Radiographic changes in forefoot geometry with weightbearing.

Quality assessment of forefoot surgery depends mainly on weightbearing radiographs. A prospective study has been performed to compare the influence of weightbearing on forefoot geometry. Dorsoplantar radiographs for weightbearing and non-weightbearing conditions were performed in 99 patients. Hallux valgus angle, the intermetatarsal angles between the first and second and first and fifth metatarsals and intermetatarsal distance were measured using an interactive digitizer connected to a computer. The intermetatarsal angles showed a statistically significant increase during weightbearing. Unrelated to the severity of hallux valgus deformity, hallux valgus angles demonstrated an inverse behavior showing larger values under non-weightbearing conditions. For that reason, radiological evaluation of forefoot geometry strictly requires similar weightbearing conditions and comparable positioning of the foot.