Acetabular Dysplasia Linked to Increased Risk of Hip Osteoarthritis in Women and Older Adults: Research Suggests

The findings, published in the journal Osteoarthritis and Cartilage, highlight the importance of monitoring individuals with AD for potential progression to osteoarthritis to enable early intervention and management.

Hip osteoarthritis (OA) has no curative nonsurgical treatment, making prevention vital. However, understanding risk factors for radiographic hip OA (RHOA) remains limited. Subtle hip shape abnormalities, such as acetabular dysplasia, may precede OA development and represent potential targets for prevention. AD, characterized by insufficient coverage of the femoral head by the acetabulum, leads to mechanical cartilage stress and may contribute to OA progression. Previous studies suggest an association between AD and RHOA, but inconsistencies and limited statistical power have hindered conclusive evidence.

Against the above background, Noortje S. Riedstra, Erasmus Medical Center, the Netherlands, and colleagues aimed to explore the relationship between various radiographic definitions of AD and incident RHOA, including subgroup analyses.

For this purpose, the researchers selected hips free of RHOA at baseline with a follow-up period of 4–8 years from the World COACH consortium. They calculated the Wiberg center edge angle (WCEA), acetabular depth width ratio (ADR), and modified acetabular index (mAI) to assess acetabular dysplasia. AD was defined as WCEA ≤ 25°, with secondary analyses using thresholds such as WCEA ≤ 20°, ADR ≤ 250, mAI ≥ 13°, and their combinations.

A logistic regression model with generalized mixed effects (3 levels) was applied, adjusting for age, biological sex, and body mass index (BMI). Descriptive statistics were reported stratified by age, sex, and BMI.

Key Findings:

• The analysis included a total of 18,807 hips from 9 studies. Baseline characteristics included an average age of 61.84 years (± 8.32), a mean BMI of 27.40 kg/m² (± 4.49), and 70.1% of women.
• Of the hips studied, 4766 hips (25.3%) had WCEA ≤ 25°.
• During a follow-up period of 4–8 years (mean 5.8 ± 1.6), 378 hips (2.0%) developed incident RHOA.
• There was an association between acetabular dysplasia and the development of RHOA (adjusted OR [aOR] 1.80).
• Secondary analyses confirmed that all other definitions of AD were also associated with incident RHOA, with aOR values ranging from 1.52 to 1.96.
• Descriptive statistics indicated a higher relative risk (RR) of developing RHOA in AD hips compared to non-AD hips in the following groups:
  • Age group 61–70 (RR 1.70)
  • BMI < 25 (RR 1.66)
  • Female hips (RR 1.73)

"Our study confirmed that acetabular dysplasia is a significant risk factor for the development of incident radiographic hip osteoarthritis (RHOA) in hips free of RHOA at baseline. Through an individual participant data (IPD) meta-analysis with large sample size, uniform AD measurements across radiographs, and a standardized RHOA outcome, the study provided a robust evaluation of the AD-RHOA association," the authors wrote.

They emphasized that identifying modifiable risk factors like AD is critical for preventing hip osteoarthritis, improving quality of life, and advancing individualized care and the development of targeted treatments in the future.

Reference:

Riedstra NS, Boel F, van Buuren MMA, Ahedi H, Arbabi V, Arden N, Baart S, Bierma-Zeinstra S, Cicuttini F, Cootes TF, Crossley KM, Felson D, Giellis WP, Heerey J, Jones G, Kluzek S, Lane NE, Lindner C, Lynch JA, van Meurs JBJ, Mosler A, Nelson AE, Nevitt M, Oei E, Runhaar J, Tang J, Weinans H, Agricola R. Acetabular dysplasia and the risk of developing hip osteoarthritis within 4-8 years; an individual participant data meta-analysis of 18,807 hips from the World COACH consortium. Osteoarthritis Cartilage. 2024 Dec 8:S1063-4584(24)01479-1. doi: 10.1016/j.joca.2024.12.001. Epub ahead of print. PMID: 39657871.