Abstract
Using arthroscopy, we studied the status of reduction in developmental dysplasia of the hip. Hips were examined in 2 boys and 15 girls, aged 5 months to 3 years (average, 1 year 4 months) . All joints were irreducible and treated with Pavlik harness or overhead traction. We performed hip arthroscopy using a medial approach with a 2.7-mm arthroscope under general anesthesia and observed the status of reduction during manipulation. We classified the status of reduction into four types: type 1, the femoral head remained outside the acetabular labrum and was irreducible (7 joints) ; type 2, the femoral head was moved on the labrum but was incompletely reducible (4 joints) ; type 3, the top of the femoral head was moved over the labrum but was incongruent and arthroscopically visible (2 joints) ; and type 4, the femoral head was completely reducible and arthroscopically invisible (4 joints) . Type 1 joints were treated with open reduction, and type 2 joints were treated with either open reduction or closed reduction. Joints of types 3 and 4 were treated with closed reduction. Hip arthroscopy is useful for selective screening of irreducible developmental dysplasia of the hip.
