The prevalence of pincer morphology in early adolescents from the general population: a population-based study (Generation R).

Objective: Pincer morphology can lead to femoroacetabular impingement syndrome (FAIS) and may be a modifiable risk factor for hip osteoarthritis (OA). Currently, no studies investigate the prevalence of pincer morphology in early adolescence-the period when this bony shape likely develops. The purpose of this study was to estimate the prevalence and birth-assigned sex distribution of pincer morphology in early adolescents from the general population in the Netherlands.

Methods: This study was embedded in the Generation R study, a population-based prospective cohort in Rotterdam, the Netherlands. Around the age of 13 years, participants underwent high-resolution dual-energy x-ray absorptiometry (DXA) of their full-body and right hip. The lateral center edge angle (LCEA) was automatically determined based on landmarks outlining the hip contour, and pincer morphology was defined as a LCEA ≥ 40°. The overall and birth-assigned sex-specific prevalence was presented as a percentage with 95% confidence interval (CI).

Results: A total of 3,986 adolescents (median age 13.5 years [2.5th - 97.5th percentile, 13.2 - 14.6]; 46.8% males) were included. The overall prevalence of pincer morphology was 3.1% (95% CI 2.6% - 3.6%). The prevalence in male and female adolescents was 3.0% (95% CI 2.2% - 3.7%) and 3.3% (95% CI 2.5% - 4.0%), respectively.

Conclusion: Among early adolescents from the general population in the Netherlands, the estimated prevalence of pincer morphology was 3.1%. Male and female adolescents had a similar prevalence of pincer morphology. These findings could inform the timing of prevention strategies for pincer morphology, potentially reducing the risk of FAIS and hip OA.