Foot and Ankle Radiographic Parameters in Korean Adults Vary by Sex and Age.

Although many radiographic measurements of the foot and ankle have been used, reference values for normal functional groups are rarely reported. These can change according to sex and age; therefore, this study aimed to: (1) determine reference values for radiographic foot and ankle angles in an asymptomatic healthy Korean population, and (2) compare differences in the measurements according to sex and age. A total of 200 healthy volunteers were recruited, including 100 young adults (50 males, 50 females) aged 20 to 35 years, and 100 older adults (50 males, 50 females) aged 60 to 69 years. Weightbearing ankle anteroposterior views, talar tilt, and tibiotalar angles were measured. On the weightbearing foot anteroposterior views, the hallux valgus, hallux interphalangeal, and talo-first metatarsal angles were measured. On the weightbearing lateral foot views, the calcaneal pitch, lateral talo-calcaneal, lateral talo-first metatarsal, and lateral calcaneo-first metatarsal angles were measured. Values were stratified by sex and age, and statistically compared. The hallux valgus, calcaneal pitch, and lateral calcaneo-first metatarsal angles were affected by both sex and age; the hallux interphalangeal angle was affected by age and the lateral talo-first metatarsal angle by sex. We presented reference values for foot and ankle radiographic measurements in a healthy Korean population; several radiographic indices varied significantly by sex or age, which were grossly similar to previous studies based on white race. The study data can serve as a basis for evaluation of foot and ankle disorders.