Cam morphology in Japanese adolescent male football player: a prospective study with 3-year follow-up

BACKGROUND: Cam morphology developed during adolescent increases the risk of hip osteoarthritis by 4.3-6.2-fold over 5 and 10 years. Although cam morphology are believed to occur during the growth period, when significant physical changes take place, no studies have examined the relationship with physical maturation indicators. AIM: The aim of this study was twofold: (1) to examine the prevalence of cam morphology in Japanese adolescent football players.; (2) to investigate if cam morphology development is associated with peak height velocity age(PHVA) status. METHODS: Fifty-seven adolescent male football players (114 hips) were prospectively 1enrolled. Hip morphology was assessed using dual-energy X-ray absorptiometry at baseline and at 1- and 2-year follow-up. Participants with missing data, longitudinal height records required for estimating peak height velocity age (PHVA), were excluded. Consequently, 47 participants (94 hips) were included in the final analysis. Cam morphology on these time points was defined as: (A) visual scores of the anterior head-neck junction, classified as: (1) normal, (2) flattening, and (3) prominence. We calculated the years from age at PHV of each participant by subtracting the chronological age from the age at PHV to determine the period until the peak of growth. RESULTS: Cam morphology based on visual scores was found in 79 of 94 hips(84.0%, 39 kicking leg, 40 shaft leg)at in 2-year follow-up. non-association between cam morphology development based on visual scores and PHVA status (OR = 1.08, 95% CI 0.81-1.52, p = 0.517). CONCLUSION: Although previous studies have suggested a lower prevalence of cam morphology in East Asian football players than in Western populations, we observed a relatively high hip-level prevalence of DXA-defined cam morphology, increasing from 53.2% (50/94 hips) at baseline to 84.0% (79/94 hips) at the 2-year follow-up, in this cohort of 47 Japanese adolescent football players. In addition, cam morphology developed both before and after peak height velocity age (PHVA), indicating that its development is not confined to a specific stage of biological maturation.