This is a Type 1 Deformity – Failure of Formation
Ectrodactyly is a deficiency of one or more digits often described as a “claw-like” hand. Sometimes also referred to as: split hand, cleft hand, or lobster hand. With ectrodactyly, there can be up to 3 missing rays in the hand or foot. ( A ray = metacarpal bone + the finger). There are many types and combinations of this deformity. Ectrodactyly can be seen in isolation or with other congenital anomalies. Polydactyly and syndactyly can occur with ectrodactyly in the same hand. Despite the appearance of this deficit, many people with this condition have functional hands, have normal family lives and have jobs.
Ectrodactyly is classified as type I, Failure of Formation. The main pathogenic mechanism to trigger this abnormality is failure of apical ectodermal ridge signaling which causes a wedge-shaped deficit of the apical ectoderm of the limb bud. Usually caused by an autosomal-Dominant gene deficit, rarely a recessive gene is the cause. The exact chromosomal defect is not defined yet. The risk of passing the abnormal gene to a child is 50%.
Time to Play the Brain Game:
Q) Ectrodactyly is also known as:
A) Split hand or cleft hand and it is often described as “claw like” and often the patient will only have the thumb and one finger.
Non-Surgical management:
- Often surgery is not indicated if the hand is functional
- Prosthetics to improve function
Indications for surgery:
- Absent thumb
- Deforming syndactyly
- Abnormal bones that will progress the deformity
- Narrowed 1st web space
Types of surgery:
- Re-create an intercarpal ligament to close the cleft
- Creation of a radial digit
- Repositioning of the thumb to improve pinch or grip
- Release of the syndactyly
- Widen the 1st web space & minimize the cleft
- Use of tendon graft to connect the common extensor tendons to prevent digital separation during extension
Time to Play the Brain Game:
Q) Cleft hand is always bilateral and is associated with other syndromes. True or False?
A) Cleft hand can be unilateral or bilateral and can appear as an isolated case or with other syndromes.