Lack of Metabolic Bone Disease in Patients with Fracture of the Femoral Neck*

Abstract

To determine if osteoporosis and osteomalacia are pathogenetic factors in femoral neck fracture, such patients were compared to vertebral fracture patients and controls. Cortial bone was measured in hand X-rays and cancellous bone in iliac crest biopsies, which were also used to assess osteoid, tetracycline and resorbing surface. Vertebral fracture patients had a reduction of 53 and 41% in cancellous and cortical bone, respectively, compared to the controls; in the much older femoral fracture patients the reductions were 19 and 16%. Three femoral fracture patients had mild osteomalacia from identifiable causes. Another had bone fluorosis and 1 had metastatic carcinoma. Excluding these, the osteoid-covered surface of bone was less than in vertebral fracture patients and controls. Pathologic osteoporosis and osteomalacia are not major factors in the pathogenesis of femoral neck fractures, though the normal age-related reduction in bone mass may contribute. There may be another age-related factor weakening the femoral neck. When assessed by a sensitive histochemical technique for osteoclast identification, bone resorption was not increased in either of the fracture groups.