Comparison of the outcomes of distraction osteogenesis for first and fourth brachymetatarsia

Brachymetatarsia is the presence of an abnormally short metatarsal, and distraction osteogenesis has been used for its treatment. The purpose of the present study was to compare the outcomes of patients who underwent distraction osteogenesis for the treatment of first and/or fourth brachymetatarsia.

The data from forty-eight patients (sixty-four feet, seventy-four metatarsals) who underwent distraction osteogenesis for the treatment of brachymetatarsia were reviewed. The indications for surgery included a metatarsal that was at least 10 mm shorter than the adjacent metatarsal and that had an unacceptable cosmetic appearance. The study group comprised thirty-two first brachymetatarsia in nineteen patients (Group A) and forty-two fourth brachymetatarsia in twenty-nine patients (Group B). The average age was twenty years in Group A and eighteen years in Group B. The average duration of follow-up was 58.1 months in Group A and 56.1 in Group B. Metatarsal length, lengthening gain, healing time and index, and the American Orthopaedic Foot and Ankle Society hallux metatarsophalangeal-interphalangeal and lesser metatarsophalangeal-interphalangeal scores were evaluated.

All patients were satisfied with the final length of the metatarsal and all had achieved bone union at the time of the last follow-up. The mean lengthening gain was 17.2 mm (42.9%) in Group A and 16.3 mm (37.3%) in Group B. The mean healing index was 71.0 days/cm in Group A and 67.3 days/cm in Group B. The mean American Orthopaedic Foot and Ankle Society score was 91.2 points in Group A and 92.8 points in Group B at the last follow-up (twenty-two excellent, nine good, and one fair results in Group A, and twenty-nine excellent, eleven good, and two fair results in Group B). The most common complication was metatarsophalangeal joint stiffness, which occurred in thirteen rays in Group A and in twelve rays in Group B; malalignment of the lengthened metatarsal was observed six times in each group. No significant intergroup differences in the outcomes were found.

Distraction osteogenesis for first and/or fourth brachymetatarsia provided successful lengthening of a metatarsal with eventual osseous union and was associated with similar outcomes in terms of healing index, function score, and the prevalence of complications between the two groups, although frequent complications were encountered and no improvement in foot function was found.