Temporary screw epiphysiodesis for correction of ankle valgus in children with multiple hereditary exostoses

Abstract

Aims: In patients with multiple hereditary exostosis (MHE), the development of ankle valgus is a common deformity. The aim of this study was to evaluate whether temporary screw epiphysiodesis of the medial distal tibia leads to a correction of the deformity and to provide further information on the timing and duration of the operative treatment, considering sex-specific differences and a concomitant fibular shortening or relevant exostoses. Methods: The data of 37 MHE patients with a total of 68 ankles, and 35 patients with idiopathic ankle valgus with a total of 56 ankles, were analyzed retrospectively. The lateral distal tibia angle was measured before and after treatment. We also assessed complications, relevant exostoses, and a fibular shortening, as well as sex-specific differences in the correction rate. Results: Ankle valgus improved in all but one patient of the MHE group with a mean valgus correction of 9.6° (control group: 9.9°). The correction rate was significantly lower in the MHE group than in the control group (0.5° vs. 0.8° per month, p < 0.001), resulting in a significantly higher wearing time in the MHE group (20.12 vs. 14.59 months, p = 0.002). No significant sex-specific differences were found neither in the MHE group nor in the control group. Complications were observed in five ankles of the MHE group (screw breakage during explantation) and none in the control group. Concomitant exostoses or fibular shortening did not affect the correction of ankle valgus. Conclusion: Temporary screw epiphysiodesis is an effective method for the treatment of ankle valgus in MHE patients. As the correction rate per month is lower in MHE patients, operative treatment should be performed earlier to achieve satisfactory correction.