The Effect of First Metatarsophalangeal Arthrodesis on Transverse Plane Deviation of the Second Toe: A Retrospective Radiographic Study

The purpose of this retrospective, radiographic study was to examine the effect of first metatarsophalangeal arthrodesis on the transverse plane deviation of the second metatarsophalangeal joint. Sixty-nine patients (76 feet) were separated into 3 groups based on preoperative diagnosis: group 1, hallux valgus; group 2, hallux rigidus; and group 3, rheumatoid forefoot deformity with concomitant lesser metatarsal head resection. Intermetatarsal, hallux abduction, and second metatarsophalangeal angles were measured on preoperative and follow-up anteroposterior radiographs. Multivariate analysis found a significant postoperative change (P < .001) in both the intermetatarsal and hallux abduction angles for all groups, but no significant change in the second metatarsophalangeal angle for any group. There was also no significant difference in the number of patients with medial versus lateral second toe deviation in each group. The addition of a second ray procedure, such as a digital arthrodesis or second metatarsal decompression osteotomy, in groups 1 and 2 did not correlate to the amount of change in second metatarsophalangeal deviation. However, there was a significant correlation (r = .330; P = .004) between the amount of change in the hallux abduction angle and the amount of change in the second metatarsophalangeal angle. A lack of change in the second metatarsophalangeal angle in patients with hallux valgus and hallux rigidus suggests that the creation of a stable medial buttress may protect the lesser digits. However, in patients with rheumatoid, this lack of change denotes a postoperative recurrence of lateral deviation of the second toe despite lesser metatarsal head resection and stabilization of the hallux.