Syndactyly

Definition

 

Webbed fingers

 

Aetiology

 

Usually spontaneous but can be inherited

Due to a failure of separation during embryonic development

 

Epidemiology

 

Most common congenital hand abnormality 1:2000

 

Family History in 20-40% / AD

 

Associations

 

Polydactyly

Amniotic bands

Toe webbing

VECTRAL

Craniofacial abnormalities

Apert's syndrome

 

Classification

 

Simple / Complex 

- simple skin only

- complex has bony involvement

 

Complete / Incomplete 

- extent of finger involved distally

 

DDx

 

Acrosyndactyly 

- fusion of fingers distally with proximal fenestrations

 

Brachysyndactyly 

- shortening of syndactyl digit

 

Anatomy

 

Middle & ring finger commonest 60%

 

Thumb & index rarest

- Apert's

 

Bilateral in 50%

 

Frequent anomalous sharing of

- musculotendinous structures

- artery / veins / nerves

 

Management

 

Timing

 

Surgery aged 1 year

- minimise bony deformity

- especially if thumb / index as in Apert's syndrome

- once child safe for anaesthetic

 

Important surgical principles

 

1.  Beware NV abnormality

- usually normal number in simple syndactyly

- may be absent in complex

- may divide much more distally

 

2.   Skin shortages

- may need FT skin graft

 

3.   Release one side at a time

- may jeopardise vascularity to finger

- 3/12 between each side

 

4.   Need to create web space

- Zig Zag incisions with volar or dorsal flap for web space (Vickers) 

- important not to deepen web space too much as looks unsightly

- web space deepening often limited by digital artery bifurcation

 

5.  Division of border digits done early to avoid angular deformity

 

Complications

 

Clinodactyly

- due to shortening of graft

- not seen with Vickers technique

 

Web creep 

- return of webbing 

- revise as teenager so only need one further surgery

- web space reconstruction

 

Neurovascular injury