Outcome measures

The criteria for successful treatment were as follows: stable and concentric reduction achieved; Graf type-I on US examination; no signs of acetabular dysplasia on anteroposterior pelvis; no sign of hip instability or dislocation on clinical examination; and no subsequent treatment was needed during the follow-up period. Treatment was considered to have failed if: subsequent closed reduction and hip spica cast immobilization were required; presence of residual acetabular dysplasia; and re-dislocation or subluxation over the follow-up period. The type and incidence rate of treatment-related complications were recorded, including AVN, femoral nerve palsy and skin lesions.