. This analysis can serve as a guide for researchers and clinicians in selecting suitable performance-based tests or a battery of tests to assess function following hip or knee arthroplasty.

Effect of Context Specificity on Response to the Shortened WOMAC Function Scale in Patients Undergoing Total Knee Arthroplasty

OBJECTIVE

To determine, in patients undergoing total knee arthroplasty (TKA), whether increasing context specificity of selected items of the shortened version of the Western Ontario and McMaster Universities Osteoarthritis Index function (WOMAC-F) scale (ShortMAC-F) (1) enhanced the convergent validity of the ShortMAC-F with performance-based mobility measures (ii) affected mean scale score, structural validity, reliability, and interpretability.

DESIGN

Secondary analysis of randomized clinical trial data.

SETTING

A tertiary teaching hospital.

PARTICIPANTS

Patients undergoing TKA (N=114).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The ShortMAC-F was modified by specifying the "ascending stairs" and "rising from sitting" items to enquire about difficulty in performing the tasks without reliance on compensatory strategies, whereas the modified "level walking" item enquired about difficulty in walking 400 m. Before and 12 weeks after TKA, patients completed the WOMAC-F questionnaire, modified ShortMAC-F questionnaire, knee pain scale questionnaire, sit-to-stand test, fast gait speed test, and stair climb test. Interpretability was evaluated by calculating anchor-based substantial clinical benefit estimates.

RESULTS

The modified ShortMAC-F correlated significantly more strongly than ShortMAC-F or WOMAC-F with pooled performance measures (differences in correlation values, 0.12-0.14). Increasing item context specificity of the ShortMAC-F did not influence its psychometric properties of unidimensionality (comparative fit and Tucker-Lewis indices, >0.95; root mean square error of approximation, 0.05-0.08), reliability (Cronbach's α, 0.75-0.83), correlation with pain intensity (correlation values, 0.48-0.52), and substantial clinical benefit estimates (16 percentage points); however, it resulted in lower mean score (4.5-4.8 points lower).

CONCLUSIONS

The modified ShortMAC-F showed sufficient measurement properties for clinical application, and it seemed more adept than WOMAC-F at correlating with performance-based measures in TKA.

Exploratory study of the lateral body sway predictability as frame of reference for gait rehabilitation following a total knee arthroplasty

AIMS

The aim of the present study was to investigate whether the predictability of fronto-parallel trunk rotations (lateral body sway) could serve as a frame of reference to monitor recovery after total knee arthroplasty (TKA).

METHODS

Before surgery, 11 TKA patients were asked to perform a treadmill walking task at three different speeds. In addition, their gait abilities were scored on three standard clinical walking tests. The treadmill walking task was repeated at three different timepoints following surgery, i.e., at 3, 6 and 12 months post-TKA. The movements of the trunk were digitized with an inertial sensor to capture the amplitude and the sample entropy (SEn) of the lateral body sway that were evaluated in separate ANOVAs.

RESULTS

Before surgery the TKA group showed larger body sway (P = 0.025) with smaller SEn values (P = 0.038), which both restored to levels of healthy adults in the 12 months following surgery. Systematic correlations between the SEn values and the clinical test scores were found.

CONCLUSIONS

The current findings show that movement behavior of the trunk in the fronto-parallel plane was affected by knee osteoarthritis and suggest that the predictability of the lateral body sway may serve as an index of recovery after TKA.

Responsiveness of Subjective and Objective Measures of Pain and Function Following Operative Interventions for Musculoskeletal Conditions: A Narrative Review

OBJECTIVE

Musculoskeletal (MSK) disorders affect ~50% of US adults and 75% of those over the age of 65, representing a sizable economic and disability burden. Outcome measures, both objective and subjective, help clinicians and investigators determine whether interventions to treat MSK conditions are effective. This narrative review qualitatively compared the responsiveness of different types of outcome measures, a key measurement characteristic that assesses an outcome measure's ability to detect change in patient status.

METHODS

We evaluated elective orthopedic interventions as a model for assessing responsiveness because the great majority of patients improves following surgery. We searched for articles reporting responsiveness (quantified as effect size [ES]) of subjective and objective outcome measures after orthopedic surgery and included 16 articles reporting 17 interventions in this review.

RESULTS

In 14 of 17 interventions, subjective function measures had an ES 10% greater than that of objective function measures. Two reported a difference in ES of <10%. The sole intervention that demonstrated higher ES of objective function used a composite measure. Sixteen interventions reported measures of subjective pain and/or mixed measures and subjective function. In nine interventions, subjective pain had a higher ES than subjective function by >10%, in three, subjective function had a higher ES than subjective pain by >10%, and in the remaining four, the difference between pain and function was <10%.

CONCLUSION

These findings reinforce the clinical observation that subjective pain generally changes more than function following elective orthopedic surgery. They also suggest that subjective function measures are more responsive than objective function measures, and composite scores may be more responsive than individual performance tests.

Factors Related to Expectations in Individuals Waiting for Total Knee Arthroplasty

Purpose

There is no consensus on how age and expectations influence planning for total knee arthroplasty (TKA). This study developed and evaluated a new expectation questionnaire and assessed the relationship between preoperative expectations and patient characteristics.

Method

The questionnaire evaluated expectations for mobility, pain, participation, and rate of recovery after surgery. Fifty-five participants completed a 6-minute walk test and expectation questionnaire prior to TKA; 17 participants repeated the questionnaire one week later for reliability testing. Analysis of the questionnaire included intra-class correlation coefficient (ICC), homoscedasticity, skewness, kurtosis, multicollinearity, and descriptive measures. A four-step hierarchical linear regression was completed to determine the relationship of patient age, BMI, previous contralateral TKA, and 6-minute walk test scores to expectations.

Results

The questionnaire showed good/high test-retest reliability (ICC 0.84; 95% CI: 0.57, 0.94; p > 0.001). The final model was significant in predicting expectation scores R2 = 0.19 (p = 0.017).

Conclusions

This questionnaire reliably measures patient expectations before TKA; however, further research is needed. Although we anticipated younger age to be related to higher expectations, higher function prior to TKA appears to be more strongly associated with higher expectations.

Change in Pain During Physical Activity Following Total Knee Arthroplasty: Associations With Improved Physical Function and Decreased Situational Pain Catastrophizing

Background and Objectives

Knee osteoarthritis is one of the primary causes of chronic pain among older adults and because of the aging population, the number of total knee arthroplasties (TKAs) performed is exponentially increasing. While pain reduction is a goal of TKA, movement-evoked pain is rarely assessed pre- and post-TKA. We characterized the distributions of change in pain, function, and situational catastrophizing in patients from presurgery to 3 months postsurgery and explored associations among these pre-post changes.

Research Design and Methods

This prospective study longitudinally assessed movement-evoked pain, function, and situational catastrophizing in patients with knee osteoarthritis (N = 92) using in-person performance-based tests (6-min walk test [6MWT], stair-climb test [SCT]) prior to and 3 months after TKA. Patients also completed the Western Ontario McMaster Universities Scales (WOMAC) pain and function subscales, and Pain Catastrophizing Scale, presurgery and 3- and 6-months postsurgery.

Results

Movement-evoked pain and function on performance tests significantly improved from pre- to post-TKA. Improved SCT function was associated with reduced SCT pain and catastrophizing. Similarly, reduced pain during the SCT was associated with reduced catastrophizing during the SCT. However, 6MWT function was not associated with 6MWT pain or catastrophizing; yet reduced pain during the 6MWT was associated with reduced catastrophizing during the 6MWT. Reduced movement-evoked pain during both performance tests was consistently associated with improved WOMAC function and pain, whereas improved function on performance tests was inconsistently associated with WOMAC function and pain. Notably, greater movement-evoked pain on both performance tests at 3-month post-TKA was associated with worse WOMAC function and pain at 6 months, whereas better function on performance tests at 3 months was associated with better WOMAC function, but not related to WOMAC pain at 6 months.

Discussion and Implications

Findings highlight the importance of situation-specific and in vivo assessments of pain and catastrophizing during physical activity.

Inertial-Sensor-Based Monitoring of Sample Entropy and Peak Frequency Changes in Treadmill Walking during Recovery after Total Knee Arthroplasty

This study aimed to investigate whether sample entropy (SEn) and peak frequency values observed in treadmill walking could provide physical therapists valuable insights into gait rehabilitation following total knee arthroplasty (TKA). It was recognized that identifying movement strategies that during rehabilitation are initially adaptive but later start to hamper full recovery is critical to meet the clinical goals and minimize the risk of contralateral TKA. Eleven TKA patients were asked to perform clinical walking tests and a treadmill walking task at four different points in time (pre-TKA, 3, 6, and 12 months post-TKA). Eleven healthy peers served as the reference group. The movements of the legs were digitized with inertial sensors and SEn and peak frequency of the recorded rotational velocity-time functions were analyzed in the sagittal plane. SEn displayed a systematic increase during recovery in TKA patients (p < 0.001). Furthermore, lower peak frequency (p = 0.01) and sample entropy (p = 0.028) were found during recovery for the TKA leg. Movement strategies that initially are adaptive, and later hamper recovery, tend to diminish after 12 months post-TKA. It is concluded that inertial-sensor-based SEn and peak frequency analyses of treadmill walking enrich the assessment of movement rehabilitation after TKA.

More Predictable and Less Automatized Movements during Walking -not during Repetitive Punching- in Knee Osteoarthritis

Using the non-affected leg as stable frame of reference for the affected leg in gait assessment in knee osteoarthritis (KO) fails due to compensatory mechanisms. Assessing the cyclical movements of the upper extremities in a frequency-controlled repetitive punching task may provide an alternative frame of reference in gait assessment in patients with KO. Eleven participants with unilateral KO and eleven healthy controls were asked to perform treadmill walking and repetitive punching. The KO group showed more predictable (p = 0.020) and less automatized (p = 0.007) movement behavior than controls during treadmill walking. During repetitive punching, the KO group showed a similar degree of predictability (p = 0.784) but relative more automatized movement behavior (p = 0.013). Thus, the predictability of the movement behavior of the upper extremities during repetitive punching seems unaffected by KO and could provide an alternative frame of reference in gait assessment in patients with KO.

Comparison of Functional Recovery Between Unicompartmental and Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND

Comparisons of functional recovery between unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) using performance-based tests are lacking. Therefore, this study aimed to compare 2-minute walk test (2MWT) and Timed Up-and-Go test (TUG) results between UKA and TKA for isolated medial knee osteoarthritis (OA). We hypothesized that UKA yields faster functional recovery than TKA as measured with the 2MWT and TUG.

METHODS

We conducted a randomized controlled trial comparing medial UKA and TKA in patients with isolated medial knee OA. A total of 110 patients were enrolled; after 11 exclusions, 99 patients (50 UKA, 49 TKA) were included in the final analysis. The patients were tested using the 2MWT and TUG preoperatively and at 6 weeks, 3 and 6 months, and 1 and 2 years postoperatively. Patient-reported outcome measures (PROMs) were also evaluated. The mean 2MWT, TUG, and PROM results were compared between groups at each time point.

RESULTS

The mean 2MWT distance after UKA was significantly longer than that after TKA at 6 weeks (96.5 ± 22.6 m for UKA compared with 81.1 ± 19.1 m for TKA; difference, 18 m [95% confidence interval (CI),10.4 to 25.6 m]; p < 0.001), 3 months (102.1± 24.4 compared with 87.5 ± 22.3 m; difference, 14.7 m [95% CI, 5.4 to 24.0 m]; p = 0.002), and 6 months (102.8 ± 16.2 compared with 89.6 ± 15.3 m; difference, 13.2 m [95% CI, 6.9 to 19.5 m]; p < 0.001). The values at 1 and 2 years were similar after UKA and TKA. The mean TUG after UKA was also significantly shorter than that after TKA at 6 weeks and 3 months. The mean PROMs were similar after both treatments, with the exception of the Oxford Knee Score and subscales of the Knee injury and Osteoarthritis Outcome Score at 6 weeks and 3 months postoperatively.

CONCLUSIONS

The 2MWT indicated that UKA for isolated medial knee OA enabled faster recovery than TKA did at 6 weeks to 6 months, and earlier recovery was also seen with the TUG at 6 weeks to 3 months. The 2MWT and TUG results after UKA and TKA were similar to one another at 1 and 2 years.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

The Value of a Standardized Knee Functional Assessment in Predicting the Outcomes of Total Knee Arthroplasty

Questionnaires and physical tests are tools to determine the ability of an individual to perform tasks of the daily living. In our institution, a standardized knee performance evaluation including patient-reported outcome measures (PROMs) and physical performance tests has been applied to all patients undergoing total knee arthroplasty (TKA). Our goal was to identify which preoperative tools influence the outcomes of a TKA and if physical performance tests can be of value if used along with PROMs in predicting functional outcomes. Classification and regression tree was used to analyze which preoperative factors influence function after TKA. Western Ontario and McMaster Universities Arthritis Index (WOMAC) function (WOMAC-F), 6-minute walk test (6MWT), and timed up and go (TUG) test at the 12th postoperative month were the dependent variables. Age, body mass index, preoperative WOMAC function and pain score, muscle strength, 6MWT, and TUG test score were used as preoperative predictors of dependent variables. TUG ≤19.3 seconds and age <62 years were preoperative predictors of better scores in the WOMAC-F (5.5). Strength of extensor muscles of the nonoperated knee ≥99.43 N·m/kg and 6MWT> 328 m were preoperative predictors of a better postoperative 6MWT (499 m). TUG <12.3 seconds and 6MWT ≥421 m were preoperative predictors of better postoperative TUG (7.3 seconds). Preoperative performance in physical tests had an influence on postoperative outcome scores than PROMs after TKA. Less age, good muscular strength, greater capacity of walking, and smaller TUG times were associated with better outcomes.

Measurement properties of performance-based measures to assess physical function in knee osteoarthritis: A systematic review

OBJECTIVE

To systematically review the measurement properties of performance-based measures to assess physical function in people with knee osteoarthritis.

DATA SOURCES

PubMed, Web of Science, Embase, Scopus, CINAHL, and PsycINFO were searched in May 2022.

METHODS

This study was conducted in accordance with the guidelines recommended by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Clinical trials on the psychometric properties of performance-based tools for measuring physical function in people with knee osteoarthritis were included. Two reviewers independently rated measurement properties using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN). "Best evidence synthesis" was made using COnsensus-based Standards for the selection of health Measurement INstruments outcomes and the quality of findings.

RESULTS

Thirty-six out of 3425 publications were eligible for inclusion. Thirty-two performance-based measures were evaluated including 26 single-activity measures and 6 multi-activity measures. Measurement properties evaluated included internal consistency (2 measures), reliability (23 measures), measurement error (20 measures), hypotheses testing for construct validity (22 measures), and responsiveness (23 measures). On balance of the limited evidence, the walk 40 m fast-paced test and 6-minute walking test were the best rated walking tests. The 30-second chair stand test and timed up and go test were the best rated sit-to-stand tests. The Performance Tests Measures and Physical Activity Restrictions may be the suitable multi-activity measures for knee osteoarthritis.

CONCLUSIONS

Further good quality research investigating the measurement properties, and in particular, the measurement error of performance-based measures in patients with knee osteoarthritis is needed.

Associations between Patient-Reported and Clinician-Reported Outcome Measures in Patients after Traumatic Injuries of the Lower Limb

Both clinician-reported outcome measures (CROMs) measures and patient-reported outcome measures (PROMs) are applied to evaluate outcomes in rehabilitation settings. The previous data show only a low to moderate correlation between these measures. Relationships between functional performance measures (Clinician-Reported Outcome Measures, CROMs) and Patient-Reported Outcome Measures (PROMs) were analysed in rehabilitation patients with traumatic injuries of the lower limb. A cohort of 315 patients with 3 subgroups (127 hip, 101 knee and 87 ankle region) was analysed before and after 3 weeks of inpatient rehabilitation. All three groups showed significant improvements in PROMs with low to moderate effect sizes. Moderate to high effect sizes were found for CROMs. Correlation coefficients between CROMs and PROMs were low to moderate. The performance consistency between PROMs and CROMs ranged from 56.7% to 64.1%. In this cohort of rehabilitation patients with traumatic injuries, CROMs showed higher effect sizes than PROMs. When used in combination, patient-reported outcome and performance measures contribute to collecting complementary information, enabling the practitioner to make a more accurate clinical evaluation of the patient’s condition.

Performance-based physical function correlates with walking speed and distance at 3 months post unilateral total knee arthroplasty

BACKGROUND

After total knee arthroplasty (TKA), walking speed and distance are main concerns of patients.

RESEARCH QUESTION

Which physical functions affect walking speed and distance after TKA?

METHODS

Cross-sectional data from 149 patients who underwent unilateral primary TKA and completed performance-based physical function tests. Instrumental gait evaluation for spatiotemporal parameters, isometric knee extensor and flexor strength of both knees, 6-minute walk test (6MWT), timed up-and-go (TUG) test, timed stair climbing test (SCT), and knee flexion and extension range of motion (ROM) of surgical knee were examined. Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and EuroQol five dimensions (EQ-5D) questionnaires were also performed.

RESULTS

Univariate analyses revealed that post-operative walking speed showed significant positive correlations with cadence, stride length, propulsion index of surgical and non-surgical knee, peak torque (PT) of the extensor of surgical and non-surgical knee and flexor of surgical and non-surgical knee, 6MWT, EQ-5D, and significant negative correlations with gait cycle duration, TUG, SCT-ascent and descent, and WOMAC-pain scores. Post-operative walking distance had significant positive correlations with walking speed, cadence, stride length, swing phase duration, propulsion index of surgical and non-surgical knee, PT of the extensor of surgical and non-surgical knee, EQ-5D, and significant negative correlation with gait cycle duration, double support duration, TUG, SCT-ascent and descent. In the multivariate linear regression analyses, TUG, cadence, stride length and propulsion index of non-surgical knee were factor correlated with post-operative walking speed. The SCT-ascent and descent, TUG and propulsion index of surgical knee were factor correlated with post-operative walking distance.

SIGNIFICANCE

Physical performance factors correlated with walking speed and distance at 3 months after surgery. Based on these observations, rehabilitation of bilateral muscle strength and functional mobility would be important for functional recovery after unilateral TKA.

Psychometric properties of the 4-meter walk test after total knee arthroplasty

OBJECTIVE

To determine the reliability, responsiveness, and convergent validity of the Four-Meter Walk Test (4mWT) compared to the Six-Minute Walk Test (6MWT) surrounding total knee arthroplasty (TKA).

DESIGN

Secondary analysis of a randomized controlled trial.

SETTING

Research laboratory.

PARTICIPANTS

One hundred sixty-two patients (aged 63.5 ± 7.4 (mean ± sd) years; 89 females) undergoing TKA participated.

MAIN OUTCOME MEASURES

4mWT (usual and fastest) and 6MWT were measured 1-2 weeks preoperatively, and 1, 2, 3, 6 and 12 months post-operatively.

RESULTS

4mWT demonstrated excellent test-retest reliability with Interclass Correlation Coefficients (ICC's) ranging from 0.80 to 0.93 s. 4mWT also demonstrated small measurement error with Standard Error of Measurement (SEM) ranging from 0.15 to 0.35 s. 4mWT (fastest) demonstrated similar responsiveness to 6mWT in the first 2 months after surgery and better responsiveness from 2 to 3 months after surgery. Convergent validity between 6MWT and 4mWT (fastest) was high, with Pearson correlation coefficients ranging from 0.73 to 0.81.

CONCLUSIONS

The 4mWT (fastest) has excellent test-retest reliability, shows high responsiveness sufficient for clinical outcomes in the immediate postoperative time periods, and exhibits high convergent validity with 6MWT. Given space and time requirements to conduct each test, 4mWT may be preferred for routine clinical assessment.IMPLICATIONS FOR REHABILITATIONWalking ability•Walking is an important functional ability for patients who undergo total knee arthroplasty (TKA).•While the Six-Minute Walk Test is a validated measure of walking ability in the TKA population, its clinical utility is limited by the space and time it takes to perform the test.•The Four-Meter Walk Test (fastest speed) is a valid, reliable, and responsive alternative to the 6MWT and is recommended for routine clinical use after TKA.

Physical Performance Tests Provide Distinct Information in Both Predicting and Assessing Patient-Reported Outcomes Following Lumbar Spine Surgery

STUDY DESIGN

Secondary analysis of randomized controlled trial data.

OBJECTIVE

The aim of this study was to examine whether preoperative physical performance is an independent predictor of patient-reported disability and pain at 12 months after lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

Patient-reported outcome measures (PROMs) are commonly used to assess clinical improvement after lumbar spine surgery. However, there is evidence in the orthopedic literature to suggest that PROMs should be supplemented with physical performance tests to accurately evaluate long-term outcomes.

METHODS

A total of 248 patients undergoing surgery for degenerative lumbar spine conditions were recruited from two institutions. Physical performance tests (5-Chair Stand and Timed Up and Go) and PROMs of disability (Oswestry Disability Index: ODI) and back and leg pain (Brief Pain Inventory) were assessed preoperatively and at 12 months after surgery.

RESULTS

Physical performance tests and PROMs significantly improved over 12 months following lumbar spine surgery (P < 0.01). Weak correlations were found between physical performance tests and disability and pain (ρ = 0.15 to 0.32, P < 0.05). Multivariable regression analyses controlling for age, education, preoperative outcome score, fusion, previous spine surgery, depressive symptoms, and randomization group found that preoperative 5-Chair Stand test was significantly associated with disability and back pain at 12-month follow-up. Each additional 10 seconds needed to complete the 5-Chair Stand test were associated with six-point increase in ODI (P = 0.047) and one-point increase in back pain (P = 0.028) scores. The physical performance tests identified an additional 14% to 19% of patients as achieving clinical improvement that were not captured by disability or pain questionnaires.

CONCLUSION

Results indicate that physical performance tests may provide distinct information in both predicting and assessing clinical outcomes in patients undergoing lumbar spine surgery. Our findings suggest that the 5-Chair Stand test may be a useful test to include within a comprehensive risk assessment before surgery and as an outcome measure at long-term follow-up.

LEVEL OF EVIDENCE

3.

Responsiveness, minimal important difference, minimal relevant difference, and optimal number of patients for a study

Several terms are used to describe changes in PROM scores in relation to treatments. Whether the change is small, large, or relevant is defined in different ways, yet these change scores are used to recommend or oppose treatments. They are also used to calculate the necessary number of patients for a study. This article offers a theoretical explanation behind the terms responsiveness, minimal important difference (MID), minimal important change (MIC), minimal relevant difference (MIREDIF), and threshold of clinical importance. It also gives instructions on how these and the optimal number of patients for a study are calculated. Responses to two domains of the Knee Injury and Osteoarthritis Outcome Score (KOOS), before and 1 year after reconstruction of the anterior cruciate ligament of 164 patients, are used to illustrate the calculations. This paper presents the most common methods used to calculate and interpret MID. Results vary substantially across domains, patient location on the scale, and health conditions. The optimal number of patients depends on the minimal relevant difference (MIREDIF), the standard error of the measure (SEM), the desired statistical power for the measurement, and the responsiveness of the measurement instrument (the PROM). There is often uncertainty surrounding the calculation and interpretation of responsiveness, MID, and MIREDIF, as these concepts are complex. When MID is used to evaluate research results, authors should specify how the MID was calculated, and its relevance for the study population. These measures should only be used after thorough consideration to justify healthcare decisions.

Effect of Outpatient Rehabilitation on Functional Mobility After Single Total Knee Arthroplasty: A Randomized Clinical Trial

Importance

Even without evidence, rehabilitation practitioners continue to introduce new interventions to enhance the mobility outcomes for the increasing population with a recent total knee arthroplasty (TKA).

Objective

To compare post-TKA functional mobility outcomes among 3 newly developed physical therapy protocols with a standard-of-care post-TKA rehabilitation protocol.

Design, Setting, and Participants

This randomized clinical trial included 4 study arms implemented in 15 outpatient clinics within a single health system in the Baltimore, Maryland, and Washington, District of Columbia, region from October 2013 to April 2017. Participants included patients who underwent elective unilateral TKA, were aged 40 years and older, and began outpatient physical therapy within 24 days after TKA. A total of 505 patients were screened and 386 participants were enrolled. Patients provided informed consent and were randomly assigned to 1 of 4 groups. Blinding patients and treating therapists was not feasible owing to the nature of the intervention. Analysis was conducted under the modified intent-to-treat principle from October 2017 to May 2019.

Interventions

The control group used a standard recumbent bike for 15 to 20 minutes each session. Interventions used 1 of 3 modalities for 15 to 20 minutes each session: (1) a body weight-adjustable treadmill, (2) a patterned electrical neuromuscular stimulation device, or (3) a combination of the treadmill and electrical neuromuscular stimulation.

Main Outcomes and Measures

Outcomes included the Activity Measure for Post-acute Care basic mobility score, a patient-reported outcome measure, and the 6-minute walk test. Outcomes were measured at baseline, monthly, and on discharge from outpatient therapy.

Results

Data from 363 patients (mean [SD] age, 63.4 [7.9] years; 222 [61.2%] women) were included in the final analysis, including 92 participants randomized to the control group, 91 participants randomized to the treadmill group, 90 participants randomized to the neuromuscular stimulation device group, and 90 participants randomized to the combination intervention group. Activity Measure for Post-acute Care scores at discharge were similar across groups, ranging from 61.1 to 61.3 (P = .99) with at least 9.0 points improvement (P = .80) since baseline. The distances as measured by the 6-minute walking test were not statistically different across groups (range, 382.9-404.5 m; P = .60).

Conclusions and Relevance

This randomized clinical trial found no statistically or clinically significant differences in outcomes across the 4 arms. Because outcomes were similar among arms, clinicians should instead consider relative cost in tailoring TKA rehabilitation.

Trial Registration

ClinicalTrials.gov Identifier: NCT02426190.

Falling risk in patients with end-stage knee osteoarthritis

Although 25% of patients with end-stage knee osteoarthritis (OA) have reported a fall, there is limited information about risk factors for falling in patients awaiting total knee arthroplasty (TKA). The purpose of this study was to identify clinical and functional measures related to fall risk. A total of 259 participants awaiting TKA for OA participated in this secondary cross-sectional study. Participants were divided into fallers and non-fallers based on falling history in the prior 6 months. Clinical measures (hip and knee pain, neck and low back pain (LBP), knee range of motion, and quadriceps strength) and functional measures (six-minute walk test (6MWT), timed up and go test, and Knee Injury and Osteoarthritis Outcome Score (KOOS)) were assessed in patients 2-4 weeks prior to TKA. Independent t tests were used to examine differences between groups. Odds ratio was calculated to identify clinical risk factors for falling. Of all participants, 47 (18%) reported a fall in the previous 6 months. Fallers had 30% greater LBP (3.0 ± 2.5 vs. 2.1 ± 2.6; p = 0.025). Fallers walked 12% shorter distance in the 6MWT than non-fallers (378 ± 100 vs. 422 ± 105 m; p = 0.010). For every 1-point increase in LBP on a 0-10 scale, there was a 14% greater risk of falling (p = 0.028). For every 10-m increase in 6MWT, there was a 3.8% reduction in fall risk (p = 0.011). Greater LBP and worse walking endurance are associated with falls in individuals with end-stage OA. Future studies should determine if interventions that reduce LBP and improve walking performance also reduce the chance of falling.

Orthoses versus gait retraining: Immediate response in improving physical performance measures in healthy and medial knee osteoarthritic adults

The conservative techniques of treating knee osteoarthritis (kOA) include wearing orthoses such as knee braces and laterally wedged insoles and applying gait modification techniques such as toe-in gait and toe-out gait. This study aimed at assessing the immediate effects of these techniques in improving physical function of healthy and kOA participants. Five Osteoarthritis Research Society International (OARSI) recommended performance-based tests were randomly applied to measure physical function: (1) 30-second chair stand test (30CST), (2) 40-m (4 × 10) fast-paced walk test (40FPW), (3) stair climb test (SCT), (4) timed up and go test (TUGT) and (5) 6-minute walk test (6MWT) during a single-visit on 20 healthy and 20 kOA patients (age: 59.5 ± 7.33 and 61.5 ± 8.63 years, BMI: 69.95 ± 9.86 and 70.45 ± 8.80 kg/m²). The interventions included natural gait, toe-out gait, toe-in gait, laterally wedged insoles and knee brace. Analysis was performed through repeated-measures ANOVA and independent sample t-test. 30CST and TUGT showed no significant differences for the five test conditions (p > 0.05). Toe-out showed profound effects via pairwise comparison in impairing the physical function while knee brace improved it during 40FPW, SCT and 6MWT. In general, all the tested conservative techniques except laterally wedged insoles had immediate effects on physical performance measures in both healthy and medial knee osteoarthritis participants. The valgus knee brace improved the parameters the most, while toe-out gait impaired them the most. Future studies can develop strategies for improving gait retraining methods on the basis of issues identified by this study.

The effect of mobilization with movement on pain and function in patients with knee osteoarthritis: a randomized double-blind controlled trial

BACKGROUND

Few studies have investigated the effects of mobilization with movement (MWM) in patients with knee osteoarthritis (OA) compared to other procedures. Sham procedures are generally more appropriate control than using no or usual treatments. Moreover, studies investigating the widespread hypoalgesic effects of MWM in patients with knee OA are lacking. The aim was to investigate the effect of MWM on function and pain in patients with knee OA compared to sham MWM.

METHODS

This is a randomized double-blind (patients and assessor) controlled trial. Forty adult patients with knee OA of grade II and above were recruited to receive either MWM treatment or sham MWM for the knee. The outcome measures included the following: a visual analogue scale (VAS) for pain, the pressure pain threshold (PPT) test, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index, the timed up and go (TUG) test, knee strength and knee range of motion (ROM). The measurements were taken at baseline, immediately after intervention and 2 days later.

RESULTS

Compared with sham MWM, MWM resulted in greater immediate improvement in pain [mean difference (95% CI): - 2.2 (- 2.8, - 1.6)], PPT at both the knee [176 (97, 254)] and shoulder [212 (136, 288)], TUG time [- 1.6 (- 2.1, - 1.1)], knee flexor strength [2.0 (1.3, 2.7)] and extensor strength [5.7 (4.1, 7.2)] and knee flexion ROM [12.8 (9.6, 15.9)] (all, p < 0.001) but not knee extension ROM [- 0.8 (- 1.6, 0.1)] (p = 0.067). After 2 days of intervention, patients who received MWM also demonstrated a greater improvement in pain [- 1.0 (- 1.8, - 0.1)], PPT at the shoulder [107 (40, 175)], TUG time [- 0.9 (- 1.4, - 0.4)], knee flexor strength [0.9 (0.2, 1.7)] and extensor strength [2.9 (2.1, 3.9)] and knee flexion ROM [8.3 (4.7, 11.9)] (all, p ≤ 0.026). However, WOMAC scores and knee extension ROM showed no evidence of change at any stage after intervention (p ≥ 0.067).

CONCLUSIONS

MWM provided superior benefits over sham MWM in terms of local and widespread pain, physical function (walking), knee flexion and extension muscle strength and knee flexion ROM for at least 2 days in patients with knee OA.

TRIAL REGISTRATION

ClinicalTrials.gov ( NCT02865252 ), registered on August 12, 2016.

Incorporating hip abductor strengthening exercises into a rehabilitation program did not improve outcomes in people following total knee arthroplasty: a randomised trial

QUESTION

In adults following primary total knee arthroplasty, does the incorporation of hip abductor strengthening exercises into a 6-week rehabilitation program improve muscle strength, functional performance and patient-reported outcomes at the end of rehabilitation and at 26 weeks?

DESIGN

Randomised controlled trial with concealed allocation, blinded assessors and intention-to-treat analysis.

PARTICIPANTS

One hundred and five adults admitted to an inpatient rehabilitation facility immediately following total knee arthroplasty.

INTERVENTION

Participants in both groups attended 12 days of inpatient physiotherapy followed by 6 weeks of outpatient physiotherapy, which aimed to improve knee range of movement, strength and mobility. The experimental group completed a standard rehabilitation protocol with the addition of hip abductor strengthening. The control group completed the same standard rehabilitation protocol, with the addition of 15 minutes of general functional exercises.

OUTCOME MEASURES

Primary outcomes were the Knee Injury and Osteoarthritis Outcome Score (KOOS) and isometric hip abductor muscle strength normalised to body mass index. Secondary outcome measures included the stair climb test, 6-minute walk test, Timed Up and Go test, 40-m fast-paced walk test, 30-second chair stand test, step test, isometric quadriceps muscle strength, Lower Extremity Functional Scale, and Short Form-12.

RESULTS

The experimental intervention did not result in significantly greater improvements in hip strength, KOOS or any of the secondary outcome measures than the control intervention at 6 weeks or 26 weeks.

CONCLUSION

Similar improvements in muscle strength, functional performance and patient-reported outcomes were observed whether specific hip-strengthening exercises were incorporated or general functional exercises were continued instead as part of a postoperative rehabilitation program for participants after total knee arthroplasty.

REGISTRATION

ANZCTR 12615000863538.

Twenty-four-week hospital-based progressive resistance training on functional recovery in female patients post total knee arthroplasty

BACKGROUND

After total knee arthroplasty (TKA) surgery, a decline in muscle strength is associated with a decrease in function. The aim of this study was to demonstrate the effect of a further 24 weeks of hospital-based resistance training under supervision, and precise dose on knee functional recovery and daily activities for female TKA patients.

METHODS

Twenty-nine patients who underwent unilateral primary TKA were allocated into either resistance training (RT) (n = 14) or control (CON) (n = 15) groups. All patients were assessed, with an isokinetic dynamometer, for hip and knee flexor and extensor muscle strength, physical function test, and Knee Injury and Osteoarthritis Outcome Score (KOOS). Resistance training was initiated three months after index surgery. The assessments were performed before exercise (Baseline), in the middle of the resistance training at 12 weeks (Mid-exercise), completion of the resistance training (Post-exercise), and 12 weeks after resistance training completion (Follow-up). A statistical test was performed by using generalized estimating equations.

RESULTS

Patients in RT had more of an increase in both knee extensor and flexor muscle strength than those in CON at the Post-exercise assessment. The six-minute walk test distance was more in RT compared with CON at the same Post-exercise assessment. Furthermore, the RT group had increases in Activities of daily living and Sports subscales compared to the CON group.

CONCLUSIONS

A further 24 weeks of hospital-based progressive resistance training facilitated improvement in knee muscle strength and functional outcome in TKA patients. Active hospital-based progressive resistance training is recommended for rehabilitation following TKA surgery.

Medium-Term Outcomes of Digital Versus Conventional Home-Based Rehabilitation After Total Knee Arthroplasty: Prospective, Parallel-Group Feasibility Study

Background

Physical rehabilitation is recommended after total knee arthroplasty (TKA). With the expected increase in TKA over the next few decades, it is important to find new ways of delivering cost-effective interventions. Technological interventions have been developed with this intent, but only preliminary evidence exists regarding their validity, with short follow-up times.

Objective

This study aimed to present the follow-up results of a feasibility study comparing two different home-based programs after TKA: conventional face-to-face sessions and a digital intervention performed through the use of an artificial intelligence-powered biofeedback system under remote clinical monitoring.

Methods

The digital intervention uses a motion tracker allowing 3D movement quantification, a mobile app and a Web portal. This study presents the results of the previous single-center, prospective, parallel-group, feasibility study including an 8-week active treatment stage and further assessments at 3 and 6 months post-TKA. Primary outcome was the Timed Up and Go score, and secondary outcomes were the Knee Osteoarthritis Outcome Scale (KOOS) score and knee range of motion.

Results

A total of 59 patients completed the study (30 in the digital intervention group and 29 in the conventional rehabilitation group) and follow-up assessments. During the active treatment stage, patients in the digital intervention group demonstrated high engagement and satisfaction levels, with an 82% retention rate. Both groups attained clinically relevant improvements from baseline to 6 months post-TKA. At the end of the 8-week program, clinical outcomes were superior in the digital intervention group. At the 3- and 6-month assessments, the outcomes remained superior for the Timed Up and Go score (P<.001) and all KOOS subscale scores (at 3 months, P<.001 overall; at 6 months, KOOS Symptoms: P=.006, Pain: P=.002, Activities of Daily Living: P=.001, Sports: P=.003, and Quality of Life: P=.001). There was progressive convergence between both groups in terms of the knee range of motion, which remained higher for standing flexion in the digital intervention group than the conventional group at 6 months (P=.01). For the primary outcome, at 6 months, the median difference between groups was 4.87 seconds (95% CI 1.85-7.47), in favor of the digital intervention group.

Conclusions

The present study demonstrates that this novel digital intervention for independent home-based rehabilitation after TKA is feasible, engaging, and capable of maximizing clinical outcomes in comparison to conventional rehabilitation in the short and medium term; in addition, this intervention is far less demanding in terms of human resources.

Trial Registration

ClinicalTrials.gov NCT03047252; https://clinicaltrials.gov/ct2/show/NCT03047252

Effectiveness of Later-Stage Exercise Programs vs Usual Medical Care on Physical Function and Activity After Total Knee Replacement: A Randomized Clinical Trial

IMPORTANCE

Several functional limitations persist after total knee replacement (TKR). Intensive exercise programs could resolve these limitations but are not well tolerated by many patients until a later stage (>2 months) after surgery. Evidence for exercise at a later stage after TKR is limited.

OBJECTIVES

To compare the effectiveness of later-stage exercise programs after TKR and to explore heterogeneity of treatment effects.

DESIGN, SETTING, AND PARTICIPANTS

Three-arm single-blind randomized clinical trial (January 7, 2015, to November 9, 2017) using an intent-to-treat approach with follow-ups at 3 months and 6 months. The setting was Allegheny County, Pennsylvania (an outpatient physical therapy clinic and 4 community centers). Participants had primary TKR performed more than 2 months previously, were 60 years or older, experienced moderate functional limitations, and were medically cleared to exercise.

INTERVENTIONS

Clinic-based physical therapy exercise (physical therapy arm), community-based group exercise (community arm), and usual care (control arm). The control arm continued their usual care, whereas the exercise arms participated in supervised exercise programs lasting 12 weeks.

MAIN OUTCOMES AND MEASURES

The primary outcome was arm differences in the Western Ontario and McMaster Universities Osteoarthritis Index-Physical Function (WOMAC-PF) at 3 months. The secondary outcomes included performance-based tests germane to knee replacement and additional surveys of physical function. Data were analyzed by linear mixed models and responder analysis.

RESULTS

A total of 240 participants (mean [SD] age, 70 [7] years; 61.7% female) were allocated to physical therapy (n = 96), community exercise (n = 96), or control (n = 48). All 3 arms demonstrated clinically important improvement. At 3 months, between-arm analyses for the WOMAC-PF demonstrated no differences between physical therapy and community (-2.2; 98.3% CI, -4.5 to 0.1), physical therapy and control (-2.1; 98.3% CI, -4.9 to 0.7), and community and control (0.1; 98.3% CI, -2.7 to 2.9). Performance-based tests demonstrated greater improvement in the physical therapy arm compared with both the community (0.1 z score units; 98.3% CI, 0.0-0.2) and control (0.3 z score units; 98.3% CI, 0.1-0.4) arms and the community arm compared with the control arm (0.2 z score units; 98.3% CI, 0.0-0.3). The physical therapy arm had more than 17.7% responders than the community arm and more than 19.0% responders than the control arm. There was no difference in responder rates between the community and control arms.

CONCLUSIONS AND RELEVANCE

Based on the primary outcome, participation in late-stage exercise programs after TKR offered no benefit over usual care. The benefits of physical therapy identified by the secondary outcomes and responder analysis require confirmation.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02237911.

Benefits of direct patient discharge to outpatient physical therapy after total knee arthroplasty

Purpose: To investigate the effectiveness of home health physical therapy followed by outpatient physical therapy as compared to patients discharged directly to outpatient physical therapy in improving functional performance, strength/activation and residual knee pain outcomes among patients who received a total knee arthroplasty.Materials and methods: A secondary analysis of longitudinal data in which patients with total knee arthroplasty underwent home health physical therapy or were discharged directly to outpatient physical therapy. Main outcome measures included the stair climb test, timed up and go, 6-min walk test, quadriceps and hamstring strength, quadriceps activation and residual knee pain.Results: Patients referred to home health physical therapy prior to outpatient physical therapy demonstrated significantly greater declines in stair climb test (10.3; 95% CI [6.5, 14.1]; t = 5.41; p < 0.0001), timed up and go (2.0; 95% CI [1.0, 3.0]; t = 4.10; p < 0.0001), 6-min walk (53.8; 95% CI [29.4, 78.2]; t = 4.35; p < 0.0001), quadriceps strength (21.7%; 95% CI [19.3%, 24.9%]; t = 2.53; p = 0.01), hamstring strength (44.7%; 95% CI [43.4%, 45.7%], t = 3.17; p = 0.002) and higher residual knee pain (0.53; 95% CI [0.04, 1.03]; t = 2.17; p = 0.03) 1 month after total knee arthroplasty compared to those referred directly to outpatient physical therapy.Conclusions: These findings suggest that patients discharged directly to outpatient physical therapy had a more rapid recovery 1 month after total knee arthroplasty. Additional research is needed to investigate the potential causal relation between care pathways and clinical outcomes following total knee arthroplasty.Implications for rehabilitationTotal knee arthroplasty, typically performed to alleviate end-stage knee osteoarthritis, is the most commonly performed elective surgery in the United States.Despite improvement in pain, objective measurements of functional performance and strength often remain at preoperative levels one year after total knee arthroplasty.Patients discharged directly to higher intensity outpatient physical therapy have a more rapid recovery after total knee arthroplasty compared with those patients who received two weeks of home health prior to undergoing outpatient physical therapy.

Improving Physical Activity Through Adjunct Telerehabilitation Following Total Knee Arthroplasty: Randomized Controlled Trial Protocol

Background

Physical activity remains low and nearly unchanged from preoperative levels following total knee arthroplasty (TKA), and this is thought to underlie long-term functional limitations, secondary health problems, and higher health care costs after TKA.

Objective

Our objective is to determine whether a telehealth-based intervention could improve physical activity and functional outcomes after TKA.

Design

The design is a 2-arm, parallel, assessor-blinded, randomized controlled trial with baseline, midintervention, postintervention, and 6-month follow-up assessments.

Setting

The setting is one academic medical center and one Veterans Affairs health care system.

Participants

One hundred US military veterans (aged 50-85 years) scheduled for unilateral TKA will participate in this study.

Intervention

The telehealth-based intervention to change physical activity behavior will be delivered through 10 sessions each of 30 minutes over a 12-week period. Participants will be provided with a wearable physical activity monitor to receive feedback on step count and guide goal-setting. Control participants will receive telehealth-based education on nonbehavioral aspects of health for the same frequency and duration as the intervention group. For both groups, telehealth sessions will occur concurrently with standardized outpatient rehabilitation.

Measurements

The primary outcome will be change in physical activity, assessed as daily step counts measured using an accelerometer-based sensor. Secondary outcomes will be measured using the Life-Space Assessment questionnaire and change in physical function (30-Second Chair-Stand Test, Timed "Up & Go" Test, Six-Minute Walk Test, Western Ontario and McMaster Universities Osteoarthritis Index, and Veterans RAND 12-Item Health Survey).

Limitations

Participant and interventionist blinding is not possible.

Conclusions

This trial will assess the efficacy of a novel behavior-change intervention to improve physical activity and physical function in patients after TKA. Effective physical activity behavior change could provide clinicians with a technique to augment current practice and resolve poor physical activity outcomes, long-term health problems, and high costs following TKA.

Preoperative quadriceps weakness preferentially predicts postoperative aberrant movement patterns during high-demand mobility following total knee arthroplasty

BACKGROUND

Nearly all patients with total knee arthroplasty show aberrant movement patterns during tasks requiring greater joint demand compared to matched peers. Greater movement compensation leads to increased loading onto other joints, decreased functional capacity and limited reserve for independence later in life. Understanding how preoperative predictors contribute to postoperative aberrant movement patterns is needed to make better decisions for patients considering total knee arthroplasty.

METHODS

Forty-seven patients were tested preoperatively and six months following primary total knee arthroplasty. Demographic (age, sex, body mass), self-reported (knee pain, perception of physical performance, physical activity level), physical performance (quadriceps strength, lower limb power and timed stair climbing) and surgical metrics were collected as predictor variables. Three-dimensional models based on joint mechanic asymmetry during a decline walking task were collected at six months postoperatively. Decline walking is a preferred means to assess the surgical knee's contribution to limb performance during high-demand tasks. Bootstrap inclusion fraction was employed to compare the stability of each predictor variable prior to the final regression model.

RESULTS

Preoperative quadriceps strength (β = 0.33; p = 0.04) showed a significant relationship with knee extensor angular impulse during loading phase. No other predictor variable had any meaningful relationship with aberrant movement patterns (p > 0.05).

CONCLUSION

Our findings highlight patients' preoperative quadriceps strength as a meaningful predictor of postoperative performance. Preoperative quadriceps strength should be addressed when considering the knee's ability to contribute to higher demanding mobility tasks following surgery.

Confounding pain and function: the WOMAC's failure to accurately predict lower extremity function

Background

Investigations have revealed the Western Ontario and McMaster Universities Osteoarthritis Index's (WOMAC) inability to provide distinct assessments of pain and function. The Lower Extremity Functional Scale (LEFS) has not displayed this deficiency. Our purposes were to investigate further the WOMAC physical function's (WOMAC-PF) ability to accurately assess lower extremity mobility in patients undergoing total knee arthroplasty (TKA) and to establish a relationship between pre- and post-TKA WOMAC-PF and LEFS scores that accounts for the apparent bias WOMAC pain scores impose on WOMAC-PF scores.

Methods

WOMAC, LEFS, and Timed-up-and-go measures were administered before TKA and 4 days, 6 weeks, and 3 months after TKA. To evaluate the WOMAC-PF and LEFS ability to provide a distinct assessment of pain and function, a paired t-test compared pre-TKA and 4 days after TKA values. Generalized estimating equation (GEE) analysis assessed the relationship between pre- and post-TKA values: dependent variable WOMAC-PF scores; independent variables LEFS scores, and measurement occasions.

Results

Timed-up-and-go and LEFS demonstrated a reduction in lower extremity function (P < .001); pain decreased (P < .001); and there was no significant change in WOMAC-PF scores (P = .61). GEE analysis revealed a linear relationship between WOMAC-PF and LEFS with similar slope coefficients for all four occasions. The relationship between WOMAC-PF and LEFS scores was virtually identical for the postarthroplasty assessment occasions.

Conclusions

Our findings support previous investigations that showed the WOMAC-PF's inability to provide a valid assessment in change in function. The GEE analysis coefficients can be used to convert LEFS scores to WOMAC-PF scores that adjust for the bias between pre- and post-TKA assessments.

Home-based Rehabilitation With A Novel Digital Biofeedback System versus Conventional In-person Rehabilitation after Total Knee Replacement: a feasibility study

In-person home-based rehabilitation and telerehabilitation can be as effective as clinic-based rehabilitation after total knee arthroplasty (TKA), but require heavy logistics and are highly dependent on human supervision. New technologies that allow independent home-based rehabilitation without constant human supervision may help solve this problem. This was a single-center, feasibility study comparing a digital biofeedback system that meets these needs against conventional in-person home-based rehabilitation after TKA over an 8-week program. Primary outcome was the change in the Timed Up and Go score between the end of the program and baseline. Fifty-nine patients completed the study (30 experimental group; 29 conventional rehabilitation). The study demonstrated a superiority of the experimental group for all outcomes. Adverse events were similar in both groups. This is the first study to demonstrate that a digital rehabilitation solution can achieve better outcomes than conventional in-person rehabilitation, while less demanding in terms of human resources.

A Feasibility Study of Percutaneous Peripheral Nerve Stimulation for the Treatment of Postoperative Pain Following Total Knee Arthroplasty

INTRODUCTION

The objective of the present feasibility study was to investigate the use of a new treatment modality-percutaneous peripheral nerve stimulation (PNS)-in controlling the often severe and long-lasting pain following total knee arthroplasty (TKA).

METHODS

For patients undergoing a primary, unilateral TKA, both femoral and sciatic open-coil percutaneous leads (SPR Therapeutics, Cleveland, OH) were placed up to seven days prior to surgery using ultrasound guidance. The leads were connected to external stimulators and used both at home and in the hospital for up to six weeks total.

RESULTS

In six of seven subjects (86%), the average of daily pain scores across the first two weeks was <4 on the 0-10 Numeric Rating Scale for pain. A majority of subjects (four out of seven; 57%) had ceased opioid use within the first week (median time to opioid cessation for all subjects was six days). Gross sensory/motor function was maintained during stimulation, enabling stimulation during physical therapy and activities of daily living. At 12 weeks following surgery, six of seven subjects had improved by >10% on the Six-Minute Walk Test compared to preoperative levels, and WOMAC scores improved by an average of 85% compared to before surgery. No falls, motor block, or lead infections were reported.

CONCLUSIONS

This feasibility study suggests that for TKA, ultrasound-guided percutaneous PNS is feasible in the immediate perioperative period and may provide analgesia without the undesirable systemic effects of opioids or quadriceps weakness induced by local anesthetics-based peripheral nerve blocks.

Training with Hybrid Assistive Limb for walking function after total knee arthroplasty

BACKGROUND

The Hybrid Assistive Limb (HAL, CYBERDYNE) is a wearable robot that provides assistance to patients while walking, standing, and performing leg movements based on the intended movement of the wearer. We aimed to assess the effect of HAL training on the walking ability, range of motion (ROM), and muscle strength of patients after total knee arthroplasty (TKA) for osteoarthritis and rheumatoid arthritis, and to compare the functional status after HAL training to the conventional training methods after surgery.

METHODS

Nine patients (10 knees) underwent HAL training (mean age 74.1 ± 5.7 years; height 150.4 ± 6.5 cm; weight 61.2 ± 8.9 kg), whereas 10 patients (11 knees) underwent conventional rehabilitation (mean age 78.4 ± 8.0 years; height 150.5 ± 10.0 cm; weight 59.1 ± 9.8 kg). Patients underwent HAL training during 10 to 12 (average 14.4 min a session) sessions over a 4-week period, 1 week after TKA. There was no significant difference in the total physical therapy time including HAL training between the HAL and control groups. Gait speed, step length, ROM, and muscle strength were evaluated.

RESULTS

The nine patients completed the HAL training sessions without adverse events. The walking speed and step length in the self-selected walking speed condition, and the walking speed in the maximum walking speed condition were greater in the HAL group than in the control group at 4 and 8 weeks (P < 0.05). The step length in the maximum walking speed condition was greater in the HAL group than in the control group at 2, 4, and 8 weeks (P < 0.05). The extension lag and knee pain were lower in the HAL group than in the control group at 2 weeks (P < 0.05). The muscle strength of knee extension in the HAL group was greater than that in the control group at 8 weeks (P < 0.05).

CONCLUSION

HAL training after TKA can improve the walking ability, ROM, and muscle strength compared to conventional physical therapy for up to 8 weeks after TKA. Since the recovery of walking ability was earlier in the HAL group than in the control group and adverse events were not observed in this pilot study, HAL training after TKA can be considered a safe and effective rehabilitation intervention.

TRIAL REGISTRATION

UMIN, UMIN000017623 . Registered 19 May 2015.

Validity and Responsiveness of the Two-Minute Walk Test for Measuring Functional Recovery After Total Knee Arthroplasty

BACKGROUND

The 2-minute walk test (2mwt) is a performance-based test that evaluates functional recovery after total knee arthroplasty (TKA). This study evaluated its validity compared with the modified Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), modified Knee Score, Numerical Pain Rating Scale, and Timed Up and Go test, and its responsiveness in assessing functional recovery in TKA patients.

METHODS

This prospective cohort study included 162 patients undergoing primary TKA between 2013 and 2015. We used patient-reported outcome measures (modified WOMAC, OKS, modified Knee Score, Numerical Pain Rating Scale) and performance-based tests (2mwt and Timed Up and Go test) at baseline and 3, 6, and 12 months postoperatively. The construct validity of 2mwt was determined between the 2mwt distances walked and other outcome measurements. To assess responsiveness, effect size and standardized response mean were analyzed. Minimal clinically important difference of 2mwt at 12 months after TKA was also calculated.

RESULTS

All outcome measurements improved significantly from baseline to 3, 6, and 12 months postoperatively. Bivariate analysis revealed mild to moderate associations between the 2mwt and modified WOMAC function subscales, and moderate to strong associations with OKS. Mild to moderate correlations were found for pain and stiffness between 2mwt and other outcome measurements. The effect size and standardized response mean at 12 months were large, with a minimal clinically important difference of 12.7 m.

CONCLUSION

2mwt is a validated performance-based test with responsiveness properties. Being simple and easy to perform, it can be used routinely in clinical practice to evaluate functional recovery after TKA.

Comparative Analysis of High-Velocity Versus Low-Velocity Exercise on Outcomes After Total Knee Arthroplasty: A Randomized Clinical Trial

BACKGROUND AND PURPOSE

High-velocity (HV) exercise is defined as performing a concentric muscle contraction as fast as possible, or in 1 second or less. Low-velocity (LV) exercise is defined as using 2 seconds to complete the contraction. A comparison of HV to LV exercise performed by community dwelling older adults indicates that HV exercise produces greater gains in power and scores for the 8-ft up-and-go, 30-seond chair stand, and continuous scale physical function performance tests. The effectiveness of HV strengthening exercises has not been identified for individuals who undergo total knee arthroplasty (TKA). The purpose of this research study was to compare the effects of a 6-week exercise program, using either LV or HV contractions, on functional performance, gait, and pain of individuals who have undergone TKA.

METHODS

Adults aged 60 to 89 years with a mean (standard deviation) age of 71.2 (6.8) years who underwent TKA an average of 15 days prior were randomly assigned to an HV exercise (n = 19) or LV exercise (n = 19) training group. The training program lasted for 12 sessions, over 6 to 7 weeks. The primary outcome was functional performance rated with the 6-Minute Walk Test. Secondary measures were the stair climb test, Timed Up and Go test, gait velocity, gait deviations measured with the Gait Abnormality Rating Scale, and pain via a visual analog scale. A 2×2 mixed model analysis of variance (group × time) was used for all outcomes. Comparison between LV and HV groups for posttest gait velocity and Gait Abnormality Rating Scale used independent t test and Mann-Whitney U test, respectively.

RESULTS

At baseline no differences between groups were noted for sex, age, and height. The LV group weighed more and had more comorbid conditions. Spearman's ρ demonstrated that the greater comorbidities of the LV group correlated with a slower stair climb test at baseline. At posttest both groups exhibited significantly improved scores for all outcome measurements except the visual analog scale for pain. The HV group, but not the LV group, reported a significant decrease in pain at the end of the 6-week training program.

CONCLUSIONS

Both HV and LV progressive exercises equally improve functional performance. Only the HV group reported significantly decreased pain at posttest.

Standardized Patient Reported Outcomes Do Not Capture Functional Deficits of Patients Following Contemporary Total Knee Replacement: Descriptive Study

BACKGROUND

The physical function subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC-PF) is widely used and endorsed by professional organizations for patients with knee osteoarthritis. Its use post total knee replacement (TKR) has been challenged as it may not represent the high level of functional performance that is expected by patients who undergo contemporary TKR with more advanced techniques and care pathways.

OBJECTIVE

To assess whether the items of the WOMAC-PF reflect the activity limitations identified by patients following TKR.

DESIGN

Data for this descriptive study were obtained from baseline assessments of a randomized clinical trial comparing exercise interventions following TKR.

METHODS

Participants completed the WOMAC-PF and identified activity limitations in the Canadian Occupational Performance Measure (COPM) in the same day. The responses to both questionnaires were compared.

RESULTS

This investigation included 50 participants (36 women, mean age 63.8±6.7). The WOMAC-PF failed to capture 50% of the activity limitations identified by participants in the COPM. These activities included kneeling, squatting, carrying/lifting items, strength/endurance exercise, floor transfer, lower extremity exercise, walking up/down hills, yard work, climbing a ladder, driving, managing the environment, carrying objects up/down stairs, gait initiation, balance, and going up/down curbs. Only one activity on the WOMAC-PF (going shopping) was not identified by participant responses on the COPM.

LIMITATIONS

Participants were included if they had TKR between 3 and 6 months prior, which may limit generalizability to those immediately after TKR, and the study sample was relatively small.

CONCLUSIONS

In individuals following TKR, the WOMAC-PF failed to represent a subset of higher level, more physically demanding activities that were identified as important by patients following TKR.

Efficacy of pre-operative quadriceps strength training on knee-extensor strength before and shortly following total knee arthroplasty: protocol for a randomized, dose-response trial (The QUADX-1 trial)

BACKGROUND

Patients with knee osteoarthritis (OA) report knee pain, limitation in physical activities and low quality of life. The two primary treatments for knee OA are non-surgical treatment (e.g., exercise) and surgery (total knee arthroplasty (TKA)); however, national guidelines recommend non-surgical treatment to be tried prior to surgical procedures. Patients with knee OA are characterized by decreased muscle strength, particularly in the knee-extensor muscles. Correspondingly, decreased knee-extensor strength is found to be associated with an increased risk of development, progression and severity of knee OA symptoms. Recent trials suggest a positive effect of pre-operative exercise on pre- and post-operative outcome; however, the most effective pre-operative knee-extensor strength exercise dosage is not known. The purpose of the present trial is to investigate the efficacy of three different exercise dosages of pre-operative, home-based, knee-extensor strength exercise on knee-extensor strength before and shortly after surgery in patients eligible for TKA due to end-stage knee OA.

METHODS

In this randomized dose-response trial with a three-arm parallel design, 140 patients with end-stage knee OA (candidates for TKA) are randomized to one of three exercise dosages (two, four or six session/week) of knee-extensor strength exercise (three sets, 12 repetitions at 12 RM, per exercise session) for 12 weeks. The knee-extensor strength exercise is home-based (unsupervised) and performed with an elastic exercise band following an initial exercise instruction. Adherence is objectively quantified using a sensor attached to the exercise band. The primary outcome will be the change in knee-extensor strength. Following the 12-week exercise period, the need for TKA surgery is re-assessed by an orthopedic surgeon.

DISCUSSION

Decreased knee-extensor strength is a major challenge in patients with knee OA. Exercise programs focusing on knee-extensor strength are found to be more effective in relieving knee OA pain and symptoms compared to more general exercise programs. However, the optimal exercise dosage for knee-extensor strength deficits in patients with knee OA is inconclusive. Knowledge on the dose-response relationship for knee-extensor strength exercise in patients with knee OA will help guide future non-surgical treatment in this patient population.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02931058 . Pre-registered on 10 October 2016.

A Feasibility Study for Improved Physical Activity After Total Knee Arthroplasty

Physical activity outcomes are poor following total knee arthroplasty (TKA). The purpose was to evaluate feasibility of a physical activity feedback intervention for patients after TKA. Participants completing conventional TKA rehabilitation were randomized to a physical activity feedback (PAF; n = 22) or control (CTL; n = 23) group. The PAF intervention included real-time activity feedback, weekly action planning, and monthly group support meetings (12 weeks). The CTL group received attention control education. Feasibility was assessed using retention, adherence, dose goal attainment, and responsiveness with pre- and postintervention testing. The PAF group had 100% retention, 92% adherence (frequency of feedback use), and 65% dose goal attainment (frequency of meeting goals). The PAF group average daily step count increased from 5,754 (2,714) (pre) to 6,917 (3,445) steps/day (post). This study describes a feasible intervention to use as an adjunct to conventional rehabilitation for people with TKA.

Physical therapists collect different outcome measures after total joint arthroplasty as compared to most orthopaedic surgeons: a New England study

Background

Following total knee and hip arthroplasty, patient progress can be assessed with patient-reported outcome measures (PROMs) and performance-based outcome measures (PBOMs). The American Joint Replacement Registry 2016 guide recommends collecting several measures, including Patient Reported Outcome Measure Information System Global, Knee Injury and Osteoarthritis Outcome Score Jr, and Hip Injury and Osteoarthritis Outcome Score Jr. This study aimed to assess the current and anticipated use of PROMs and PBOMs by New England physical therapists.

Methods

An online survey was conducted in July and August of 2015 asking physical therapists in New England to rate their current and anticipated future use of PROMs and PBOMs in terms of clinical decision making associated with the treatment and care of patients after total hip and knee replacement.

Results

There were 122 responses. The most often used and recommended PROMS were the Numeric Pain Rating Scale (99.2% and 97.5%, respectively) and Lower Extremity Function Scale (76.2% and 77.0%). There was significant variability in the use of different PBOMs, but the most often used and recommended were the Timed Up and Go (93.4% and 85.2%) and the Single Leg Balance Test (90.2% and 87.7%).

Conclusions

This study suggests that orthopaedic surgeons and physical therapists use different PROMs and PBOMs for postoperative assessment of total joint patients and highlights the need for more collaboration and consistency between these disciplines.

Effectiveness of an interactive telerehabilitation system with home-based exercise training in patients after total hip or knee replacement: study protocol for a multicenter, superiority, no-blinded randomized controlled trial

Background

Total hip or knee replacement is one of the most frequently performed surgical procedures. Physical rehabilitation following total hip or knee replacement is an essential part of the therapy to improve functional outcomes and quality of life. After discharge from inpatient rehabilitation, a subsequent postoperative exercise therapy is needed to maintain functional mobility. Telerehabilitation may be a potential innovative treatment approach. We aim to investigate the superiority of an interactive telerehabilitation intervention for patients after total hip or knee replacement, in comparison to usual care, regarding physical performance, functional mobility, quality of life and pain.

Methods/design

This is an open, randomized controlled, multicenter superiority study with two prospective arms. One hundred and ten eligible and consenting participants with total knee or hip replacement will be recruited at admission to subsequent inpatient rehabilitation. After comprehensive, 3-week, inpatient rehabilitation, the intervention group performs a 3-month, interactive, home-based exercise training with a telerehabilitation system. For this purpose, the physiotherapist creates an individual training plan out of 38 different strength and balance exercises which were implemented in the system. Data about the quality and frequency of training are transmitted to the physiotherapist for further adjustment. Communication between patient and physiotherapist is possible with the system. The control group receives voluntary, usual aftercare programs. Baseline assessments are investigated after discharge from rehabilitation; final assessments 3 months later. The primary outcome is the difference in improvement between intervention and control group in 6-minute walk distance after 3 months. Secondary outcomes include differences in the Timed Up and Go Test, the Five-Times-Sit-to-Stand Test, the Stair Ascend Test, the Short-Form 36, the Western Ontario and McMaster Universities Osteoarthritis Index, the International Physical Activity Questionnaire, and postural control as well as gait and kinematic parameters of the lower limbs. Baseline-adjusted analysis of covariance models will be used to test for group differences in the primary and secondary endpoints.

Discussion

We expect the intervention group to benefit from the interactive, home-based exercise training in many respects represented by the study endpoints. If successful, this approach could be used to enhance the access to aftercare programs, especially in structurally weak areas.

Trial registration

German Clinical Trials Register (DRKS), ID: DRKS00010009. Registered on 11 May 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2173-3) contains supplementary material, which is available to authorized users.

Inflammation and post-operative recovery in patients undergoing total knee arthroplasty-secondary analysis of a randomized controlled trial

OBJECTIVE

Reduced function persists for many patients after total knee arthroplasty (TKA). Inflammation is part of osteoarthritis' pathophysiology, and surgery induces a marked inflammatory response. We therefore wanted to explore the role of inflammation in long-term recovery after TKA, and thus conducted this secondary analysis of our randomized controlled trial (RCT) of physical rehabilitation ± progressive strength training (PST). We aimed to investigate whether (1) inflammation is associated with functional performance, knee-extension strength, and knee pain before TKA; (2) PST affects inflammation, and the inflammatory state over time; (3) baseline or surgery-induced inflammation modifies the effect of rehabilitation ± PST on change in 6-min walk test (Δ6MWT); and (4) baseline or surgery-induced inflammation is associated with Δ6MWT following TKA.

DESIGN

In the primary trial report's per-protocol analysis, 72/82 patients were included. Sixty had ≥1 blood sample before and after TKA, and were included in this secondary analysis. Inflammation was measured by interferon γ-inducible protein (IP)-10, soluble urokinase plasminogen activator receptor (suPAR), interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α at baseline; day 1, week 4, 8, and 26 after TKA.

RESULTS

At baseline, suPAR (P = 006) was negatively associated with 6MWT. Neither baseline nor surgery-induced inflammation modified the response to rehabilitation ± PST. Only surgery-induced IL-10 was associated with Δ6MWT_{26 weeks-baseline} (P = 0.001), also adjusted for 6MWT_baseline, age, sex and body mass index (BMI).

CONCLUSION

In this secondary analysis, only increased surgery-induced IL-10 response was associated with decreased long-term functional performance after TKA. The importance of controlling the surgery-induced immune response remains to be investigated further.

TRIAL IDENTIFICATION

NCT01351831.

Relationship between physical performance and self-reported function in healthy individuals across the lifespan

BACKGROUND

Functional outcome measures in clinical trials of musculoskeletal conditions need to be meaningful to individuals.

OBJECTIVES

To investigate the relationship between physical performance and self/proxy-reported function in 1000 healthy children and adults.

DESIGN

Cross-sectional observational study (1000 Norms Project).

METHODS

One thousand males and females aged 3-101 years, healthy by self-report and without major physical disability, were recruited. Twelve performance-based tests were analysed: vertical and long jump, two hand dexterity tests, four balance tests, stepping reaction time, 30-second chair stand, timed up-and-down stairs, and six-minute walk. Self/proxy-reported function was assessed using the Infant-Toddler Quality of Life questionnaire, Child Health Questionnaire, Assessment of Quality of Life (AQoL)-6D Adolescent, AQoL-8D, International Physical Activity Questionnaire and work ability question. Bivariate and multivariate correlational analyses were constructed for infants (3-4y), children (5-10y), adolescents (11-17y), adults (18-59y) and older adults (60+).

RESULTS/FINDINGS

Socio-demographic characteristics were similar to the Australian population. Among infants/children, greater jump and sit-to-stand performance correlated with higher proxy-reported function (p < 0.05). There were no significant relationships observed for adolescents (p > 0.05). Greater jump, dexterity, balance, reaction time, sit-to-stand, stair-climbing and six-minute walk performance correlated with higher self-reported function in adults (r = -0.097 to.231; p < 0.05) and older adults (r = -0.135 to 0.625; p < 0.05). Multivariate regression modelling revealed a collection of independent performance measures explaining up to 46% of the variance in self/proxy-reported function.

CONCLUSIONS

Many performance-based tests were significantly associated with self/proxy-reported function. We have identified a set of physical measures which could form the basis of age-appropriate functional scales for clinical trials of musculoskeletal conditions.

A Systematic Review of Measurement Properties of Patient-Reported Outcome Measures Used in Patients Undergoing Total Knee Arthroplasty

BACKGROUND

While clinical research on total knee arthroplasty (TKA) outcomes is prevalent in the literature, studies often have poor methodological and reporting quality. A high-quality patient-reported outcome instrument is reliable, valid, and responsive. Many studies evaluate these properties, but none have done so with a systematic and accepted method. The objectives of this study were to identify patient-reported outcome measures (PROMs) for TKA, and to critically appraise, compare, and summarize their psychometric properties using accepted methods.

METHODS

MEDLINE, EMBASE, SCOPUS, Web of Science, PsycINFO, and SPORTDiscus were systematically searched for articles with the following inclusion criteria: publication before December 2014, English language, non-generic PRO, and evaluation in the TKA population. Methodological quality and evidence of psychometric properties were assessed with the COnsensus-based standards for the selection of health Status Measurement INstruments (COSMIN) checklist and criteria for psychometric evidence proposed by the COSMIN group and Terwee et al.

RESULTS

One-hundred fifteen studies on 32 PROMs were included in this review. Only the Work, Osteoarthritis or joint-Replacement Questionnaire, the Oxford Knee Score, and the Western Ontario and McMaster Universities Arthritis Index had 4 or more properties with positive evidence.

CONCLUSION

Most TKA PROMs have limited evidence for their psychometric properties. Although not all the properties were studied, the Work, Osteoarthritis or joint-Replacement Questionnaire, with the highest overall ratings, could be a useful PROM for evaluating patients undergoing TKA. The methods and reporting of this literature can improve by following accepted guidelines.

Hip Abductor Strengthening Improves Physical Function Following Total Knee Replacement: One-Year Follow-Up of a Randomized Pilot Study

BACKGROUND

Total knee replacement (TKR) is the commonest surgical procedure for patients with severe pain and impaired physical function following end stage knee osteoarthritis. The hip abductors are well renowned in stabilization of the trunk and hip during walking, maintaining the lower limb position, and transferring the forces from the lower limbs to the pelvis.

OBJECTIVE

To assess the efficacy of hip abductor strengthening exercise on functional outcome using performance based outcome measures following total knee replacement.

METHODS

An observer blinded randomized pilot trial design was conducted at Manipal hospital, Bangalore, India. Participants designated for elective TKR were randomized to experimental group hip abductor strengthening along with standard rehabilitation (n=10) or control group standard rehabilitation alone (n=10). Participants followed for one year to assess physical function using performance based outcomes, such as timed up and go test, single leg stance test, six minute walk test, knee extensor strength and hip abductor strength.

RESULT

Eighteen participants with a mean age of 63.1 ± 5.5 years (8 Males and 10 Females) completed the study. Improvement in hip abduction strength, single leg stand test was superior in hip abductor strengthening group at 3 months and 1 year when compared to standard rehabilitation alone.

CONCLUSION

Hip abductor strengthening showed superior improvements in single leg stance test and six minute walk test. Hip abductor strengthening exercises has the potential to improve physical function following total knee replacement.