Radial Polydactyly: Double or nothing?

Thumb duplication or ‘radial polydactyly’ is the most common congenital upper limb anomaly (‘CULA’) affecting the thumb. The clinical presentation of this highly heterogeneous patient population may vary from a subtle doubling of the nail lunula, to complex synpolydactyly with synostosis, intrinsic and extrinsic muscle anomalies, and joint instability. Therefore, defining an optimal treatment strategy for each individual case remains challenging.

The aim of this thesis was to improve treatment for radial polydactyly by studying outcome within the International Classification for Functioning, Disability, and Health (‘ICF’) framework. In pursuit of valid and generalizable findings, we gathered data in an international, multicenter setting, with long-term follow-up, and focussed on the most common radial polydactyly types (i.e., types II, IV, and IV with triphalangeal components or ‘IV-Tph’).