Can on-top plasty for atypical radial polydactyly realize a functional reconstruction corresponding to appearance?

On-top plasty may be the best option for reconstructing atypical radial polydactyly, consisting of a developed distal portion in one thumb and a developed proximal portion in the other thumb. However, it is unclear if patients can gain thumb function corresponding to the reconstructed appearance. We performed a retrospective bibliographic review to summarize the current literature and present our department’s on-top plasty experiences. Over the last ten years, our department performed three on-top plasty radial polydactyly reconstructions. We surveyed the appearance and use of the reconstructed thumb and the patient’s satisfaction level during postoperative follow-up. We also retrieved published case reports describing on-top plasty for polydactyly reconstruction to compare with our cases. Our patients had an acceptable thumb appearance and were satisfied with the gained function of the thumb. However, two patients required revision surgery. We found 11 studies in the literature describing on-top plasty for polydactyly treatment, four of which reported a limited range of thumb motion, but no patient or their family complained about the result. Most patients who undergo on-top plasty for radial polydactyly can expect a fair to good appearance after surgery. Although instability or limitation of the joint arc is possible, the reconstruction satisfies patients regarding function and appearance.