Osteoporosis influences the late period of fracture healing in a rat modelprepared by ovariectomy and low calcium diet

To elucidate the influence of osteoporosis on the fracture healing, we prod uced a rat osteoporosis model by ovariectomy and by maintaining a low calci um diet; and monitored the healing process radiographically, histologically , and biomechanically for 12 weeks. Radiologic, histologic and biomechanica l findings of the fracture areas 6 weeks after making the fractures were al most identical in both the osteoporosis group and the control group. Howeve r, 12 weeks after making the fractures, newly generated bones in the osteop orosis group showed histological osteoporotic changes and their bone minera l density on the fracture site decreased. These findings show that estrogen -deficient and low calcium conditions greatly affect the bone in the later period of the healing process, but do not affect remarkably the early heali ng period. This is clinically important when we consider fracture treatment s for patients with osteoporosis due to menopause. (C) 1999 Elsevier Scienc e Ltd. All rights reserved.