Cancellous bone in human acetabulum: microradiographic and histomorphometric aspects.

The acetabular cancellous bone of 18 subjects aged 57-88 years was characterized by low mass and a poorly ramified pattern according to microradiographic analysis. There was no correlation between the histomorphometric data of this region and those of the iliac crest. Microcalluses were visible in 13 acetabular samples, whereas they were absent from the iliac crest. As the acetabular trabeculae appeared decidedly longitudinal, age-related bone rarefaction is suggested to occur in two different ways: uniform thinning of the trabeculae and selective disappearance of transverse elements. The remaining longitudinal trabeculae are considered to be most useful for the weight-bearing function of the hip joint.