Cohort profile: Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) - an international consortium of prospective cohort studies with individual participant data on hip osteoarthritis.

PURPOSE: Hip osteoarthritis (OA) is a major cause of pain and disability worldwide. Lack of effective therapies may reflect poor knowledge on its aetiology and risk factors, and result in the management of end-stage hip OA with costly joint replacement. The Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) consortium was established to pool and harmonise individual participant data from prospective cohort studies. The consortium aims to better understand determinants and risk factors for the development and progression of hip OA, to optimise and automate methods for (imaging) analysis, and to develop a personalised prediction model for hip OA. PARTICIPANTS: World COACH aimed to include participants of prospective cohort studies with ≥200 participants, that have hip imaging data available from at least 2 time points at least 4 years apart. All individual participant data, including clinical data, imaging (data), biochemical markers, questionnaires and genetic data, were collected and pooled into a single, individual-level database. FINDINGS TO DATE: World COACH currently consists of 9 cohorts, with 38 021 participants aged 18-80 years at baseline. Overall, 71% of the participants were women and mean baseline age was 65.3±8.6 years. Over 34 000 participants had baseline pelvic radiographs available, and over 22 000 had an additional pelvic radiograph after 8-12 years of follow-up. Even longer radiographic follow-up (15-25 years) is available for over 6000 of these participants. FUTURE PLANS: The World COACH consortium offers unique opportunities for studies on the relationship between determinants/risk factors and the development or progression of hip OA, by using harmonised data on clinical findings, imaging, biomarkers, genetics and lifestyle. This provides a unique opportunity to develop a personalised hip OA risk prediction model and to optimise methods for imaging analysis of the hip.

Anatomical site of radiographic degeneration is an independent variable influencing outcome of total knee arthroplasty.

OBJECTIVES: We aimed to determine whether the site of anatomical degenerative change could be identified as an independent risk factor influencing clinical outcome of total knee arthroplasty (TKA) 12 months postoperatively. METHODS: We compared preoperative, postoperative and the change observed in Oxford Knee Score (OKS) amongst TKA patients categorised as primarily medial, lateral or patellofemoral osteoarthritis (PFJOA). Multivariable regression analysis was conducted on 434 consecutive knees in 333 patients, adjusting for sex, age and body mass index (BMI). RESULTS: Adjusted estimates showed that preoperatively, patients with medial and lateral osteoarthritis (OA) had a lower mean OKS of 2.1 (p â€‹= â€‹0.049) and 2.3 (p â€‹= â€‹0.056) points respectively, while those with PFJOA had mean scores 2.7 points higher (p â€‹= â€‹0.062). There was no statistically significant difference between compartments in absolute postoperative OKS. The greatest improvement of 30.1 points (95% confidence interval (CI) 16.9-36.0, p â€‹= â€‹0.012) in OKS was observed for those with lateral OA, followed by 28.9 points (95% CI 16.7-35.3, p â€‹= â€‹0.049) for those with medial OA. The improvement observed postoperatively in patients with PFJOA was less than that observed for the average of the cohort at 24.5 (95% CI 11.5-29.7, p â€‹= â€‹0.088). CONCLUSIONS: The site of compartmental involvement in knee OA is an independent factor influencing clinical outcome of TKA. With arthroplasty registry adoption of patient-reported outcome measures (PROMs), this study supports precise anatomical categorisation of knee OA in outcome studies. LEVEL OF EVIDENCE: Level III, Retrospective consecutive clinical study.

A prospective cohort study on cam morphology and its role in progression of osteoarthritis.

BACKGROUND: Cam morphology contributes to the development of hip osteoarthritis (OA) but is less studied in the general population. This study describes its associations with clinical and imaging features of hip OA. METHODS: Anteroposterior hip radiographs of 1019 participants from the Tasmanian Older Adult Cohort (TASOAC) were scored at baseline for α angle (cam morphology) in both hips. Using the Altman's atlas, radiographic hip OA (ROA) was assessed at baseline. Hip pain and right hip structural changes were assessed on a subset of 245 magnetic resonance images (MRI) at 5 years. Joint registry data for total hip replacement (THR) was acquired 14 years from baseline. RESULTS: Of 1906 images, cam morphology was assessed in 1016 right and 890 left hips. Cross-sectionally, cam morphology modestly associated with age (prevalence ratio [PR]: 1.02 P = .03) and body mass index (BMI) (PR: 1.03-1.07, P = .03) and strongly related to male gender (PR: 2.96, P < .001). Radiographically, cam morphology was prevalent in those with decreased joint space (PR: 1.30 P = .03) and osteophytes (PR: 1.47, P = .03). Longitudinally, participants with right cam and high BMI had more hip pain (PR: 17.9, P = .02). At the end of 5 years of follow-up these participants were also more likely to have structural changes such as bone marrow lesions (BMLs) (PR: 1.90 P = .04), cartilage defects (PR: 1.26, P = .04) and effusion-synovitis at multiple sites (PR: 1.25 P = .02). Cam morphology at baseline in either hip predicted up to threefold risk of THR (PR: 3.19, P = .003) at the end of 14 years. CONCLUSION: At baseline, cam morphology was linked with age, higher weight, male gender, early signs of radiographic OA such as joint space narrowing (JSN) and osteophytes (OST). At follow-up, cam predicted development of hip BMLs, hip effusion-synovitis, cartilage damage and THR. These findings suggest that cam morphology plays a significant role in early OA and can be a precursor or contribute to hip OA in later life.

Efficacy, safety, and dose-dependence of the analgesic effects of opioid therapy for people with osteoarthritis: systematic review and meta-analysis.

OBJECTIVE: To evaluate the efficacy and safety of opioids for analgesic therapy for people with osteoarthritis. STUDY DESIGN: Systematic review and meta-analysis of randomised, placebo-controlled trials of opioid therapies for treating the pain of osteoarthritis. The primary outcome was medium term pain relief (six weeks to less than 12 months). Quality of evidence was assessed with GRADE criteria. DATA SOURCES: MEDLINE, EMBASE, the Cochrane Database of Systematic Reviews and Central Register of Controlled Trials, CINAHL, PsycINFO, AMED, and the WHO International Clinical Trials Registry; trials published to 31 October 2020. DATA SYNTHESIS: We extracted pain, disability, health-related quality of life, and adverse events data for 36 eligible trials (overall dose range: 10-210 oral morphine milligram equivalents [MME] per day). Continuous pain and disability outcomes were converted to common 0-100-point scales; changes of less than ten points were deemed to be very small effects. Differences in dichotomous outcomes were expressed as risk ratios. Data were pooled for meta-analysis in random effects models. The evidence from 19 trials (8965 participants; dose range, 10-126 MME/day) for very small medium term pain relief (mean difference [MD], -4.59 points; 95% CI, -7.17 to -2.02 points) was low quality, as was that from 16 trials (6882 participants; dose range, 10-126 MME/day) for a very small effect on disability (MD, -4.15 points; 95% CI, -6.94 to -1.35 points). Opioid dose was not statistically significantly associated with either degree of pain relief or incidence of adverse events in a meta-regression analysis. Evidence that opioid therapy increased the risk of adverse events (risk ratio, 1.43; 95% CI, 1.29-1.59) was of very low quality. CONCLUSIONS: Opioid medications may provide very small pain and disability benefits for people with osteoarthritis, but may also increase the risk of adverse events. PROSPERO REGISTRATION: CRD42019142813 (prospective).

The efficacy and safety of paracetamol for pain relief: an overview of systematic reviews.

OBJECTIVE: To evaluate the efficacy and safety of paracetamol as an analgesic medication in a range of painful conditions. STUDY DESIGN: Systematic review of systematic reviews of the analgesic effects of paracetamol in randomised, placebo-controlled trials. Conduct of systematic reviews was assessed with AMSTAR-2; confidence in effect estimates (quality of evidence) was assessed with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria. DATA SOURCES: MEDLINE, EMBASE, PsycINFO, Cochrane Database of Systematic Reviews; systematic reviews published 1 January 2010 - 30 April 2020. DATA SYNTHESIS: We extracted pain and adverse events outcomes from 36 systematic reviews that assessed the efficacy of paracetamol in 44 painful conditions. Continuous pain outcomes were expressed as mean differences (MDs; standardised 0-10-point scale); dichotomous outcomes were expressed as risk ratios (RRs). There is high quality evidence that paracetamol provides modest pain relief for people with knee or hip osteoarthritis (MD, -0.3 points; 95% CI, -0.6 to -0.1 points) and after craniotomy (MD, -0.8 points; 95% CI, -1.4 to -0.2 points); there is moderate quality evidence for its efficacy in tension-type headache (pain-free at 2 hours: RR, 1.3; 95% CI, 1.1-1.4) and perineal pain soon after childbirth (patients experiencing 50% pain relief: RR, 2.4; 95% CI, 1.5-3.8). There is high quality evidence that paracetamol is not effective for relieving acute low back pain (MD, 0.2 points; 95% CI, -0.1 to 0.4 points). Evidence regarding efficacy in other conditions was of low or very low quality. Frequency of adverse events was generally similar for people receiving placebo or paracetamol, except that transient elevation of blood liver enzyme levels was more frequent during repeated administration of paracetamol to patients with spinal pain (RR, 3.8; 95% CI, 1.9-7.4). CONCLUSIONS: For most conditions, evidence regarding the effectiveness of paracetamol is insufficient for drawing firm conclusions. Evidence for its efficacy in four conditions was moderate to strong, and there is strong evidence that paracetamol is not effective for reducing acute low back pain. Investigations that evaluate more typical dosing regimens are required. PROSPERO REGISTRATION: CRD42015029282 (prospective).

Quantification of hip effusion-synovitis and its cross-sectional and longitudinal associations with hip pain, MRI findings and early radiographic hip OA.

BACKGROUND: Hip effusion-synovitis may be relevant to osteoarthritis (OA) but is of uncertain etiology. The aim of this study was to describe the cross-sectional and longitudinal associations of hip effusion-synovitis with clinical and structural risk factors of OA in older adults. METHODS: One hundred ninety-six subjects from the Tasmanian Older Adult Cohort (TASOAC) study with a right hip STIR (Short T1 Inversion Recovery) Magnetic Resonance Imaging (MRI) on two occasions were included. Hip effusion-synovitis CSA (cm2) was assessed quantitatively. Hip pain was determined by WOMAC (Western Ontario and McMaster Universities Osteoarthritis) while hip bone marrow lesions (BMLs), cartilage defects (femoral and/or acetabular) and high cartilage signal were assessed on MRI. Joint space narrowing (0-3) and osteophytes (0-3) were measured on x-ray using Altman's atlas. RESULTS: Of 196 subjects, 32% (n = 63) had no or a small hip effusion-synovitis while 68% (n = 133) subjects had a moderate or large hip effusion-synovitis. Both groups were similar but those with moderate or large hip effusion-synovitis were older, had higher BMI and more hip pain. Cross-sectionally, hip effusion-synovitis at multiple sites was associated with presence of hip pain [Prevalence ratio (PR):1.42 95%CI:1.05,1.93], but not with severity of hip pain. Furthermore, hip effusion-synovitis size associated with femoral defect (ßeta:0.32 95%CI:0.08,0.56). Longitudinally, and incident hip cartilage defect (PR: 2.23 95%CI:1.00, 4.97) were associated with an increase in hip effusion-synovitis CSA. Furthermore, independent of presence of effusion-synovitis, hip BMLs predicted incident (PR: 1.62 95%CI: 1.13, 2.34) and worsening of hip cartilage defects (PR: 1.50 95%CI: 1.20, 1.86). While hip cartilage defect predicted incident (PR: 1.11 95%CI: 1.03, 1.20) and worsening hip BMLs (PR: 1.16 95%CI: 1.04, 1.30). CONCLUSIONS: Hip effusion-synovitis at multiple sites (presumably reflecting extent) may be associated with hip pain. Hip BMLs and hip cartilage defects are co-dependent and predict worsening hip effusion-synovitis, indicating causal pathways between defects, BMLs and effusion-synovitis.

Hip Shape as a Predictor of Osteoarthritis Progression in a Prospective Population Cohort.

OBJECTIVE: Hip morphology plays a significant role in the incidence and progression of hip osteoarthritis (OA). We hypothesized that hip shape would also be associated with other key factors and tested this in a longitudinal community-based cohort combining radiographic, magnetic resonance imaging (MRI), dual-energy x-ray absorptiometry (DXA), and clinical data. METHODS: Baseline DXA images of the left hip of 831 subjects from the Tasmanian Older Adult Cohort were analyzed using an 85-point statistical shape model. Hip pain was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index, and muscle strength was measured using a dynamometer. Hip structural changes were assessed using MRI and radiographic OA using plain radiographs. RESULTS: Six shape modes accounted for 68% of shape variation. At baseline, modes 1, 2, 4, and 6 were associated with radiographic hip OA; modes 1, 3, 4, and 6 were correlated with hip cartilage volume; and all except mode 2 were correlated with muscle strength. Higher mode 1 and lower mode 3 and mode 6 scores at baseline predicted hip pain at followup and higher mode 1 and mode 2 scores were associated with hip effusion-synovitis. Higher scores for mode 2 (decreasing acetabular coverage) and lower scores for mode 4 (nonspherical femoral head) at baseline predicted 10-year total hip replacement (THR), while mode 4 alone was correlated with bone marrow lesions (BMLs), effusion-synovitis, and increased cartilage signal. CONCLUSION: Hip shape is associated with radiographic OA, THR, hip pain, effusion-synovitis, BMLs, muscle strength, and hip structural changes. These data suggest that different shape modes reflect multiple facets of hip OA.

Correlates of Hip Cartilage Defects: A Cross-sectional Study in Older Adults.

OBJECTIVE: Knee cartilage defects are a key feature of osteoarthritis (OA) but correlates of hip defects remain unexplored. The aims of this cross-sectional study were to describe the correlates of hip cartilage defects. METHODS: The study included 194 subjects from the Tasmanian Older Adult Cohort who had right hip short-tau inversion recovery magnetic resonance imaging (MRI). Hip cartilage defects were assessed and categorized as grade 0 = no defects, grade 1 = focal blistering or irregularities on cartilage or partial thickness defect, and grade 2 = full thickness defect. Hip pain was determined by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Hip structural changes were measured on MRI, and hip radiographic OA (ROA) was assessed. Leg strength and physical activity were assessed using dynamometer and pedometers, respectively. Data were analyzed using log binomial and linear regression. RESULTS: Of 194 subjects, 24% (n = 48) had no defects, 34% (n = 66) had grade 1, and 41% (n = 80) had grade 2. In multivariable analyses, any hip defects were associated with greater hip pain [prevalence ratio (PR) 1.20, 95% CI 1.02-1.35] and lower mean leg strength (men; mean ratio 0.83, 95% CI 0.67-0.98). Grade 1 defects were associated with hip bone marrow lesions (BML; PR 1.42, 95% CI 1.03-1.96) and high cartilage signal (men; PR 1.84, 95% CI 1.27-2.70), but not with hip pain or other structural findings. Grade 2 defects were associated with greater hip pain (PR 1.40, 95% CI 1.09-1.80), hip BML (PR 1.45, 95% CI 1.15-1.85), hip effusion cross-sectional area (PR 1.14, 95% CI 1.01-1.30), hip ROA (men; PR 1.60, 95% CI 1.13-2.25), and steps/day (PR 0.97, 95% CI 0.96-0.99). CONCLUSION: Grade 2 defects in both sexes and grade 1 defects (mostly in men) are associated with clinical, demographic, and structural factors relevant for OA. Damage to the hip cartilage could be one of the major causes of rapid disease progression and pathophysiology of hip defects. The topic needs further study.

The association between hip muscle cross-sectional area, muscle strength, and bone mineral density.

Studies examining the association between muscle size, muscle strength, and bone mineral density (BMD) are limited. Thus, this study aimed to describe the association between hip muscles cross-sectional area (CSA), muscle strength, and BMD of the hip and spine. A total of 321 subjects from the Tasmanian Older Adult Cohort study with a right hip MRI scan conducted between 2004 and 2006 were included. Hip muscles were measured on MR images by OsiriX (Geneva) software measuring maximum muscle CSA (cm(2)) of gluteus maximus, obturator externus, gemelli, quadratus femoris, piriformis, pectineus, sartorius, and iliopsoas. Dual-energy X-ray absorptiometry measured total hip, femoral neck, and spine BMD, and lower limb muscle strength was assessed by dynamometer. Muscle CSA of the hip flexors (pectineus, sartorius, and iliopsoas) and the hip rotators, obturator externus, and quadratus femoris were associated with both total hip and femoral neck BMD (all p < 0.05). The associations between CSA of pectineus and sartorius and BMD were stronger in women (p = 0.01-0.001) compared to men (p = 0.12-0.54). Additionally, only gemelli CSA was associated with BMD of the spine (p = 0.002). Gluteus maximus and piriformis showed no relationship with BMD. CSA of most hip muscles (except gluteus maximus and gemelli) were positively associated with leg strength (p = 0.02 to <0.001). Lastly, leg strength was weakly associated with BMD (p = 0.11-0.007). Hip muscle CSA, and to a lesser extent muscle strength, were positively associated with hip BMD. These data suggest that both higher muscle mass and strength may contribute to the maintenance of bone mass and prevention of disease progression in older adults.

A population-based study of the association between hip bone marrow lesions, high cartilage signal, and hip and knee pain.

The objective of this study was to describe the cross-sectional and longitudinal relationship between hip bone marrow lesions (BMLs), high cartilage signal, and hip and knee pain. One hundred ninety-eight participants in the Tasmanian Older Adult Cohort Study with right hip MRI conducted at two time points, approx. 2.3 years apart, were included. Short T1 Inversion Recovery MR images were used to quantitatively measure hip BML size and determine high cartilage signal presence. Hip and knee pain were individually assessed using the Western Ontario and McMaster Universities Osteoarthritis index pain score. Fifty-five participants (28%) had either femoral and/or acetabular BMLs. Cross-sectionally, the presence of large femoral, acetabular, or any hip BMLs was associated with higher odds of hip pain (OR = 4.42, 95% CI = 1.37-19.7; OR = 5.23, 95% CI = 1.17-22.9; OR = 4.43, 95% CI = 1.46-13.2, respectively). High cartilage signal was strongly associated with hip BMLs (OR = 6.45, 95% CI = 3.37-12.6), but not with pain. Longitudinally, incident acetabular (Mean diff = +5.90, 95% CI = +3.78 to +8.15) and femoral BMLs (Mean diff = +1.18, 95% CI = 0.23-1.94) were associated with worsening hip pain, while resolving femoral BMLs were associated with a decrease in knee pain (Mean diff = -3.18, 95% CI = -5.99 to -0.50). The evidence is consistent for hip, but not knee pain, and strongly suggests that large hip BMLs are associated with hip pain. Furthermore, high cartilage signal is asymptomatic, but strongly associated with hip BMLs. These findings suggest that hip BMLs play an important role in hip osteoarthritis.