Foot polydactyly is a common foot deformity that is usually corrected surgically early in life to facilitate shoewear. When the polydactyly involves a widened metatarsal head with a single metatarsal epiphysis that articulates with 2 toes, surgical correction involves removal of part of the ring apophysis of the metatarsal. Traumatic injury to the ring apophysis, such as a Salter VI lawn mower injury to the foot, frequently results in angular deformity and/or metatarsal shortening. The purpose of this study was to evaluate whether careful surgical resection of the ring apophysis causes growth deformity.

Radiographs and operative reports were reviewed in children with postaxial polydactyly. Those who had a widened metatarsal head that were surgically corrected with partial physeal resection including the ring apophysis were further examined. The fifth and second metatarsal lengths were measured in triplicate and their ratios were compared using a Wilcoxon rank sum test.

There were 131 children with postaxial polydactyly identified, of whom 7 (5 bilateral) had preoperative and postoperative radiographs suitable for measurement. The median age at surgery was 13 months with mean follow up time of 17.25 months. Of the 12 toes surgically corrected only 1 showed a significant difference in metatarsal length ratios compared preoperative to postoperatively. There was no significant difference in metatarsal length ratios after surgical correction overall.

No statistically significant length deformity was demonstrated following surgical removal of the ring apophysis. While this study is small, out of the 54 cases that were reviewed, only 2 had complications requiring reoperation. The remainder had no recorded complaints of pain or angular deformity. Despite the absence of documented follow up, it is likely that patients would have returned had they had experienced pain, deformity of the foot, or difficulty in shoewear.