Presentation
Road traffic accident. No other complaints.
Patient Data
Oblique fracture across proximal shaft of 4th proximal phalanx.
Bifurcation of distal phalanx of thumb, with unduplicated epiphysis.
Carpal bones are normal in configuration. All other epiphyses are normal in configuration.
The clinical photograph shows that nail bed and soft tissue planes of the affected part are also "partially duplicated" in parallel with the bony change underneath.
The patient is wearing a finger brace for the fracture at proximal phalanx of ring finger.
Case Discussion
This is a Wassel type-I pre-axial (radial) polydactyly: bifid (not duplicated) distal epiphysis. This type covers about 2% of all polydactylies, with type-IV being the commonest (40%). Phalanx duplication or polydactyly itself is type 3 under Swanson's classification of skeletal developmental conditions, which was subsequently adopted by relevant international societies.
The patient has not faced any functional difficulties including writing, hence the discovery is incidental. There is also no clinical evidence of any associated congenital anomalies. Nonetheless, the patient may still be advised a skeletal survey, followed by evaluation of other systems if necessary.
In the absence of associated deformities and functional limitations, treatment of this deformity by surgical remodeling would depend on the patient's desire for cosmetic correction.