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

Characterization of clinical data for patient stratification in moderate osteoarthritis with support vector machines, regulatory network models, and verification against osteoarthritis Initiative data

Knee osteoarthritis (OA) diagnosis is based on symptoms, assessed through questionnaires such as the WOMAC. However, the inconsistency of pain recording and the discrepancy between joint phenotype and symptoms highlight the need for objective biomarkers in knee OA diagnosis. To this end, we study relationships among clinical and molecular data in a cohort of women (n = 51) with Kellgren-Lawrence grade 2-3 knee OA through a Support Vector Machine (SVM) and a regulation network model. Clinical descriptors (i.e., pain catastrophism, depression, functionality, joint pain, rigidity, sensitization and synovitis) are used to classify patients. A Youden's test is performed for each classifier to determine optimal binarization thresholds for the descriptors. Thresholds are tested against patient stratification according to baseline WOMAC data from the Osteoarthritis Initiative, and the mean accuracy is 0.97. For our cohort, the data used as SVM inputs are knee OA descriptors, synovial fluid proteomic measurements (n = 25), and transcription factor activation obtained from regulatory network model stimulated with the synovial fluid measurements. The relative weights after classification reflect input importance. The performance of each classifier is evaluated through ROC-AUC analysis. The best classifier with clinical data is pain catastrophism (AUC = 0.9), highly influenced by funcionality and pain sensetization, suggesting that kinesophobia is involved in pain perception. With synovial fluid proteins used as input, leptin strongly influences every classifier, suggesting the importance of low-grade inflammation. When transcription factors are used, the mean AUC is limited to 0.608, which can be related to the pleomorphic behaviour of osteoarthritic chondrocytes. Nevertheless, funcionality has an AUC of 0.7 with a decisive importance of FOXO downregulation. Though larger and longitudinal cohorts are needed, this unique combination of SVM and regulatory network model shall help to stratify knee OA patients more objectively.

Outcomes Vary by Pre-Operative Physical Activity Levels in Total Knee Arthroplasty Patients

Physical activity (PA) is suggested to reduce osteoarthritis pain; however, it may be avoided by patients requiring arthroplasty. Our goal was to investigate objective and patient-reported outcomes as a function of pre-operative PA levels in patients undergoing total knee arthroplasty (TKA). A total of 1941 patients enrolled in a multicenter prospective cohort study investigating a smartphone-based care management platform for self-directed rehabilitation underwent TKA and were included in the analysis. Activity was categorized based on the cohort's step count quartiles into low, moderate, and high pre-operative PA. Pre-operative and post-operative pain, EQ5D5L, KOOS JR, and step counts were compared by ANOVA according to activity group. Pre-operative pain scores increased with the decreasing activity level (all, p < 0.05) and were most improved post-operatively in the low PA group. High PA patients demonstrated the smallest improvements in EQ-5D-5L and KOOS JR. Low and moderate PA patients increased physical activity by three months, reaching 176% and 104% of pre-operative steps; high PA patients did not return to full step counts by one year post-operatively. Patients undergoing TKA who present with higher levels of physical activity report lower levels of pain and higher function pre-operatively but appreciate less improvement up to one year post-operatively. These results may be helpful in appropriate counseling of patient expectations before TKA.

Multicenter, prospective cohort study: immediate postoperative gains in active range of motion following robotic-assisted total knee replacement compared to a propensity-matched control using manual instrumentation

BACKGROUND

Range of motion (ROM) following total knee replacement (TKR) has been associated with patient satisfaction and knee function, and is also an early indicator of a successful procedure. Robotic-assisted TKR (raTKR) is considered to reproduce more precise resections, and, as a result, may be associated with improved early patient satisfaction compared to manual TKR (mTKR). The purpose of this study was to evaluate the early postoperative active ROM (aROM) between raTKR and mTKR.

METHODS

A total of 216 mTKR patients were propensity-matched, in terms of age, gender, comorbidities, and BMI, to 216 raTKR cases. Intraoperative and immediate postoperative adverse events were collected. Knee flexion and extension aROM were measured preoperatively and at one- and three months after operation.

RESULTS

Changes in flexion aROM were significantly greater in raTKR vs. mTKR at one- (6.9°, 95% CI: 3.5, 10.4°) and three months (4.9°, 95% CI: 2.1, 7.7°). Flexion aROM was greater at three postoperative months compared to preoperative aROM only in the raTKR group, and raTKR patients had higher odds of achieving ≥ 90° of flexion at one month after operation (OR: 2.15, 95% CI: 1.16, 3.99). There were no significant differences between groups in intraoperative (P > 0.999) or postoperative adverse events.

CONCLUSIONS

Compared with mTKR, raTKR resulted  in less loss of aROM immediately after operation and a faster recovery of aROM within three months after operation.

TRIAL REGISTRATION

Clinicaltrials.gov (NCT# 03737149).

Spatiotemporal parameters from remote smartphone-based gait analysis are associated with lower extremity functional scale categories

Objective

Self-report tools are recommended in research and clinical practice to capture individual perceptions regarding health status; however, only modest correlations are found with performance-based results. The Lower Extremity Functional Scale (LEFS) is one well-validated measure of impairment affecting physical activities that has been compared with objective tests. More recently, mobile gait assessment software can provide comprehensive motion tracking output from ecologically valid environments, but how this data relates to subjective scales is unknown. Therefore, the association between the LEFS and walking variables remotely collected by a smartphone was explored.

Methods

Proprietary algorithms extracted spatiotemporal parameters detected by a standard integrated inertial measurement unit from 132 subjects enrolled in physical therapy for orthopedic or neurological rehabilitation. Users initiated ambulation recordings and completed questionnaires through the OneStep digital platform. Discrete categories were created based on LEFS score cut-offs and Analysis of Variance was applied to estimate the difference in gait metrics across functional groups (Low-Medium-High).

Results

The main finding of this cross-sectional retrospective study is that remotely-collected biomechanical walking data are significantly associated with individuals' self-evaluated function as defined by LEFS categorization (n = 132) and many variables differ between groups. Velocity was found to have the strongest effect size.

Discussion

When patients are classified according to subjective mobility level, there are significant differences in quantitative measures of ambulation analyzed with smartphone-based technology. Capturing real-time information about movement is important to obtain accurate impressions of how individuals perform in daily life while understanding the relationship between enacted activity and relevant clinical outcomes.

Stepping Beyond Counts in Recovery of Total Hip Arthroplasty: A Prospective Study on Passively Collected Gait Metrics

Gait quality parameters have been used to measure recovery from total hip arthroplasty (THA) but are time-intensive and previously could only be performed in a lab. Smartphone sensor data and algorithmic advances presently allow for the passive collection of qualitative gait metrics. The purpose of this prospective study was to observe the recovery of physical function following THA by assessing passively collected pre- and post-operative gait quality metrics. This was a multicenter, prospective cohort study. From six weeks pre-operative through to a minimum 24 weeks post-operative, 612 patients used a digital care management application that collected gait metrics. Average weekly walking speed, step length, timing asymmetry, and double limb support percentage pre- and post-operative values were compared with a paired-sample t-test. Recovery was defined as the post-operative week when the respective gait metric was no longer statistically inferior to the pre-operative value. To control for multiple comparison error, significance was set at p < 0.002. Walking speeds and step length were lowest, and timing asymmetry and double support percentage were greatest at week two post-post-operative (p < 0.001). Walking speed (1.00 ± 0.14 m/s, p = 0.04), step length (0.58 ± 0.06 m/s, p = 0.02), asymmetry (14.5 ± 19.4%, p = 0.046), and double support percentage (31.6 ± 1.5%, p = 0.0089) recovered at 9, 8, 7, and 10 weeks post-operative, respectively. Walking speed, step length, asymmetry, and double support all recovered beyond pre-operative values at 13, 17, 10, and 18 weeks, respectively (p < 0.002). Functional recovery following THA can be measured via passively collected gait quality metrics using a digital care management platform. The data suggest that metrics of gait quality are most negatively affected two weeks post-operative; recovery to pre-operative levels occurs at approximately 10 weeks following primary THA, and follows a slower trajectory compared to previously reported step count recovery trajectories.

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.

Radiofrequency ablation prior to total knee arthroplasty does not improve post-surgical pain or recovery: a double-blinded, multi-center, randomized clinical trial

Background

Radiofrequency ablation (RFA) targeting the genicular nerves is an effective treatment for knee pain due to osteoarthritis. The aim of this study was to determine the effects of two RFA interventions delivered preoperatively on early postoperative pain management and subjective outcomes after total knee arthroplasty (TKA).

Methods

One hundred forty-three participants were enrolled in this double blinded, sham-controlled prospective randomized trial. Participants assigned at random to traditional RFA (t-RFA) (n=50), cooled RFA (c-RFA) (n=49), or sham (n=44) procedures prior to TKA. Outcomes were recorded at postoperative day 3, week 1, week 2, week 12, month 6, and month 12 following TKA. Primary outcomes included hospital length of stay (LOS), opioid consumption (reported as MEQ, or daily morphine equivalents), time to narcotic cessation (reported in days), and pain scores (reported as NRS, or Numeric Rating Scale). Secondary outcomes included Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) measures. All side effects and complications were reported. Participants were followed for a year to detect any unexpected side effects.

Results

Compared with sham controls, t-RFA and c-RFA did not affect inpatient LOS, pain scores, or opioid consumption. There were no reductions in time to opioid cessation, pain scores, or WOMAC scores at any time point post-TKA.

Conclusions

RFA of the genicular nerves prior to TKA did not affect opioid use or time to cessation, pain, or WOMAC scores, following TKA. Current techniques of t-RFA and c-RFA of these specific geniculate nerves preoperatively are not indicated as routine interventions to improve short-term surgical recovery after TKA.

Trial Registration

The trial was registered on ClinicalTrials.gov (NCT02925442).

Does obesity affect patient-reported outcomes following total knee arthroplasty?

Background

There is an existing perception that obesity has a negative impact on complications following total knee arthroplasty (TKA). However, data on the impact of obesity levels on patient-reported outcomes (PROMs) is sparse. We investigated the association between different obesity classes with PROMs among patients who underwent TKA.

Methods

We performed retrospective secondary analyses on data extracted from the total joint replacement data repository (Alberta, Canada) managed by the Alberta Bone and Joint Health Institute (ABJHI). Patients had WOMAC and EQ5D scores measured at baseline in addition to 3 and/or 12 months following TKA. Patients were stratified according to the World Health Organization (WHO) classification, into five body mass index (BMI) groups of normal, overweight, BMI class I, BMI class II, and BMI class III. The association between BMI and mean changes in WOMAC subscales (pain, function, and stiffness) and EQ-5D-5L index over the time intervals of baseline to 3 months and 3 to 12 months following TKA was assessed. Linear mixed-effects models were used, and the models were adjusted for age, sex, length of surgery, comorbidities, year of surgery, and geographical zone where the surgery was performed.

Results

Mean age was 65.5 years (SD = 8.7). Postoperatively, there was a significant improvement (p < 0.001) in WOMAC subscales of patient-reported pain, function, and stiffness, as well as EQ-5D-5L regardless of BMI group. Although, patients in BMI class II and class III reported significantly improved pain 3 months after TKA compared to those with normal BMI, all BMI groups attained similar level of pain reduction at 12 months after TKA. The greatest improvement in all WOMAC subscales, as well as EQ5D index, occurred between baseline and 3 months (adjusted p < 0.0001).

Conclusion

The findings indicate that patients reported improved pain, function, and stiffness across all BMI groups following TKA. Patients with BMI classified as obese reported similar benefits to those with BMI classified as normal weight. These results may help health care providers to discuss expectations regarding the TKA recovery in terms of pain, function, and quality of life improvements with their TKA candidates.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-04997-4.

Systematic review and meta-analysis of measurement properties of the Hip disability and Osteoarthritis Outcome Score - Physical Function Shortform (HOOS-PS) and the Knee Injury and Osteoarthritis Outcome Score - Physical Function Shortform (KOOS-PS)

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate all evidence on measurement properties of the Hip disability and Osteoarthritis Outcome Score - Physical function Shortform (HOOS-PS) and the Knee Injury and Osteoarthritis Outcome Score - Physical function Shortform (KOOS-PS).

DESIGN

This study was conducted according to the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guideline for systematic reviews of PROMs. MEDLINE, EMBASE, The Cochrane Library, CINAHL and PsychINFO through February 2019 were searched. Eligible studies evaluated patients with hip or knee complaints and described a measurement property, interpretability, feasibility, or the development of either the HOOS-PS or KOOS-PS.

RESULTS

Twenty-three studies were included. For both questionnaires, the content validity was found inconsistent and the quality evidence was moderate for a sufficient reliability and high for an insufficient construct validity. The HOOS-PS had a high quality evidence of sufficient structural validity and internal consistency (pooled Cronbach's alpha 0.80; n = 3761) and low quality evidence of sufficient measurement error and indeterminate responsiveness. Concerning the KOOS-PS, the quality evidence was high for an insufficient responsiveness, moderate for an inconsistent structural validity and internal consistency and low for an inconsistent measurement error.

CONCLUSIONS

The inconsistent evidence for content validity implies that scores on the HOOS-PS and KOOS-PS may inadequately reflect physical functioning. Furthermore, there is evidence for insufficient construct validity and responsiveness in patients with knee osteoarthritis receiving conservative treatment. Using the HOOS-PS or KOOS-PS as outcome measurement instruments for comparing outcomes, measuring improvements or benchmarking in patients with hip or knee complaints or undergoing arthroplasty should only be done with great caution.

REVIEW REGISTRATION

PROSPERO number CRD42017069539.

Cross-Cultural Adaptation and Validation of the Simplified Chinese Version of the Lower Extremity Functional Scale

Purpose

The purpose of this study was to cross-culturally adapt and validate the Simplified Chinese version of the Lower Extremity Functional Scale (SC-LEFS).

Methods

The original English version of the Lower Extremity Functional Scale was translated and cross-culturally adapted into Simplified Chinese according to international guidelines. The SC-LEFS and 36-Item Short-Form Health Survey were administered to 213 patients with lower extremity musculoskeletal disorders. Psychometric properties including internal consistency, test-retest reliability, content validity, and construct validity were tested.

Results

There were no floor or ceiling effects for the SC-LEFS. The scale had high values for internal consistency (Cronbach α = 0.97) and test-retest reliability (intraclass correlation coefficient = 0.97). Corrected item-total correlations for every item ranged from 0.67 to 0.89. And the item-level content validity index (I-CVI) for each item ranged from 0.78 to 1.00. Principal component analysis revealed a one-factor structure. Nine of ten prior hypotheses were confirmed, which further supports good construct validity within the SC-LEFS.

Conclusion

The SC-LEFS has high internal consistency, good test-retest reliability and content validity, convergent construct validity, and a one-factor structure. Thus, it could be regarded as a reliable and valid tool to assess activity limitations in Chinese patients with lower extremity musculoskeletal disorders.