Conjoint Associate Professor Stephen Oakley

Background: Within the general population, levels of C-reactive protein (CRP) are positively associated with atherosclerotic cardiovascular disease (CVD). Whether CRP is causally implicated in atherogenesis or is the results of atherosclerosis is disputed. A role of CRP to protect endothelium-derived nitric oxide (EDNO) has been suggested. We examined the association of CRP with EDNO-dependent vasomotor function and subclinical measures of atherosclerosis and arteriosclerosis in patients with raised CRP resulting from rheumatoid arthritis (RA). Methodology/Principal Findings: Patients with RA (n = 59) and healthy control subjects (n = 123), underwent measures of high sensitivity CRP, flow-mediated dilation (FMD, dependent on EDNO), intima-media thickness (IMT, a measure of subclinical atherosclerosis) and aortic pulse wave velocity (PWV, a measure of arteriosclerosis). IMT and PWV were elevated in patients with RA compared to controls but FMD was similar in the two groups. In patients with RA, IMT and PWV were not correlated with CRP but FMD was positively independently correlated with CRP (P<0.01). Conclusions/Significance: These findings argue against a causal role of CRP in atherogenesis and are consistent with a protective effect of CRP on EDNO bioavailability. © 2010 Holmes et al.

Objective. Work disability is a serious consequence of rheumatoid arthritis (RA). We conducted a 6-month, prospective randomized controlled trial comparing assessments of function, work, coping, and disease activity in employed patients with RA receiving occupational therapy intervention versus usual care. Methods. Employed patients with RA with increased perceived work disability risk were identified by the RA Work Instability Scale (WIS; score =10). Patients were stratified into medium- (score =10 and <17) and high-risk (=17) groups, then randomized into occupational therapy or usual care groups. Assessments were conducted at baseline and 6 months. The primary outcome was the Canadian Occupational Performance Measure (COPM), a standardized patient self-report of function. Other outcomes included the disability index (DI) of the Health Assessment Questionnaire (HAQ); Disease Activity Score in 28 joints (DAS28); RA WIS; EuroQol Index; visual analog scales (VAS) for pain, work satisfaction, and work performance; and days missed/month. Independent sample t-tests and Mann-Whitney U tests were used. Results. We recruited 32 employed patients with RA. At baseline the groups were well matched. At 6 months the improvement in the occupational therapy group was significantly greater than that in the usual care group for all functional outcomes (COPM performance P < 0.001, COPM satisfaction P < 0.001, HAQ DI P = 0.02) and most work outcomes (RA WIS [P = 0.04], VAS work satisfaction [P < 0.001], VAS work performance [P = 0.01]). Additionally, Arthritis Helplessness Index (P = 0.02), Arthritis Impact Measurement Scales II pain subscale (P = 0.03), VAS pain (P = 0.007), EuroQol Index (P = 0.02), EuroQol global (P = 0.02), and DAS28 (P = 0.03) scores significantly improved. Conclusion. Targeted, comprehensive occupational therapy intervention improves functional and work-related outcomes in employed RA patients at risk of work disability. © 2009, American College of Rheumatology.

Objective. To evaluate the relationship between the Disease Activity Score 28-joint count (DAS28), Health Assessment Questionnaire (HAQ), and Rheumatoid Arthritis-Work Instability Scale (RA-WIS); and to define thresholds for clinical assessments associated with moderate to high RA-WIS. Methods. Employed patients with RA were evaluated using DAS28, HAQ, and RA-WIS during routine clinics. Relationships between these assessments were evaluated by simple correlation. Multiple linear regression modeling was performed using RA-WIS as an outcome variable and HAQ, DAS28, age, sex, occupation, and disease duration as input variables. Receiver-operating characteristic curves were then formulated to determine optimal DAS28, and HAQ cutoff points for RA-WIS = 10, along with the odds ratio (OR). Results. Ninety patients with RA completed the RA-WIS, which was moderately correlated with DAS28 (r =0.53) and HAQ (r = 0.66). Fifty-four percent of RA-WIS was explained by DAS28 (p = 0.002), HAQ (p = 0.001), and sex (p = 0.04). A DAS28 of 3.81 and HAQ of 0.55 were clinically important thresholds. High DAS28 and HAQ were associated with high RA-WIS (ORDAS 14.17, ORHAQ 25.13, ORDAS+HAQ 29.9). Conclusion. Functional impairment and disease activity significantly and independently contributed to patient-perceived work instability risk. The Journal of Rheumatology Copyright © 2009. All rights reserved.

Introduction: Arthroscopy has been used to evaluate articular cartilage (AC) pathology in osteoarthritis (OA) for outcome measurement and validation of non-invasive imaging. However, many fundamental aspects of arthroscopic assessment remain un-validated. Objectives: This study evaluated arthroscopic estimates of extent of chondropathy. Methods: Serial arthroscopic assessments were performed in a group of 15 sheep before and after bilateral stifle medial meniscectomy (MMx). Post-mortem assessments were performed in un-MMx sheep and 4 and 16 weeks post-MMx. Arthroscopic assessments of the extent of each grade of chondropathy were compared with a non-arthroscopic hybrid assessment that incorporated biomechanical, thickness and macroscopic assessments. Results: Arthroscopy evaluated only 36% of AC and missed significant pathological changes, softening and chondro-osteophyte, occurring in peripheral regions. The patterns of change in arthroscopic assessments were similar to those of the non-arthroscopic assessment but there was a very strong tendency to over-estimate the extent of softened AC after MMx. In spite of these limitations arthroscopic assessments were responsive to change. Estimates of the extent of normal and softened AC were most responsive to change over time followed by estimates of superficial and deep fibrillation. Arthroscopy was as an excellent discriminator between normal and OA. Assessments of chondro-osteophyte and exposed bone were not responsive to change. Conclusions: Arthroscopic estimates of extent of chondropathy are prone to substantial error. While experience and training may reduce these errors other approaches may more effectively improve performance. © 2006 Osteoarthritis Research Society International.

Objectives: The aims of this study were to: 1. Evaluate the performance of arthroscopy for the diagnosis of chondropathy and to compare it to that of direct non-arthroscopic assessments; 2. Determine intra-observer reliability of arthroscopic assessments; 3. Evaluate the effects of the arthroscopic video quality and probing upon diagnostic performance. Design: The ovine medial meniscectomy (MMx) model of early osteoarthritis (OA) was used assuming that pre-MMx articular cartilage (AC) was "normal" and post-MMx AC "chondropathic". Video recordings of arthroscopic assessments of each stifle compartment were evaluated. Scores were given for the quality of the video and the amount of probing. The diagnostic performances of dynamic shear modulus (G), light microscopic assessment and superficial zone collagen birefringence assessments were evaluated and compared to that of arthroscopy. Intra-observer reliability of arthroscopic assessments was also evaluated. Results: Arthroscopic assessments had high sensitivity (91-100%), specificity (62-88%) and accuracy (75-93%) for the diagnosis of chondropathy 16 weeks after MMx. Arthroscopy compared favourably with the direct non-arthroscopic assessments in the lateral compartment and was found to have extremely high intra-observer reliability (kappa 0.78-1.00). The quality of arthroscopic video recordings and the amount of probing did not significantly influence accuracy or reliability. Conclusions: Arthroscopy performs as well as direct non-arthroscopic assessments of AC for diagnosis of early OA. These results suggest that arthroscopy can be used as a "gold standard" for the validation of non-invasive assessments like magnetic resonance imaging and that arthroscopic diagnosis can be based on small amounts of video footage without AC probing. © 2005 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Objectives. Our primary objective was to explore the full potential of the ovine medial meniscectomy (MMx) model of early osteoarthritis (OA) for studies to validate non-destructive articular cartilage (AC) assessments and therapeutic interventions. Our secondary objective was to re-evaluate the relationships between the different types of AC assessment after MMx in sheep. Methods. Macroscopic assessments, dynamic shear modulus (G*), phase lag and AC thickness measurements were performed at a total of 5437 reference points on all six articular surfaces in four normal joints and 16 MMx ovine stifle (knee) joints. Comparisons with histologic assessments of gross structural damage, collagen organisation (birefringence) and proteoglycan content were possible at 702 of these points. Results. Histologic gross structural damage and proteoglycan loss were seen throughout the joint with greatest severity (fibrillation) in closest proximity to the MMx site. Increases in AC (30-50%) thickness, reductions in G* (30-40%) and collagen birefringence intensity (15-30%) occurred more evenly throughout the joint. Macroscopic softening was evident only when G* declined by 80%. G* correlated with AC thickness (¿=-0.47), collagen organisation (¿=0.44), gross structural damage (¿=-0.44) and proteoglycan content (¿=0.42). Multivariate analysis showed that collagen organisation contributed twice as much to dynamic shear modulus (t=6.66) as proteoglycan content (t=3.21). Collagen organisation (¿=0.11) and proteoglycan content (¿=0.09) correlated only weakly to phase lag. Conclusions. Macroscopic assessments were insensitive to AC softening suggesting that arthroscopic assessments of AC status might also perform poorly. Collagen integrity was more important for the maintenance of AC stiffness (G*) than proteoglycan content. The development of major AC softening and thickening throughout the joint following MMx suggested involvement of non-mechanical (e.g., protein and biochemical) chemical and cytokine mediated processes in addition to the disturbance in biomechanical loading. The ovine MMx model provides a setting in which the spectrum of AC changes associated with the initiation and progression of OA may be evaluated. © 2004 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Background and Objectives: To review the performance of arthroscopic assessment of articular cartilage damage in osteoarthritis. Methods: The literature was reviewed for publications containing data regarding validity and reliability of arthroscopic systems of cartilage evaluation in knee osteoarthritis. Results: Fifty-two distinct measurement systems were identified in 60 publications. There were 30 simple severity-scoring systems, 3 global visual analogue scale systems, and 19 composite systems. No systems consisted solely of measurements of lesion size or site, although 13 systems used either or both of these for the calculation of composite scores. Only 6 publications (10%) undertook any reliability evaluation and these generally used inappropriate methods of statistical analysis. Thirty-five publications (58%) evaluated validity. Construct validity was tested using several constructs (clinical in 2, magnetic resonance imaging in 10, radiographs in 10, or other arthroscopic assessments in 5 publications). Criterion validity was ascertained by using several methods including cartilage histology, histochemistry, or biomechanics in 10 publications. Responsiveness was determined in 1 publication. Discussion: Many publications evaluated composite systems but only a few evaluated fundamental aspects of arthroscopic measurement. Conceptually, composite scoring systems have the best validity; however, at present, there is only enough evidence to support the use of simple chondropathy severity scores and there are little data on the responsiveness of these methods. A proposed program for comprehensive evaluation and development of valid and responsive arthroscopic assessments of articular cartilage is outlined. © 2003 Elsevier Inc. All rights reserved.

Objectives: (a)To determine the accuracy and reliability of arthroscopic measurements of cartilage lesion diameter in an artificial right knee model; (b) to determine whether the use of a set of variable angle elongated probes improves performance; and (c) to identify other sources of variability. Methods: Ovoid "lesions" were drawn on the five cartilage surfaces of four plastic knees models. Two observers assessed these 20 lesions arthroscopically, measuring two diameters in orientations parallel and orthogonal to the probe. Observer 1 (orthopaedic surgeon) and observer 2 (arthroscopic rheumatologist) made two sets of measurements, firstly with the conventional probe and five months later with the variable angle elongated (VAE) probes. The knees were disarticulated to determine true lesion diameter. Results: Observer 1 had negligible bias and good accuracy regardless of orientation or probe type. Observer 2 demonstrated both bias and poor accuracy using the conventional probe. Both improved using VAE probes. Poor interobserver reliability with conventional probes also improved using VAE probes. Major sources of variability could be traced to the probe type, the characteristics of the operator, and the orientation of the lesion in relation to the probe; the lesion location itself did not cause variability. Conclusions: Variation in accuracy and poor interobserver reliability of measurements with conventional methods of cartilage lesion diameter measurement improved when specially designed measurement probes were used. Arthroscopic measurements performed as well as most clinical and radiographic measures. These findings have important implications for the use of arthroscopy as an outcome in multicentre trials where arthroscopists have different levels of experience.