[Hip dysplasia in infancy. Proton spin tomography and computerized tomography].

Magnetic resonance imaging (MRI) and computed tomography (CT) are useful techniques for the objective documentation of the relation between the femoral head and the acetabulum after closed or open reduction of a developmental dislocation of the hip joint. Before the ossification nucleus of the femoral head is sufficiently developed, MRI is preferred. For the evaluation of reduction from the 2nd year on, MRI and CT are equivalent. However, in older children MRI may also be indicated for the evaluation of cartilaginous structures or the diagnosis of femoral head necrosis. CT in older patients may also be useful for 30 analysis of bony structures, e.g. for planning complex osteotomies.