Radiographic hip osteoarthritis and acetabular dysplasia in Turkish men and women

The prevalence of hip osteoarthritis (OA) varies with different regions, and the reasons for this remain unclear. Mild acetabular dysplasia has been considered a risk factor for hip OA, but recent studies have not confirmed this. In Turkey, the prevalence of significant radiographic hip OA, i.e. Kellgren-Lawrence (K-L) grades 3 and 4, is lower than in Western populations. We aimed to investigate the potential effects of radiographic measures of acetabular dysplasia on this discrepancy. Ninety-two Turkish patients (65 males, 27 females) aged 55 and over were studied. Plain supine abdominal radiographs and intravenous pyelographs were evaluated. Centre-edge (CE) angle and acetabular depth (AD) of each hip were measured, and K-L grading was done. The mean CE angles ± SD of right and left hips were 34±7° and 35±7° (range 14–52 and 18–50), respectively. The mean AD±SD of right and left hips was 13.7±3.4 and 13.6±3.4 (range 6–23 and 8–25), respectively. Mean CE angle or acetabular depth of the hips with K-L grade 2 did not differ from those with grades 0 and 1. There was no patient with grade 3 or 4. The prevalence of acetabular dysplasia based on a CE angle of <25° was 9.8% in both right and left hips. When it was defined as having an AD of <9 mm, the prevalence was 4.3% and 1.1% in the right and left hips, respectively. Overall, 10.4% of the hips (13% of the men and 3.7% of the women) had acetabular dysplasia based on at least one of these measurements. Mild acetabular dysplasia appears to be relatively common among Turks aged 55 and over. However, it does not seem to play a major role in the development of radiographic hip OA.