Mini-Invasive Treatment for Brachymetatarsia of the Fourth Ray in Females: Percutaneous Osteotomy With Mini-Burr and External Fixation-A Case Series

Abstract

Brachymetatarsia is a rare disease defined by metatarsal shortening and characterized by aesthetic dissatisfaction with or without pain. The aim of our study was to evaluate the outcomes of fourth ray brachymetatarsia treated with percutaneous osteotomy using a mini-burr and gradual lengthening with external fixation. A total of 7 females were recruited for the study; 6 (85.71%) of whom had a bilateral deformity, for a total of 13 feet affected by fourth ray brachymetatarsia. Percutaneous diaphysis osteotomy with a mini-burr followed by metatarsal elongation was performed. Metatarsal lengthening was measured as the difference between the preoperative and postoperative length at external fixator removal. The American Orthopaedic Foot and Ankle Society lesser toe metatarsophalangeal-interphalangeal score, patient satisfaction, restoration of Leliévre parabola, and treatment time were evaluated. Numerical data are reported as the mean ± standard deviation and 95% confidence intervals. The Mann-Whitney U test was used to compare the changes in the AOFAS score with a level of significance of p < .05. The mean metatarsal lengthening was 17.46 ± 4.89 (95% confidence interval [CI] 14.8 to 20.12) mm and the mean treatment time was 99.23 ± 8.53 (95% CI 94.59 to 103.87) days. The mean American Orthopaedic Foot and Ankle Society lesser toe metatarsophalangeal-interphalangeal score improved significantly from 76.38 ± 2.66 (95% CI 74.77 to 78.03) preoperatively to 86.46 ± 1.45 (95% CI 84.85 to 88.07) postoperatively (p < .01). In 12 of 13 feet (92.31%), the Leliévre parabola was restored, and the patients were satisfied with the clinical outcomes. The results of our study demonstrate that percutaneous osteotomy with the mini-burr and external fixation is an effective treatment for lengthening of fourth ray brachymetatarsia. Furthermore, we found good clinical and functional outcomes, high patient satisfaction, and a similar duration of treatment compared with other gradual lengthening procedures.

Keywords: brachymetatarsia; external fixator; metatarsal lengthening; mini-burr.