Association between hip pain and radiographic hip osteoarthritis in primary care: the CHECK cohort

Background The diagnosis of hip osteoarthritis (OA) is often based on clinical symptoms, such as pain and stiffness, and radiographic features. However, the association between hip pain and hip radiographic OA (ROA) remains uncertain. Aim To examine the association between hip pain and hip ROA. Design and setting Cross-sectional analysis of a Dutch cohort, the Cohort Hip and Cohort Knee (CHECK) study. Method The participants (aged 45-65 years) had all experienced hip and/or knee pain for which they had not had a prior consultation or were within 6 months of their first consultation with a GP. Using weight-bearing anteroposterior pelvis radiographs, definite and early-stage hip ROA were defined as Kellgren and Lawrence grade & GE;2 and & GE;1, respectively. Presence of ROA and pain was assessed in the hips of all participants. The association between hip pain and ROA was assessed using generalised estimating equations. Results The prevalence of definite ROA was 11.0% (n = 218/1982 hips), with prevalence in painful and pain-free hips of 13.3% (n = 105/789) and 9.5% (n = 113/1193), respectively. Prevalence of early-stage hip ROA was 35.3% (n = 700/1982), with prevalence in painful and pain-free hips of 41.2% (n = 325/789) and 31.4% (n = 375/1193), respectively. Compared with pain-free hips, the odds ratio painful hips was 1.51 (95% confidence interval [CI] = 1.16 to 1.98) for definite ROA and 1.47 (95% CI = 1.24 to 1.75) for early-stage ROA. Conclusion Hip pain was associated with definite and early -stage hip ROA, yet the overall ROA prevalence was modest and the prevalence among pain-free hips was substantial. Therefore, radiographs provided little assistance with help to identify patients with hip OA among patients who recently presented with hip or knee complaints.