Abstract
Aim
To compare the rate and severity of avascular necrosis following medial open and closed reduction in developmental hip dysplasia and the resulting influence on femoral and acetabular development.
Method
The radiographs and hospital records of 118 patients with dislocation of the hip were reviewed. 57 patients (66 hips) underwent medial open reduction and 61 patients (75 hips) underwent closed reduction. Mean follow-up was 10.9 years (5 years to 17.4 years). Avascular necrosis (AVN) was recorded according to the Bucholz and Ogden classification. The acetabular index was measured pre-operatively, at 1 and 4 years following surgery. The final radiograph was assigned a Severin grade. Sharp and centre-edge angles were recorded at final follow-up. A Severin grade I or II was considered a satisfactory result and a grade III to V an unsatisfactory result. Initial non-operative measures, such as Pavlik harness treatment and traction were documented. Additional surgical interventions were noted.
Results
The rate of clinically significant AVN (types 2, 3, 4) following medial open reduction was 28.7% versus 17.3% following closed reduction. The rate of Type 2 AVN was 22.7% versus 10.6% respectively. Early acetabular development was similar in both groups. Long-term follow-up showed an unsatisfactory outcome (Severin grade III-V) following medial open reduction in 32% versus 8% in the closed reduction group.
Conclusion
Our findings suggest that medial open reduction is associated with a higher rate of AVN than closed reduction. Type 2 AVN was twice as common in the medial open reduction group. More unsatisfactory results were seen in the medial open reduction group at long term follow up.
