Postoperative deviation in Wassel types II and III radial polydactyly: a retrospective analysis of 73 thumbs.

This study examined the relationship between osteochondral stability and postoperative deviation at the interphalangeal (IP) joint in Wassel types II and III radial polydactyly. Cases with cartilaginous fusion between the radial distal phalanx and the proximal phalanx were classified as type IIB, while the remaining cases were categorized as type IIA. In conventional surgery, the cartilage was routinely resected on the radial aspect of the proximal phalangeal head, while in the modified procedure, this was preserved to avoid postoperative radial deviation. Postoperatively, there was no significant difference between both procedures in type IIA thumbs regarding IP joint deviation, whereas in type IIB/III thumbs, IP joint deviation was significantly higher in the conventional group (mean 19° [SD 16°]) compared to the modified group (mean 0.8° [SD 4.9°]). Surgeons should exercise caution against excessive cartilage excision to preserve osteochondral stability during procedures, especially for type IIB and III radial polydactylies.Level of evidence: IV.