Consequences of Avulsion Fracture of the Proximal Phalanx Caused by a Technical Failure of Hallux Valgus Surgery.

Several cases of avulsion fracture of the proximal phalanx of the big toe during the lateral capsular release procedure were observed. However, these fractures have not been reported as a complication of hallux valgus surgery. The purpose of the present study was to report the proximal phalanx base fracture as an unrecognized complication and to evaluate the clinical and radiographic consequences of this complication. We retrospectively reviewed 225 feet that had undergone hallux valgus surgery involving proximal chevron osteotomy and distal soft tissue release from May 2009 to December 2012. Of these 225 feet (198 patients), 12 (5.3%) developed proximal phalanx base fracture postoperatively. These patients were assigned to the fracture group. The remaining patients were assigned to the nonfracture group. Patients were followed to observe whether the fractures united and whether degenerative changes developed at the first metatarsophalangeal joint because of this fracture. The mean follow-up period was 36 (range 12 to 72) months. All the subjects in the fracture and nonfracture groups underwent weightbearing anteroposterior and lateral radiographs of the foot at the initial presentation and final follow-up point. The 2 groups were compared with respect to the hallux valgus angle, intermetatarsal angle, range of motion, American Orthopaedic Foot and Ankle Society score, satisfaction, and degenerative changes. No significant differences were found in age, follow-up period, hallux valgus angle, intermetatarsal angle, range of motion of the first metatarsophalangeal joint, American Orthopaedic Foot and Ankle Society score, satisfaction, and degenerative changes between the 2 groups. Ten (83.3%) of the 12 fractures healed, 2 (16.7% of the fractures, 0.89% of the operated feet) progressed to asymptomatic nonunion, and 3 (1.33%) developed first metatarsophalangeal joint degeneration. Avulsion fracture of the proximal phalanx of the big toe is an uncommon complication of hallux valgus surgery. It seems to be caused by excessive tension placed on the lateral soft tissues that attach to the base of the proximal phalanx at the time of plantarlateral soft tissue release. However, this fracture does not seem to cause significant clinical problems.