Validation of Physical Performance Tests in Individuals with Advanced Knee Osteoarthritis

Optimal cut-off scores of performance-based tests of physical function to discriminate disease severity in patients with knee osteoarthritis

BACKGROUND

A set of physical tests representing typical activities relevant to persons with knee osteoarthritis (KOA) is recommended by the Osteoarthritis Research Society International (OARSI). The objective of this study was to designate the cut-off values for OARSI-recommended performance-based tests to better discriminate disease severity in patients with KOA.

METHODS

As recommended by the OARSI, we conducted the 30-s chair stand test (30-s CST), 40-m fast-paced walk test (40-m FPWT), stair climb test (SCT), 6-min walk test (6MWT), and timed up and go test (TUG). To investigate the discriminative power of the performance test scores using the Kellgren-Lawrence (K-L) grading system, receiver operating characteristic (ROC) curve analysis was performed. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was used to assess self-administered health status.

RESULTS

Forty-eight patients with bilateral KOA were included this study. The area under the curves for four of the five performance tests (30-s CST, six-step SCT, 40-m FPWT, and TUG) had acceptable discrimination (0.753-0.793), while the 6MWT had excellent discrimination (0.860). The stepwise multiple regression analysis demonstrated that 6MWT and 30-s CST were significant and independent determinants of WOMAC score, explaining 48% of the variance (P < 0.001).

CONCLUSION

The OARSI performance tests can discriminate disease severity in individuals with KOA. The 6MWT has the highest level of discriminative validity among all. In addition, despite the correlation between all five tests and the WOMAC score, 6MWT and 30-s CST are independent and significant determinants of the WOMAC.

Plasma zonulin levels forecast sarcopenia and physical performance in patients with knee osteoarthritis

PURPOSE

Knee Osteoarthritis (KOA) is a common disease in the elderly; however, its causative factors remain poorly elucidated. We investigated the potential contribution of intestinal mucosal disruption to the severity of KOA and physical capacity.

METHOD

We recruited women, healthy controls (age = 65.3 ± 6.6 years, n = 75) and patients with mild (age = 70.5 ± 3.8 years), moderate (age = 68.3 ± 5.5 years), and poor KOA (age = 73.8 ± 4.5 years, n = 43-50/group), characterized on oxford knee scoring (OKS) system. We also measured plasma zonulin as a marker of intestinal mucosal disruption alongwith plasma biochemistry, body composition, short physical performance battery (SPPB) score, gait speed, and hand grip strength (HGS) in control and KOA patients.

RESULTS

KOA patients had elevated plasma zonulin levels, along with lower appendicular skeletal muscle mass (ASMI), and higher body fats than controls (all p < 0.05). Furthermore, KOA patients had lower SPPB scores, gait speed, and HGS than controls (all p < 0.05). Simple regression analysis revealed robust negative correlations of plasma zonulin with OKS, HGS, gait speed, and SPPB scores in KOA patients. These patients also exhibited higher levels of markers of inflammation and oxidative stress. Zonulin also exhibited significant areas under the curve in diagnosing low OKS scores, reduced physical capacity, and muscle weakness in KOA patients.

SIGNIFICANCE

Taken together, increased intestinal permeability may contribute to the reduced functional performance in KOA, and plasma zonulin may be a useful diagnostic tool in KOA.

Investigation of the validity and reliability of the short physical performance battery in patients undergoing total knee arthroplasty

BACKGROUND

Practical, applicable, valid, and reliable tools are needed to assess physical performance in patients with Total Knee Arthroplasty (TKA) in a variety of settings, including routine clinical assessment, research studies, and community-based programs.

OBJECTIVE

The aim of this study is to evaluate the validity and reliability of the Short Physical Performance Battery (SPPB) among patients with TKA.

METHODS

We included 45 patients who underwent TKA surgery (mean age 68.89 ± 9.26). The SPPB, Timed up and go (TUG) test and, Hospital for Special Surgery (HSS) Knee Score were administered to the patients. SPPB was performed twice on the same day with 1 h rest.

RESULTS

The ICC(2,1) coefficient, MDC95 and SEM values were 0.97, 1.02 and 0.37 respectively. The Pearson correlation coefficient of the SPPB with the TUG and HSS was -.78, and 0.74 respectively.

CONCLUSION

SPPB has excellent reliability, and strong validity in assessing physical performance in patients with TKA. SPPB can identify even minimal detectable difference in physical performance and can be reliably used to monitor patient outcomes in the postoperative period for a comprehensive assessment of TKA in many physical performance domains, including balance, walking speed, and lower extremity strength.

CLINICAL TRIAL NUMBER

NCT06201637.

Feasibility of a Multimodal Prehabilitation Program before Elective Knee and Hip Arthroplasty in Older Adults

OBJECTIVES

Hip osteoarthritis and knee osteoarthritis cause significant disability and pain in older adults, often leading to hip or knee replacement surgery. Prehabilitation programs have been established for these surgeries, but there are few programs for orthogeriatrics. We evaluated the feasibility of a new multimodal prehabilitation program (MPP) for older adults before hip or knee replacement due to arthrosis: the Prehabilitation for Os (PRE4OS) study.

DESIGN

We conducted a multicenter feasibility study in the Greater Paris area.

SETTING AND PARTICIPANTS

Eligible adults were aged ≥75 years old awaiting hip or knee replacement with at least a 6-week delay before surgery and able to participate in the MPP follow-up. The MPP included weekly hospital sessions providing nutritional, psychological, functional, and cognitive support, along with weekly home sessions featuring physiotherapist visits.

METHODS

The primary outcome was at least 80% of 1-day hospital (ODH) sessions performed by 80% of participants. Secondary outcomes included intervention achievement, quality of life, and nutritional and functional status changes. Participant's satisfaction was qualitatively assessed via structured phone interviews presurgery and at 30 days postsurgery.

RESULTS

From September 2021 to September 2023, a total of 27 individuals participated in the PRE4OS study. The mean (SD) age was 83 (4.3) years, with 7 males (26%) and median baseline Activities of Daily Living score 5.5 (interquartile range 5.5-6.0). Surgeries were for insertion of hip prosthesis in 17 participants (63%) and knee prosthesis in 10 (37%). The primary outcome was achieved in 89% of participants, with comparable rates for hip and knee prostheses. In total, 60% of participants rated the MPP as "excellent" presurgery and 100% at 30 days postsurgery, expressing a willingness to recommend the protocol to a friend or family.

CONCLUSION AND IMPLICATIONS

The MPP was feasible for individuals before hip or knee replacement and was well received. Further randomized trials are needed to assess its clinical impact.

Association of neighborhood-level disadvantage beyond individual sociodemographic factors in patients with or at risk of knee osteoarthritis

OBJECTIVE

Lower socioeconomic status (SES) is a risk factor for poorer pain-related outcomes. Further, the neighborhood environments of disadvantaged communities can create a milieu of increased stress and deprivation that adversely affects pain-related and other health outcomes. Socioenvironmental variables such as the Area Deprivation Index, which ranks neighborhoods based on socioeconomic factors could be used to capture environmental aspects associated with poor pain outcomes. However, it is unclear whether the ADI could be used as a risk assessment tool in addition to individual-level SES.

METHODS

The current study investigated whether neighborhood-level disadvantage impacts knee pain-related outcomes above sociodemographic measures. Participants were 188 community-dwelling adults who self-identified as non-Hispanic Black or non-Hispanic White and reported knee pain. Area Deprivation Index (ADI; measure of neighborhood-level disadvantage) state deciles were derived for each participant. Participants reported educational attainment and annual household income as measures of SES, and completed several measures of pain and function: Short-form McGill Pain Questionnaire, Western Ontario and McMaster Universities Osteoarthritis Index, and Graded Chronic Pain Scale were completed, and movement-evoked pain was assessed following the Short Physical Performance Battery. Hierarchical linear regression analyses were used to assess whether environmental and sociodemographic measures (i.e., ADI 80/20 [80% least disadvantaged and 20% most disadvantaged]; education/income, race) were associated with pain-related clinical outcomes.

RESULTS

Living in the most deprived neighborhood was associated with poorer clinical knee pain-related outcomes compared to living in less deprived neighborhoods (ps < 0.05). Study site, age, BMI, education, and income explained 11.3-28.5% of the variance across all of the individual pain-related outcomes. However, the ADI accounted for 2.5-4.2% additional variance across multiple pain-related outcomes.

CONCLUSION

The ADI accounted for a significant amount of variance in pain-related outcomes beyond the control variables including education and income. Further, the effect of ADI was similar to or higher than the effect of age and BMI. While the effect of neighborhood environment was modest, a neighborhood-level socioenvironmental variable like ADI might be used by clinicians and researchers to improve the characterization of patients' risk profile for chronic pain outcomes.

Functional assessment in patients with castration-resistant prostate cancer treated with darolutamide: results from the DaroAcT study

BACKGROUND

Androgen receptor inhibitors (ARIs) are approved for the treatment of advanced prostate cancer; however, some patients may experience symptoms and side effects that hinder their physical functioning. The Timed Up and Go (TUG) and Short Physical Performance Battery (SPPB) tests are used to assess physical functioning in older adults and are recommended assessments for patients with prostate cancer, despite lacking validation in this setting.

METHODS

DaroAct (NCT04157088) was an open-label, multicenter, phase 2b study designed to evaluate the effects of the ARI darolutamide (lead-in phase) and darolutamide vs enzalutamide (randomized phase) on physical functioning in men with castration-resistant prostate cancer (CRPC). Only the lead-in phase, in which participants received darolutamide 600 mg twice daily, was completed. The TUG and SPPB tests were used to assess physical functioning.

RESULTS

The lead-in phase enrolled 30 participants. During 24 weeks of treatment, 8 (32.0%) of 25 evaluable participants exhibited clinically meaningful worsening in TUG from baseline (primary endpoint). At the week 24 visit, 5 (21.7%) of 23 participants had worsening in TUG time, and 8 (33.3%) of 24 participants had worsening in SPPB score. Because only 48% of participants had the same outcome on the TUG and SPPB tests, the study was terminated without initiating the randomized comparison.

CONCLUSION

Most participants showed no clinically meaningful worsening in physical functioning after 24 weeks of darolutamide treatment, but poor agreement between tests was observed. Tools to accurately and consistently measure the impact of ARIs on physical functioning in patients with CRPC are needed.

The Efficacy of the Addition of tDCS and TENS to an Education and Exercise Program in Subjects with Knee Osteoarthritis: A Randomized Controlled Trial

Knee osteoarthritis (KOA) has a significant impact on patients' quality of life. This study aimed to assess the effectiveness of integrating transcranial direct current stimulation (tDCS) and transcutaneous electrical nerve stimulation (TENS) into an education and exercise program with the aim of decreasing pain and improving physical function in KOA. A randomized controlled trial with 65 KOA patients was conducted. The subjects were assigned to one of the following three groups: education and active exercise plus (1) double active tDCS and TENS, (2) active tDCS and sham TENS, and (3) double sham tDCS and TENS. Sessions were conducted over a 20 min period, whilst data on pain, chronic pain clinical variables, and physical function were collected. Although all groups showed improvement in pain-related symptoms in the short and medium term, the addition of tDCS and/or TENS did not significantly enhance the benefits of the exercise and education program. These findings suggest that an education and active exercise program in the treatment of KOA has a positive effect on pain, with or without the addition of tDCS and/or TENS.

Short Physical Performance Battery reliability and validity in adults with mild to moderate intellectual disability

BACKGROUND

People with intellectual disability have poor balance skills and greater fall risk. The Short Physical Performance Battery (SPPB) provides comprehensive information on functional status and can predict fall risk. However, the reliability and validity of the SPPB have not been evaluated in people with intellectual disability.

METHODS

Seventy-eight adults with intellectual disability were assessed using the SPPB twice. Reliability was analysed with intraclass correlation coefficient and validity was assessed against the Timed Up & Go (TUG) test and the stabilometric test using Spearman's rho.

RESULTS

Reliability was moderate to high in all SPPB components except for the semi-tandem and full tandem positions. The SPPB summary score indicated moderate test-retest reliability and showed mostly significant moderate associations with the TUG and poor agreement with the stabilometric test.

CONCLUSIONS

The SPPB summary score indicated high internal consistency, moderate reliability, and moderate validity when applied to adults with intellectual disability.

Do Patient Reported Outcomes Reflect Objective Measures of Function? Implications for Total Knee Arthroplasty

BACKGROUND

Patient Reported Outcomes (PROs) are used in research, clinical practice, and by federal reimbursement models to assess outcomes for patients who have knee osteoarthritis (OA) and total knee arthroplasty (TKA). We examined a large cohort of patients to determine if commonly used PROs reflect observed evaluation as measured by standardized functional tests (SFTs).

METHODS

We used data from the Osteoarthritis Initiative, a ten-year observational study of knee osteoarthritis patients. Two cohorts were examined: 1) participants who received TKA (n=281) and 2) participants who have native OA (n=4,687). The PROs included Western Ontario and McMaster Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), 12-Item Short Form Health Survey (SF-12), and Intermittent and Constant Pain Score (ICOAP). The SFTs included 20 and 400 meter (M) walks and chair stand pace. Repeated measures correlation coefficients were used to determine the relationship between PROs and SFTs.

RESULTS

The PROs and SFTs were not strongly correlated in either cohort. The magnitude of the repeated measures correlation (r_rm) between KOOS, WOMAC, SF-12, and ICOAP scores and SFT measurements in native knee OA patients ranged as follows: 400 M walk pace (0.08 to 0.20), chair stand pace (0.05 to 0.12), and 20 M pace (0.02 to 0.21), all with P<0.05. In the TKA cohort, values ranged as follows: 400 M walk pace (0.00 to 0.29), chair stand time (0.02 to 0.23), and 20 M pace (0.03 to 0.30). Due to the smaller cohort size, the majority, but not all had P values <0.05.

CONCLUSION

There is not a strong association between PROs and SFTs among patients who have knee OA or among patients who received a TKA. Therefore, PROs should not be used as a simple proxy for observed evaluation of physical function. Rather, PROs and SFTs are complementary and should be used in combination for a more nuanced and complete characterization of outcome.

Addition of tDCS and TENS to an education and exercise program in subjects with knee osteoarthritis: A study protocol

BACKGROUND

Knee osteoarthritis often leads to chronic pain that frequently becomes disabling.Osteoarthritis has been linked to maladaptive plasticity in the brain, which can contribute to chronic pain. Therapies including neuromodulation and peripheral electrical stimulation are used to counteract the maladaptive plasticity of the brain.

OBJECTIVE

To determine the efficacy of the addition of tDCS and TENS to an education and exercise program in reducing pain.

METHODS

Over a 2-week study period, 60 participants will complete an exercise and educational intervention. Eligible participants accepting to participate will be subsequently randomized into one of the three treatment groups: 1) Active Transcranial Direct Current Stimulation (tDCS) and active Transcutaneous Electrical Nerve Stimulation (TENS); 2) Active tDCS and sham TENS; 3) Sham tDCS and sham TENS.

RESULTS

The primary outcome will be subjective pain intensity.

SECONDARY OUTCOMES

quality of life, physical function, central sensitization, and pain adjuvants (uncertainty, catastrophizing kinesiophobia, adverse events).

CONCLUSION

This clinical trial will provide data on the effect that the addition of tDCS and/or TENS to an education and exercise program may have to counteract maladaptive plastic changes and improve the benefits of exercises, and whether the combination of both neuromodulator techniques may have a higher magnitude of effect.

Factors associated with falls in patients with knee osteoarthritis: A cross-sectional study

Falls represent an important adverse effect associated with knee osteoarthritis and result in a significant financial burden on the healthcare system. Therefore, identification of fall predictors is essential to minimize fall incidence. However, few studies have investigated falls and fall predictors, particularly focused on the fear of falls and proprioception. In this study, we investigated significant fall predictors in patients with knee osteoarthritis in Malang, Indonesia. Our findings may serve as useful guidelines to develop geriatric fall prevention programs. This cross-sectional survey using purposive sampling was performed between April and July 2021 and included 372 participants. We recorded the following data: sociodemographic and medical history questionnaire responses, visual analog scale scores, Hopkins falls grading scale scores, Fall Efficacy Scale-International scores, proprioception test findings, knee injury and osteoarthritis outcome score (KOOS), range of motion (ROM), chair stand test and the timed up and go test performance. Data were analyzed using the chi-square and t tests, and multivariate logistic regression to determine significant fall predictors. Multivariate logistic regression analysis showed a lower risk of falls in patients with better proprioception and ROM than in the other groups (odds ratio 0.55 vs 0.96). The risk of falls was higher in patients with higher KOOS symptoms, fear of falls, diagnosis of low back pain and diabetes mellitus, and increased body mass index than in the other groups (odds ratio 1.41, 2.65, 1.27, 3.45, and 1.10, respectively. Our study shows that knee proprioception and ROM serve as protective factors against falls, whereas KOOS symptoms, fear of falls, low back pain, diabetes mellitus, and body mass index were associated with a high risk of falls, with diabetes mellitus and fear of falls being the most significant risk factors. These findings may be useful to policy makers to develop a fall prevention program that can be implemented in community health care centers across Indonesia to deliver individualized, person-centered care and improve fall prevention strategies through a systematic process comprising evaluation, intervention, and monitoring to minimize fall risk.

Validity of the Osteoarthritis Research Society International (OARSI) recommended performance-based tests of physical function in individuals with symptomatic Kellgren and Lawrence grade 0-2 knee osteoarthritis

BACKGROUND

Performance-based physical tests have been widely used as objective assessments for individuals with knee osteoarthritis (KOA), and the core set of tests recommended by the Osteoarthritis Research Society International (OARSI) aims to provide reliable, valid, feasible and standardized measures for clinical application. However, few studies have documented their validity in roentgenographically mild KOA. Our goal was to test the validity of five performance-based tests in symptomatic KOA patients with X-ray findings of Kellgren and Lawrence (K-L) grade 0-2.

METHODS

We recruited a convenience sample of thirty KOA patients from outpatient clinics and 30 age- and sex-matched asymptomatic controls from the community. They performed five OARSI-recommended physical tests and the KOA group answered the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index. The tests included the 9-step stair-climbing test (9 s-SCT), timed up and go (TUG) test, 30-second chair-stand test (30sCST), 40-m fast walking-test (40MFPW) and 6-minute walking test (6MWT). The discriminant validity of these physical tests were assessed by comparisons between the KOA and control groups, receiver operating curve and multivariate logistic regression analysis. The convergent/divergent validity was assessed by correlation between the physical tests results and the three subscale scores of the WOMAC in the KOA group.

RESULTS

The KOA group had significantly worse performance than the control group. The percentage of difference was the largest in the 9 s-SCT (57.2%) and TUG tests (38.4%). Meanwhile, Cohen's d was above 1.2 for the TUG test and 6MWT (1.2 ~ 2.0), and between 0.8 and 1.2 for the other tests. The areas under the curve to discriminate the two groups were mostly excellent to outstanding, except for the 30sCST. Convergent validity was documented with a moderate correlation between the 9 s-SCT and the physical function (WOMAC-PF) subscale scores (Spearman's ρ = 0.60).

CONCLUSIONS

The OARSI recommended core set was generally highly discriminative between people with K-L grade 0-2 KOA and their controls, but convergent/divergent validity was observed only in the 9 s-SCT. Further studies are required to evaluate the responsiveness of these tests and understand the discordance of physical performance and self-reported measures.

Arthritis, physical function, and disability among older Mexican Americans over 23 years of follow-up

OBJECTIVE

Arthritis is a common chronic condition in the ageing population. Its impact on physical function varies according to sociodemographic and race/ethnic factors. The study objective was to examine the impact of arthritis on physical function and disability among non-disabled older Mexican Americans over time.

DESIGN

A 23-year prospective cohort study of 2230 Mexican Americans aged 65 years and older from the Hispanic Established Population for the Epidemiologic Study of the Elderly (1993/94-2016). The independent variable was self-reported physician-diagnosed arthritis, and the outcomes included Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), mobility, Short Physical Performance Battery (SPPB), and handgrip strength. Covariates were sociodemographic, medical conditions, body mass index, depressive symptoms, and cognitive function. General linear mixed models were performed to estimate the change in SPPB and muscle strength. General Equation Estimation models estimated the odds ratios (OR) of becoming ADL- or IADL- or mobility - disabled as a function of arthritis. All variables were used as time-varying except for sex, education, and nativity.

RESULTS

Overall, participants with arthritis had higher odds ratio (OR) of any ADL [OR = 1.35, 95% Confidence Interval (CI) = 1.09-1.68] and mobility (OR = 1.34, 95% CI = 1.18-1.52) disability over time than those without arthritis, after controlling for all covariates. Women, but not men, reporting arthritis had increased risk for ADL and mobility disability. The total SPPB score declined 0.18 points per year among those with arthritis than those without arthritis, after controlling for all covariates (p-value < .010).

CONCLUSIONS

Our study demonstrates the independent effect of arthritis in increasing ADL and mobility disability and decreased physical function in older Mexican Americans over 23-years of follow-up.

Comparison of Patient-Reported Outcomes and Functional Assessment Using a Marker-Less Image Capture System in End-Stage Knee Arthritis

BACKGROUND

Patient self-assessment of knee function in end-stage osteoarthritis (OA) and following total knee arthroplasty (TKA) using patient-reported outcome measures (PROMs) has become standard for defining disability. The relationship of PROMs to functional performance requires a continued investigation. The purpose of this study was to determine correlations between patient demographics, PROMs, and functional performances using a marker-less image capture system (MICS).

METHODS

Patients indicated for elective TKA completed the Knee Injury and Osteoarthritis Score for Joint Replacement (KOOS-JR) and an office-based functional assessment using a MICS. Patient age, body mass index (BMI), and gender were collected. A total of 112 patients were enrolled. Their mean age was 65.0 (±9.7) years, mean BMI was 32.5 (±6.6) kg/m², and mean KOOS-JR was 14.5 (±5.7). The relationships between patient characteristics, KOOS-JR, MICS Alignment (coronal), MICS Mobility (flexion), and composite Total Joint scores were described using Spearman's correlation coefficients.

RESULTS

BMI was weakly correlated with KOOS-JR (ρ = -0.22, P = .024), whereas age was not. Age and BMI were not correlated with performance scores. There were weak to no correlations between KOOS-JR and MICS Alignment (ρ = -0.01, P = .951), Mobility (ρ = 0.33, P < .001), and Total Joint scores (ρ = 0.06, P = .504).

CONCLUSION

This study found no strong correlation between KOOS-JR and functional performance using a validated MICS for patients with end-stage knee OA. Further study is warranted in determining the relationship between PROMs and performance to optimize outcomes of patients undergoing nonoperative or surgical interventions for knee OA. The use of high-fidelity functional assessment tools that can be integrated into clinical workflow, such as the MICS used in this study, should permit PROM/functional performance comparisons in large populations.

The combination of osteoporosis and low lean mass correlates with physical function in end-stage knee osteoarthritis: A retrospective observational study

We aimed to investigate the prevalence of osteoporosis and low lean mass, either together or in isolation, and their association with physical function, pain, and quality of life (QOL) in patients with end-stage knee osteoarthritis (OA). This retrospective cross-sectional observational study included 578 patients (77 males and 501 females) diagnosed with end-stage knee OA. Patients were divided into 4 groups based on body composition parameters: control, osteoporosis, low lean mass, and osteoporosis + low lean mass. All participants underwent performance-based physical function tests, including a stair climbing test (SCT), a 6-minute walk test, a timed up and go test, and instrumental gait analysis, to examine spatiotemporal parameters. Self-reported physical function and pain levels were measured using the Western Ontario McMaster Universities Osteoarthritis Index and visual analog scale, respectively. Self-reported QOL was measured using the EuroQOL 5 dimensions (EQ-5D) questionnaire. Of 578 patients, 268 (46.4%) were included in the control group, 148 (25.6%) in the osteoporosis group, 106 (18.3%) in the low lean mass group, and 56 (9.7%) in the osteoporosis + low lean mass group. Analysis of variance revealed that the scores for the osteoporosis + low lean mass group in the SCT-ascent, SCT-descent, and timed up and go test were significantly higher, whereas those for the 6-minute walk test, gait speed, and cadence were significantly lower than those for the other groups (P < .05). After adjusting for age, sex, and body mass index, multiple linear regression analysis identified SCT-ascent (β = 0.140, P = .001, R2 = 0.126), SCT-descent (β = 0.182, P < .001, R2 = 0.124), gait speed (β = -0.116, P = .005, R2 = 0.079), and cadence (β = -0.093, P = .026, R2 = 0.031) as being significantly associated with osteoporosis + low lean mass. Thus, osteoporosis + low lean mass correlates with poor physical function, but not pain and QOL, in patients with end-stage knee OA.

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.

Patients Surviving Critical COVID-19 have Impairments in Dual-task Performance Related to Post-intensive Care Syndrome

Objective

The purpose was to examine Dual Task (DT) performance in patients surviving severe and critical COVID-19 compared to patients with chronic lung disease (CLD). Secondarily, we aimed to determine the psychometric properties of the Timed Up and Go (TUG) test in patients surviving COVID-19.

Design

Prospective, cross-sectional, observational study.

Setting

Academic medical center within United States.

Patients

Ninety-two patients including 36 survivors of critical COVID-19 that required mechanical ventilation (critical-COVID), 20 patients recovering from COVID-19 that required supplemental oxygen with hospitalization (severe-COVID), and 36 patients with CLD serving as a control group.

Measurements and Main Results

Patients completed the TUG, DT-TUG, Short Physical Performance Battery (SPPB), and Six Minute Walk Test (6MWT) 1-month after hospital discharge. A subset of patients returned at 3-months and repeated testing to determine the minimal detectable change (MDC). Critical-COVID group (16.8 ± 7.3) performed the DT-TUG in significantly slower than CLD group (13.9 ± 4.8 s; P = .024) and Severe-COVID group (13.1 ± 5.1 s; P = .025). Within-subject difference between TUG and DT-TUG was also significantly worse in critical-COVID group (−21%) compared to CLD (−10%; P = .012), even despite CLD patients having a higher comorbid burden (P < .003) and older age (P < .001). TUG and DT-TUG demonstrated strong to excellent construct validity to the chair rise test, gait speed, and 6MWT for both COVID-19 groups (r = −0.84to 0.73, P < .05). One- and 3-months after hospital discharge there was a floor effect of 14% (n = 5/36) and 5.2% (n = 1/19), respectively for patients in the critical-COVID group. Ceiling effects were noted in four (11%) critical-COVID, six (30%) severe-COVID patients for the TUG and DT-TUG at 1-month.

Conclusion

The ability to maintain mobility performance in the presence of a cognitive DT is grossly impaired in patients surviving critical COVID-19. DT performance may subserve the understanding of impairments related to Post-intensive care syndrome (PICS) for survivors of critical illness.

Association of Self-Reported Functional Limitations among a National Community-Based Sample of Older United States Adults with Pain: A Cross-Sectional Study

The characteristics of self-reported functional limitations among older United States (US) adults with pain are currently unknown. This cross-sectional study aimed to determine the characteristics associated with functional limitations among non-institutionalized older (≥50 years) US adults with pain using 2017 Medical Expenditure Panel Survey (MEPS) data. Eligible subjects were alive for the calendar year, aged ≥50 years, and experienced pain within the past four weeks. Hierarchical logistic regression models were utilized to determine significant characteristics associated with functional limitations (outcome variable; yes, no). Functional limitations included difficulty with bending, stooping, climbing stairs, grasping objects, lifting, reaching overhead, standing for long periods of time, or walking. Extrapolation of national data values was possible by adjusting for the complex MEPS design. We found approximately 22 million of the 57 million older US adults (≥50 years) who reported pain had a functional limitation in 2017. Characteristics associated with functional limitations included: gender, race, ethnicity, employment status, marital status, pain intensity, physical health, number of chronic conditions, and frequent exercise status. Knowledge of characteristics associated with functional limitations may provide an opportunity to identify and resolve gaps in patient care among this population.

Validity and reliability of smartphones in measuring joint position sense among asymptomatic individuals and patients with knee osteoarthritis: A cross-sectional study

BACKGROUND

Quantifying proprioception deficit in patients with osteoarthritis (OA) may be important in evaluating treatment effectiveness. This study investigated the concurrent and known-groups validity as well as test-retest reliability of a smartphone application in assessing joint position sense (JPS) in asymptomatic individuals and patients with knee OA.

METHODS

Sixty-four knees, from 16 asymptomatic controls and 16 patients with bilateral OA, were assessed twice with a 1-week interval in between. The smartphone Goniometer Pro application and isokinetic dynamometer simultaneously quantified JPS, in terms of absolute repositioning error (RE) angle, during active and passive limb movements at selected angles.

RESULTS

Both devices showed moderate to almost perfect correlations in measuring JPS; whether active (intra-class correlation coefficient (ICC) >0.87) or passive (ICC >0.97). The mean RE angle differences between the two devices were <0.77° (passive JPS) and <2.76° (active JPS). Both devices were capable of distinguishing patients and asymptomatic controls at 55° and 80°. The smartphone showed moderate test-retest reliability of active JPS measurement (ICC = 0.51) in the two groups, similar to that of the isokinetic dynamometer (ICC = 0.62), but with a high measurement error.

CONCLUSIONS

Smartphone application is a valid alternative to the isokinetic dynamometer in assessing JPS in patients with knee OA and asymptomatic controls. The two devices could distinguish patients and asymptomatic volunteers during passive JPS measured at 55° and 80°. Both devices have moderate reliability in quantifying active JPS, but reliability results should be considered with caution.