Congenital musculoskeletal malformation in South African Blacks: a study of incidence.

Ten thousand South African Black neonates were examined on the day after delivery for assessment of the frequency of congenital malformation of the musculoskeletal system. In 15 neonates it was found that the hip joints could be dislocated by the Ortolani or Barlow techniques. This instability persisted to 1 week of age in only 3 instances. This incidence figure is approximately 10% of the average reported for White's neonates. Talipes equinovarus deformity was found in 35 infants, an incidence of 3,5/1 000, or approximately three times the incidence cited for Whites. Calcaneovalgus deformity, however, was found in 3 infants only-- a much lower incidence than that found among Whites. There was a similar infrequency in the incidence of spina bifida aperta (cystica), which was noted in 7 infants. This figure correlates with reports from North America, but is substantially lower than the cited incidence in Wales and parts of England. Polydactyly, usually consisting of a postaxial pedunculated skin tag only, was the most common deformity found, the incidence being 8,8/1 000.