The treatment of developmental dysplasia of the hip (DDH) in children remains controversial, we describe the clinical and radiological outcomes of 47 hips in 43 children treated with open surgery by one surgeon between 2004 and 2008 for DDH.

The mean age at operation was 25 months (5 to 113) with a mean follow up of 89 months (22 to 169).

46 hips had an anterior open reduction, 1 had a medial approach performed and 16 had anterior open reductions only. 5 of the primary operations also had a pelvic osteotomy, 7 had a femoral osteotomy and 18 had a combined femoral and pelvic osteotomy.

7 (15%) of the hips required a second operation for dislocation, subluxation or dysplasia.

At the latest follow up 40 of the 45 hips where Severin grades were recordable (89%) were graded as excellent or good, Severin class I or II. Clinically significant AVN (grade II to III according to the Kalamchi and MacEwen classification) was seen in 5 (11%) of the hips.

We found a pelvic osteotomy to be a risk factor for AVN (p 0.02) and age at operation to be a risk factor for poor morphology at final follow up (p 0.03).

We proceed to open surgery in patients over 12 months old or those with failed closed reduction. Over 18 months old a pelvic osteotomy should be performed in selective cases depending on intra-operative stability, but we will now consider doing this as a staged procedure and delaying the osteotomy for a period of time after open reduction to reduce the risk of AVN. We will also have a much lower threshold for performing a femoral shortening osteotomy in these patients as open reduction with Salters osteotomy alone tended to have a poorer outcome.