Carpal deviation in congenital ulnar deficiency.

In patients with hypoplasia of the ulna, the role of the fibrocartilaginous anlage of the ulna in the development of deformity is controversial. Between 1971 and 1982, we treated eight such patients with eleven affected extremities. We maintained them on a conservative regimen of static splinting, and surgery was not undertaken unless there was uncorrectable ulnar deviation at the wrist of 30 degrees or more. Resection of the anlage had to be performed in only one patient. Progression of uncorrectable ulnar deviation at the wrist rarely occurs in patients with ulnar deficiency; therefore, routine precautionary excision of the anlage is not justified.