Radiographic Outcomes Following Primary Arthrodesis of the First Metatarsophalangeal Joint in Hallux Abductovalgus Deformity

The purpose of this study was to evaluate the radiographic outcomes of primary metatarsophalangeal joint arthrodesis for hallux abductovalgus deformities. Between January 2004 and March 2009, 56 consecutive patients (58 feet) underwent primary arthrodesis of the metatarsophalangeal joint (MTPJ) for severe hallux abductovalgus deformity and or hallux rigidus. Results were assessed by primary radiographic outcome measurements (hallux valgus and first-second intermetatarsal angle). Overall, the mean hallux valgus (HA) angle improved significantly from 31.9° to 13.4° (P < .01). The mean first-second intermetatarsal (IM) angle correction was also signficantly reduced from 14.0° to 9.7° (P < .01). When separated by deformity group (mild, moderate, and severe), the mean hallux valgus and first-second intermetatarsal angles demonstrated statistically significant correction in all groups when comparing preoperative and postoperative values (P < .01). Primary arthrodesis provides predictable radiographic outcomes and effective correction for patients with differing severity of hallux abductovalgus deformity and arthritis of the first metatarsophalangeal joint. A separate proximal osteotomy for severe metatarsus primus varus correction may not be necessary because of the correction achieved at the metatarsophalangeal joint arthrodesis level. The results of this study demonstrate that as the severity of the preoperative deformity increases, the amount of postoperative radiographic (HA and IM angle measurement) correction after MTPJ arthrodesis will improve correspondingly.