Examination of Postoperative Outcomes Using Morphological and X-Ray Classifications and Selection of the Toe to Be Excised in Postaxial Polydactyly of the Foot

The treatment of postaxial polydactyly requires excision of the medial fifth or lateral sixth toe, and separation of the adjacent fourth/fifth toes if the adjacent toes exhibit skin syndactyly. Morphological changes in the retained toes and reoperation are common problems after such surgery. This study examined the effects of preoperative classifications and selecting the medial fifth or lateral sixth toe for excision on the postoperative outcomes of surgery for postaxial polydactyly. From April 2006 to March 2019, surgery for postaxial polydactyly was performed on 55 feet in 49 patients. The patients' mean age at surgery was 28.8 months. Postoperative esthetic and bone alignment scores, the reoperation rate, and postoperative dysfunction were examined. The postoperative esthetic and bone alignment evaluations were performed by examining postoperative photograph and X-ray images using original scoring systems. The surgical procedure was chosen by the surgeon-in-charge during a preoperative conference after considering the toe growth and bone alignment. In the postoperative esthetic evaluation, excising the lateral sixth toe produced significantly better outcomes than excising the medial fifth toe. The morphological classification also indicated that excising the lateral sixth toe produced better outcomes, as it resulted in the bifurcated toes being clearly independent. Interestingly, the postoperative X-ray-based bone alignment score was not correlated with the esthetic score. The reoperation rate tended to be high after medial fifth toe excision. There were no postoperative functional complications. Lateral sixth toe excision for postaxial polydactyly of the foot produces good postoperative esthetic outcomes.