Results of External Fixation and Metatarsophalangeal Joint Fixation With K-Wire in Brachymetatarsia.

Background: Brachymetatarsia is a rare foot deformity caused by the premature closure of the metatarsal physis. It may result in functional as well as cosmetic alterations, which may require operative management.

Methods: A prospective study examining outcomes of 48 cases of brachymetatarsia with gradual bone lengthening at a rate of 1 mm/d using an external fixator and metatarsophalangeal joint fixation was performed. The difference between the length before treatment and after external fixator removal was measured. The patients were assessed at 2, 4, 6, and 8 weeks postoperatively; at the end of the period of distraction; and 1 year after surgery. The total number of patients was 26, and surgery was performed in 48 metatarsals. The mean age was 17.0 ± 4.1 (range, 11-24) years, and all were female.

Results: The fourth metatarsal was the most frequently affected, representing 98% of the cases; the third metatarsal represented the other 2%. The average length gained was 18.6 ± 6.7 mm, and the average length gained as a proportion of the original metatarsal length was 38.2% ± 3.1% (range, 13%-24%). The mean healing time was 71.0 (range, 64-104) days, and the mean healing index (healing time divided by centimeters of length gained [d/cm]) was 38.4 (range, 38.2-50.1) d/cm.

Conclusion: Gradual bone lengthening at a rate of 1 mm/d using an external fixator and intramedullary nailing was a safe and efficient method, representing a minimally invasive procedure with a low incidence of complications and satisfactory results for the patient.

Level Of Evidence: Level IV, retrospective case series.