Prevalence of early hip OA features on MRI in high-impact athletes. The femoroacetabular impingement and hip osteoarthritis cohort (FORCe) study.

OBJECTIVE: To compare early hip osteoarthritis (OA) features on magnetic resonance imaging (MRI) in high-impact athletes with and without hip and/or groin pain, and to evaluate associations between early hip OA features, the International Hip Outcome Tool (iHOT33) and Copenhagen Hip and Groin Outcome Score (HAGOS). DESIGN: This case-control study evaluated data of the femoroacetabular impingement and hip osteoarthritis cohort (FORCe). One hundred and eighty-two symptomatic (hip and/or groin pain >6 months and positive flexion-adduction-internal-rotation (FADIR) test) and 55 pain-free high-impact athletes (soccer or Australian football (AF)) without definite radiographic hip OA underwent hip MRI. The Scoring Hip Osteoarthritis with MRI (SHOMRI) method quantified and graded the severity of OA features. Each participant completed the iHOT33 and HAGOS. RESULTS: Hip and/or groin pain was associated with higher total SHOMRI (0-96) (mean difference 1.4, 95% CI: 0.7-2.2), labral score (adjusted incidence rate ratio (aIRR) 1.33, 95% CI: 1.1-1.6). Differences in prevalence of cartilage defects, labral tears and paralabral cysts between symptomatic and pain-free participants were inconclusive. There was a lower prevalence of effusion-synovitis in symptomatic participants when compared to pain-free participants (adjusted odds ratio (aOR) 0.46 (95% CI: 0.3-0.8). Early hip OA features were not associated with iHOT33 or HAGOS. CONCLUSIONS: A complex and poorly understood relationship exists between hip and/or groin pain and early hip OA features present on MRI in high-impact athletes without radiographic OA. Hip and/or groin pain was associated with higher SHOMRI and labral scores.

Muscle size and composition in people with articular hip pathology: a systematic review with meta-analysis.

OBJECTIVE: To synthesise and evaluate the current evidence investigating muscle size and composition in non-inflammatory articular hip pathology. METHODS: A systematic review of five electronic databases, using three concepts; articular hip pathology (e.g., osteoarthritis (OA)); hip muscles; and outcomes (e.g., muscle size and adiposity) was undertaken. Studies addressing non-inflammatory or non-traumatic articular hip pain, using measures of muscle size and adiposity were included and appraised for risk of bias. Data was extracted to calculate standardised mean differences (SMD) and pooled where possible for meta-analysis. RESULTS: Thirteen cross-sectional studies were included; all studies measured muscle size and 5/13 measured adiposity. In OA, there was low to very low quality evidence of no difference in hip muscle size, compared with matched controls. In unilateral OA, there was low to very low quality evidence of smaller size in gluteus minimus (SMD -0.38; 95% confidence interval (CI) -0.74, -0.01), gluteus medius (-0.44; 95% CI: -0.83, -0.05) and gluteus maximus (-0.39; 95% CI: -0.75, -0.02) muscles in the symptomatic limb. Individual studies demonstrated non-uniform changes in muscle size in OA. No significant difference was observed in muscle size in other pathologies or in adiposity for any group. CONCLUSION: There is some low quality evidence that specific hip muscles are smaller in unilateral hip OA. Variation in the magnitude of differences indicate changes in size are not uniform across all muscles or stage of pathology. Studies in larger cohorts investigating muscle size and composition across the spectrum of articular pathologies are required to clarify these findings.

The association between statistical shape modeling-defined hip morphology and features of early hip osteoarthritis in young adult football players: Data from the femoroacetabular impingement and hip osteoarthritis cohort (FORCe) study.

Objective: To explore the relationship between radiographic hip shape and features of early hip osteoarthritis (OA) on magnetic resonance imaging (MRI) in young male and female football players without radiographic hip OA. Design: We used baseline data from a cohort of symptomatic and asymptomatic football players aged 18-50 years. Hip shape was assessed on anteroposterior radiographs with statistical shape modeling (SSM) for men and women separately. Cartilage defects and labral tears were graded using the Scoring Hip Osteoarthritis with MRI (SHOMRI) system. We used logistic regression with generalized estimating equations to estimate associations between each hip shape variant, called shape modes, and cartilage defects or labral tears. Results: We included 229 participants (446 hips, 77.4% male). For each sex, 15 shape modes were analyzed. In men, three shape modes were associated with cartilage defects: adjusted odds ratios (aOR) 0.75 (95%CI 0.58-0.97) per standard deviation (SD) for mode 1; 1.34 (95%CI 1.05-1.69) per SD for mode 12; and 0.61 (95%CI 0.48-0.78) per SD for mode 15; and one also with labral tears: aOR 1.30 (95%CI 1.01-1.69) per SD for mode 12. These modes generally represented variations in the femoral neck and subtypes of cam morphology, with and without pincer morphology. For women, there was no evidence for associations with the outcomes. Conclusions: Several hip shape variants were associated with cartilage defects on MRI in young male football players. Specifically, one subtype of cam morphology was associated with both cartilage defects and labral tears. Hip shape was not associated with early OA features in women.