Effects of bed rest on bone metabolism in patients with femoral neck fracture.

Abstract

The effect of continuous 1 week bed rest during traction on bone metabolism were studied in patients with femoral neck fracture. Bone demineralization was assessed by measuring serum calcium (Ca), phosphorus (P), and alkaline phosphatase (AlkP) before, during, and after 1 week-bed rest with skeletal traction. In addition, 24-hour urinary excretion of calcium and phosphorus were measured. Serum Ca did not change significantly before, during, and after bed rest, whereas serum P increased after 1 week bed rest and postoperatively remained significantly elevated. Serum AlkP did not increase with bed rest, but became elevated postoperatively. Urinary Ca excretion increased from 105.8 +/- 15.2 to 138.0 +/- 15.4 mg/24h after 1 week of bed rest, and remained elevated postoperatively. In contrast, urinary P excretion initially increased 495.1 +/- 65.0 to 610.8 +/- 87.7 mg/24h, and subsequently decreased to a level significantly less than the admission level. These results suggest that 1 week bed rest for the patients with femoral neck fracture resulted in bone atrophy and demineralization.