The structure and mechanical properties of the plated bone following point contact-dynamic compression plate and dynamic compression plate fixation / 中华骨科杂志

ABSTRACT

Objective To compare the effects of point contact-dynamic compression plates (PC-DCP) and dynamic compression plates (DCP) on bone structure and mechanical properties of the plated bone in the intact goat tibia model. Methods Ten matured goats were used. The bilateral intact tibia of goats were fixed with DCP and PC-DCP respectively. The goats were sacrificed at 12 and 24 weeks after operation, and the tibiae were harvested. The structure of bone under plate was studied both by CT scan and histomorphology. The mechanical properties of the plated bone were examined by torsional test. Results At 12 weeks after internal fixation, there was obvious osteoporosis in the cortical bone underneath the plate in the DCP group compared with that of the PC-DCP group. Both of the cortical bone thickness underneath the plate and the torsion strength of the plated tibiae were significantly higher in the PC-DCP group than that in DCP group (P0.05). Conclusion The underlying bone resorption after rigid plate fixation is induced by both the disturbance of the bone blood supply and stress shielding. However, the former is the main cause in the early stage of fixation. PC-DCP is able to prevent bone resorption in the early stage of fixation.