Measurement properties of the WOMAC LK 3.1 pain scale

Cartilage Oligomeric Matrix Protein in Osteoarthritis and Obesity-Do New Considerations Emerge?

The diagnosis of osteoarthritis (OA) is based on radiological changes that are delayed, along with clinical symptoms. Early and very early diagnosis at the stage of molecular pathology may eventually offer an opportunity for early therapeutic intervention that may retard and prevent future damage. Cartilage oligomeric matrix protein (COMP) is a non-collagenous extracellular matrix protein that promotes the secretion and aggregation of collagen and contributes to the stability of the extracellular matrix. There are contradictory literature data and currently, the parameter is used only for scientific purposes and its significance is not well-determined. The serum level of COMP in patients with metabolic type OA of the knee has not been evaluated. The aim of the study was to analyze serum COMP levels in metabolic knee OA and controls with different BMI. Our results showed that the mean COMP values were significantly higher in the control group (1518.69 ± 232.76 ng/mL) compared to the knee OA patients (1294.58 ± 360.77 ng/mL) (p = 0.0012). This may be related to the smaller cartilage volume in OA patients. Additionally, COMP levels negatively correlated with disease duration (p = 0.04). The COMP level in knee OA with BMI below 30 kg/m2 (n = 61, 1304.50 ± 350.60 ng/mL) was higher compared to cases with BMI ≥ 30 kg/m2 (n = 76, 1286.63 ± 370.86 ng/mL), but the difference was not significant (p = 0.68). Whether this finding is related to specific features in the evolution of the metabolic type of knee OA remains to be determined. Interestingly, comparison of COMP levels in the controls with different BMI revealed significantly higher values in overweight and obese individuals (1618.36 ± 203.76 ng/mL in controls with BMI ≥ 25 kg/m2, n = 18, 1406.61 ± 216.41 ng/mL, n = 16; p = 0.0092). Whether this finding is associated with increased expression of COMP in the adipose tissue or with more intensive cartilage metabolism in relation to higher biomechanical overload in obese patients, considering the earlier development of metabolic type knee OA as an isolated finding, remains to be determined.

Dispositional traits help explain individual differences in relationships between a radiographic knee osteoarthritis measure, pain, and physical function

Background

The concordance between radiograph-derived Kellgren-Lawrence (KL) scores for knee osteoarthritis (KOA) and experimental and clinical pain and KOA-related physical function is conflicting.

Objectives

We investigate whether the inclusion of dispositional traits reduces variability between KOA radiographic findings, experimental pain, clinical pain, and function in individuals with knee pain.

Design

This study is a cross-sectional, secondary analysis of data collected from the UPLOAD-II study.

Methods

Adults aged 45-85 years with and without knee pain were enrolled. Data collected included sociodemographics, knee radiographs, experimental pain, clinical pain and function, and trait affect. Vulnerable and protective dispositional traits were classified from combined positive and negative trait affect measures. KL scores were determined from the knee radiographs. Unadjusted and adjusted (age, sex, comorbidities, and body mass index) regression analyses were completed with SAS version 9.4 (Cary, NC, USA).

Results

The study included 218 individuals with a mean age of 58 years, 63.6% women, and 48.2% non-Hispanic black adults. Dispositional traits were associated with the experimental pain measures. No association between radiographic KOA and experimental pain was observed. In a combined and adjusted analysis, dispositional traits were predictive of knee punctate pain temporal summation (p = 0.0382). Both dispositional traits and radiographic KOA scores independently and combined were predictive of Graded Chronic Pain Scale pain and function, and Western Ontario and McMaster University pain and function (ps ⩽ 0.01). Improvements in R2 were noted across all models with the inclusion of dispositional traits.

Conclusion

Consideration of dispositional traits reduces the variability between radiographic KOA and pain and function. Non-pathological and associated pain-related psychological factors and dispositional traits might serve as parsimonious proxy tools to improve clinical assessments.

Registration

N/A.

Effects of aquatic exercises in patients after total hip arthroplasty: A systematic review

BACKGROUND

Total hip arthroplasty (THA) is a surgical procedure that can alter physical function and quality of life.

OBJECTIVES

The aim was to verify the effects of aquatic exercises compared with exercises on land, control or other modalities, in patients undergoing THA on the primary outcomes: self-reported physical function, quality of life and pain; and secondary outcomes: muscle strength, functional capacity and gait.

DESIGN

Systematic review that followed the PRISMA Statement and PROSPERO registered. The search was performed in the following databases: Web of Science, Embase, Medline, Cinahl, Lilacs, SPORTDiscus, Cochrane Library, Scopus, SciELO, and PEDro, from 1945 to 2022. The risk of bias assessment was performed using the Risk of Bias 2 (RoB2) from the Cochrane Collaboration.

RESULTS

Three randomized controlled trials (RCTs) were included, with a total of 364 participants. In the selection process, two publications from the same study were found. The RoB2 assessment classified one RCT as "high risk of bias" and the others as "low risk of bias". Therefore, the analysis of the results considered only studies with a low risk of bias. For the self-reported physical function outcome, evaluated by WOMAC, improvement was observed in favor of aquatic exercises, when started on the 14th postoperative day. Pain improved after 24th week postoperative, in favor of exercise (effect size between 0.2 and 0.4). Quality of life, verified only by one RCT, improved at each time point evaluated (effect size between 0.01 and 0.10). The functional capacity showed no difference between the groups. This was the first systematic review to assess the benefits of aquatic exercises specifically in THA and it was possible to infer that the exercises initiated after 14 days of postoperative are safer. The protocol should include proprioceptive, coordination, and resistance exercises. The session can last around 30 min and is held three times a week.

CONCLUSION

Decision making for treatment in the postoperative of THA may include aquatic exercises as a safe and efficacious alternative to improve self-reported physical function, pain, quality of life, and muscle resistance.

Elucidating factors contributing to disparities in pain-related experiences among adults with or at risk for knee osteoarthritis

Background and purpose

We and others have reported ethnic/race group differences in clinical pain, physical function, and experimental pain sensitivity. However, recent research indicates that with consideration for socioenvironmental factors, ethnicity/race differences become less or non-significant. Understanding of factors contributing to pain inequities are needed. Guided by the NIA and NIMHD Health Disparities Research Frameworks, we evaluate the contributions of environmental and behavioral factors on previously reported ethnic/race group differences in: (1) clinical pain, (2) physical function, and (3) experimental pain in individuals with knee pain.

Methods

Baseline data from Understanding of Pain and Limitations in Osteoarthritis Disease (UPLOAD) and UPLOAD-2 studies were analyzed. Participants were adults 45 to 85 years old who self-reported as non-Hispanic white (NHW) or black (NHB) with knee pain. A health assessment and quantitative sensory testing were completed. Sociodemographics, environmental, health, clinical and experimental pain, and physical functioning measures were included in nested regressions.

Results

Pooled data from 468 individuals, 57 ± 8 years of age, 63% women, and 53% NHB adults. As NHB adults were younger and reported greater socioenvironmental risk than the NHW adults, the term sociodemographic groups is used. With inclusion of recognized environmental and behavioral variables, sociodemographic groups remained a significant predictor accounting for <5% of the variance in clinical pain and physical function and <10% of variance in experimental pain.

Conclusion

The incorporation of environmental and behavioral factors reduced relationships between sociodemographic groups and pain-related outcomes. Pain sites, BMI, and income were significant predictors across multiple models. The current study adds to a body of research on the complex array of factors contributing to disparities in pain-related outcomes.

Development of a score map to guide interpretation of WOMAC Pain scores prior to knee arthroplasty

BACKGROUND

Scores from patient reported outcome measures (PROMs) are challenging to interpret for both clinicians and patients. PROMs obtained prior to knee arthroplasty (KA) could be used to inform important decisions related to KA made by both patients and clinicians. The purpose of this study was to develop a "score map" to allow for efficient and meaningful use of PROMs scores for patients considering KA.

METHODS

Knee arthroplasty data obtained between one day and twelve months preoperatively from two multicenter studies were combined and used to develop and test the accuracy of a Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain Scale score map. To develop the score map, individual item scores were used to determine the most probable responses to items for the entire range of possible WOMAC Pain scores. Predicted WOMAC Pain scores, using the most probable response for each possible score on the score map, were compared to actual presurgical WOMAC Pain scores using Weighted Kappa (Κ_w) agreement coefficients. The score map is an easy-to-use graphical display of the entire range of WOMAC Pain scores from no pain to extreme pain for each item comprising the WOMAC Pain scale.

RESULTS

Data from 780 patients were used in the analyses. The score map predicted WOMAC Pain scores and showed substantial agreement with actual WOMAC Pain scores Κ_w = 0.68 (95 %CI = 0.58, 0.77) to Κ_w = 0.77 (95 % CI = 0.75, 0.79). Perfect prediction of actual scores occurred between 55.1 % and 62.5 % of the time for all WOMAC Pain items.

CONCLUSION

The WOMAC Pain score map has potential for facilitating a variety of important clinical decisions and discussions between patients and practitioners during healthcare encounters related to KA candidacy. For example, by comparing a patents' scores to literature-based estimates, patients may better understand how their WOMAC Pain scores compare to other persons who underwent KA, how much a score may change, on average, after surgery and whether this change might be acceptable to them.

Serum Leptin and Resistin Levels in Knee Osteoarthritis-Clinical and Radiologic Links: Towards Precise Definition of Metabolic Type Knee Osteoarthritis

Obesity is considered a major risk factor for the development and progression of knee osteoarthritis (OA). Apart from the mechanical effect of obesity via increase in mechanical overload of weight-bearing joints, an association with hand OA has been observed. There has been increasing interest in the role of adipokines in the pathogenesis of OA in the recent years. It has been suggested that their systemic effects link obesity and OA. In this regard, the aim of the current study was measurement and analysis of serum levels of leptin and resistin in patients with knee OA with different body mass index (BMI). Seventy-three patients with primary symptomatic knee OA at the age between 35 and 87 years (mean age 66 years) were included in the study (67 women and 6 men). The patients were from 2nd to 4th radiographic stage according to Kellgren–Lawrence scale. 43 patients were with concomitant obesity (BMI ≥ 30 kg/m², mean values 38.34 ± 8.20) and 30 patients with BMI < 30 kg/m² (mean values 25.07 ± 2.95). Eleven individuals with different BMIs, including cases with obesity but without radiographic knee OA, were examined as a control group. Serum levels of leptin and resistin were measured via ELISA method. In patients with knee OA and BMI ≥ 30 kg/m², serum levels of leptin (39.546 ± 12.918 ng/mL) were significantly higher as compared with healthy individuals (15.832 ± 16.531 ng/mL, p < 0.05) and the patients with low BMI (p < 0.05). In patients with BMI < 30 kg/m² the levels of leptin (13.010 ± 10.94 ng/mL) did not differ significantly from the respective values in the control group (p = 0.48). Serum levels of resistin were also higher in knee OA patients in comparison with healthy controls, but the difference was statistically significant only for patients with high BMI (2.452 ± 1.002 ng/mL in the group with BMI ≥ 30 kg/m²; 2.401 ± 1.441 ng/mL in patients with BMI < 30 kg/m²; 1.610 ± 1.001 ng/mL in the control group, p < 0.05). A correlation was found between the serum levels of leptin and radiographic stage of OA, i.e., higher leptin levels were present in the more advanced 3rd and 4th radiographic stage, while for resistin a correlation was observed in the patient subgroup with BMI < 30 kg/m². Serum leptin and resistin levels and clinical characteristics were analyzed in patients with different clinical forms of OA. Novel clinical correlations have been found in the current study in patients with isolated knee OA vs. cases with presence of other disease localizations. It has been observed that patients with isolated knee OA were significantly younger and had higher BMI as compared with cases in whom OA is combined with other localizations i.e., spondyloarthritis ± presence of hip OA and with generalized OA. This supports the hypothesis that presence of obesity promotes earlier development of knee OA as an isolated localization of the disease in younger patients before appearance of osteoarthritic changes at other sites. The levels of leptin and resistin in isolated knee OA were also higher. Serum levels of leptin and resistin in combination with patients’ clinical characteristics suggest existence of different clinical and laboratory profile through which more precise definition of metabolic phenotype of knee OA would be possible. Considering the fact that obesity is a modifiable risk factor that has an impact on progression of knee OA, different approaches to influence obesity may offer potential for future disease-modifying therapeutic interventions.

Effectiveness of Dry Needling Therapy on Pain, Hip Muscle Strength, and Physical Function in Patients With Hip Osteoarthritis: A Randomized Controlled Trial

OBJECTIVE

To investigate the short-term effects of dry needling (DN) on physical function, pain, and hip muscle strength in patients with hip osteoarthritis (OA).

DESIGN

A double-blind, placebo-control, randomized controlled trial.

SETTING

Private practice physiotherapy clinic.

PARTICIPANTS

Patients with unilateral hip OA (N=45) were randomly allocated to a DN group, sham DN group, or control group.

INTERVENTIONS

Patients in the DN and sham groups received 3 treatment sessions. Three active myofascial trigger points (MTrPs) were treated in each session with DN or a sham needle procedure. The treatment was applied in active MTrPs of the iliopsoas, rectus femoris, tensor fasciae latae, and gluteus minimus muscles.

MAIN OUTCOME MEASURES

Physical function was assessed with the Western Ontario and McMaster Universities (WOMAC) physical function subscale, the timed Up and Go test, and the 40-meter self-paced walk test. Intensity of hip pain related to physical function was evaluated using the visual analog scale and WOMAC pain subscale. The maximal isometric force of hip muscles was recorded with a handheld dynamometer.

RESULTS

Significant group by time interactions were shown for physical function, pain, and hip muscle force variables. Post hoc tests revealed a significant reduction in hip pain and significant improvements in physical function and hip muscle strength in the DN group compared with the sham and control groups. The DN group showed within- and between-groups large effect sizes (d>0.8).

CONCLUSIONS

DN therapy in active MTrPs of the hip muscles reduced pain and improved hip muscle strength and physical function in patients with hip OA. DN in active MTrPs of the hip muscles should be considered for the management of hip OA.

Association of subchondral bone marrow lesion localization with weight-bearing pain in people with knee osteoarthritis: data from the Osteoarthritis Initiative

Background

Subchondral bone marrow lesions (BMLs) detected on MRI in knee osteoarthritis (OA) are associated with knee pain. The prevalence and progression of subchondral BMLs are increased by mechanical knee load. However, associations of subchondral BML location with weight-bearing knee pain are currently unknown. In this study, we aim to demonstrate associations of subchondral BML location and size with weight-bearing knee pain in knee OA.

Methods

We analyzed 1412 and 582 varus knees from cross-sectional and longitudinal Osteoarthritis Initiative datasets, respectively. BML scores were semi-quantitatively analyzed with the MRI Osteoarthritis Knee Score for 4 subchondral regions (median and lateral femorotibial, medial and lateral patellofemoral) and subspinous region. Weight-bearing and non-weight-bearing pain scores were derived from WOMAC pain items. Correlation and negative binomial regression models were used for analysis of associations between the BML scores and pain at baseline and changes in the BML scores and changes in pain after 24-month follow-up.

Results

Greater BML scores at medial femorotibial and lateral patellofemoral compartments were associated with greater weight-bearing pain scores, and statistical significance was retained after adjusting for BML scores at the other 4 joint compartments and other OA features, as well as for non-weight-bearing pain, age, sex, and body mass index (BMI) (medial femorotibial; B = 0.08, p = 0.02. patellofemoral; B = 0.13, p = 0.01). Subanalysis revealed that greater medial femorotibial BML scores were associated with greater pain on walking and standing (B = 0.11, p = 0.01, and B = 0.10, p = 0.04, respectively). Lateral patellofemoral BML scores were associated with pain on climbing, respectively (B = 0.14, p = 0.02). Increases or decreases over 24 months in BML score in the medial femorotibial compartment were significantly associated with increases or decreases in weight-bearing pain severity after adjusting for non-weight-bearing pain, age, sex, baseline weight-bearing pain, BMI, and BML at the other 4 joint compartments (B = 0.10, p = 0.01).

Conclusions

Subchondral BML size at the medial femorotibial joint compartment was specifically associated with the severity and the change in weight-bearing pain, independent of non-weight-bearing pain, in knee OA. Specific associations of weight-bearing pain with subchondral BMLs in weight-bearing compartments of the knee indicate that BMLs in subchondral bone contribute to biomechanically induced OA pain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02422-0.

Effectiveness of Curcuma longa Extract for the Treatment of Symptoms and Effusion-Synovitis of Knee Osteoarthritis : A Randomized Trial

BACKGROUND

Current pharmacologic therapies for patients with osteoarthritis are suboptimal.

OBJECTIVE

To determine the efficacy of Curcuma longa extract (CL) for reducing knee symptoms and effusion-synovitis in patients with symptomatic knee osteoarthritis and knee effusion-synovitis.

DESIGN

Randomized, double-blind, placebo-controlled trial. (Australian New Zealand Clinical Trials Registry: ACTRN12618000080224).

SETTING

Single-center study with patients from southern Tasmania, Australia.

PARTICIPANTS

70 participants with symptomatic knee osteoarthritis and ultrasonography-defined effusion-synovitis.

INTERVENTION

2 capsules of CL (n = 36) or matched placebo (n = 34) per day for 12 weeks.

MEASUREMENTS

The 2 primary outcomes were changes in knee pain on a visual analogue scale (VAS) and effusion-synovitis volume on magnetic resonance imaging (MRI). The key secondary outcomes were change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and cartilage composition values. Outcomes were assessed over 12 weeks.

RESULTS

CL improved VAS pain compared with placebo by -9.1 mm (95% CI, -17.8 to -0.4 mm [P = 0.039]) but did not change effusion-synovitis volume (3.2 mL [CI, -0.3 to 6.8 mL]). CL also improved WOMAC knee pain (-47.2 mm [CI, -81.2 to -13.2 mm]; P = 0.006) but not lateral femoral cartilage T2 relaxation time (-0.4 ms [CI, -1.1 to 0.3 ms]). The incidence of adverse events was similar in the CL (n = 14 [39%]) and placebo (n = 18 [53%]) groups (P = 0.16); 2 events in the CL group and 5 in the placebo group may have been treatment related.

LIMITATION

Modest sample size and short duration.

CONCLUSION

CL was more effective than placebo for knee pain but did not affect knee effusion-synovitis or cartilage composition. Multicenter trials with larger sample sizes are needed to assess the clinical significance of these findings.

PRIMARY FUNDING SOURCE

University of Tasmania and Natural Remedies Private Limited.

Functional Near-Infrared Spectroscopy to Assess Central Pain Responses in a Nonpharmacologic Treatment Trial of Osteoarthritis

BACKGROUND AND PURPOSE

Knee osteoarthritis (OA) is a common source of pain in older adults. Although OA-induced pain can be relieved with analgesics and anti-inflammatory drugs, the current opioid epidemic is fostering the exploration of nonpharmacologic strategies for pain mitigation. Amongs these, transcranial direct current stimulation (tDCS) and mindfulness-based meditation (MBM) hold potential for pain-relief efficacy due to their neuromodulatory effects of the central nervous system, which is known to play a fundamental role in pain perception and processing.

METHODS

In this double-blind study, we used functional near-infrared spectroscopy (fNIRS) to investigate the effects of tDCS combined with MBM on underlying pain processing mechanisms at the central nervous level in older adults with knee OA. Nineteen subjects were randomly assigned to two groups undergoing a 10-day active tDCS and MBM regimen and a sham tDCS and MBM regimen, respectively.

RESULTS

Our results showed that the neuromodulatory intervention significantly relieved pain only in the group receiving active treatment. We also found that only the active treatment group showed a significant increase in oxyhemoglobin activation of the superior motor and somatosensory cortices colocated to the placement of the tDCS anodal electrode. To our knowledge, this is the first study in which the combined effect of tDCS and MBM is investigated using fNIRS.

CONCLUSION

In conclusion, fNIRS can be effectively used to investigate neural mechanisms of pain at the cortical level in association with nonpharmacological, self-administered treatments.

Identification of Tools for the Functional and Subjective Assessment of Patients in an Aquatic Environment: A Systematic Review

Aquatic therapy is one of the most common treatments for alleviating musculoskeletal pathologies. Its effectiveness has been evaluated with functional tests and questionnaires. Functional tests are used in aquatic therapy; however, in most cases, they are carried out in a non-aquatic environment and, as such, their results may differ from those of tests performed in an aquatic environment. A systematic review was performed to assess the accuracy of functional tests and patient-reported outcomes to assess aquatic therapy interventions. The authors conducted a literature search in July 2019. In total, 70,863 records were identified after duplicates removed. Of these, 14 records were included about functional tests assessment in aquatic environment and 725 records for questionnaires. The majority of the tests had also been assessed in a dry environment, allowing differences and similarities between the tests in the two environments to be observed. Different variables have been assessed in tests included in the present systematic review (cardiorespiratory, neuromuscular, kinematic, physiological, kinetic responses and rating of perceived exertion) which are included in the manuscript. Visual Analogue Scale, Western Ontario and McMaster Universities Osteoarthritis Index and the 12-item Short Form Health Survey were the assessments most commonly used by the different authors.

Core Outcome Measurement Instruments for Clinical Trials of Total Knee Arthroplasty: A Systematic Review

(1) Background: We have updated knowledge of the psychometric qualities of patient-reported outcome measures and, for the first time, systematically reviewed and compared the psychometric qualities of physical tests for patients with knee osteoarthritis who are undergoing total knee arthroplasty. This work was conducted to facilitate the choice of the most appropriate instruments to use in studies and clinical practice. (2) Methods: A search of medical databases up to December 2019 identified the studies and thus the instruments used. The quality of the measurement properties was assessed by the Bot et al. criteria. (3) Results: We identified 20 studies involving 25 instruments. Half of the instruments were questionnaires (n = 13). Among the condition-specific instruments, the Oxford knee score, Knee injury and Osteoarthritis Outcomes Score, and the Western Ontario and McMaster Universities Osteoarthritis index had the highest overall scores. Concerning generic tools, the Medical Outcomes Study Short-Form 36 (SF-36) or SF-12 obtained the highest overall score. For patient-specific tools, the Hospital Anxiety and Depression Scale ranked the highest. Some physical tests seemed robust in psychometric properties: 6-min Walk Test, five times Sit-To-Stand test, Timed Up and Go test strength testing of knee flexor/extensor by isometric or isokinetic dynamometer and Pressure Pain Threshold. (4) Conclusion: To make stronger recommendations, key areas such as reproducibility, responsiveness to clinical change, and minimal important change still need more rigorous evaluations. Some promising physical tests (e.g., actimetry) lack validation and require rigorous studies to be used as a core set of outcomes in future studies.

The WOMAC Pain Scale and Crosstalk From Co-occurring Pain Sites in People With Knee Pain: A Causal Modeling Study

OBJECTIVE

The Western Ontario and McMaster Universities Osteoarthritis (WOMAC) pain scale quantifies knee pain severity with activities of daily living, but the potential impact of pain in other body regions on WOMAC pain scores has not been explored using a causal modeling approach. The purpose of this study was to determine if pain in other areas of the body impact WOMAC pain scores, a phenomenon referred to as "crosstalk."

METHODS

Cross-sectional datasets were built from public use data available from the Osteoarthritis Initiative (OAI) and the Multicenter Osteoarthritis Study (MOST). The WOMAC Pain Scale and generic hip, knee, ankle, foot and back pain measures were included. Three nested regression models grounded in causally based classical test theory determined the extent of crosstalk. Improvements in the coefficient of determination across the 3 models were used to determine the presence of crosstalk.

RESULTS

Causal modeling provided evidence of crosstalk in both OAI and MOST datasets. For example, in OAI, multiple statistical models demonstrated significant increases in coefficient of determination values (P < .0001) as additional pain areas were added to the models.

CONCLUSIONS

Crosstalk appears to be a clinically important source of error in the WOMAC Pain Scale, particularly for patients with a larger number of painful body regions and when contralateral knee joint pain is more severe.

IMPACT STATEMENT

This study has important implications for arthritis research. It also should raise clinician awareness of the threat to score interpretation and the need to consider the extent of pain in other body regions when interpreting WOMAC pain scores.

Association of Varus Knee Thrust During Walking With Worsening Western Ontario and McMaster Universities Osteoarthritis Index Knee Pain: A Prospective Cohort Study

OBJECTIVE

To investigate the 2-year association of varus knee thrust observed during walking to the odds of worsening Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) knee pain in older adults with or at risk of osteoarthritis (OA).

METHODS

Video recordings of self-paced walking trials of Multicenter Osteoarthritis Study participants were assessed for the presence of varus thrust at baseline. Knee pain was assessed using the WOMAC questionnaire at baseline and at 2 years. Logistic regression was used to estimate the odds of worsening knee pain (defined as either any increase in WOMAC score or as clinically important worsening), adjusting for age, sex, race, body mass index, clinic site, gait speed, and static knee alignment. Analyses were repeated, stratified by baseline radiographic OA status and among the subset of knees without baseline WOMAC pain.

RESULTS

A total of 1,623 participants contributed 3,204 knees. Varus thrust was observed in 31.5% of knees. Knees with varus thrust had 1.44 times (95% confidence interval [95% CI] 1.19-1.73) the odds of any worsening and 1.37 times (95% CI 1.11-1.69) the odds of clinically important worsening WOMAC pain compared to knees without thrust. Knees with thrust without baseline WOMAC pain had 2.01 times (95% CI 1.47-2.74) the odds of incident total pain.

CONCLUSION

Results indicate that varus thrust is a risk factor for worsening and incident knee pain. Targeting varus thrust through noninvasive therapies could prevent development or worsening of knee pain in older adults with or at risk for knee OA.

Translation and Validation of the German New Knee Society Scoring System

BACKGROUND

In 2011 the Knee Society Score (KSS) was revised to include patient expectations, satisfaction, and physical activities as patient-reported outcomes. Since the new KSS has become a widely used method to evaluate patient status after TKA, we sought to translate and validate it for German-speaking populations.

QUESTIONS/PURPOSES

After translation of the new KSS into German using established guidelines, we sought to test the new German version for (1) validity; (2) responsiveness; and (3) reliability.

METHODS

The new KSS form was translated and adapted according to the available guidelines. The final version was used to validate the German version of the new KSS (GNKSS) in 133 patients undergoing TKA, of which 100 patients were included in the study as per inclusion criteria. Patients completed the GNKSS form along with the German WOMAC and the German SF-36 scores preoperatively and at the 2-year postoperative followup. Construct validity was tested by comparing domain scores of the GNKSS with domain scores of the German WOMAC and the SF-36. Responsiveness was evaluated by comparing pre- and postoperative scores in all questionnaires in all patients using standardized response means. To evaluate reliability, every second patient (n = 50) in the whole group was asked to complete the GNKSS form a second time 1 week after their 2-year followup; 39 patients responded. This sample group was considered representative after testing the difference among age, sex, body mass index, operation side, preoperative or postoperative GNKSS, and WOMAC scores with the original group. Intraclass correlation coefficients (ICCs) were used to assess reliability and Cronbach's α was an indicator of internal consistency of each domain score.

RESULTS

Construct validity was excellent pre- and postoperatively between the GNKSS and the WOMAC for domains including symptoms, satisfaction, total functional score, and total score and activity subdomains, except the expectation domain and advanced and discretionary subdomains of the GNKSS and the stiffness domain of WOMAC. The expectation domain showed either no significant correlation or only weak correlations with the domains of WOMAC pre- as well as postoperatively (r ranging between -0.19 and -0.34). Correlation of the function section of the GNKSS as well as the physical function and role-physical domains of the SF-36 pre- and postoperatively were moderate to strong, respectively, with statistically significant (p < 0.001) r values of 0.49 and 0.48 preoperatively and 0.73 and 0.65 postoperatively. Correlation of the symptom section of the GNKSS and bodily pain domain of the SF-36 was also strong pre- and postoperatively. Regarding responsiveness, all domains of the GNKSS showed large changes except the expectation domain. The symptom and functional sections of the GNKSS showed higher responsiveness than the corresponding pain and function domains of the WOMAC and bodily pain and physical function domains of the SF-36. Also, the total score changes were larger for the GNKSS compared with the WOMAC. No floor or ceiling effect was observed. Reliability was excellent with ICCs of 0.83 to 0.97 as an indicator of test-retest reliability and Cronbach's α values of 0.78 to 0.85 preoperatively and 0.92 to 0.94 postoperatively as an indicator of internal consistency for all domains and subdomains.

CONCLUSIONS

The GNKSS is a valid, responsive, reliable, and consistent outcome measurement tool that may be used to evaluate the outcome of TKA.

LEVEL OF EVIDENCE

Level II, diagnostic study.

Comparisons of Neuromuscular Training Versus Quadriceps Training on Gait and WOMAC Index in Patients With Knee Osteoarthritis and Varus Malalignment

Objective

The purpose of this study was to compare the effects of neuromuscular training (NMT) and quadriceps training (QT) on the altered gait patterns and Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index in patients with knee osteoarthritis (OA) and varus malalignment.

Methods

Sixty-six patients with knee pain ≥2 on 100-mm visual analog scale, radiographic knee OA changes ≥2 on Kellgren-Lawrence grading scale, and genu varum were allocated randomly into either the neuromuscular training group or quadriceps training group. Twelve weeks of supervised exercise protocol was given to the participants of both groups, which included 3 sessions per week. Primary outcomes were gait variables and self-reported physical function (WOMAC index).

Results

Of 66 knee OA patients, only 31 (94%) in the NMT group and 28 (84.8%) in the QT group completed the exercise protocol and were included in the analysis. There was a significant improvement in gait velocity (P = .022), stride length (P = .009), and global WOMAC index (P = .011) in the NMT group compared to the QT group. However, the scores of cadence (P = .226), gait cycle (P = .332), and double limb support (P = .054) were not found significant in the NMT group compared with the QT group.

Conclusion

The NMT group showed improvement in some of the gait parameters as well as improvement in pain, stiffness, and functional limitation compared with conventional QT. No additional improvement was found in cadence, gait cycle, and double limb support in patients who received NMT.

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.

Psychological health is associated with knee pain and physical function in patients with knee osteoarthritis: an exploratory cross-sectional study

Background

Depressive symptoms are a major comorbidity in older adults with knee osteoarthritis (OA). However, the type of activity-induced knee pain associated with depression has not been examined. Furthermore, there is conflicting evidence regarding the association between depression and performance-based physical function. This study aimed to examine (i) the association between depressive symptoms and knee pain intensity, particularly task-specific knee pain during daily living, and (ii) the association between depressive symptoms and performance-based physical function, while considering other potential risk factors, including bilateral knee pain and ambulatory physical activity.

Methods

Patients in orthopaedic clinics (n = 95; age, 61–91 years; 67.4% female) who were diagnosed with radiographic knee OA (Kellgren/Lawrence [K/L] grade ≥ 1) underwent evaluation of psychological health using the Geriatric Depression Scale (GDS). Knee pain and physical function were assessed using the Japanese Knee Osteoarthritis Measure (JKOM), 10-m walk, timed up and go (TUG), and five-repetition chair stand tests.

Results

Ordinal logistic regression analysis showed that depression, defined as a GDS score ≥ 5 points, was significantly associated with a worse score on the JKOM pain-subcategory and a higher level of task-specific knee pain intensity during daily living, after being adjusted for age, sex, body mass index (BMI), K/L grade, and ambulatory physical activity. Furthermore, depression was significantly associated with a slower gait velocity and a longer TUG time, after adjusting for age, sex, BMI, K/L grade, presence of bilateral knee pain, and ambulatory physical activity.

Conclusions

These findings indicate that depression may be associated with increased knee pain intensity during daily living in a non-task-specific manner and is associated with functional limitation in patients with knee OA, even after controlling for covariates, including bilateral knee pain and ambulatory physical activity.

Electronic supplementary material

The online version of this article (10.1186/s40359-018-0234-3) contains supplementary material, which is available to authorized users.

Neuropathic pain in end-stage hip and knee osteoarthritis: differential associations with patient-reported pain at rest and pain on activity

OBJECTIVE

We investigated whether pain at rest and pain on activity were differentially associated with neuropathic pain scores in individuals with end-stage hip and knee OA.

DESIGN

Study participants were 843 patients with hip or knee OA scheduled for total joint arthroplasty. In pre-surgery questionnaires, measures of socio-demographics, health status, medication use, neuropathic pain (painDETECT), pain at rest and pain on activity (WOMAC pain items), depression (HADS) and pain catastrophizing (PCS) were collected. Multivariable linear regression models were estimated for men and women separately to examine the association between neuropathic pain scores (outcome) and study measures, entered in blocks.

RESULTS

Sample mean age was 65.1 years (SD: 9.6); 57.1% were women. Mean painDETECT scores were significantly higher (P ≤ֹ 0.001) for women (11.2 ± 6.6 out of 38) than men (9.3 ± 7.0), with 35.6% of women and 27.7% of men meeting cut-offs for possible or likely neuropathic pain. In the final regression model for women, the coefficients for both types of pain were statistically significant, although the coefficient for pain at rest was 1.6 times greater than that for pain on activity. For men, only pain at rest was significantly associated with neuropathic pain scores.

CONCLUSIONS

Findings support that possible neuropathic pain is experienced by a notable proportion of patients with end-stage hip and knee OA and is more strongly associated with pain at rest than pain on activity, particularly in men. Clinical presentation of pain at rest may warrant more thorough evaluation for potential neuropathic pain and have implications for appropriate pain management.

Identification of pain categories associated with change in pain in patients receiving placebo: data from two phase 3 randomized clinical trials in symptomatic knee osteoarthritis

Background

Pain is the principal clinical symptom of osteoarthritis (OA), and development of safe and effective analgesics for OA pain is needed. Drug development of new analgesics for OA pain is impaired by substantial change in pain in patients receiving placebo, and more data describing clinical characteristics and pain categories particularly associated with this phenomenon is needed.

The purpose of this post-hoc analysis was to investigate clinical characteristics and pain categories and their association with radiographic progression and placebo pain reduction (PPR) in OA patients as measured the Western Ontario and McMasters Arthritis (WOMAC).

Methods

Pooled data from the placebo groups of two phase III randomized clinical trials in patients with knee OA followed for 2 years were analyzed. Differences between individual sub-scores and pain categories of weight-bearing and non-weight bearing pain over time were assessed. Selected patient baseline characteristics were assessed for association with PPR. Association between pain categories and radiographic progression was analyzed.

Results

The reduction of pain in placebo-treated patients was significantly higher in the composite of questions related to weight-bearing pain compared to non-weight-bearing pain of the target knee. Baseline BMI, age and JSW were not associated with pain change. Pain reduction was higher in the Target knee, compared to the Non-Target knee at all corresponding time-points. A very weak correlation was found between weight-bearing pain and progression in the non-target knee.

Conclusions

These results indicate that the reduction in pain in patients treated with placebo is significantly different between pain categories, as weight-bearing pain was significantly more reduced compared to non-weight-bearing pain. Further research in pain categories in OA is warranted.

Trial Registration

NCT00486434 (trial 1) and NCT00704847 (trial 2)

Synovial fluid pro-inflammatory profile differs according to the characteristics of knee pain

OBJECTIVE

The role of inflammation and pain in osteoarthritis (OA) is not fully understood. We evaluated the association between pro-inflammatory biomarkers and pain.

METHODS

We used baseline data and samples from a randomized controlled trial of colchicine for symptomatic knee OA. Severity of pain of the more symptomatic knee was assessed by National Health and Nutrition Examination Survey-I (NHANES-I) criterion and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain index. Pains on movement and at rest were self-reported on an 11-point Likert scale. Severity of radiographic tibiofemoral OA was assessed by Kellgren and Lawrence (KL) grade. Concentrations of synovial fluid (sf) IL-1β, IL-6, IL-8, TNFα, C-terminal telopeptides of Type I collagen (CTXI) and C-telopeptide of Type II collagen (CTXII), as well as urinary (u) CTXII were measured.

RESULTS

Of the 109 patients enrolled in the study, 70 patients (70% women) with synovial fluid obtained by direct aspiration were included for analysis. The mean ± SD age and body mass index (BMI) of the patients were 57.6 ± 8.3 years and 28.8 ± 5.2 kg/m². After adjustment for age, sex, and BMI, sf IL-6 and IL-8 were statistically significantly associated with 11-point pain on movement, but not with pain at rest. No significant associations were observed with WOMAC pain scores. sf IL-1β (analyzed as detectable/non-detectable) was inversely associated with pain. In contrast, after adjustment, Sf TNFα was associated with WOMAC total pain and both pain on movement and at rest. sf/u CTXII was associated with radiographic severity, but not with knee pain.

CONCLUSIONS

This study provides indication that OA pain mechanisms may differ according to the characteristics of the pain.

Coexisting lateral tibiofemoral osteoarthritis is associated with worse knee pain in patients with mild medial osteoarthritis

OBJECTIVE

To examine the clinical impact of coexisting lateral osteoarthritis (OA) in knees with mild medial OA.

DESIGN

In patients with Kellgren/Lawrence (K/L) grade 2 OA in the medial compartment (n = 100; age: 56-89 years; 80.0% female), anteroposterior knee radiography was used to assess the presence of lateral OA, using grading systems from the Osteoarthritis Research Society International (OARSI) atlas and the K/L classification. The Japanese Knee Osteoarthritis Measure (JKOM), knee range of motion (ROM), and performance-based functional measures (10 m walk, timed up and go and five repetition chair stand maneuvers) were evaluated. The outcomes were compared between patients with and without lateral OA using an analysis of covariance (ANCOVA) or nonparametric rank ANCOVA. Furthermore, ordinal logistic regression analysis was performed, with responses on individual JKOM pain questionnaires as the outcomes and lateral OA as the predictor.

RESULTS

Knees with coexisting lateral OA had a significantly worse score of JKOM pain question compared with those without, after adjusting for covariates. The presence of lateral OA was significantly associated with knee pain while ascending/descending stairs and standing. These results were consistent between different definitions of the K/L and OARSI grading systems. The knee ROM and performance-based functional measures were not significantly different between patients with and without lateral OA.

CONCLUSION

Knees with concomitant lateral and mild medial OA may be more symptomatic compared to those without lateral OA. These findings might help to define a clinically distinct subgroup based on a simple radiographic finding in mild knee OA.

Aquatic Exercise for the Treatment of Hip and Knee Osteoarthritis

<LEAP> highlights the findings and application of Cochrane reviews and other evidence pertinent to the practice of physical therapy. The Cochrane library is a respected source of reliable evidence related to health care. Cochrane systematic reviews explore the evidence for and against the effectiveness and appropriateness of interventions-medications, surgery, education, nutrition, exercise-and the evidence for and against the use of diagnostic tests for specific conditions. Cochrane reviews are designed to facilitate the decisions of clinicians, patients, and others in health care by providing a careful review and interpretation of research studies published in the scientific literature. Each article in this PTJ series summarizes a Cochrane review or other scientific evidence on a single topic and presents clinical scenarios based on real patients or programs to illustrate how the results of the review can be used to directly inform clinical decisions. This article focuses on an older adult with severe knee joint pain. Can aquatic exercise help this patient with knee osteoarthritis?

Effect of Intra-articular Triamcinolone vs Saline on Knee Cartilage Volume and Pain in Patients With Knee Osteoarthritis: A Randomized Clinical Trial

IMPORTANCE

Synovitis is common and is associated with progression of structural characteristics of knee osteoarthritis. Intra-articular corticosteroids could reduce cartilage damage associated with synovitis but might have adverse effects on cartilage and periarticular bone.

OBJECTIVE

To determine the effects of intra-articular injection of 40 mg of triamcinolone acetonide every 3 months on progression of cartilage loss and knee pain.

DESIGN, SETTING, AND PARTICIPANTS

Two-year, randomized, placebo-controlled, double-blind trial of intra-articular triamcinolone vs saline for symptomatic knee osteoarthritis with ultrasonic features of synovitis in 140 patients. Mixed-effects regression models with a random intercept were used to analyze the longitudinal repeated outcome measures. Patients fulfilling the American College of Rheumatology criteria for symptomatic knee osteoarthritis, Kellgren-Lawrence grades 2 or 3, were enrolled at Tufts Medical Center beginning February 11, 2013; all patients completed the study by January 1, 2015.

INTERVENTIONS

Intra-articular triamcinolone (n = 70) or saline (n = 70) every 12 weeks for 2 years.

MAIN OUTCOMES AND MEASURES

Annual knee magnetic resonance imaging for quantitative evaluation of cartilage volume (minimal clinically important difference not yet defined), and Western Ontario and McMaster Universities Osteoarthritis index collected every 3 months (Likert pain subscale range, 0 [no pain] to 20 [extreme pain]; minimal clinically important improvement, 3.94).

RESULTS

Among 140 randomized patients (mean age, 58 [SD, 8] years, 75 women [54%]), 119 (85%) completed the study. Intra-articular triamcinolone resulted in significantly greater cartilage volume loss than did saline for a mean change in index compartment cartilage thickness of -0.21 mm vs -0.10 mm (between-group difference, -0.11 mm; 95% CI, -0.20 to -0.03 mm); and no significant difference in pain (-1.2 vs -1.9; between-group difference, -0.6; 95% CI, -1.6 to 0.3). The saline group had 3 treatment-related adverse events compared with 5 in the triamcinolone group and had a small increase in hemoglobin A1c levels (between-group difference, -0.2%; 95% CI, -0.5% to -0.007%).

CONCLUSIONS AND RELEVANCE

Among patients with symptomatic knee osteoarthritis, 2 years of intra-articular triamcinolone, compared with intra-articular saline, resulted in significantly greater cartilage volume loss and no significant difference in knee pain. These findings do not support this treatment for patients with symptomatic knee osteoarthritis.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01230424.

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.

The effects of curcuminoids on musculoskeletal pain: a systematic review

BACKGROUND

Western countries are increasingly using complementary and alternative medicine (CAM) to assist with relieving ailments. Turmeric, from the ginger family Zingiberaceae, has a history of use for medicinal purposes. The polyphenols found in turmeric (curcuminoids) have demonstrated anti-inflammatory and pain relieving properties. With the use of CAMs increasing, it is important for the effectiveness of curcuminoids to be established.

OBJECTIVES

To identify the effectiveness of the use of curcuminoids for the amelioration of musculoskeletal pain.

INCLUSION CRITERIA TYPES OF PARTICIPANTS

Persons experiencing musculoskeletal pain, including experimentally induced musculoskeletal pain.

TYPES OF INTERVENTION(S)/PHENOMENA OF INTEREST

The current review considered studies that evaluated the use of curcuminoids.

TYPES OF CONTROLS

Any form including placebo, treatment as usual or before and after measurements.

TYPES OF STUDIES

Both experimental and epidemiological study designs including randomized controlled trials (RCTs), non-RCTs, quasi-experimental and before and after studies were eligible for consideration in this review. Studies published in English were considered without date restriction.

OUTCOMES

The current review considered studies that included measurement of pain. Outcome measures included visual analog scales, and/or pain questionnaires. Secondary outcome measures of functionality (activities of daily living and range of motion) were included. Any data provided on adverse events were considered.

SEARCH STRATEGY

The databases PubMed, CINAHL, Embase and ProQuest were searched in March 2015 (and updated in April 2016) using the Joanna Briggs Institute (JBI) three-step search strategy. The reference lists of identified articles were reviewed for additional studies.

METHODOLOGICAL QUALITY

Papers selected were assessed by two independent reviewers using standardized instruments from the JBI Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI).

DATA EXTRACTION

Data were extracted using the data extraction tool from JBI-MAStARI. Data extracted included details about the populations, interventions, study methods and outcomes.

DATA SYNTHESIS

Narrative and tabular synthesis was conducted. Meta-analysis was precluded due to methodological and clinical heterogeneity across all included studies.

RESULTS

Thirteen studies with a combined total of 1101 participants were included. Three studies of limited sample size examined the effects of curcuminoids compared with the use of placebo on musculoskeletal pain, with one study showing a statistically significant effect. Four studies examined the effects of curcuminoids compared with non-selective non-steroidal anti-inflammatory drugs on musculoskeletal pain. Two of these four studies were non-inferiority studies showed that the use of both curcuminoids and ibuprofen were associated with a similar significant reduction in pain over the study durations of four and six weeks, respectively, with curcuminoid use non-inferior to the use of ibuprofen over the study durations. Six studies investigated presentations of curcuminoid-containing herbomineral mixtures versus placebo or active controls.

CONCLUSION

There is insufficient evidence to recommend that curcuminoids be considered for relieving pain and improving function in musculoskeletal pain conditions. This finding needs to be considered in the context of limitations imposed by the variability in the quality of studies, small sample sizes, short duration of interventions, a gender-bias toward females, absence of long-term data extraction and small number of relevant studies.

The effect of vitamin D supplementation on knee osteoarthritis, the VIDEO study: a randomised controlled trial

OBJECTIVE

Epidemiological data suggest low serum 25-hydroxyvitamin D₃ (25-OH-D₃) levels are associated with radiological progression of knee osteoarthritis (OA). This study aimed to assess whether vitamin D supplementation can slow the rate of progression.

METHOD

A 3-year, double-blind, randomised, placebo-controlled trial of 474 patients aged over 50 with radiographically evident knee OA comparing 800 IU cholecalciferol daily with placebo. Primary outcome was difference in rate of medial joint space narrowing (JSN). Secondary outcomes included lateral JSN, Kellgren & Lawrence grade, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, function, stiffness and the Get up and Go test.

RESULTS

Vitamin D supplementation increased 25-OH-D₃ from an average of 20.7 (standard deviation (SD) 8.9) μg/L to 30.4 (SD 7.7) μg/L, compared to 20.7 (SD 8.1) μg/L and 20.3 (SD 8.1) μg/L in the placebo group. There was no significant difference in the rate of JSN over 3 years in the medial compartment of the index knee between the treatment group (average -0.01 mm/year) and placebo group (-0.08 mm/year), average difference 0.08 mm/year (95% confidence interval (CI) [-0.14-0.29], P = 0.49). No significant interaction was found between baseline vitamin D levels and treatment effect. There were no significant differences for any of the secondary outcome measures.

CONCLUSION

Vitamin D supplementation did not slow the rate of JSN or lead to reduced pain, stiffness or functional loss over a 3-year period. On the basis of these findings we consider that vitamin D supplementation has no role in the management of knee OA.

Rest Pain and Movement-Evoked Pain as Unique Constructs in Hip and Knee Replacements

Objective

There is limited information about the extent to which the association between preoperative and chronic postoperative pain is mediated via pain‐on‐movement or pain‐at‐rest. We explored these associations in patients undergoing total hip replacement (THR) and total knee replacement (TKR).

Methods

A total of 322 and 316 patients receiving THR and TKR, respectively, were recruited into a single‐center UK cohort (Arthroplasty Pain Experience) study. Preoperative, acute postoperative, and 12‐month pain severity was measured using self‐reported pain instruments. The association between preoperative/acute pain and chronic postoperative pain was investigated using structural equation modeling (SEM).

Results

Patients with high levels of preoperative pain were more likely to report chronic pain after THR (β = 0.195, P = 0.02) and TKR (β = 0.749, P < 0.0001). Acute postoperative pain‐on‐movement was not associated with chronic pain after TKR or THR after adjusting for preoperative pain; however, acute pain‐at‐rest was associated with chronic pain after THR (β = 0.20, P < 0.0002) but not TKR after adjusting for preoperative pain. Analysis of pain‐at‐rest and pain‐on‐movement highlighted differences between THR and TKR patients. Chronic pain‐at‐rest after THR was weakly associated with pain‐at‐rest during the preoperative (β = 0.11, P = 0.068) and acute postoperative period (β = 0.21, P < 0.0001). In contrast, chronic pain‐on‐movement after TKR was strongly associated with the severity of pain‐on‐movement during the preoperative period (β = 0.51, P = 0.001).

Conclusion

SEM illustrated the different patterns of association between measures of pain over time in patients undergoing THR and TKR for osteoarthritis. These findings highlight the importance of future work that explores the mechanisms underlying pain‐on‐movement and pain‐at‐rest.

Cross-sectional and Longitudinal Associations between Knee Joint Effusion Synovitis and Knee Pain in Older Adults

OBJECTIVE

To describe the cross-sectional and longitudinal associations between knee regional effusion synovitis and knee pain in older adults.

METHODS

Data from a population-based random sample (n = 880, mean age 62 yrs, 50% women) were used. Baseline knee joint effusion synovitis was graded (0-3) using T2-weighted magnetic resonance imaging (MRI) in the suprapatellar pouch, central portion, posterior femoral recess, and subpopliteal recess. Effusion synovitis of the whole joint was defined as a score of ≥ 2 in any subregion. Other knee structural (including cartilage, bone marrow, and menisci) lesions were assessed by MRI at baseline. Knee pain was assessed by the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire at baseline and 2.6 years later. Multivariable analyses were performed after adjustment for age, sex, body mass index, and other structural lesions.

RESULTS

The prevalence of effusion synovitis was 67%. Suprapatellar pouch effusion synovitis was significantly and independently associated with increased total and nonweight-bearing knee pain in both cross-sectional and longitudinal analyses (for an increase in total knee pain of ≥ 5, RR 1.26 per grade, 95% CI 1.04-1.52), and increased weight-bearing knee pain in longitudinal analysis only. Effusion synovitis in posterior femoral recess and central portion were independently associated with increases in nonweight-bearing pain (RR 1.63 per grade, 95% CI 1.32-2.01 and RR 1.29 per grade, 95% CI 1.01-1.65, respectively) in longitudinal analyses only.

CONCLUSION

Knee joint effusion synovitis has independent associations with knee pain in older adults. Suprapatellar pouch effusion synovitis is associated with nonweight-bearing and weight-bearing knee pain, while posterior femoral recess and central portion effusion synovitis are only associated with nonweight-bearing pain.

Preoperative widespread pain sensitization and chronic pain after hip and knee replacement: a cohort analysis

Supplemental Digital Content is Available in the Text.

Preoperative widespread pressure pain sensitivity is not predictive of the amount of pain relief that patients gain from total hip or knee replacement.

Chronic pain after joint replacement is common, affecting approximately 10% of patients after total hip replacement (THR) and 20% of patients after total knee replacement (TKR). Heightened generalized sensitivity to nociceptive input could be a risk factor for the development of this pain. The primary aim of this study was to investigate whether preoperative widespread pain sensitivity was associated with chronic pain after joint replacement. Data were analyzed from 254 patients receiving THR and 239 patients receiving TKR. Pain was assessed preoperatively and at 12 months after surgery using the Western Ontario and McMaster Universities Osteoarthritis Pain Scale. Preoperative widespread pain sensitivity was assessed through measurement of pressure pain thresholds (PPTs) at the forearm using an algometer. Statistical analysis was conducted using linear regression and linear mixed models, and adjustments were made for confounding variables. In both the THR and TKR cohort, lower PPTs (heightened widespread pain sensitivity) were significantly associated with higher preoperative pain severity. Lower PPTs were also significantly associated with higher pain severity at 12 months after surgery in the THR cohort. However, PPTs were not associated with the change in pain severity from preoperative to 12 months postoperative in either the TKR or THR cohort. These findings suggest that although preoperative widespread pressure pain sensitivity is associated with pain severity before and after joint replacement, it is not a predictor of the amount of pain relief that patients gain from joint replacement surgery, independent of preoperative pain severity.

Measurement properties of the Western Ontario and McMaster Universities Osteoarthritis Index: a systematic review

OBJECTIVE

To conduct a systematic review of the measurement properties of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and to evaluate the quality of WOMAC measurement studies using COSMIN (Consensus-Based Standards for the Selection of Health Measurement Instruments) criteria.

METHODS

A search was conducted in the MEDLINE, CINAHL, Embase, PsycINFO, Scopus, and SPORTDiscus databases through September 2013. Data that assessed the WOMAC measurement model, reliability, validity, respondent burden, and equivalence across methods of administration were extracted. Overall study quality was rated following COSMIN criteria.

RESULTS

A total of 76 articles from 22 countries were included. Internal consistency reliability was consistently high (≥0.90) for the function scale and acceptable (≥0.70) for the pain and stiffness scales. Test-retest reliability was acceptable. Score equivalence was demonstrated across paper and electronic methods of data collection. Floor and ceiling effects were low except for notable (24-38%) proportions of patients achieving the best possible scores on the pain and stiffness scales 1-23 years after arthroplasty. Five exploratory factor analyses did not support a measurement model in which the pain and function items were distinct. Correlations between the WOMAC pain and function scales were high (median 0.79). The WOMAC pain and function scales had similar correlations with other pain measures, and therefore the WOMAC pain scale did not show divergent validity. COSMIN criteria were not fully met in most studies.

CONCLUSION

The WOMAC scales were reliable, but its pain scale was highly related to physical function. Further research into joint-specific pain measures that have broader content validity is needed.

Comparison of measurement properties of the P4 pain scale and disease specific pain measures in patients with knee osteoarthritis

OBJECTIVE

To compare measurement properties of the P4 pain scale, Western Ontario and McMaster Universities Arthritis Index pain subscale (WOMAC-pain), and Intermittent and Constant Osteoarthritis Pain (ICOAP) measure in patients with knee osteoarthritis (OA).

DESIGN

A secondary analysis from a randomized controlled trial included participants (n = 156) with knee OA that were consulting with a surgeon regarding knee arthroplasty. They completed pain measures (P4, WOMAC-pain, ICOAP) and WOMAC-function subscale (WOMAC-function) at baseline and 2 weeks. Measurement properties assessed in various subgroups included floor/ceiling effects, test-retest reliability using intraclass correlation coefficients (ICC2,1), internal consistency using Cronbach's ɑ, factorial structure of each pain measure combined with WOMAC-function using principal component analysis, and responsiveness using standardized response mean (SRM).

RESULTS

P4 had low floor and ceiling effects (<1%). P4 test-retest reliability (ICC2,1 = 0.72), internal consistency (Chronbach's ɑ = 0.91), and responsiveness (SRM = 0.56) were similar to the values for WOMAC-pain and ICOAP. Factorial structure of P4 and ICOAP were separate from WOMAC-function items. WOMAC-pain and WOMAC-function items loaded on similar factors. ICOAP-constant subscale had a large floor effect (33%).

CONCLUSIONS

P4 should be used to measure pain in patients with knee OA. It had acceptable measurement properties which is comparable to more widely used pain measures. WOMAC-pain shared a factorial structure with WOMAC-function indicating these measures might be capturing the same construct, questioning its validity to measure pain separately from function. ICOAP had acceptable properties. More work should compare pain measures in less severely affected OA populations.

Popliteal cysts and subgastrocnemius bursitis are associated with knee symptoms and structural abnormalities in older adults: a cross-sectional study

Introduction

The role of popliteal cysts and subgastrocnemius bursitis in knee joint homeostasis is uncertain. The aim of this study is to describe cross-sectional associations between popliteal cysts, subgastrocnemius bursitis, knee symptoms and structural abnormalities in older adults.

Methods

A cross-sectional sample of 900 randomly-selected subjects (mean age 63 years, 48% female) were studied. Knee pain, stiffness and dysfunction were assessed by self-administered Western Ontario McMaster Osteoarthritis Index (WOMAC) questionnaire. Radiographic knee osteophyte and joint space narrowing (JSN) were recorded. Magnetic resonance imaging (MRI) was utilized to assess popliteal cysts, subgastrocnemius bursitis, cartilage defects and bone marrow lesions (BMLs).

Results

Popliteal cysts were present in 11.7% and subgastrocnemius bursitis in 12.7% of subjects. Subgastrocnemius bursitis was more common in those with popliteal cyst (36.2% versus 9.7%, P <0.01). In multivariable analyses, popliteal cysts were significantly associated with increased osteophytes in both medial and lateral tibiofemoral compartments while subgastrocnemius bursitis was associated with increased osteophytes and JSN in the medial tibiofemoral compartment. Both were significantly associated with cartilage defects in all compartments, and with BMLs in the medial tibiofemoral compartment. Furthermore, both popliteal cysts and subgastrocnemius bursitis were significantly associated with increased weight-bearing knee pain but these associations became non-significant after adjustment for cartilage defects and BMLs.

Conclusions

Popliteal cysts and subgastrocnemius bursitis are associated with increased symptoms as well as radiographic and MRI-detected joint structural abnormalities. Longitudinal data will help resolve if they are a consequence or a cause of knee joint abnormalities.

Treatment of advanced stage gonarthrosis with prolotherapy: case report

Introduction

This case report aims to discuss the clinical and radiological outcomes of prolotherapy at a patient whom to total knee prosthesis had been planned but surgery couldn’t be performed due to co-morbidities.

Case Presentation

A 72 year old woman presented with severe pain at her knees for over 5 years. Treatment methods include weight loss, decreasing the weight bearing on the joint, stretching exercises, nonsteroid anti-inflammatory and steroid drugs, and physiotherapy. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale was applied to measure the osteoarthritis level of the patient: Pain level; 25 points, stiffness level; 10 points, Physical function loss; 80 points, and total WOMAC 115 points. At radiological evaluation, the patient was diagnosed as grade IV osteoarthritis due to significant osteophyte presence and complete joint space narrowing. Six sessions of knee prolotherapy protocol was applied to the patient, one session monthly.

Conclusions

Significant improvement was noted at WOMAC scale (Pain level; 5 points, stiffness level; 2 points, Physical function loss; 15 points, and total WOMAC 22 points). Osteoarthritis level of the patient was improved to grade I at radiological evaluation after a year. Our case is the report that presents radiological evidence in addition to clinical findings of improvement of osteoarthritis level. As a result of this case report, further studies aiming to offer a different minimally invasive treatment option to the patients before surgery may be performed. We are in the opinion that prolotherapy may be preferred more commonly as an efficient method once the importance of ligamentous structures at pathogenesis of osteoarthritis is established.

Relationship between knee pain and the presence, location, size and phenotype of femorotibial denuded areas of subchondral bone as visualized by MRI

OBJECTIVE

Conflicting associations between imaging biomarkers and pain in knee osteoarthritis (OA) have been reported. A relation between pain and denuded areas of subchondral bone (dABs) has been suggested and this study explores this relationship further by relating the presence, phenotype, location and size of dABs to different measures of knee pain.

METHODS

633 right knees from the Osteoarthritis Initiative (OAI) (250 men, age 61.7 ± 9.6 yrs, BMI 29.4 ± 4.7 kg/m(2)) were included. Manual segmentation of the femorotibial cartilage plates was performed on 3 T coronal fast low angle shot with water excitation (FLASHwe) images. dABs were defined as areas where the subchondral bone was uncovered by cartilage. The following measures of pain were used: weightbearing-, non-weightbearing-, moderate-to-severe-, infrequent- and frequent knee pain.

RESULTS

Using pain measures from subjects without dABs as a reference, those with at least one dAB had a 1.64-fold higher prevalence ratio [PR, 95% confidence interval (CI) 1.24-2.18] to have frequent and 1.45-fold higher for moderate-to-severe knee pain (95% CI 1.13-1.85). Subjects with dABs in central subregions had a 1.53-fold increased prevalence of having weightbearing pain (95% CI 1.20-1.97), especially when the central subregion was moderately (>10%) denuded (PR 1.81, 95% CI 1.35-2.42). Individuals with cartilage-loss-type dABs had a slightly higher prevalence (PR 1.13, 95% CI 1.00-1.27) of having frequent knee pain compared to individuals with intra-chondral-osteophyte-type dABs.

CONCLUSION

This study supports a positive relation between femorotibial dABs and knee pain, especially when the dABs are located centrally (i.e., in weightbearing regions) or when the respective central subregion is moderately denuded.

A rapid, novel method of volumetric assessment of MRI-detected subchondral bone marrow lesions in knee osteoarthritis

PURPOSE

To assess reliability and validity of a semi-automated quantitative method for osteoarthritis (OA)-related bone marrow lesion (BML) assessment in the femur and tibia.

METHODS

In a cross-sectional study of subjects with knee OA, we examined concurrent criterion and clinical validation of a novel method of semi-automated quantitative BML measurement. The primary outcome was total segmented BML volume in femoral and tibial medial and lateral knee compartments. Criterion validation was examined through comparison of BML volumes with Whole-Organ Magnetic Resonance Imaging Score (WORMS) scoring. Clinical validation was examined via associations of tibial and femoral BML volume with the Western Ontario and McMaster University OA Index weight-bearing pain questions.

RESULTS

Among the 115 subjects, mean age was 62 years, mean BMI 30.4 (kg/m(2)), 84% were white and 52% male. The intra-class correlation coefficients (ICC) for intra-reader reliability was 0.96 and 0.97 for inter-reader reliability. Significant Spearman's correlations were found between segmented BML volume and WORMS BML scoring for tibial medial (0.75) and lateral (0.73) compartments, and for femoral medial (0.72) and lateral (0.88) compartments. Significant positive associations were found between weight-bearing pain and total femoral BML volume (P < 0.003), but not total tibial BML (P < 0.101).

CONCLUSION

We have documented a moderately strong correlation between a novel measurement method of femoral and tibial BML volume and semi-quantitative WORMS scores, providing evidence of criterion validity. The hypothesis that weight-bearing pain was associated with BML volume was confirmed for total femoral BML volume but not total tibial BML volume. The lack of association between tibial BML volume and pain requires further investigation.

Effect of vitamin D supplementation on progression of knee pain and cartilage volume loss in patients with symptomatic osteoarthritis: a randomized controlled trial

IMPORTANCE

Knee osteoarthritis (OA), a disorder of cartilage and periarticular bone, is a public health problem without effective medical treatments. Some studies have suggested that vitamin D may protect against structural progression.

OBJECTIVE

To determine whether vitamin D supplementation reduces symptom and structural progression of knee OA.

DESIGN, SETTING, AND PATIENTS

A 2-year randomized, placebo-controlled, double-blind, clinical trial involving 146 participants with symptomatic knee OA (mean age, 62.4 years [SD, 8.5]; 57 women [61%], 115 white race [79%]). Patients were enrolled at Tufts Medical Center in Boston between March 2006 and June 2009.

INTERVENTION

Participants were randomized to receive either placebo or oral cholecalciferol, 2000 IU/d, with dose escalation to elevate serum levels to more than 36 ng/mL.

MAIN OUTCOME MEASURES

Primary outcomes were knee pain severity (Western Ontario and McMaster Universities [WOMAC] pain scale, 0-20: 0, no pain; 20, extreme pain), and cartilage volume loss measured by magnetic resonance imaging. Secondary end points included physical function, knee function (WOMAC function scale, 0-68: 0, no difficulty; 68, extreme difficulty), cartilage thickness, bone marrow lesions, and radiographic joint space width.

RESULTS

Eighty-five percent of the participants completed the study. Serum 25-hydroxyvitamin D levels increased by a mean 16.1 ng/mL (95% CI, 13.7 to 18.6) in the treatment group and by a mean 2.1 mg/mL (95% CI, 0.5 to 3.7) (P < .001) in the placebo group. Baseline knee pain was slightly worse in the treatment group (mean, 6.9; 95% CI, 6.0 to 7.7) than in the placebo group (mean, 5.8; 95% CI, 5.0 to 6.6) (P = .08). Baseline knee function was significantly worse in the treatment group (mean, 22.7; 95% CI, 19.8 to 25.6) than in the placebo group (mean, 18.5; 95% CI, 15.8 to 21.2) (P = .04). Knee pain decreased in both groups by a mean -2.31 (95% CI, -3.24 to -1.38) in the treatment group and -1.46 (95% CI, -2.33 to -0.60) in the placebo group, with no significant differences at any time. The percentage of cartilage volume decreased by the same extent in both groups (mean, -4.30; 95% CI, -5.48 to -3.12 vs mean, -4.25; 95% CI, -6.12 to -2.39) (P = .96). There were no differences in any of the secondary clinical end points.

CONCLUSION AND RELEVANCE

Vitamin D supplementation for 2 years at a dose sufficient to elevate 25-hydroxyvitamin D plasma levels to higher than 36 ng/mL, when compared with placebo, did not reduce knee pain or cartilage volume loss in patients with symptomatic knee OA.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00306774.

Associations of varus thrust and alignment with pain in knee osteoarthritis

OBJECTIVE

To investigate associations of varus thrust and varus static alignment with pain in patients with knee osteoarthritis (OA).

METHODS

This was a cross-sectional study of participants from a randomized controlled trial of vitamin D treatment for knee OA. Participants were video recorded while walking and scored for presence of varus thrust. Static alignment was measured on standard posteroanterior knee radiographs. Pain questions from the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire were used to assess symptoms. We calculated means for total WOMAC pain in relation to varus thrust and static varus alignment (i.e., corrected anatomic alignment<178 degrees). Ordinal logistic regressions were performed, with responses on individual WOMAC pain questions as the outcomes and varus thrust and varus alignment as the predictors.

RESULTS

There were 82 participants, 60% of whom were female. The mean±SD age was 65.1±8.5 years, and the mean±SD body mass index was 30.2±5.4 kg/m2. The mean total WOMAC pain score was 6.3 versus 3.9, respectively, in those with versus without definite varus thrust (P=0.007) and 5.0 versus 4.2 in those with versus without varus alignment (P=0.36). Odds ratios for pain with walking and standing were 4.7 (95% confidence interval 1.8-11.9) and 5.5 (95% confidence interval 2.2-14.2), respectively, in those with and those without definite varus thrust. There were no significant associations between varus alignment and responses to individual WOMAC pain questions. Sensitivity analyses suggested that varus classified using a more stringent definition might have been associated with pain on walking and standing.

CONCLUSION

In patients with knee OA, varus thrust, and possibly varus static alignment, were associated with pain, specifically during weight-bearing activities. Treatment of varus thrust (e.g., via bracing or gait modification) may lead to improvement of symptoms.

Evaluation of outcome measures for use in clinical practice for adults with musculoskeletal conditions of the knee: a systematic review

BACKGROUND

This systematic review reported on the clinimetric properties of outcome measures for use in clinical practice for adults with musculoskeletal conditions of the knee.

METHODS

A systematic search was performed in Medline, EMBASE, Cinahl and AMED to identify studies examining the clinimetric properties of outcome measures for adults undergoing conservative treatment of ligament injuries, meniscal lesions, patellofemoral pain and osteoarthritis of the knee. Outcomes measures taking less than 20 min to administer and requiring minimal equipment and space were included. Pairs of authors used a checklist to record the characteristics of the outcome measures, their reported clinimetric properties and the demographics of the study populations. The OMERACT filters of 'truth' and 'discrimination' were applied to the data for each outcome measure by an expert panel.

RESULTS

Forty-seven studies were included evaluating 37 outcome measures. Ten outcome measures had adequate supporting evidence for 'truth' and 'discrimination': AAOS, AKPS, goniometer measurement, IKDC, KOOS, LEFS, Lysholm, Tegner, WOMAC and WOMET. However none of the outcome measures had been comprehensively tested across all clinimetric properties.

CONCLUSION

Despite the widespread use of some outcome measures in clinical practice and primary research, data on the clinimetric properties were available for only 37 and of these only 10 had adequate supporting evidence for use in this population. However, before a core set of outcome measures can be recommended use in clinical practice, for adults with musculoskeletal conditions of the knee, consensus should be obtained on 'feasibility' in terms of burden on the clinician and the participant.

A walking model to assess the onset of analgesia in osteoarthritis knee pain

OBJECTIVE

To assess a walking model utilizing a set of standardized treadmill walks to measure acute analgesic response in osteoarthritis (OA) of the knee.

DESIGN

Randomized, double-blind, placebo-controlled, multiple dose, three-period crossover study. Patients > or =45 years of age (N=22) with symptomatic knee OA were randomized to naproxen 500 mg bid, tramadol/acetaminophen 37.5 mg/325 mg in forced titration, or placebo in each of three periods. Patients performed multiple 20-minute treadmill walks on Day 1 and Day 3 at a consistent self-selected pace predetermined at screening. Pain intensity (PI) during the walks was assessed on an 11-point numerical rating scale at 0, 3, 6, 9, 12, 15, 18, and 20 min. The primary endpoint was the time-weighted average (TWA) change from baseline PI on Day 3 for the two self-paced walks for the active treatments vs placebo. Time to moderate pain (TTMP) was a key secondary endpoint.

RESULTS

Compared with placebo, the TWA change from baseline PI on Day 3 was significantly better with tramadol/acetaminophen (P=0.043) but not with naproxen (P=0.089). TWA change from baseline on Day 1 was also significantly better with both tramadol/acetaminophen (P=0.001) and naproxen (P=0.048) compared with placebo. TTMP was significantly better for tramadol/acetaminophen and naproxen than placebo (P<0.001 to P=0.015) for walks on Day 1 after a single dose and on Day 3.

CONCLUSIONS

This novel OA pain model was able to discriminate both tramadol/acetaminophen and naproxen from placebo after single and multiple doses. ClinicalTrials.gov identifier: NCT00772967.

The visual analogue WOMAC 3.0 scale--internal validity and responsiveness of the VAS version

BACKGROUND

Many people suffer with Osteoarthritis (OA) and subsequent morbidity. Therefore, measuring outcome associated with OA is important. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) has been a widely used patient reported outcome in OA. However, there is relatively little evidence to support the use of the Visual Analogue Scale (VAS) version of the scale. We aimed to explore the internal validity and responsiveness of this VAS version of the WOMAC.

METHODS

Patients with chronic hip or knee pain of mechanical origin, waiting for a hip or knee joint replacement completed the WOMAC as part of a study to investigate the effects of acupuncture and placebo controls. Validity was tested using factor analysis and Rasch analysis, and responsiveness using standardised response means.

RESULTS

Two hundred and twenty one patients (mean age 66.8, SD 8.29, 58% female) were recruited. Factor and Rasch analysis confirmed unidimensional Pain and Physical Functioning scales, capable of transformation to interval scaling and invariant over time. Some Differential Item Functioning (DIF) was observed, but this cancelled out at the test level. The Stiffness scale fitted the Rasch model but adjustments for DIF could not be made due to the shortness of the scale. Using the interval transformed data, Standardised Response Means were smaller than when using the raw, ordinal data.

CONCLUSIONS

The WOMAC Pain and Physical Functioning subscales satisfied unidimensionality and ordinal scaling tests, and the ability to transform to an interval scale. Some Differential Item Functioning was observed, but this cancelled out at the test level and, by doing so, at the same time removed the disturbance of unidimensionality. The scaling characteristics of sets of items which use VAS require further analysis, as it would appear that they can lead to spurious levels of responsiveness and scale compression because they exaggerate the distortion of the ordinal scale.

TRIAL NUMBER

UKCRN study ID: 4881 ISRCTN78434638.

Using hierarchical linear modeling to explore predictors of pain after total hip and knee arthroplasty as a consequence of osteoarthritis

Hierarchical linear modeling was used to establish differences in, and the average pattern of, recovery of the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and 2 composite performance-specific measures of pain as well as to determine if significant individual variations exist in the growth curves for each measure. Predictors of postoperative pain were also of interest. One hundred forty-seven patients undergoing unilateral primary hip or knee arthroplasty completed 4 performance measures-self-paced 40-m walk, timed up and go, stair test, and 6-minute walk-and the WOMAC prearthroplasty and at multiple points in time between 2 and 27 weeks postarthroplasty. Although patients reported different levels of postoperative pain initially, similar recovery patterns were noted. Predictive variables were found to be site of joint arthroplasty and WOMAC prearthroplasty pain scores for the WOMAC pain subscale, the site of joint arthroplasty and sex for the first composite pain score, and sex for the second composite.

Bone marrow lesions and joint effusion are strongly and independently associated with weight-bearing pain in knee osteoarthritis: data from the osteoarthritis initiative

OBJECTIVE

It is widely believed that there are multiple sources of pain at a tissue level in osteoarthritis (OA). Magnetic Resonance Images (MRIs) provide a wealth of anatomic information and may allow identification of specific features associated with pain. We hypothesized that in knees with OA, bone marrow lesions (BMLs), synovitis, and effusion would be associated with weight-bearing and (less so with) non-weight-bearing pain independently.

METHODS

In a cross-sectional study of persons with symptomatic knee OA using univariate and multivariate logistic regressions with maximal BML, effusion, and synovitis defined by Boston Leeds Osteoarthritis Knee Score as predictors, and knee pain using weight-bearing and non-weight-bearing Western Ontario and McMaster University OA Index pain questions as the outcome, we tested the association between MRI findings and knee symptoms.

RESULTS

160 participants, mean age 61 (+/-9.9), mean body mass index (BMI) 30.3 (+/-4.7) and 50% female, stronger associations were seen with weight-bearing compared with non-weight-bearing knee pain with adjusted risk ratios (RRs) of weight-bearing knee pain, for increasing maximal BML scores of 1.0 (referent) (maximal BML=0), 1.2, 1.9, and 2.0 (P for trend=0.006). For effusion scores, adjusted RRs of knee pain were 1.0, 1.7, 2.0, and 2.6 (P for trend=0.0004); and for synovitis scores, adjusted ORs were 1.0, 1.4, 1.5, and 1.9 (P for trend=0.22).

CONCLUSION

Cross-sectionally, maximal BML and effusion scores are independently associated with weight-bearing and less so with non-weight-bearing knee pain, supporting the idea that pain in OA is multifactorial. These MRI features should be considered as possible new treatment targets in knee OA.

Does isolated patellofemoral osteoarthritis matter?

OBJECTIVES

To describe the structure-pain and structure-function associations in isolated patellofemoral osteoarthritis (PF OA).

DESIGN

Population-based study of 819 adults aged > or =50 years with knee pain. The severity of knee pain, stiffness and disability were measured using the Western Ontario and McMaster Osteoarthritis Index (WOMAC). Three radiographic views of the knee were obtained.

RESULTS

Isolated PF OA was mild in 142 participants and moderate/severe in 44. Mean WOMAC scores for pain, stiffness and function were associated with radiographic severity of PF OA (F(2,389)=4.7, P=0.01; F(2,392)=4.5, P=0.012 and F(2,392)=6.1, P=0.002, respectively, adjusted for age, gender, and body mass index (BMI)). Post-hoc tests demonstrated statistically significant differences for mean pain, stiffness and function score between those with mild PF OA and those with normal X-rays. In task-specific items there was evidence of a stepped response, the proportion of participants with moderate/severe/extreme pain or difficulty in performing everyday tasks increasing with the severity of PF OA. The strongest association was observed for pain going up and down stairs (age-gender-BMI adjusted odds ratio (OR) 3.0; 95% confidence interval (CI) 1.4,6.6. Functional tasks most strongly related to radiographic severity were: descending stairs (OR 3.2; (CI 1.5,6.5)), getting in/out of the bath (3.2; 1.5,6.6), getting in/out of a car (3.0; 1.4,6.1).

CONCLUSIONS

Mild isolated PF OA is significantly associated with symptoms of pain, stiffness and functional limitation. Further research on its recognition in clinical practice and the development of targeted treatments to prevent or slow progression are warranted.

Measurement properties of performance-specific pain ratings of patients awaiting total joint arthroplasty as a consequence of osteoarthritis

PURPOSE

To estimate the test-retest reliability of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain sub-scale and performance-specific assessments of pain, as well as the association between these measures for patients awaiting primary total hip or knee arthroplasty as a consequence of osteoarthritis.

METHODS

A total of 164 patients awaiting unilateral primary hip or knee arthroplasty completed four performance measures (self-paced walk, timed up and go, stair test, six-minute walk) and the WOMAC. Scores for 22 of these patients provided test-retest reliability data. Estimates of test-retest reliability (Type 2,1 intraclass correlation coefficient [ICC] and standard error of measurement [SEM]) and the association between measures were examined.

RESULTS

ICC values for individual performance-specific pain ratings were between 0.70 and 0.86; SEM values were between 0.97 and 1.33 pain points. ICC estimates for the four-item performance pain ratings and the WOMAC pain sub-scale were 0.82 and 0.57 respectively. The correlation between the sum of the pain scores for the four performance measures and the WOMAC pain sub-scale was 0.62.

CONCLUSION

Reliability estimates for the performance-specific assessments of pain using the numeric pain rating scale were consistent with values reported for patients with a spectrum of musculoskeletal conditions. The reliability estimate for the WOMAC pain sub-scale was lower than typically reported in the literature. The level of association between the WOMAC pain sub-scale and the various performance-specific pain scales suggests that the scores can be used interchangeably when applied to groups but not for individual patients.