Bone density, histomorphometry and biochemistry in patients with fractures of the hip or spine.

Bone density in the lumbar spine and distal radius, histomorphometric values of iliac crest biopsies and biochemical parameters, including vitamin D metabolites, were determined in 30 women with recent hip fractures and in 19 women with spinal fragility fractures. In both groups, as compared with age- and sex-matched controls, bone density in the spine and peripheral skeleton was reduced. In the peripheral skeleton the degree of osteopenia in the two groups was equal, but loss of trabecular bone in the spine was disproportionate and more extensive in the group with spinal fragility fractures. In the patients with hip fractures the percentage of trabecular bone occupied by osteoid in the iliac crest biopsies was increased in 11 of the 25 patients. Osteomalacia was further suggested by the lower mean levels of serum calcium and phosphate and lower mean urinary excretion of calcium in this group. In the patients with spinal fractures histomorphometry showed that the osteoid and trabecular resorption surfaces were increased and the relative thickness of the osteoid seams was decreased, indicating increased bone turnover. This evidence was further reinforced by the increased mean serum concentration of 1,25(OH)2D and increased urinary excretion of calcium. The results support the view that these two groups of patients suffer from different forms of osteoporosis.