Distal leg bone loss after open fracture: preliminary data

Bone loss after immobilization due to traumatic injury is a well known clinical state, even if no data are available about bone loss rate measurement. We studied 5 patients treated with osteosynthesis within the 6th hours after midshaft tibia-fibula open fracture. Weight-bearing was allowed starting from the 70th day. Dual energy Gd-153 photonabsorptiometry was used to measure distal leg bone mineral density. WE measured BMD of both fractured and contralateral tibia and fibula, at a skeletal site distal to the fracture for a bone lenght of 1,6 cm starting from ankle interarticular line. Coefficient of variation detrmined by repeated measures in vivo was 4,2%. Three patients with identical injury were treated with porcine calcitonin for 3 months after operation; we observed a bone mass decrease at injured leg less evident than in untreated patients; the maximum BMD decrease in treated patients was observed al 30th day, while the contralateral leg showed BMD variations quite similar to those of untreated patients. Our data suggest that measurement of bone mass by dual photonabsorptionetry during fracture healing represents a good experimental model to evaluate bone mass changes after traumatic injure and immobilisation, and to evaluate bone mass response to pharmacological therapy.