Obesity-associated Morphological Changes in Acetabular Growth and Development: Potential Implications for Slipped Capital Femoral Epiphysis.

Background: The morphology of the femur and acetabulum along with metabolic abnormalities associated with childhood obesity plays a role in the pathogenesis of Slipped Capital Femoral Epiphysis (SCFE). This study investigates the relationship between childhood obesity and acetabular morphology using automated 3D-CT analysis in a large pediatric cohort. Methods: This retrospective cross-sectional study included 4,888 children and adolescents aged 7-19 years who underwent pelvic CT scans for abdominal pain between 2004 and 2022. After excluding patients with documented hip pathology, we performed automated 3D segmentation and measurements of acetabular diameter, depth, and version, as well as center-edge angles (CEA) at multiple acetabular regions. Generalized additive models (GAMs) were used to assess the relationship between BMI status (obese vs. non-obese) and acetabular morphology, with adjusting for sex and age. Results: Obese patients exhibited significantly larger acetabular diameters and depths from ages 7-13 years, with differences ranging from 0 to 2 mm. Acetabular version increased with age in both groups but was consistently lower (more retroverted) in obese patients, with significant differences ranging from 1° to 3.5° for proximal version and 1°-3° for central version. Posterior, superior, and anterior coverage were also significantly larger in obese subjects, with differences ranging from 1° to 5°. Conclusion: Obesity in children and adolescents is associated with significant alterations in acetabular morphology, including increased diameter, depth, and focal coverage, as well as reduced version, suggesting a distinct pattern of acetabular growth. These morphological differences may contribute to altered hip mechanics which combined with other anatomic and metabolic factors may increase the susceptibility to SCFE in obese children. Key Concepts: (1)Obesity is associated with alterations in acetabular morphology, which may have implications for the development of hip pathology in obese patients, including SCFE.(2)The study demonstrated that obese subjects exhibited lower values of acetabular version, i.e more retroverted acetabula compared to their healthy-weight counterparts after age 10.(3)Posterior acetabular coverage, as measured by the CEA at the 9 and 10 positions, was slightly larger in obese patients compared to healthy-weight individuals between the ages of 9 and 14, after which there was no significant difference.(4)Anterior acetabular coverage, measured at the 1, 2, and 3 o'clock positions, demonstrated significant differences between obese and healthy-weight subjects with obese patients demonstrating larger coverage anteriorly than non-obese patients.(5)Further research is recommended to determine whether the acetabular morphologic differences observed in this study may play a role in early recognition or screening in children at risk for SCFE. Level of Evidence: Level III, Retrospective Cohort Study.