Polydactyly
Definition
Congenital duplication of a finger
Epidemiology
1/3000
Classification
| Preaxial | Central | Postaxial |
|---|---|---|
| Radial side | Duplication index / middle / ring finger | Ulna side |
|
Caucasian Sporadic
|
Rare |
African americans Autosomal dominant with variable penetrance |
|
Multiple variations - bifid distal / proximal phalanx - duplicate distal / proximal phalanx - duplicate metacarpal |
Type A: Fully developed digit with bones and joints
Type B: Rudimentary, non functional. Skin tag |
Post axial / ulna sided management
Type B: Simple soft tissue
Tie string & autoamputates at birth
Type A: Fully developed duplicate
Operate at ~ 1 year of age
- old enough to be safe for operation
- amputate outside extra digit
Thumb polydactyly
Wassell classification
Type I: bifid distal phalanx
Type II: duplicate distal phalanx
Type III: bifid proximal phalanx + Duplicate Distal Phalanx
Type IV: duplicate Distal Phalanx + Duplicate Distal Phalanx
Type V: bifid 1st metacarpal + Duplicate Distal and Proximal Phalanx
Type VI: duplicate 1st metacarpal + Distal Phalanx + Proximal Phalanx
Type VII: triphalangeal thumb (triangular or rectangular extra middle phalanx) + normal thumb
Most common variety
- Type IV
- duplicated proximal phalanx with single metacarpal
Management
One dominant, more fully formed thumb
- remove small thumb
- remove radial thumb
- reconstruct unstable MCPJ
Syndactyly
Definition
Failure of fingers to separate normally
Most common middle and ring finger
Epidemiology
Most common congenital hand abnormality 1:2000
Family History in 20-40% / AD
Etiology
Usually spontaneous but can be inherited (Autsomal dominant)
Association with syndromes - Poland, Apert's
Classification
Simple - connected by skin and soft tissue only
Complex - bony involvement
Complete - webbing reaches to end of finger
Incomplete - webbing stops short of end of finger
Operative management
Issues
Timing
- one year old / safe for anesthesia
Vascular
- release one side at at time
- abnormal NV bundles
Skin
- Cronin zig zag incisions
- may need full thickness skin flaps