Hip Joint Instability After the Neonatal Period: Diagnosis and Treatment of 20 Consecutive Cases

Abstract

A consecutive series of 20 children (21 hips) with idiopathic hip joint instability, diagnosed after the neonatal period, is presented. The diagnosis was confirmed by hip joint arthrography. In all the children, 1.5-21 months old at the time of diagnosis, closed reduction could be achieved. They were treated in plaster directly or after treatment of contractures in the adductor muscles of the hip joint. Stability was rapidly attained during plaster treatment. The results of the treatment in plaster were checked by a second arthrography in two thirds of the cases, and all cases have been clinically and radiologically evaluated 1-4.5 years after diagnosis. All of the children developed clinically stable hips and they walk normally. In two hips signs of avascular necrosis of the femoral head were found and in three hips (two children) the skeletal development was markedly delayed. In 81 per cent (17/21 hips) the prognosis was considered good; it is uncertain in the remaining four hips. The appropriate period of fixation in plaster related to the age of the child is discussed.