The global burden of hip and knee osteoarthritis: estimates from the global burden of disease 2010 study

Intra-articular Autologous Conditioned Plasma Injections Provide Safe and Efficacious Treatment for Knee Osteoarthritis: An FDA-Sanctioned, Randomized, Double-blind, Placebo-controlled Clinical Trial

BACKGROUND

Platelet-rich plasma (PRP) injections have become an intriguing treatment option for osteoarthritis (OA), particularly OA of the knee. Despite the plethora of PRP-related citations, there is a paucity of high-level evidence that is comparable, cohort specific, dose controlled, injection protocol controlled, and double-blinded.

PURPOSE

To determine the safety and efficacy of leukocyte-poor PRP autologous conditioned plasma (ACP) for knee OA treatment through a feasibility trial regulated by the US Food and Drug Administration (FDA).

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

In accordance with FDA protocol, patient selection was based on strict inclusion/exclusion criteria; 114 patients were screened, and 30 were ultimately included in the study. These patients were randomized to receive either ACP (n = 15) or saline placebo (n = 15) for a series of 3 weekly injections. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores served as the primary efficacy outcome measure. Patients were followed for 1 year.

RESULTS

No adverse events were reported for ACP administration. Furthermore, the results demonstrated no statistically significant difference in baseline WOMAC scores between the 2 groups. However, in the ACP group, WOMAC scores at 1 week were significantly decreased compared with baseline scores, and the scores for this group remained significantly lower throughout the study duration. At the study conclusion (12 months), subjects in the ACP group had improved their overall WOMAC scores by 78% from their baseline score, compared with 7% for the placebo group.

CONCLUSION

ACP is safe and provides quantifiable benefits for pain relief and functional improvement with regard to knee OA. No adverse events were reported for ACP administration. After 1 year, WOMAC scores for the ACP subjects had improved by 78% from their baseline score, whereas scores for the placebo control group had improved by only 7%. Other joints affected with OA may also benefit from this treatment.

Does increasing applied load lead to contact changes indicative of knee osteoarthritis? A subject-specific FEA study

This study investigated whether increased loading (representing obesity) in the extended knee and flexed knee led to increased stresses in areas of typical medial and lateral osteoarthritis cartilage lesions, respectively. We created two paired sets of subject-specific finite element models; both sets included models of extended knees and of flexed knees. The first set represented normal loading; the second set represented increased loading. All other variables were held constant. The von Mises stresses and contact areas calculated on the tibial cartilage surfaces of the paired models were then compared. In the extended knee models, applying a larger load led to increased stress in the anterior and central regions of the medial tibial cartilage. These are the typical locations of medial osteoarthritis cartilage lesions. Therefore, the results support that increased loading in the extended knee may result in medial osteoarthritis. In the flexed knee models, applying a larger load increased stress in the anterior and central regions of the lateral tibial cartilage. Lateral osteoarthritis cartilage lesions typically occur centrally and posteriorly. Therefore, these results do not support our hypothesis. Shear stress was increased in areas of typical lateral lesions, however, and should be investigated in future studies.

Validity and reliability of Internet-based physiotherapy assessment for musculoskeletal disorders: a systematic review

Purpose The purpose of this review is to systematically explore and summarise the validity and reliability of telerehabilitation (TR)-based physiotherapy assessment for musculoskeletal disorders. Method A comprehensive systematic literature review was conducted using a number of electronic databases: PubMed, EMBASE, PsycINFO, Cochrane Library and CINAHL, published between January 2000 and May 2015. The studies examined the validity, inter- and intra-rater reliabilities of TR-based physiotherapy assessment for musculoskeletal conditions were included. Two independent reviewers used the Quality Appraisal Tool for studies of diagnostic Reliability (QAREL) and the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool to assess the methodological quality of reliability and validity studies respectively. Results A total of 898 hits were achieved, of which 11 articles based on inclusion criteria were reviewed. Nine studies explored the concurrent validity, inter- and intra-rater reliabilities, while two studies examined only the concurrent validity. Reviewed studies were moderate to good in methodological quality. The physiotherapy assessments such as pain, swelling, range of motion, muscle strength, balance, gait and functional assessment demonstrated good concurrent validity. However, the reported concurrent validity of lumbar spine posture, special orthopaedic tests, neurodynamic tests and scar assessments ranged from low to moderate. Conclusion TR-based physiotherapy assessment was technically feasible with overall good concurrent validity and excellent reliability, except for lumbar spine posture, orthopaedic special tests, neurodynamic testa and scar assessment.

Aquatic exercise for the treatment of knee and hip osteoarthritis

BACKGROUND

Osteoarthritis is a chronic disease characterized by joint pain, tenderness, and limitation of movement. At present, no cure is available. Thus only treatment of the person's symptoms and treatment to prevent further development of the disease are possible. Clinical trials indicate that aquatic exercise may have advantages for people with osteoarthritis. This is an update of a published Cochrane review.

OBJECTIVES

To evaluate the effects of aquatic exercise for people with knee or hip osteoarthritis, or both, compared to no intervention.

SEARCH METHODS

We searched the following databases up to 28 April 2015: the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library Issue 1, 2014), MEDLINE (from 1949), EMBASE (from 1980), CINAHL (from 1982), PEDro (Physiotherapy Evidence Database), and Web of Science (from 1945). There was no language restriction.

SELECTION CRITERIA

Randomized controlled clinical trials of aquatic exercise compared to a control group (e.g. usual care, education, social attention, telephone call, waiting list for surgery) of participants with knee or hip osteoarthritis.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, extracted data and assessed risk of bias of the included trials. We analysed the pooled results using standardized mean difference (SMD) values.

MAIN RESULTS

Nine new trials met the inclusion criteria and we excluded two earlier included trials. Thus the number of participants increased from 800 to 1190 and the number of included trials increased from six to 13. Most participants were female (75%), with an average age of 68 years and a body mass index (BMI) of 29.4. Osteoarthritis duration was 6.7 years, with a great variation of the included participants. The mean aquatic exercise duration was 12 weeks. We found 12 trials at low to unclear risk of bias for all domains except blinding of participants and personnel. They showed that aquatic exercise caused a small short term improvement compared to control in pain (SMD -0.31, 95% CI -0.47 to -0.15; 12 trials, 1076 participants) and disability (SMD -0.32, 95% CI -0.47 to -0.17; 12 trials, 1059 participants). Ten trials showed a small effect on quality of life (QoL) (SMD -0.25, 95% CI -0.49 to -0.01; 10 trials, 971 participants). These effects on pain and disability correspond to a five point lower (95% CI three to eight points lower) score on mean pain and mean disability compared to the control group (scale 0 to 100), and a seven point higher (95% CI 0 to 13 points higher) score on mean QoL compared with control group (scale 0 to 100). No included trials performed a radiographic evaluation. No serious adverse events were reported in the included trials with relation to aquatic exercise.

AUTHORS' CONCLUSIONS

There is moderate quality evidence that aquatic exercise may have small, short-term, and clinically relevant effects on patient-reported pain, disability, and QoL in people with knee and hip OA. The conclusions of this review update does not change those of the previous published version of this Cochrane review.

Patient-Reported Measures of Physical Function in Knee Osteoarthritis

Knee osteoarthritis is a common cause of an array of functional limitations in older adults, and the accurate assessment of such limitations is critical for practicing clinicians and scientists. Patient-reported measures are a valuable resource to track the type and severity of limitation, although the psychometric performance of each instrument should be thoroughly evaluated before adoption. This article reviews the validity, reliability, sensitivity to change, and responsiveness of 3 patient-reported measures of physical function: the Western Ontario and McMaster Universities Osteoarthritis Index, the Knee Injury and Osteoarthritis Outcome Score, and the Patient Reported Outcomes Measurement Information System Physical Function scale.

Patterns of Coexisting Lesions Detected on Magnetic Resonance Imaging and Relationship to Incident Knee Osteoarthritis: The Multicenter Osteoarthritis Study

OBJECTIVE

To identify patterns of coexisting lesions seen on magnetic resonance imaging (MRI) in knees that are free of radiographic osteoarthritis (OA) and to examine the relationship of these MRI-detected lesions to incident OA.

METHODS

Study subjects were individuals enrolled in the Multicenter Osteoarthritis Study, a prospective cohort study. In each subject, 1 knee in which radiographic OA was absent in both the tibiofemoral and patellofemoral joints at baseline was selected for study, with followup for 84 months. We used a novel approach, latent class analysis, to group the constellation of MRI lesions in each joint, i.e., cartilage damage, bone marrow lesion, meniscal tear, meniscal extrusion, synovitis, and effusion, into a manageable number of subgroups. The association of these subgroups with incident radiographic OA in the same joint was assessed using logistic regression.

RESULTS

Among 885 eligible knees (203 with incident disease in the tibiofemoral joint, 64 with incident disease in the patellofemoral joint), 4 latent subgroups in the tibiofemoral joint were identified (described briefly as minimal lesions, mild lesions, moderate lesions [but limited meniscal lesions], and severe lesions). The odds ratios of incident tibiofemoral joint OA in the latter 3 subgroups (compared to the knees with minimal lesions as the referent) were 5.6, 1.8, and 5.0, respectively. A similar set of 4 subgroups in the patellofemoral joint was identified, except that the fourth subgroup had limited meniscal lesions. The odds ratios of incident disease in the patellofemoral joint were 3.8, 5.1, and 13.7 in the subgroups with mild lesions, moderate lesions, and severe lesions, respectively.

CONCLUSION

Different patterns of coexisting MRI lesions, which have different implications with regard to risk of knee OA, were identified. Meniscal damage seemed to play a different role in the development of incident disease in tibiofemoral versus patellofemoral joints.

Re-Infection Outcomes Following One- And Two-Stage Surgical Revision of Infected Knee Prosthesis: A Systematic Review and Meta-Analysis

BACKGROUND

Periprosthetic joint infection (PJI) is a serious complication of total knee arthroplasty. Two-stage revision is the most widely used technique and considered as the most effective for treating periprosthetic knee infection. The one-stage revision strategy is an emerging alternative option, however, its performance in comparison to the two-stage strategy is unclear. We therefore sought to ask if there was a difference in re-infection rates and other clinical outcomes when comparing the one-stage to the two-stage revision strategy.

OBJECTIVE

Our first objective was to compare re-infection (new and recurrent infections) rates for one- and two-stage revision surgery for periprosthetic knee infection. Our second objective was to compare between the two revision strategies, clinical outcomes as measured by postoperative Knee Society Knee score, Knee Society Function score, Hospital for Special Surgery knee score, WOMAC score, and range of motion.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, EMBASE, Web of Science, Cochrane Library, reference lists of relevant studies to August 2015, and correspondence with investigators.

STUDY SELECTION

Longitudinal (prospective or retrospective cohort) studies conducted in generally unselected patients with periprosthetic knee infection treated exclusively by one- or two-stage revision and with re-infection outcomes reported within two years of revision surgery. No clinical trials comparing both revision strategies were identified.

REVIEW METHODS

Two independent investigators extracted data and discrepancies were resolved by consensus with a third investigator. Re-infection rates from 10 one-stage studies (423 participants) and 108 two-stage studies (5,129 participants) were meta-analysed using random-effect models after arcsine transformation.

RESULTS

The rate (95% confidence intervals) of re-infection was 7.6% (3.4-13.1) in one-stage studies. The corresponding re-infection rate for two-stage revision was 8.8% (7.2-10.6). In subgroup analyses, re-infection rates remained generally similar for several study-level and clinically relevant characteristics. Postoperative clinical outcomes of knee scores and range of motion were similar for both revision strategies.

LIMITATIONS

Potential bias owing to the limited number of one-stage revision studies and inability to explore heterogeneity in greater detail.

CONCLUSIONS

Available evidence from aggregate published data suggest the one-stage revision strategy may be as effective as the two-stage revision strategy in treating infected knee prostheses in generally unselected patients. Further investigation is warranted.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2015: CRD42015017327.

Disability in Adolescents and Adults Diagnosed With Hypermobility-Related Disorders: A Meta-Analysis

OBJECTIVE

To (1) establish the association of the most common reported symptoms on disability; and (2) study the effectiveness of treatment on disability in patients with Ehlers-Danlos syndrome-hypermobility type (EDS-HT)/hypermobility syndrome (HMS).

DATA SOURCES

An electronic search (Medical Subject Headings and free-text terms) was conducted in bibliographic databases CENTRAL/MEDLINE.

STUDY SELECTION

Comparative, cross-sectional, longitudinal cohort studies and (randomized) controlled trials including patients with HMS/EDS-HT aged ≥17 years were considered for inclusion. A class of symptoms was included when 5 publications were available. In regards to treatment (physical, cognitive interventions), only (randomized) controlled trials were considered. Surgical and medicinal interventions were excluded.

DATA EXTRACTION

Bias was assessed according to the methodological scoring tools of the Cochrane collaboration. Z-score transformations were applied to classify the extent of disability in comparison with healthy controls and to ensure comparability between studies.

DATA SYNTHESIS

Initially, the electronic search yielded 714 publications, and 21 articles remained for analysis after selection. The following symptoms were included for meta-analysis: pain (n=12), fatigue (n=6), and psychological distress (n=7). Pain (r=.64, P=.021), fatigue (r=.91, P=.011), and psychological distress (r=.86, P=.018) had a significant impact on disability. Regarding treatment, a significant pain reduction was achieved by a variety of physical and cognitive approaches. Treatment effectiveness on disability was not established.

CONCLUSIONS

Disability can affect patients with HMS/EDS-HT significantly and is highly correlated with both physical and psychological factors. Although evidence is available that physical and psychological treatment modalities can induce significant pain reduction, the evidence regarding disability reduction is lacking.

Why don't patients take their analgesics? A meta-ethnography assessing the perceptions of medication adherence in patients with osteoarthritis

Whilst analgesics and medications have demonstrated efficacy for people with osteoarthritis, their effectiveness is dependent on adherence. This has previously been reported as particularly low in this population. The purpose of this meta-ethnography was to explore possible perceptions for this. A systematic review of published and unpublished literature was undertaken. All qualitative studies assessing the attitudes or perceptions of people with osteoarthritis towards medication adherence were eligible. Study quality was assessed using the Critical Appraisal Skills Programme qualitative tool. Analysis was undertaken using a meta-ethnography approach, distilling to a third-order construct and developing a line of argument. From 881 citations, five studies met the eligibility criteria. The meta-ethnography generated a model where medication adherence for people with osteoarthritis is perceived as a balance between the willingness and preference to take medications with the alterative being toleration of symptoms. Motivators to influence this 'balance' may fluctuate and change over time but include: severity of symptoms, education and understanding of osteoarthritis and current medications, or general health which may raise issues for poly-pharmacy as other medications are added or substituted into the patient's formulary. Medicine adherence in people with osteoarthritis is complex, involving motivators which will fluctuate in impact on individuals at different points along the disease progression. Awareness of each motivator may better inform clinicians as to what education, support or change in prescription practice should be adopted to ensure that medicine adherence is individualised to better promote long-term behaviour change.

Patient-Related Risk Factors for Periprosthetic Joint Infection after Total Joint Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Periprosthetic joint infections (PJIs) are dreaded complications of total joint arthroplasties. The risk of developing PJIs is likely to be influenced by several patient factors such as sociodemographic characteristics, body mass index (BMI), and medical and surgical histories. However, the nature and magnitude of the long-term longitudinal associations between these patient-related factors and risk of developing PJIs are uncertain.

OBJECTIVE

To conduct a systematic review and meta-analysis to assess the associations between several patient-related factors and PJI.

DATA SOURCES

MEDLINE, EMBASE, Web of Science, Cochrane Library, and reference lists of relevant studies from inception to September 2015.

STUDY SELECTION

Longitudinal studies with at least one-year of follow-up for PJIs after total joint arthroplasty.

DATA EXTRACTION AND SYNTHESIS

Two investigators extracted data on study characteristics, methods, and outcomes. A consensus was reached with involvement of a third. The relative risk (RR) with 95% confidence intervals was used as the summary measure of association across studies. Study-specific RRs with 95% confidence intervals were meta-analysed using random effect models and were grouped by study-level characteristics.

RESULTS

Sixty-six observational (23 prospective cohort and 43 retrospective cohort or case-control) studies with data on 512,508 participants were included. Comparing males to females and smokers to non-smokers, the pooled RRs for PJI were 1.36 (1.18-1.57) and 1.83 (1.24-2.70) respectively. There was no evidence of any significant associations of PJI with age and high alcohol intake. Comparing BMI ≥ 30 versus < 30 kg/m(2); ≥ 35 versus < 35 kg/m(2); and ≥ 40 versus < 40 kg/m(2); the pooled RRs were 1.60 (1.29-1.99); 1.53 (1.22-1.92); and 3.68 (2.25-6.01) respectively. Histories of diabetes, rheumatoid arthritis, depression, steroid use, and previous joint surgery were also associated with increased risk of PJI. The results remained similar when grouped by relevant study level characteristics.

CONCLUSIONS

Several potentially modifiable patient-related factors are associated with the risk of developing PJIs. Identifying patients with these risk factors who are due to have arthroplasty surgery and modulating these risk factors might be essential in reducing the incidence of PJI. Further research is however warranted to assess the potential clinical utility of these risk factors as risk assessment tools for PJI.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2015: CRD42015023485.

Comparison of Diagnostic Performance of Semi-Quantitative Knee Ultrasound and Knee Radiography with MRI: Oulu Knee Osteoarthritis Study

Osteoarthritis (OA) is a common degenerative musculoskeletal disease highly prevalent in aging societies worldwide. Traditionally, knee OA is diagnosed using conventional radiography. However, structural changes of articular cartilage or menisci cannot be directly evaluated using this method. On the other hand, ultrasound is a promising tool able to provide direct information on soft tissue degeneration. The aim of our study was to systematically determine the site-specific diagnostic performance of semi-quantitative ultrasound grading of knee femoral articular cartilage, osteophytes and meniscal extrusion, and of radiographic assessment of joint space narrowing and osteophytes, using MRI as a reference standard. Eighty asymptomatic and 79 symptomatic subjects with mean age of 57.7 years were included in the study. Ultrasound performed best in the assessment of femoral medial and lateral osteophytes, and medial meniscal extrusion. In comparison to radiography, ultrasound performed better or at least equally well in identification of tibio-femoral osteophytes, medial meniscal extrusion and medial femoral cartilage morphological degeneration. Ultrasound provides relevant additional diagnostic information on tissue-specific morphological changes not depicted by conventional radiography. Consequently, the use of ultrasound as a complementary imaging tool along with radiography may enable more accurate and cost-effective diagnostics of knee osteoarthritis at the primary healthcare level.

The relationship between smoking and knee osteoarthritis in the Osteoarthritis Initiative

OBJECTIVE

To estimate the extent that smoking history is associated with symptoms and disease progression among individuals with radiographically confirmed knee Osteoarthritis (OA).

METHOD

Both cross-sectional (baseline) and longitudinal studies employed data from the Osteoarthritis Initiative (OAI) (n = 2250 participants). Smoking history was assessed at baseline with 44% current or former smokers. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) was used to measure knee pain, stiffness, and physical function. Disease progression was measured using joint space width (JSW). We used adjusted multivariable linear models to examine the relationship between smoking status and exposure in pack years (PY) with symptoms and JSW at baseline. Changes in symptoms and JSW over time were further assessed.

RESULTS

In cross-sectional analyses, compared to never-smokers high PY (≥15 PY) was associated with slightly greater pain (beta 0.36, 95% CI: 0.01-0.71) and stiffness (beta 0.20, 95% CI: 0.03-0.37); and low PY (<15 PY) was associated with better JSW (beta 0.15, 95% CI: 0.02-0.28). Current smoking was associated with greater pain (beta 0.59, 95% CI: 0.04-1.15) compared to never-smokers. These associations were not confirmed in the longitudinal study. Longitudinally, no associations were found between high or low PY or baseline smoking status with changes in symptoms (at 72 months) or JSW (at 48 months).

CONCLUSION

Cross-sectional findings are likely due residual confounding. The more robust longitudinal analysis found no associations between smoking status and symptoms or JSW. Long-term smoking provides no benefits to knee OA patients while exposing them to other well-documented serious health risks.

Evaluation of cell-laden polyelectrolyte hydrogels incorporating poly(L-Lysine) for applications in cartilage tissue engineering

To address the lack of reliable long-term solutions for cartilage injuries, strategies in tissue engineering are beginning to leverage developmental processes to spur tissue regeneration. This study focuses on the use of poly(L-lysine) (PLL), previously shown to up-regulate mesenchymal condensation during developmental skeletogenesis in vitro, as an early chondrogenic stimulant of mesenchymal stem cells (MSCs). We characterized the effect of PLL incorporation on the swelling and degradation of oligo(poly(ethylene) glycol) fumarate) (OPF)-based hydrogels as functions of PLL molecular weight and dosage. Furthermore, we investigated the effect of PLL incorporation on the chondrogenic gene expression of hydrogel-encapsulated MSCs. The incorporation of PLL resulted in early enhancements of type II collagen and aggrecan gene expression and type II/type I collagen expression ratios when compared to blank controls. The presentation of PLL to MSCs encapsulated in OPF hydrogels also enhanced N-cadherin gene expression under certain culture conditions, suggesting that PLL may induce the expression of condensation markers in synthetic hydrogel systems. In summary, PLL can function as an inductive factor that primes the cellular microenvironment for early chondrogenic gene expression but may require additional biochemical factors for the generation of fully functional chondrocytes.

The use of self-report questions to examine the prevalence of musculoskeletal problems: a test-retest study

Background

Case definition has long been an issue for comparability of results obtained for musculoskeletal pain prevalence, however the test-retest reliability of questions used to determine joint pain prevalence has not been examined. The objective of this study was to determine question reliability and the impact of question wording, ordering and the time between questions on responses.

Methods

A Computer Assisted Telephone Interviewing (CATI) survey was used to re-administer questions collected as part of a population-based longitudinal cohort study. On two different occasions questions were asked of the same sample of 203 community dwelling respondents (which were initially randomly selected) aged 18 years and over at two time points 14 to 27 days apart (average 15 days). Reliability of the questions was assessed using Cohen’s kappa (κ) and intraclass correlation coefficient (ICC) and whether question wording and period effects existed was assessed using a crossover design.

Results

The self-reported prevalence of doctor diagnosed arthritis demonstrated excellent reliability (κ = 0.84 and κ = 0.79 for questionnaires 1 and 2 respectively). The reliability of questions relating to musculoskeletal pain and/or stiffness ranged from moderate to excellent for both types of questions, that is, those related to ever having joint pain on most days for at least a month (κ = 0.52 to κ = 0.95) and having pain and/or stiffness on most days for the last month (κ = 0.52 to κ = 0.90). However there was an effect of question wording on the results obtained for hand, foot and back pain and/or stiffness indicating that the area of pain may influence prevalence estimates.

Conclusions

Joint pain and stiffness questions are reliable and can be used to determine prevalence. However, question wording and pain area may impact on estimates with issues such as pain perception and effect on activities playing a possible role in the recall of musculoskeletal pain.

Leisure time physical activity and the risk of hip or knee replacement due to primary osteoarthritis: a population based cohort study (The HUNT Study)

BACKGROUND

The relationship between leisure time physical activity (LPA) and hip and knee OA and subsequent joint replacement has not yet been clearly defined. Some studies have found the risk of knee replacement (TKR) to increase with high levels of LPA, while others have found no overall relationship to either TKR or hip replacement (THR). The aim was to investigate the association between LPA and the risk of severe end-stage OA, defined as THR or TKR due to primary OA, in a large population-based cohort.

METHODS

Participants in the Nord-Trøndelag Health Study (HUNT) were followed prospectively to identify THR and TKR using the Norwegian Arthroplasty Register. Self-reported LPA was classified as inactive, low, moderate or high. The Cox proportional hazards model was used to calculate hazard ratios (HRs) according to levels of LPA with adjustments for confounding variables. Analyses were performed by age (<45, 45-59 and ≥60 years) and sex.

RESULTS

A total of 66 964 participants (mean age 46.8 years (SD 16.3) were included in the analyses. We identified 1636 THRs and 1016 TKRs due to primary OA during 17.0 years (median) of follow-up. High LPA was significantly associated with THR for women <45 years (HR 1.78, 95 % CI 1.08-2.94) and men between 45-59 years (HR 1.53, 95 % CI 1.10-2.13) at baseline. A significant trend was found only among women < 45 years at baseline (p = 0.02). We found that LPA was significantly associated with TKR for women only (HR 1.45, 95 % CI 1.03-2.04). No measures of LPA were associated with TKR for men.

CONCLUSION

In this population-based study, high level of LPA was associated with increased risk of THR where a significant trend of LPA was seen among women <45 years at baseline. For TKR, high LPA was associated with increased risk only in women. In contrast to previous studies, this study shows a possible association between high LPA and the risk of THR.

Novel Elements of the Chondrocyte Stress Response Identified Using an in Vitro Model of Mouse Cartilage Degradation

The destruction of articular cartilage in osteoarthritis involves chondrocyte dysfunction and imbalanced extracellular matrix (ECM) homeostasis. Pro-inflammatory cytokines such as interleukin-1α (IL-1α) contribute to osteoarthritis pathophysiology, but the effects of IL-1α on chondrocytes within their tissue microenvironment have not been fully evaluated. To redress this we used label-free quantitative proteomics to analyze the chondrocyte response to IL-1α within a native cartilage ECM. Mouse femoral heads were cultured with and without IL-1α, and both the tissue proteome and proteins released into the media were analyzed. New elements of the chondrocyte response to IL-1α related to cellular stress included markers for protein misfolding (Armet, Creld2, and Hyou1), enzymes involved in glutathione biosynthesis and regeneration (Gstp1, Gsto1, and Gsr), and oxidative stress proteins (Prdx2, Txn, Atox1, Hmox1, and Vnn1). Other proteins previously not associated with the IL-1α response in cartilage included ECM components (Smoc2, Kera, and Crispld1) and cysteine proteases (cathepsin Z and legumain), while chondroadherin and cartilage-derived C-type lectin (Clec3a) were identified as novel products of IL-1α-induced cartilage degradation. This first proteome-level view of the cartilage IL-1α response identified candidate biomarkers of cartilage destruction and novel targets for therapeutic intervention in osteoarthritis.

Intra-Articular Corticosteroids in Addition to Exercise for Reducing Pain Sensitivity in Knee Osteoarthritis: Exploratory Outcome from a Randomized Controlled Trial

OBJECTIVE

To assess the effects of one intra-articular corticosteroid injection two weeks prior to an exercise-based intervention program for reducing pain sensitivity in patients with knee osteoarthritis (OA).

DESIGN

Randomized, masked, parallel, placebo-controlled trial involving 100 participants with clinical and radiographic knee OA that were randomized to one intra-articular injection on the knee with either 1 ml of 40 mg/ml methylprednisolone (corticosteroid) dissolved in 4 ml lidocaine (10 mg/ml) or 1 ml isotonic saline (placebo) mixed with 4 ml lidocaine (10 mg/ml). Two weeks after the injections all participants undertook a 12-week supervised exercise program. Main outcomes were changes from baseline in pressure-pain sensitivity (pressure-pain threshold [PPT] and temporal summation [TS]) assessed using cuff pressure algometry on the calf. These were exploratory outcomes from a randomized controlled trial.

RESULTS

A total of 100 patients were randomized to receive either corticosteroid (n = 50) or placebo (n = 50); 45 and 44, respectively, completed the trial. Four participants had missing values for PPT and one for TS at baseline; thus modified intention-to-treat populations were analyzed. The mean group difference in changes from baseline at week 14 was 0.6 kPa (95% CI: -1.7 to 2.8; P = 0.626) for PPT and 384 mm×sec (95% CI: -2980 to 3750; P = 0.821) for TS.

CONCLUSIONS

These results suggest that adding intra-articular corticosteroid injection 2 weeks prior to an exercise program does not provide additional benefits compared to placebo in reducing pain sensitivity in patients with knee OA.

TRIAL REGISTRATION

EU clinical trials (EudraCT): 2012-002607-18.

Damage-associated molecular patterns generated in osteoarthritis directly excite murine nociceptive neurons through Toll-like receptor 4

OBJECTIVE

To determine whether selected damage-associated molecular patterns (DAMPs) present in the osteoarthritic (OA) joints of mice excite nociceptors through Toll-like receptor 4 (TLR-4).

METHODS

The ability of S100A8 and α2 -macroglobulin to excite nociceptors was determined by measuring the release of monocyte chemoattractant protein 1 (MCP-1) by cultured dorsal root ganglion (DRG) cells as well as by measuring the intracellular calcium concentration ([Ca(2+) ]i ) in cultured DRG neurons from naive mice or from mice that had undergone surgical destabilization of the medial meniscus (DMM) 8 weeks previously. The role of TLR-4 was assessed using TLR-4(-/-) cells or a TLR-4 inhibitor. The [Ca(2+) ]i in neurons within ex vivo intact DRGs was measured in samples from Pirt-GCaMP3 mice. Neuronal expression of the Tlr4 gene was determined by in situ hybridization. DMM surgery was performed in wild-type and TLR-4(-/-) mice; mechanical allodynia was monitored, and joint damage was assessed histologically after 16 weeks.

RESULTS

DRG neurons from both naive and DMM mice expressed Tlr4. Both S100A8 and α2 -macroglobulin stimulated release of the proalgesic chemokine MCP-1 in DRG cultures, and the neurons rapidly responded to S100A8 and α2 -macroglobulin with increased [Ca(2+) ]i . Blocking TLR-4 inhibited these effects. Neurons within intact DRGs responded to the TLR-4 agonist lipopolysaccharide. In both of the calcium-imaging assays, it was primarily the nociceptor population of neurons that responded to TLR-4 ligands. TLR-4(-/-) mice were not protected from mechanical allodynia or from joint damage associated with DMM.

CONCLUSION

Our experiments suggest a role of TLR-4 signaling in the excitation of nociceptors by selected DAMPs. Further research is needed to delineate the importance of this pathway in relation to OA pain.

Serum Calcium Concentration Is Inversely Associated With Radiographic Knee Osteoarthritis: A Cross-Sectional Study

To examine the relationship between serum calcium (Ca) concentration and radiographic knee osteoarthritis (OA).This study covered a total of 2855 subjects. The serum Ca concentration was detected by the Arsenazo III method. The radiographic OA of the knee was defined as changes equivalent to Kellgren-Lawrence grade 2 on 1 side at least. The serum Ca concentration was categorized into 4 quartiles, which are ≤2.27, 2.28-2.34, 2.35-2.41, and ≥2.42 mmol/L, respectively. The relationship between serum Ca and radiographic knee OA was examined using the multivariable logistic analysis after adjusting a series of potential confounding factors. For each quartile of the relationship between serum Ca concentration and radiographic knee OA, the OR with 95% CI was calculated, and the one with the lowest value was considered to be the reference.An inverse association existed between serum Ca concentration and radiographic OA of the knee in the multivariable model and the model where the factors of age, sex, and BMI were adjusted. The multivariable-adjusted OR (95% CI) for radiographic knee OA in the second, third, and fourth quartiles of serum Ca concentration were 1.05 (95% CI: 0.83-1.31), 1.01 (95% CI: 0.80-1.27), and 0.79 (95% CI: 0.62-1.00), respectively, in comparison with the reference (first) quartile. A trend approaching to statistical significant (P = 0.06) was observed. Meanwhile, the relative odds of radiographic OA of the knee were decreased by 0.79 times in the fourth quartile in comparison with the reference.There is likely to be an inverse association between serum Ca concentration and radiographic OA of the knee.

Prospective change in daily walking over 2 years in older adults with or at risk of knee osteoarthritis: the MOST study

OBJECTIVE

Radiographic disease and knee pain are thought to decrease physical activity in people with knee osteoarthritis (OA), but this has not been formally studied. We examined change in objectively measured daily walking over 2 years and evaluated the association of certain risk factors with reduced walking among adults with or at risk of knee OA.

DESIGN

Steps/day over 7 days were collected at baseline and 2 years later in subjects with or at risk of knee OA from the Multicenter Osteoarthritis Study using a StepWatch. We evaluated the presence of radiographic knee osteoarthritis (ROA), knee pain, worsening of ROA and pain over 2 years, obesity, depressive symptoms, living situation, catastrophizing, fatigue, widespread pain and comorbidities with 2-year change in daily walking using regression models adjusted for potential confounders.

RESULTS

1318 met inclusion criteria (age 66.9 ± 7.7, 59% women, BMI 30.6 ± 5.9) and walked 126 ± 1700 steps/day fewer steps at 2 years (95% CI [-218, -35]). People with depressive symptoms at baseline walked 455 fewer steps/day [-872, -68], and there was a trend for people with ROA worsening to walk 183 fewer steps/day [-377.5, 11.7]. No other factors met statistical significance for change in daily walking.

CONCLUSION

Adults with or at risk of knee OA experienced only minimal declines in daily walking over 2 years. Nonetheless, depressive symptoms and may be worsening ROA are associated with a decline in steps/day in adults with or at risk of knee OA.

Theory-driven group-based complex intervention to support self-management of osteoarthritis and low back pain in primary care physiotherapy: protocol for a cluster randomised controlled feasibility trial (SOLAS)

INTRODUCTION

International clinical guidelines consistently endorse the promotion of self-management (SM), including physical activity for patients with chronic low back pain (CLBP) and osteoarthritis (OA). Patients frequently receive individual treatment and advice to self-manage from physiotherapists in primary care, but the successful implementation of a clinical and cost-effective group SM programme is a key priority for health service managers in Ireland to maximise long-term outcomes and efficient use of limited and costly resources.

METHODS/ANALYSIS

This protocol describes an assessor-blinded cluster randomised controlled feasibility trial of a group-based education and exercise intervention underpinned by self-determination theory designed to support an increase in SM behaviour in patients with CLBP and OA in primary care physiotherapy. The primary care clinic will be the unit of randomisation (cluster), with each clinic randomised to 1 of 2 groups providing the Self-management of Osteoarthritis and Low back pain through Activity and Skills (SOLAS) intervention or usual individual physiotherapy. Patients are followed up at 6 weeks, 2 and 6 months. The primary outcomes are the (1) acceptability and demand of the intervention to patients and physiotherapists, (2) feasibility and optimal study design/procedures and sample size for a definitive trial. Secondary outcomes include exploratory analyses of: point estimates, 95% CIs, change scores and effect sizes in physical function, pain and disability outcomes; process of change in target SM behaviours and selected mediators; and the cost of the intervention to inform a definitive trial.

ETHICS/DISSEMINATION

This feasibility trial protocol was approved by the UCD Human Research Ethics-Sciences Committee (LS-13-54 Currie-Hurley) and research access has been granted by the Health Services Executive Primary Care Research Committee in January 2014. The study findings will be disseminated to the research, clinical and health service communities through publication in peer-reviewed journals, presentation at national and international academic and clinical conferences.

TRIAL REGISTRATION NUMBER

ISRCTN 49875385; Pre-results.

Prevalence of rheumatic and musculoskeletal diseases and their impact on health-related quality of life, physical function and mental health in Portugal: results from EpiReumaPt- a national health survey

OBJECTIVES

To estimate the national prevalence of rheumatic and musculoskeletal diseases (RMDs) in the adult Portuguese population and to determine their impact on health-related quality of life (HRQoL), physical function, anxiety and depression.

METHODS

EpiReumaPt is a national health survey with a three-stage approach. First, 10 661 adult participants were randomly selected. Trained interviewers undertook structured face-to-face questionnaires that included screening for RMDs and assessments of health-related quality of life, physical function, anxiety and depression. Second, positive screenings for ≥1 RMD plus 20% negative screenings were invited to be evaluated by a rheumatologist. Finally, three rheumatologists revised all the information and confirmed the diagnoses according to validated criteria. Estimates were computed as weighted proportions, taking the sampling design into account.

RESULTS

The disease-specific prevalence rates (and 95% CIs) of RMDs in the adult Portuguese population were: low back pain, 26.4% (23.3% to 29.5%); periarticular disease, 15.8% (13.5% to 18.0%); knee osteoarthritis (OA), 12.4% (11.0% to 13.8%); osteoporosis, 10.2% (9.0% to 11.3%); hand OA, 8.7% (7.5% to 9.9%); hip OA, 2.9% (2.3% to 3.6%); fibromyalgia, 1.7% (1.1% to 2.1%); spondyloarthritis, 1.6% (1.2% to 2.1%); gout, 1.3% (1.0% to 1.6%); rheumatoid arthritis, 0.7% (0.5% to 0.9%); systemic lupus erythaematosus, 0.1% (0.1% to 0.2%) and polymyalgia rheumatica, 0.1% (0.0% to 0.2%). After multivariable adjustment, participants with RMDs had significantly lower EQ5D scores (β=-0.09; p<0.001) and higher HAQ scores (β=0.13; p<0.001) than participants without RMDs. RMDs were also significantly associated with the presence of anxiety symptoms (OR=3.5; p=0.006).

CONCLUSIONS

RMDs are highly prevalent in Portugal and are associated not only with significant physical function and mental health impairment but also with poor HRQoL, leading to more health resource consumption. The EpiReumaPt study emphasises the burden of RMDs in Portugal and the need to increase RMD awareness, being a strong argument to encourage policymakers to increase the amount of resources allocated to the treatment of rheumatic patients.

Associations between dietary antioxidants intake and radiographic knee osteoarthritis

The aim of the study is to examine the cross-sectional associations between dietary antioxidants (carotenoid, vitamin C, E, and selenium) intake and radiographic knee osteoarthritis (OA). A total of 4685 participants were included in this study. Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire. Radiographic knee OA was defined as Kellgren-Lawrence (K-L) grade 2 in at least one leg. A multivariable logistic analysis model was established to test the relationship between dietary antioxidants (carotenoid, vitamin C, E, and selenium) intake and radiographic knee OA with adjustment of a number of potential confounding factors. A significant positive association between dietary vitamin C intake (P value for trend was 0.04 in multivariable adjusted analysis) and radiographic knee OA was observed. The relative odds of radiographic knee OA were increased by 0.39 times in the third quintile (OR 1.39, 95 % CI 1.11-1.73), 0.42 times in the fourth quintile (OR 1.42, 95 % CI 1.13-1.79), and 0.33 times in the fifth quintile (OR 1.33, 95 % CI 1.03-1.71). However, radiographic knee OA was not significantly associated with dietary carotenoid, vitamin E, and selenium. Among dietary antioxidants, dietary vitamin C intake was positively correlated with the prevalence of radiographic knee OA, while no significant association was found between dietary intake of carotenoid, vitamin E, and selenium and the prevalence of radiographic knee OA.

Messenger RNA delivery of a cartilage-anabolic transcription factor as a disease-modifying strategy for osteoarthritis treatment

Osteoarthritis (OA) is a chronic degenerative joint disease and a major health problem in the elderly population. No disease-modifying osteoarthritis drug (DMOAD) has been made available for clinical use. Here we present a disease-modifying strategy for OA, focusing on messenger RNA (mRNA) delivery of a therapeutic transcription factor using polyethylene glycol (PEG)-polyamino acid block copolymer-based polyplex nanomicelles. When polyplex nanomicelles carrying the cartilage-anabolic, runt-related transcription factor (RUNX) 1 mRNA were injected into mouse OA knee joints, OA progression was significantly suppressed compared with the non-treatment control. Expressions of cartilage-anabolic markers and proliferation were augmented in articular chondrocytes of the RUNX1-injected knees. Thus, this study provides a proof of concept of the treatment of degenerative diseases such as OA by the in situ mRNA delivery of therapeutic transcription factors; the presented approach will directly connect basic findings on disease-protective or tissue-regenerating factors to disease treatment.

Efficacy and safety of diclofenac sodium 2% topical solution for osteoarthritis of the knee: a randomized, double-blind, vehicle-controlled, 4 week study

OBJECTIVE

Nonsteroidal anti-inflammatory drugs (NSAIDs) are standard therapy for osteoarthritis (OA). Topically applied NSAIDs reduce systemic exposure compared with oral NSAIDS, and European guidelines recommend their use. The NSAID diclofenac is available in a range of topical formulations. Diclofenac 1% gel and 1.5% four times daily and 2% twice daily (BID) solutions are approved to reduce pain from OA of the knee(s). The objective of this study was to investigate the efficacy and safety of diclofenac sodium 2% topical solution BID versus vehicle control solution for treating pain associated with OA of the knee.

RESEARCH DESIGN AND METHODS

A phase II, 4 week, randomized, double-blind, parallel-group, two-arm, vehicle-controlled study compared pain relief with diclofenac sodium 2% topical solution versus control (vehicle only) in patients aged 40 to 85 years with radiographically confirmed primary OA of the knee.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT01119898.

MAIN OUTCOME MEASURES

The primary efficacy outcome was change from baseline to the final visit in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. Secondary outcomes included additional WOMAC subscales and patient global assessment of OA. Treatment-emergent adverse events (TEAEs), skin irritation, and vital signs were assessed and collected throughout the study.

RESULTS

Of 260 patients randomized, 259 received ≥1 dose of study drug. Significantly greater reductions in least-squares mean (standard error) WOMAC pain scores were observed for diclofenac-treated (-4.4 [0.4]) versus vehicle-treated patients (-3.4 [0.4]) at the final visit (p = 0.040). The most commonly reported TEAEs were administration site conditions. The vehicle-treated group experienced slightly more TEAEs than the active treatment group (38.8% vs. 31.5%). No serious adverse events were reported.

CONCLUSIONS

Administration of diclofenac sodium 2% topical solution BID resulted in significantly greater improvement in pain reduction in patients with OA of the knee versus vehicle control and was generally well tolerated.

Osteoarthritis year in review 2015: clinical

The purpose of this review is to highlight clinical research in osteoarthritis (OA). A literature search was conducted using PubMed (http://www.ncbi.nlm.nih.gov/pubmed/) with the search terms "osteoarthritis [All Fields] AND treatment [All Fields]" and the following limits activated: humans, English language, all adult 19+ years, published between April 1, 2014 and April 1, 2015. A second literature search was then conducted with the search terms "osteoarthritis [All Fields] AND epidemiology [All Fields]", with the same limits. Reports of surgical outcome, case series, surgical technique, tissue sample or culture studies, trial protocols, and pilot studies were excluded. Of 1523, 150 were considered relevant. Among epidemiologic and observational clinical studies, themes included physical activity, early knee OA, and confidence/instability/falls. Symptom outcomes of pharmacologic treatments were reported for methotrexate, adalimumab, anti-nerve growth factor monoclonal antibodies, strontium ranelate, bisphosphonates, glucosamine, and chondroitin sulfate, and structural outcomes of pharmacologic treatments for strontium ranelate, recombinant human fibroblast growth factor 18, and glucosamine and chondroitin sulfate. Symptom outcomes of non-pharmacologic interventions were reported for: neuromuscular exercise, quadriceps strengthening, weight reduction and maintenance, TENS, therapeutic ultrasound, stepped care strategies, cognitive behavior therapy for sleep disturbance, acupuncture, gait modification, booster physical therapy, a web-based therapeutic exercise resource center for knee OA; hip physical therapy for hip OA; and joint protection and hand exercises for hand OA. Structure outcomes of non-pharmacologic interventions were reported for patellofemoral bracing.

In-Hospital Cost Analysis of Total Hip Arthroplasty: Does Surgical Approach Matter?

The purposes of this study were to determine the impact of surgical approach on costs of total hip arthroplasty (THA) from a hospital perspective and to provide an updated cost estimation of THA. A prospective, microcosting analysis was performed on 118 patients undergoing a THA through an anterior, lateral, or posterior approach. We determined that overall costs (intraoperative costs and hospital stay) were significantly less for the anterior ($7300.22; 95% confidence interval [CI], 7064.49-7535.95) vs lateral ($7853.10; 95% CI, 7577.29-8128.91; P = .031) and anterior vs posterior approach ($8287.46; 95% CI, 7906.42-8668.51; P < .001). A reduction in hospital length of stay when THA was performed through an anterior approach contributed significantly to an overall reduction in costs from a hospital perspective.

The effects of intra-articular resiniferatoxin on monosodium iodoacetate-induced osteoarthritic pain in rats

This study was performed to investigate whether an intra-articular injection of transient receptor potential vanilloid 1 (TRPV1) receptor agonist, resiniferatoxin (RTX) would alleviate behavioral signs of arthritic pain in a rat model of osteoarthritis (OA). We also sought to determine the effect of RTX treatment on calcitonin gene-related peptide (CGRP) expression in the spinal cord. Knee joint inflammation was induced by intra-articular injection of monosodium iodoacetate (MIA, 8 mg/50 µl) and weight bearing percentage on right and left hindpaws during walking, paw withdrawal threshold to mechanical stimulation, and paw withdrawal latency to heat were measured to evaluate pain behavior. Intra-articular administration of RTX (0.03, 0.003 and 0.0003%) at 2 weeks after the induction of knee joint inflammation significantly improved reduction of weight bearing on the ipsilateral hindlimb and increased paw withdrawal sensitivity to mechanical and heat stimuli. The reduction of pain behavior persisted for 3~10 days according to each behavioral test. The MIA-induced increase in CGRP immunoreactivity in the spinal cord was decreased by RTX treatment in a dose-dependent manner. The present study demonstrated that a single intra-articular administration of RTX reduced pain behaviors for a relatively long time in an experimental model of OA and could normalize OA-associated changes in peptide expression in the spinal cord.

Reference values for the Y Balance Test and the lower extremity functional scale in young healthy adults

[Purpose] This study aimed to establish gender-specific reference values for the Y Balance Test (YBT) and the Arabic version of the Lower Extremity Functional Scale (LEFS-Ar) in healthy young adults in Saudi Arabia, and to examine gender differences in the YBT and LEFS-Ar values. [Subjects and Methods] Healthy young adults (31 females, 30 males) completed the YBT and LEFS-Ar in 1 test session. Descriptive statistical analysis (mean, standard deviation, 95% confidence interval) was used to compute the YBT and LEFS-Ar reference values. Independent t-tests were used to examine gender differences in the YBT and LEFS-Ar values. [Results] Gender-specific reference values were obtained for the right, left, dominant, and non-dominant leg as well as for the average performance of both the legs. males showed greater YBT normalized reach distances than females did in the anterior, posteromedial, and posterolateral directions; furthermore, males showed higher YBT composite scores than females did. However, the LEFS-Ar values did not differ between males and females. [Conclusion] Gender-specific reference values were obtained for the YBT and LEFS-Ar in healthy young adults in Saudi Arabia. males performed better than females did in the YBT. However, no gender differences were noted in LEFS-Ar.

Trajectories of functional decline in knee osteoarthritis: the Osteoarthritis Initiative

OBJECTIVE

To describe trajectories of functional decline over 84 months and study associated risk factors among adults initially without limitation who had or were at risk of knee OA.

METHODS

We used annual measures of WOMAC physical function over 84 months from the OA Initiative. We included knees with no functional limitation (i.e. WOMAC = 0) at baseline. Knee-based trajectories of functional decline from WOMAC were identified from a group-based trajectory model (PROC TRAJ).

RESULTS

We identified five trajectories from 2110 knees (1055 participants, age 61.0 ± 9.3, BMI 27.1 ± 4.4, 52% women). Half of the knees (54%) remained free of limitation over 84 months, 26% slowly declined to a WOMAC of 1.5, 9% were limitation free for the first 36 months and declined to a WOMAC of 11.3, 6% rapidly declined over the first 12 months and gradually recovered to a WOMAC of 3.3 and 5% steadily declined to a WOMAC of 13.2. Baseline radiographic disease, knee pain, obesity and depressive symptoms at baseline were associated with trajectories of worse functional decline.

CONCLUSION

Five per cent of our sample initially without limitation was on a trajectory of progressive functional decline over 84 months later. We found worse disease and health status at baseline to be associated with faster decline over time.

Hyaluronic Acid Injections Are Associated with Delay of Total Knee Replacement Surgery in Patients with Knee Osteoarthritis: Evidence from a Large U.S. Health Claims Database

BACKGROUND

The growing prevalence of osteoarthritis (OA) and the medical costs associated with total knee replacement (TKR) surgery for end-stage OA motivate a search for agents that can delay OA progression. We test a hypothesis that hyaluronic acid (HA) injection is associated with delay of TKR in a dose-dependent manner.

METHODS AND FINDINGS

We retrospectively evaluated records in an administrative claims database of ~79 million patients, to identify all patients with knee OA who received TKR during a 6-year period. Only patients with continuous plan enrollment from diagnosis until TKR were included, so that complete medical records were available. OA diagnosis was the index event and we evaluated time-to-TKR as a function of the number of HA injections. The database included 182,022 patients with knee OA who had TKR; 50,349 (27.7%) of these patients were classified as HA Users, receiving ≥1 courses of HA prior to TKR, while 131,673 patients (72.3%) were HA Non-users prior to TKR, receiving no HA. Cox proportional hazards modelling shows that TKR risk decreases as a function of the number of HA injection courses, if patient age, gender, and disease comorbidity are used as background covariates. Multiple HA injections are therefore associated with delay of TKR (all, P < 0.0001). Half of HA Non-users had a TKR by 114 days post-diagnosis of knee OA, whereas half of HA Users had a TKR by 484 days post-diagnosis (χ2 = 19,769; p < 0.0001). Patients who received no HA had a mean time-to-TKR of 0.7 years; with one course of HA, the mean time to TKR was 1.4 years (χ2 = 13,725; p < 0.0001); patients who received ≥5 courses delayed TKR by 3.6 years (χ2 = 19,935; p < 0.0001).

CONCLUSIONS

HA injection in patients with knee OA is associated with a dose-dependent increase in time-to-TKR.

Higher incidence of rheumatoid arthritis in patients with symptomatic osteoarthritis or osteoarthritis-related surgery: a nationwide, population-based, case-control study in Taiwan

OBJECTIVES

To investigate the risk of incident rheumatoid arthritis in patients with symptomatic osteoarthritis or osteoarthritis-related surgery using a nationwide health claims database.

DESIGN

A nationwide, population-based, case-control study.

SETTING

Taiwan's National Health Insurance Research Database.

PARTICIPANTS

A total of 1147 patients (aged 20-100 years) with rheumatoid arthritis and 5735 controls who were frequency-matched for sex, 10-year age interval and year of catastrophic illness certificate application date (index year) were identified.

MAIN OUTCOME MEASURE

All participants were retrospectively traced, up to 14 years prior to their index year, for diagnosis of osteoarthritis or osteoarthritis-related surgery. Multivariate logistic regression analyses were conducted to quantify the association between rheumatoid arthritis and osteoarthritis.

RESULTS

The risks of rheumatoid arthritis were significantly higher in patients with symptomatic osteoarthritis (adjusted OR=5.24, p<0.001) and osteoarthritis-related surgery (adjusted OR=2.27, p<0.001).

CONCLUSIONS

This large nationwide, population-based, case-control study showed a higher risk of rheumatoid arthritis in Taiwanese patients with symptomatic osteoarthritis. Our findings were consistent with the hypothesis that osteoarthritis might be a triggering factor of rheumatoid arthritis in environment-sensitised and genetically susceptible individuals.

State of the evidence

PURPOSE OF REVIEW

This review focuses on recent studies of osteoarthritis epidemiology, including research on prevalence, incidence, and a broad array of potential risk factors at the person level and joint level.

RECENT FINDINGS

Studies continue to illustrate the high impact of osteoarthritis worldwide, with increasing incidence. Person-level risk factors with strong evidence regarding osteoarthritis incidence and/or progression include age, sex, socioeconomic status, family history, and obesity. Joint-level risk factors with strong evidence for incident osteoarthritis risk include injury and occupational joint loading; the associations of injury and joint alignment with osteoarthritis progression are compelling. Moderate levels of physical activity have not been linked to increased osteoarthritis risk. Some topics of high recent interest or emerging evidence for association with osteoarthritis include metabolic pathways, vitamins, joint shape, bone density, limb length inequality, muscle strength and mass, and early structural damage.

SUMMARY

Osteoarthritis is a complex, multifactorial disease, and there is still much to learn regarding mechanisms underlying incidence and progression. However, there are several known modifiable and preventable risk factors, including obesity and joint injury; efforts to mitigate these risks can help to lessen the impact of osteoarthritis.

Effectiveness of an Integrated Multidisciplinary Osteoarthritis Outpatient Program versus Outpatient Clinic as Usual: A Randomized Controlled Trial

Objective.

Osteoarthritis (OA) is one of the leading causes of pain and disability. Given the constraint in the provision of care, there is a need to develop and assess effectiveness of new treatment models. The objective was to compare satisfaction with and effectiveness of a new integrated multidisciplinary outpatient program with usual care in an outpatient clinic for patients with OA.

Methods.

Patients with clinical OA referred to a rheumatology outpatient clinic were randomized to a 3.5-h multidisciplinary group-based educational program followed by individual consultations, or to usual care. The primary outcome was satisfaction with the health service evaluated on a numerical rating scale (0 = extremely unsatisfied, 10 = extremely satisfied) after 4 months. Secondary outcomes included health-related quality of life measures.

Results.

Of 391 patients, 86.4% (n = 338) were women, and mean age was 61.2 (SD 8.0) years. At 4 months, patients who received integrated multidisciplinary care were significantly more satisfied with the health service compared with controls, with a mean difference of −1.05 (95% CI −1.68 to −0.43, p < 0.001). Among secondary outcomes, only self-efficacy with other symptoms scale (10–100) improved significantly in the multidisciplinary group compared with controls at 4 months (3.59, 95% CI 0.69–6.5, p = 0.02). At 12 months, the Australian/Canadian Hand Osteoarthritis Index pain (0–10) and fatigue scores (0–10) were slightly worse in the multidisciplinary group with differences of 0.38 (95% CI 0.06–0.71, p = 0.02) and 0.55 (95% CI 0.02–1.07, p = 0.04), respectively.

Conclusion.

Patients receiving an integrated multidisciplinary care model were more satisfied with healthcare than those receiving usual care, whereas there were no clinically relevant improvements in health outcomes.

Indirect costs of rheumatoid arthritis

It is estimated that in Poland about 400,000 persons in general suffer from inflammatory joint diseases, including rheumatoid arthritis (RA). Epidemiological surveys documenting the frequency and disturbance of musculoskeletal disorders in the Polish population are few in number. Most of the estimations are based on epidemiological data from other countries (prevalence of 0.5-1%). According to the data of the National Health Fund in Poland 135,000-157,000 persons in total are treated because of rheumatoid arthritis per year [ICD10 (International Statistical Classification of Diseases and Related Health Problems): M05, M06]. In the case of this group of diseases indirect costs significantly outweigh the direct costs. Indirect costs increase together with activity level of the disease. The cost analysis of productivity loss of RA patients indicates that sickness absenteeism and informal care are the most burdensome. At the national level it amounts in total from 1.2 billion to 2.8 billion PLN per year, depending on the method of analysis. These costs could be significantly reduced through early diagnosis and introduction of effective treatment.

Huo-Luo-Xiao-Ling (HLXL)-Dan, a Traditional Chinese Medicine, for patients with osteoarthritis of the knee: a multi-site, randomized, double-blind, placebo-controlled phase II clinical trial

OBJECTIVE

To examine the efficacy and safety of Huo-Luo-Xiao-Ling (HLXL)-Dan, a Traditional Chinese Medicine (TCM), in patients with knee osteoarthritis (OA).

DESIGN

A multi-site, randomized, double-blind, placebo-controlled phase II dose-escalation clinical trial was conducted. Eligible patients who fulfilled American College of Rheumatology criteria were randomized to receive either HLXL or placebo. Clinical assessments included measurement of knee pain and function with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), patient global assessment (PGA), and knee pain scores every 2 weeks. A Data and Safety Monitoring Board (DSMB) was established to review the data for ensuring the quality of the trial.

RESULTS

In the first stage, 28 participants were randomized to receive either low-dose HLXL-Dan (2400 mg/day) or placebo for 6 weeks. The results showed no statistical difference between the two groups. The study was then re-designed following the recommendation of DSMB. Ninety-two patients were enrolled in the second stage and were randomized to receive either high-dose HLXL-Dan (4000 mg/day for week 1-2, and 5600 mg/day for week 3-8) or placebo for 8 weeks. All outcome assessments showed significant improvements for both groups after 8 weeks but no significant between-group differences. The change (mean ± SD) of WOMAC pain and WOMAC function scores of HLXL and placebo group after 8 weeks were -1.2 ± 1.7 vs -1.4 ± 1.5, and -1.1 ± 1.6 vs -1.3 ± 1.5 respectively. No serious adverse events were reported.

CONCLUSION

Although safe to use, an 8-week treatment of HLXL-Dan was not superior to placebo for reduction in pain or functional improvement in patients with knee OA.

CLINICAL TRIAL REGISTRATION NUMBER

Clinicaltrials.gov (NCT00755326).

The Genetic Epidemiological Landscape of Hip and Knee Osteoarthritis: Where Are We Now and Where Are We Going?

Osteoarthritis (OA) is a complex disease that affects the whole joint, with multiple biological and environmental factors contributing to its development. The heritable component for primary OA accounts for ∼50% of susceptibility. So far, candidate gene studies and genome-wide association scans have established 18 OA-associated loci. These findings account for 11% of the heritability, explaining a rather small fraction of the genetic component. To further unravel the genetic architecture of OA, the field needs to facilitate more precise phenotypic definitions, high genome coverage, and large sample metaanalyses, expecting the identification of rare and low frequency variants with potentially higher penetrance, and more accurate methods for calculating phenotype-genotype correlation. Expression analysis, epigenetics, and investigation of interactions can also help clarify the implicated transcriptional regulatory pathways and provide insights into further novel pathogenic OA mechanisms leading to diagnostic biomarker identification and new, more focused therapeutic disease approaches.

Association between serum concentration of 25-hydroxyvitamin D and the risk of hip arthroplasty for osteoarthritis: result from a prospective cohort study

OBJECTIVES

There is ongoing debate regarding the optimal serum concentrations of 25-hydroxy-vitamin D for musculoskeletal health, including osteoarthritis (OA). The aim of this prospective cohort study was to determine whether serum 25-hydroxy-vitamin D concentrations were associated with the risk of hip arthroplasty for OA.

DESIGN

This study examined 9135 participants from the Australian Diabetes, Obesity and Lifestyle Study who had serum 25-hydroxy-vitamin D measured in 1999-2000 and were aged ≥40 years at the commencement of arthroplasty data collection. The incidence of hip arthroplasty for OA during 2002-2011 was determined by linking cohort records to the Australian Orthopaedic Association National Joint Replacement Registry.

RESULTS

Over an average 9.1 (standard deviation (SD) 2.7) years of follow-up, 201 hip arthroplasties for OA were identified (males n = 90; females n = 111). In males, a one-standard-deviation increase in 25-hydroxy-vitamin D was associated with a 25% increased incidence (HR 1.25, 95% CI 1.02-1.56), with a dose response relationship evident by quartiles of 25-hydroxy-vitamin D concentration (P for trend 0.04). These results were independent of age, body mass index (BMI), ethnicity, smoking status, physical activity, season of blood collection, latitude, hypertension and diabetes, area level disadvantage or after excluding those with extreme low 25-hydroxy-vitamin D concentrations. No significant association was observed in women (HR 1.10, 95% CI 0.87, 1.39).

CONCLUSIONS

Increasing serum 25-hydroxy-vitamin D concentrations were associated with an increased risk of hip arthroplasty for OA in males, while no significant association was observed in females. The mechanism for the association warrants further investigation.

Prevalence of knee osteoarthritis, risk factors, and quality of life: The Fifth Korean National Health And Nutrition Examination Survey

AIM

Although there have been regional population-based studies on the prevalence of knee osteoarthritis (KOA) and its risk factors in South Koreans, those studies in common had limited external validity. This study aims to estimate the national prevalence of KOA and its risk factors using a complex sampling design.

METHODS

This was a cross-sectional study including 9512 participants aged ≥ 50 years of The Fifth Korean National Health and Nutrition Examination Survey, who were selected using two-step stratified clustered equal-probability systematic sampling. Radiographic KOA (RKOA) was defined as a Kellgren-Lawrence grade of ≥ 2. Symptoms of KOA were evaluated through a health interview. Obesity was defined as a body mass index ≥ 27.5 kg/m²_. Quality of life was measured by the Korean version of European Quality of Life Questionnaire (EQ-5D).

RESULTS

The prevalence of RKOA was 21.1% (95% CI: 19.6-22.8%) in men, and 43.8% (42.0-45.6%) in women. The prevalence of symptomatic RKOA (SRKOA) was 4.4% (3.8-5.2%) and 19.2% (17.9-20.6%) in men and women, respectively. The EQ-5D index was lower in participants with KOA. When plotted against mean age and prevalence of obesity, regions with a higher mean age and prevalence of obesity had higher prevalence of KOA, which was also observed at the individual level. The prevalence of SRKOA was 36.6% (29.7-44.1%) in women in Jeju province.

CONCLUSION

The prevalence of SRKOA in women reached 36.6% in high-risk groups accompanied by low quality of life. The results suggest that the disease burden of KOA is high in South Korea.

The relative importance of perceived doctor's attitude on the decision to consult for symptomatic osteoarthritis: a choice-based conjoint analysis study

OBJECTIVES

Some patients spend years with painful osteoarthritis without consulting for it, including times when they are experiencing persistent severe pain and disability. Beliefs about osteoarthritis and what primary care has to offer may influence the decision to consult but their relative importance has seldom been quantified. We sought to investigate the relative importance of perceived service-related and clinical need attributes in the decision to consult a primary care physician for painful osteoarthritis.

DESIGN

Partial-profile choice-based conjoint analysis study, using a self-complete questionnaire containing 10 choice tasks, each presenting two scenarios based on a combination of three out of six selected attributes.

SETTING

General population.

PARTICIPANTS

Adults aged 50 years and over with hip, knee or hand pain registered with four UK general practices.

OUTCOME MEASURES

Relative importance of pain characteristics, level of disruption to everyday life, extent of comorbidity, assessment, management, perceived general practitioner (GP) attitude.

RESULTS

863 (74%) people responded (55% female; mean age 70 years, range: 58-93). The most important determinants of the patient's decision to consult the GP for joint pain were the extent to which pain disrupted everyday life ('most' vs 'none': relative importance 31%) and perceived GP attitude ('legitimate problem, requires treatment' vs 'part of the normal ageing process that one just has to accept': 24%). Thoroughness of assessment (14%), management options offered (13%), comorbidity (13%) and pain characteristics (5%) were less strongly associated with the decision to consult.

CONCLUSIONS

Anticipating that the GP will regard joint pain as 'part of the normal ageing process that one just has to accept' is a strong disincentive to seeking help, potentially outweighing other aspects of quality of care. Alongside the recognition and management of disrupted function, an important goal of each primary care consultation for osteoarthritis should be to avoid imparting or reinforcing this perception.

Self-reported quality care for knee osteoarthritis: comparisons across Denmark, Norway, Portugal and the UK

Objectives

To assess and compare patient perceived quality of osteoarthritis (OA) management in primary healthcare in Denmark, Norway, Portugal and the UK.

Methods

Participants consulting with clinical signs and symptoms of knee OA were identified in 30 general practices and invited to complete a cross-sectional survey including quality indicators (QI) for OA care. A QI was considered as eligible if the participant had checked ‘Yes’ or ‘No’, and as achieved if the participant had checked ‘Yes’ to the indicator. The median percentage (with IQR and range) of eligible QIs achieved by country was determined and compared in negative binominal regression analysis. Achievement of individual QIs by country was determined and compared using logistic regression analyses.

Results

A total of 354 participants self-reported QI achievement. The median percentage of eligible QIs achieved (checked ‘Yes’) was 48% (IQR 28%, 64%; range 0–100%) for the total sample with relatively similar medians across three of four countries. Achievement rates on individual QIs showed a large variation ranging from 11% (referral to services for losing weight) to 67% (information about the importance of exercise) with significant differences in achievement rates between the countries.

Conclusions

The results indicated a potential for improvement in OA care in all four countries, but for somewhat different aspects of OA care. By exploring these differences and comparing healthcare services, ideas may be generated on how the quality might be improved across nations. Larger studies are needed to confirm and further explore the findings.

The effects of resistance exercise in patients with knee osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

To analyze the effectiveness of resistance exercise in the treatment of knee osteoarthritis on pain, stiffness, and physical function.

DESIGN

Systematic review and meta-analysis of randomized controlled trials.

DATA SOURCES

PubMed, Embase, Cochrane Central Register of Controlled Trials, the Web of Science, and Chinese Biomedical Literature Database were searched from the date of inception to August 2015.

METHODS

Trials comparing effects of resistance exercise intervention with either non-intervention or psycho-educational intervention were selected by two reviewers independently. The risk of bias was assessed and studies with similar outcomes were pooled using a fixed or random effects model.

RESULTS

Data from 17 randomized clinical trials including 1705 patients were integrated. The main source of methodological bias in the selected studies was lack of double blinding. The meta-analysis results suggested that resistance exercise training relieved pain (standard mean difference [SMD]: -0.43; 95% confidence interval [CI]: -0.57 to -0.29; P < 0.001), alleviated stiffness (SMD: -0.31; 95%: CI -0.56 to -0.05; P = 0.02), and improved physical function (SMD -0.53; 95% CI: -0.70 to -0.37; P < 0.001).

CONCLUSION

Resistance exercise is beneficial in terms of reducing pain, alleviating stiffness, and improving physical function in patients with knee osteoarthritis.

Strategies for the prevention of knee osteoarthritis

Osteoarthritis (OA) has been thought of as a disease of cartilage that can be effectively treated surgically at severe stages with joint arthroplasty. Today, OA is considered a whole-organ disease that is amenable to prevention and treatment at early stages. OA develops slowly over 10-15 years, interfering with activities of daily living and the ability to work. Many patients tolerate pain, and many health-care providers accept pain and disability as inevitable corollaries of OA and ageing. Too often, health-care providers passively await final 'joint death', necessitating knee and hip replacements. Instead, OA should be viewed as a chronic condition, where prevention and early comprehensive-care models are the accepted norm, as is the case with other chronic diseases. Joint injury, obesity and impaired muscle function are modifiable risk factors amenable to primary and secondary prevention strategies. The strategies that are most appropriate for each patient should be identified, by selecting interventions to correct--or at least attenuate--OA risk factors. We must also choose the interventions that are most likely to be acceptable to patients, to maximize adherence to--and persistence with--the regimes. Now is the time to begin the era of personalized prevention for knee OA.

Assessing appropriateness of osteoarthritis care using quality indicators: a systematic review

RATIONALE, AIMS AND OBJECTIVES

Quality indicators (QIs) derived from the review of medical records, administrative databases, and patient questionnaires and interviews have been frequently used to assess the quality of osteoarthritis (OA) care. The purpose of this review is to summarize studies that have assessed the quality of OA care using QIs.

METHOD

We systematically searched MEDLINE, EMBASE, CINAHL and PsycINFO for English-language studies indexed by October 2014. Articles were included if they used any QIs for assessing the quality of OA care. We summarized the results of these studies, and with meta-analysis, generated an overall conclusion about the quality of care as measured by QIs for each treatment domain for OA care.

RESULTS

Fourteen studies assessed as being of high-quality were included in the review, with the number of QIs ranging from 1 to 21. Four of the 14 studies solely assessed the quality of OA care, while the other studies assessed health care quality for a range of conditions that included OA. The quality of OA care as assessed by a meta-analysis of QI pass rates across studies was suboptimal for all treatment domains (pass rates: pain and functional status assessment – 48.5%, 95% CI 32.6-64.6%; non-drug treatment – 36.1%, 95% CI 27.8-44.7%; drug treatment – 37.5%, 95% CI 30.8-44.5%; surgical referral – 78.9%, 95% CI 57.4-94.2%).

CONCLUSION

Despite efforts made at improving care for patients with OA, the wide divergence between evidence and consensus-based recommended care and practice has been reaffirmed.

Effects of Adding an Internet-Based Pain Coping Skills Training Protocol to a Standardized Education and Exercise Program for People With Persistent Hip Pain (HOPE Trial): Randomized Controlled Trial Protocol

BACKGROUND

Persistent hip pain in older people is usually due to hip osteoarthritis (OA), a major cause of pain, disability, and psychological dysfunction.

OBJECTIVE

The purpose of this study is to evaluate whether adding an Internet-based pain coping skills training (PCST) protocol to a standardized intervention of education followed by physical therapist-instructed home exercise leads to greater reductions in pain and improvements in function.

DESIGN

An assessor-, therapist-, and participant-blinded randomized controlled trial will be conducted.

SETTING

The study will be conducted in a community setting.

PARTICIPANTS

The participants will be 142 people over 50 years of age with self-reported hip pain consistent with hip OA.

INTERVENTION

Participants will be randomly allocated to: (1) a control group receiving a 24-week standardized intervention comprising an 8-week Internet-based education package followed by 5 individual physical therapy exercise sessions plus home exercises (3 times weekly) or (2) a PCST group receiving an 8-week Internet-based PCST protocol in addition to the control intervention.

MEASUREMENTS

Outcomes will be measured at baseline and 8, 24, and 52 weeks, with the primary time point at 24 weeks. Primary outcomes are hip pain on walking and self-reported physical function. Secondary outcomes include health-related quality-of-life, participant-perceived treatment response, self-efficacy for pain management and function, pain coping attempts, pain catastrophizing, and physical activity. Measurements of adherence, adverse events, use of health services, and process measures will be collected at 24 and 52 weeks. Cost-effectiveness will be assessed at 52 weeks.

LIMITATIONS

A self-reported diagnosis of persistent hip pain will be used.

CONCLUSIONS

The findings will help determine whether adding an Internet-based PCST protocol to standardized education and physical therapist-instructed home exercise is more effective than education and exercise alone for persistent hip pain. This study has the potential to guide clinical practice toward innovative modes of psychosocial health care provision.

Frontal plane kinematics in walking with moderate hip osteoarthritis: Stability and fall risk

BACKGROUND

Hip abductor weakness and unilateral pain in patients with moderate hip osteoarthritis may induce changes in frontal plane kinematics during walking that could affect stability and fall risk.

METHODS

In 12 fall-prone patients with moderate hip osteoarthritis, 12 healthy peers, and 12 young controls, we assessed the number of falls in the preceding year, hip abductor strength, fear of falling, Harris Hip Score, and pain. Subjects walked on a treadmill with increasing speeds, and kinematics were measured opto-electronically. Parameters reflecting gait stability and regressions of frontal plane center of mass movements on foot placement were calculated. We analyzed the effects of, and interactions with group, and regression of all variables on number of falls.

FINDINGS

Patients walked with quicker and wider steps, stood shorter on their affected leg, and had larger peak speeds of frontal plane movements of the center of mass, especially toward their unaffected side. Patients' static margins of stability were larger, but the unaffected dynamic margin of stability was similar between groups. Frontal plane position and acceleration of the center of mass predicted subsequent step width. The peak speed of frontal plane movements toward unaffected had 55% common variance with number of falls, and adding the Harris Hip Score into bivariate regression led to 83% "explained" variance.

INTERPRETATION

Quickening and widening steps probably increase stability. Shorter affected side stance time to avoid pain, and/or weakened affected side hip abductors, may lead to faster frontal plane trunk movements toward the unaffected side, which could contribute to fall risk.

Overexpression of MMP13 in human osteoarthritic cartilage is associated with the SMAD-independent TGF-β signalling pathway

Introduction

In vitro and animal model of osteoarthritis (OA) studies suggest that TGF-β signalling is involved in OA, but human data is limited. We undertook this study to elucidate the role of TGF-β signalling pathway in OA by comparing the expression levels of TGFB1 and BMP2 as ligands, SMAD3 as an intracellular mediator, and MMP13 as a targeted gene between human osteoarthritic and healthy cartilage.

Methods

Human cartilage samples were collected from patients undergoing total hip/knee joint replacement surgery due to primary OA or hip fractures as controls. RNA was extracted from the cartilage tissues. Real-time quantitative PCR was performed to measure gene expression. Mann-Whitney test was utilized to compare the expression levels of TGFB1, BMP2, SMAD3 and MMP13 in human cartilage between OA cases and controls. Spearman’s rank correlation coefficient (rho) was calculated to examine the correlation between the expression levels of the four genes studied and non-parametric regression was used to adjust for covariates.

Results

A total of 32 OA cases (25 hip OA and 7 knee OA) and 21 healthy controls were included. The expression of TGFB1, SMAD3, and MMP13 were on average 70 %, 46 %, and 355 % higher, respectively, whereas the expression of BMP2 was 88 % lower, in OA-affected cartilage than that of controls (all p < 0.03), but no difference was observed between hip and knee OA (all p > 0.4). The expression of TGFB1 was correlated with the expression of SMAD3 (rho = 0.50, p = 0.003) and MMP13 (rho = 0.46, p = 0.007) in OA-affected cartilage and the significance became stronger after adjustment for age, sex, and BMI. The expression of BMP2 was negatively correlated with both TGFB1 (rho = −0.50, p = 0.02) and MMP13 (rho = −0.48, p = 0.02) in healthy cartilage, but the significance was altered after adjustment for the covariates. There was no correlation between the expression of SMAD3 and MMP13.

Conclusions

Our results demonstrate that MMP13 expression is associated with an increased expression of TGFB1 in OA-affected cartilage, possibly through SMAD-independent TGF-β pathway. Furthermore, TGF-β/SMAD3 is overactivated in OA cartilage; yet, the consequence of this overactivation remains to be established.