Congenital dislocation of the hip in Norway. Late diagnosis CDH in the years 1970 to 1974.

A survey of 274 late detected cases of CDH born in the years 1970--74 is presented. The incidence of late cases in southeast Norway was calculated to 2.2 per 1 000 live births. The hips of all patients were examined at birth, the majority by trained pediatricians, without disclosing any hip affections. 86% were females. Only 6.9% were delivered in the breech position. One-half of the patients had luxation (20%) or subluxation (30%), the rest had dysplasia without dislocation. In 19% both hips were involved. The low incidence of breech presentations in late CDH-cases compared with the incidence among neonatal cases (15.7%) point to some etiological differences. It seems that we in Norway have two types of CDH, one caused by joint laxity and detectable at birth and another, not present at birth, with progressive dysplasia of the hip and dislocation developing during the first year of life.