兔胫骨平台骨折愈合的生物力学变化规律

Biomechanical changes of tibial plateau fracture healing in rabbits

背景:目前对于胫骨平台骨折愈合过程中生物力学变化规律的研究很少。目的:观察胫骨平台骨折愈合过程中带螺钉固定与去螺钉所承受的最大载荷及最大点能量变化。方法:采用39只新西兰大白兔制作胫骨平台骨折模型,行螺钉内固定,于术后即刻、1,2,3,4,6,8周取材胫骨标本,即刻点3只兔6个标本,其余各时间点取6只兔子、共12个标本,在万能力学试验机上进行胫骨内侧髁垂直压缩试验,分别测量带螺钉固定及去除螺钉后标本所能承受的最大载荷、最大点能量。另取3只兔的胫骨标本,测量相应数据作为对照。结果与结论:最大载荷及吸收能量在前一阶段逐渐上升,于4周时达到最大,与对照组比较差异有显著性意义(P<0.05),在8周时又降至正常水平。两组测量值的变化趋势一致。结果表明:在胫骨平台骨折愈合的早期过程中,骨折愈合强度呈单峰曲线变化,螺钉内固定充分有效。

BACKGROUND：Studies regarding the biomechanical changes during tibial plateau fractures healing are few. OBJECTIVE：To evaluate the maximal loading and maximal point energy changes with or without screw fixation during the healing process of tibial plateau fractures in rabbits. METHODS：A total of 39 New Zealand rabbits were used to establish models of tibial plateau fractures and fixed by screws. At selected time points after operation [0 （3 rabbits）,1,2,3,4,6 and 8 weeks （6 rabbits）],the tibial specimens were harvested and subjected to biomechanical testing. The maximum load of anti-compression at the medial tibial plateau and the energy to maximum in rabbits with or without fixing screws were recorded. Intact tibia specimens were measured as controls. RESULTS AND CONCLUSION：The maximum load and the energy to maximum increased during the first stage and reached the peak at 4 weeks postoperatively compared with control group （P 0.05）,then recovered to normal levels at 8 weeks. The measured values of the two groups changed similarly. In the early healing process of tibial plateau fractures,the strength of fracture healing presented a single peak curve,and the screw fixation was efficient.