The clinical features of ulnar polydactyly in a middle eastern population.

Two clinical forms of ulnar polydactyly are recognised in the literature, viz the African and the Caucasian forms. The current study investigated the clinical and radiological features of ulnar polydactyly in 94 Saudi patients. The incidence of ulnar polydactyly was one in 1000 live births. There were 41 males and 53 females. Positive family history, syndromal cases, associated hand anomalies, polydactyly of the little toe and systemic abnormalities were seen in 11%, 6%, 5%, 29% and 23% of cases, respectively. There were 50 unilateral (53%) and 44 bilateral cases (47%). In unilateral cases, the left hand was more commonly affected. Using a modified Rayan-Frey classification, the majority of cases were classified as Type II (pedunculated polydactyly, 52 (55%) cases) and Type III (a functioning and articulating extra digit without complete duplication of the metacarpal, 29 (31%) cases). It was concluded that the Saudi clinical presentation of ulnar polydactyly is somewhat different epidemiologically and lies between the African and Caucasian forms.