Quantification by dual photonabsorptiometry of local bone loss after fracture

Total bone mineral and bone mineral density modifications were evaluated during fracture healing of long bones in patients with traumatic fractures of the lower limbs, using an experimental model based on the dual photonabsorptiometry technique. Seven patients (five males and two females; mean age, 19.5 years; range, 17-23 years) with tibia and fibula midshaft open fractures treated with osteosynthesis were studied. Dual energy gadolinium-153 photonabsorptiometry was used to measure distal leg bone loss at a skeletal segment distant from the fracture to exclude callus formation. Total bone mineral (TBM) and bone mineral density (BMD) of the tibia and fibula both in the fractured leg and in the healthy contralateral leg were measured on Days 10, 20, 30, 40, 60, and 120 after trauma. TBM and BMD of the healthy contralateral leg did not present any significant modifications at the different observation times. Both TBM and BMD of the fractured leg showed a progressive reduction that reached statistical significance starting on Day 30 with maximum reduction on Day 120 when TBM and BMD were reduced to almost one-half the initial value.