Prevalence and Radiographic Morphology of Hallux Valgus in Adolescent Athletes

Hallux valgus (HV) can shift plantar loading, impair hallux function, and affect athletic performance in adolescent athletes. Although previous studies have focused mainly on dance-related sports, limited data exist regarding the prevalence and radiographic morphology of HV across broader athletic populations. In particular, the role of hallux interphalangeal alignment and proximal phalanx morphology in deformity severity remains unclear. We aimed to determine HV prevalence among adolescent athletes across various sports and to identify radiographic morphological factors associated with deformity severity.

This cross-sectional study included 280 adolescent athletes (188 males and 92 females; mean age, 13.7 ± 1.6 years) across 18 sports. Weight-bearing foot radiographs were obtained. Radiographic parameters included the HV angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), hallux interphalangeal angle (HIA), proximal-distal phalanx articular angle (PDPAA), Meary angle, calcaneal pitch angle, and medial cuneiform-fifth metatarsal height. Multivariable linear regression analyses were performed separately for dominant and nondominant feet to identify factors associated with combined deformity severity (sum of HVA and HIA).

HV was identified in 42.9% of athletes when defined as HVA ≥ 15° in either foot and was more prevalent in female than male athletes (59.8% vs. 34.6%, p < 0.001). In contrast, 93.6% of athletes had an HIA ≥ 10° in either foot, based on the conventional adult-derived threshold, with no significant sex difference. In this multi-sport adolescent athlete population, distal first metatarsal morphology (DMAA) and proximal phalanx articular morphology (PDPAA) showed the strongest independent associations with combined deformity severity. IMA and female sex were also significant factors, whereas sagittal plane alignment, body mass index, and ankle activity score were not.

This multi-sport study extends previous findings on adolescent hallux deformity by demonstrating that deformity severity is associated not only with metatarsal structural factors but also with proximal phalanx articular morphology. These findings support a broader radiographic characterization of adolescent HV, although their clinical significance requires further study.