Instability of the hip in neonates - An ethnic and geographical study in 24 101 newborn infants in Malmo

In a prospective study conducted between 1990 and 1997, 24 101 newborn infa nts were examined for neonatal instability of the hip and classified by the ethnic origin of their parents. In 63% their mother and father were of Swe dish extraction and in 24% they were born in a foreign country, Those of fo reign extraction were split into ethnic and geographical subgroups. Althoug h the incidence of treated (dislocatable-unstable) hips was greater in Swed es (7.6 parts per thousand), than in other geographical groups (5.8 parts p er thousand) it was not significantly different (p = 0.065), A total of 12. 7 parts per thousand were referred from the neonatal ward to the orthopaedi c clinic with suspected dislocatable or unstable hips; 6.8 parts per thousa nd were treated (5.4 parts per thousand dislocatable, 1.4 parts per thousan d unstable), but 5.9 parts per thousand were not treated since their ultras ound examination was normal. Two hips were diagnosed late and one case of mild avascular necrosis was fo und. Examination by dynamic ultrasound decreased the number of treated case s by 5.9 parts per thousand but was not an absolute guarantee of diagnosis.