Radiographic analysis of hallux valgus and first tarsometatarsal joint correction after isolated first metatarsophalangeal joint arthrodesis.

Arthrodesis of the first metatarsophalangeal joint is a common surgical procedure used to treat a variety of forefoot pathologies. The purpose of this study was to evaluate radiographic outcomes for hallux valgus and first tarsometatarsal joint alignment after first metatarsophalangeal joint arthrodesis. A retrospective radiographic analysis of the first intermetatarsal angle, hallux valgus angle, first metatarsal-cuneiform angle, and medial cuneiform-first metatarsal angle was performed preoperatively and postoperatively. One hundred eighty-eight procedures met inclusion criteria. Significant radiographic improvements were noted in first intermetatarsal angle (4.38°, P < 0.0001), hallux valgus angle (16.01°, P < 0.0001), first metatarsal-cuneiform angle (5.96°, P < 0.0001), and medial cuneiform-first metatarsal angle (5.68°, P < 0.0001). Significant radiographic improvements (P < 0.0001) were also noted when subjects were subdivided into first intermetatarsal angle ≤ 15° and > 15° for all measured angles. An isolated first metatarsophalangeal joint arthrodesis corrects both hallux valgus deformity and first tarsometatarsal alignment. These findings support that additional first ray procedures may not be required when performing a first metatarsophalangeal joint arthrodesis for hallux valgus.