LONG TERM FOLLOW UP OF DEVELOPMENTAL DYSPLASIA OF THE HIPS – A REVIEW OF THE OUTCOME OF AVASCULAR NECROSIS

Abstract

The authors evaluate the incidence, patterns and causative factors of avascular necrosis (AVN) in patients with developmental dysplasia of the hip (DDH) and to follow up these patients to determine what their long term functional and radiological outcome is.

All patients treated for DDH by the same consultant with the subsequent development of AVN were assessed. Outcome was assessed by grading the AVN using the Kalamchi and McEwan classification at final follow up.

A group of 250 hips with DDH were treated over a 16 year period and reviewed. All hips that developed AVN were studied. AVN was seen in 15% of hips treated with closed reduction and 62% of hips after open reduction–32% of the hips treated in the open reduction group were treated elsewhere and subsequently referred.

If use of a Pavlik harness fails, children with DDH should be treated with pre reduction traction, closed reduction and spica cast after the age of 4 months. In the surgical group a capsulorrhaphy should be avoided. Poor radiological outcome at final follow up was not necessarily equivalent to a poor clinical outcome.