[The observation of bone mineral density by dual energy X-ray absorptiometry and histology during fracture healing at the femoral fracture site of rat].

ABSTRACT

OBJECTIVE: To dynamically observe the bone mineral density and histology changes during fracture healing at the femoral fracture site, and to study the role of monitoring fracture healing by dual energy X-ray absorptiometry (DEXA). METHODS: 60 female 3-month-old SD rats were used to establish right femoral fracture model. The fractured and contralateral unfractured femorals were scanned by Dual Energy X-ray absorptiometry in 2, 4, 6, 8, 10 and 12 weeks postoperatively. The callus of each rat was examined by light microscope at the same time. RESULTS: The value of bone mineral density at rat femoral fracture site was significantly increased post-osteotomy, showing a clear healing trend. The bone mineral density at fracture site was 29.5%, 48.3%, 85.3%, 105.2% of the value obtained of the control limb 2, 4, 6 and 8 weeks postoperatively. There was a compatibility on time between bone mineral density and histology. The BMD of distal metaphysis remained reduced until 12 weeks. CONCLUSION: The change of bone mineral density at the fracture site exhibited positive correlation with the histology of fracture healing, bone mineral density can accurately quantify the extent of mineralization of callus at the fracture site. DEXA can be used as a new technique in monitoring fracture healing.