Experimental study on the repair of tibial plateau defect.
OBJECTIVE
To evaluate the effect of autograft bone, allograft bone, calcium sulfate bone cement, and calcium phosphate bone cement on the repair of tibial plateau defect in rabbits.


METHODS
We used autograft bone, allograft bone, calcium sulfate bone cement, and calcium phosphate bone cement to repair tibial plateau defect in rabbits. Gross and histologic observations, X-ray examination, and biomechanical test were conducted at 1, 2, 4, 8 weeks after operation.


RESULTS
X-ray examination found that the bone density was evidently reduced in calcium sulfate group at 8 weeks after operation; there were no marked changes in other groups. The maximal load measurements showed that autograft and allograft groups were greater than calcium sulfate and calcium phosphate groups at 1 and 2 weeks after operation. However at 4 and 8 weeks after operation, no significant difference was found among the four groups. In autograft and allograft groups, there was no significant difference in biomechanical intensity at 2, 4, and 8 weeks, but it was significantly higher than that at 1 week. In calcium sulfate and calcium phosphate groups, the outcome was ranked in descending order as 1 week less than 2 week less than 4 week equal to 8 week. Histologic examination found a great amount of new bones at 8 week in both autograft and allograft groups. In calcium sulfate group, calcium sulfate was almost absorbed and there were numerous bone trabeculations. There was a large amount of unabsorbed calcium phosphate in calcium phosphate group.


CONCLUSIONS
At 1-2 weeks postoperatively, the biomechanical intensity is higher in autograft and allograft groups than calcium sulfate and calcium phosphate groups, but after 4-8 weeks, there is no significant difference among groups. At 1-2 weeks, the biomechanical intensity in all groups is increased, but at 4-8 weeks, there is no significant increase. The rates of absorption and bone formation are quicker in calcium sulfate group than calcium phosphate group.
Department of Orthopaedics and Traumatology, Peking University People's Hospital,Beijing 100044, China.
Hai-Lin
HL
Xu
Na
N
Han
Yu-Hui
YH
Kou
Yan-Hua
YH
Wang
Hong-Bo
HB
Zhang
Bao-Guo
BG
Jiang
D000818:Animals; D001696:Biomechanical Phenomena; D001843:Bone Cements; D016025:Bone Transplantation; D007719:Knee Joint; D013977:Tibia; D014182:Transplantation, Autologous
D001843:Bone Cements