Prevalence of Cam and Pincer Morphology in the Young Athlete's Hip: A Systematic Review With Meta-Analysis.

OBJECTIVES: To (1) examine the prevalence of cam and pincer morphologies in adolescent (ages 10-19 years) and young adult (ages 20-35 years) athletes, and (2) summarize diagnostic imaging and clinical assessment methods associated with femoroacetabular impingement (FAI) syndrome. DESIGN: Epidemiology systematic review with meta-analysis. LITERATURE SEARCH: The MEDLINE, Embase, SPORTDiscus, CINAHL, and Scopus databases were searched to February 2025. STUDY SELECTION CRITERIA: English studies reporting on prevalence of FAI syndrome morphologies, whether symptomatic or not, in male/female athletes (10-35 years) were eligible. Studies were excluded if they focused on adapted or parasports or included participants who had undergone corrective surgery. DATA SYNTHESIS: Two independent raters conducted screening, extracted data, and assessed quality/risk of bias. Meta-analyses were performed for cam and pincer morphology prevalence, stratified by age group. Methods of clinical assessment and diagnostic imaging were descriptively reported. The primary analysis compared morphologies between adolescent and young adult athletes with subgroup (hip vs participant) and factor (sex) analyses. RESULTS: Forty-seven studies reporting on 1241 adolescents (16% female) and 2462 young adults (20% female) were included. Primary analysis estimates for the prevalence of cam morphology (48%; 95% confidence interval [CI]: 38, 58) and pincer morphology (18%; 95% CI: 7, 32) indicated no difference between age groups. Many studies (n = 17, 35%) assessed FAI syndrome according to Warwick recommendations (signs, symptoms, imaging). Few studies stratified findings by symptomatic state. CONCLUSION: Cam morphology appeared to develop in early adolescence. Few studies reported findings in females, and diagnostic methods were inconsistent.