可注射磷酸钙骨水泥填充固定羊胫骨平台骨折的体内生物力学研究

目的 比较磷酸钙骨水泥(CPC)与松质骨移植在修复羊外侧胫骨平台压缩性骨折中的体内生物力学特点.方法 成年健康山羊10只,双侧后肢制成外侧胫骨平台压缩性骨折模型,一侧以CPC填充(CPC组),对侧用自体骨填充(自体骨组).术后3个月和6个月各处死5只动物,取双侧胫骨观察关节面塌陷程度,摄X线片观察骨水泥降解情况,测定骨折部位抗压刚度,制备不脱钙切片观察关节面组织学改变.结果 自体骨组10个标本中的8个发生了骨折块的中重度下陷,CPC组只有3个发生了轻度下陷.X线片示3个月时骨水泥降解吸收被分割成几块,外形变模糊,6个月时大部分骨水泥被降解吸收.CPC组和自体骨组抗压刚度在3个月时分别为(226.89±62.81)N/mm和(172.97±79.82)N/mm,差异无统计学意义(t=1.369,P=0.243),6个月时分别为(471.27±212.89)N/mm和(371.05±207.98)N/mm,差异无统计学意义(t=0.948,P=0.397).组织学观察显示自体骨组关节面塌陷较严重,修复的软骨组织中纤维组织偏多;CPC组关节面软骨修复过程中对位较好,由纤维软骨形成相连接,纤维组织较少.结论 CPC的支撑效果好于自体骨,可在早期提供一定的抗压强度,防止胫骨平台关节面塌陷移位,有利于术后早期活动.

Biomechanical study of injectable calcium phosphate cement in repairing lateral tibial plateau compression fractures in goats

Objective To make a comparison of mechanical stability between calcium phosphate cement(CPC)and autograft in repairing lateral tibial plateau compression fractures in goats. Methods Bilateral tibial plateau compression fractures were made in 10 hind legs of goats.The bilateral fractures were reduced and filled with CPC and autograft respectively.Animals were executed 3 and 6 months after operation. Their bilateral tibial plateaus were obtained and the articular sudace subsidence of the plateaus was evaluated. Cement absorption was observed by X-ray examination and tibial plateau compression rigidity was tested. Articular Burface histology was evaluated with non-decalcified sections. Results Slight articular subsi- dence occurred in 3 of the 10 CPC specimens,while mediate or serious subsidence occurred in 8 of the 10 autograft specimens.X-ray showed that CPC was absorbed into several small blocs in 3 months and nearly disappeared in 6 months.Anti-compression rigidity was 226.89 ±62.81 N/mm in CPC group and 172.97 ± 79.82 N/mm in autngraft group in 3 months(t=1.369,P=0.243),and 471.27±212.89 N/nun and 371.05±207.98 N/mm in 6 months(t=0.948,P=0.397)respectively.There was no significant dif- ference between groups.Histology study showed plenty fibrous tissues existed in the repaired cartilage in au- tograft group,while fibrous tissues were scanty in the repaired cartilage in CPC group.Conclusions CPC can provide better eady fixation intensity than autograft in repairing tibial plateau compression fractures.CPC can be absorbed rapidly in hrge animals.