radial hemimelia

Radial hemimelia is a congenital absence of the radius bone of the forearm characterized by partial or total absence of the radius.

Epidemiology

It occurs in 1:30,000-100,000 live births, and is slightly more common in males than in females (sex ratio of 3:2).

Pathology

This deformity is believed to develop at about 28th to 56th day of gestation. Exact etiology has not been proved though uterine compression, vascular injury and certain maternal drug consumption have been postulated.

Prenatal ultrasound

This deformity can be detected in the anomaly scan done in the second trimester.

Classification

• type I: short distal radius
• type II: hypoplastic radius
• type III: partial absence of radius
• type IV: complete absence of radius

Associations

• Holt-Oram syndrome
• Roberts syndrome
• Rothmund-Thomson syndrome
• thrombocytopenia-absent radius (TAR) syndrome (in which characteristically the thumb is present)
• Townes-Brocks syndrome
• VACTERL association
• Fanconi anemia

Treatment and prognosis

Straightening of the hand and wrist stabilization through splinting are both techniques utilized after birth . Physiotherapy input is required in order to improve passive extension of the elbow and wrist. Surgical correction (e.g. osteotomy, arthrodesis, fibular transplants, centralisation) is used for severe cases, generally performed at age 1 . Pollicisation is used if an absent thumb is present.

Siehe auch:

• Hemimelie