Early Assessment of Prognosis in Perthes' Disease

The acetabular opening angle in Perthes' disease

“…The increase in the A angle reflects this adaptation since the diameter increases, whereas the length of the roof does not vary. All these modifications appear early (Danielsson et al 1982, Yngve and Roberts 1985, Joseph 1989. The A angle increases as early as in the necrotic stage in 67 percent of the cases, but by the time of skeletal maturity, A is more than 2' greater in only 37 percent.…”

Prognosis in Perthes' disease after noncontainment treatment

“…Yngve and Roberts (1985) described bicompartmentalization and connected it with poor prognosis. Danielsson et al (1982) and Joseph (1989) described acetabular changes in Perthes' disease and suggested that they may contribute to the prognosis if they per-sist in adulthood. In the present study, the prognostic significance of bicompartmentalization was rather low and needs further elucidation.…”

Perthes’ disease in the adolescent

“…There was little evidence of remodelling in the destructive pattern. Remodelling of the acetabulum with an increase in the radius of the acetabulum is seen in younger patients, [25][26][27] but in all three patterns of adolescent disease there was very little enlargement of the acetabulum in response to the enlargement of the femoral head (Table II). This may be because the triradiate cartilage had already fused at the onset of the disease in many of the children, and in others premature fusion occurred during the course of the disease.…”

“…Corresponding alterations in the shape and size of the acetabulum also occur in order to improve the cover of the enlarged femoral head. [24][25][26][27] Hence the extent of metaphyseal widening, enlargement of the femoral head and changes in acetabular dimensions can serve as indicators of the degree of remodelling of the proximal femur and the acetabulum. We therefore measured the acetabular and femoral radii and the metaphyseal width.…”