The Wassel classification is used to categorise radial polydactyly, based upon the most proximal level of skeletal duplication.1
Classification
| Type | Level of duplication |
|---|---|
| I | Distal phalanx |
| II | Interphalangeal joint |
| III | Proximal phalanx |
| IV | Metacarpophalangeal joint |
| V | Metacarpal |
| VI | Carpometacarpal joint |
| VII | Triphalangia |