An ultrastructural observation of fracture healing of cancellous bone after different fixations

Objective [WT5”BZ]To observe the ultrastructural changes during fracture healing of cancellous bone after different fixations. Methods Thirty adult New Zealand rabbits were used in this experiment. After a complete osteotomy between the medial and lateral femoral condyle was done, the animals were fixed with plaster, cortical and cancellous screw fixation, respectively. The distal femoral condyle was osteotomized at 3 days, and 1,2, 3 and 6 weeks,and then observed under transmission electron microscope. Results Different fixations had significant influence on degeneration of fibroblast and chondrocyte as well as function of osteoblast during fracture healing of cancellous bone except appearance of fibroblast. A new bone formation of fibroblast was also observed during fracture healing of cancellous bone. Conclusions Various mechanical environment had different influence on ultrastructure during fracture healing of cancellous bone.