骨水泥阻塞骨干髓腔后远侧骨内压的改变

Changes of intraosseous pressure of the distal femoral shaft after blocking of femoral medullary cavity with bone cement

目的:探讨骨水泥阻塞股骨近中段骨干髓腔后对股骨远端骨内压的近、远期影响。方法:实验于2002-07/2003-04在重庆医科大学实验动物中心完成。成年新西兰大白兔32只。采取兔左侧股骨髓腔内灌注聚甲基丙烯酸甲酯骨水泥而右侧不灌注作为正常对照的方法,制作骨水泥阻塞股骨近中段骨干髓腔的动物模型。将32只实验兔分成5组,随机取出8只不做模型作为正常组,其余24只制作骨水泥阻塞骨干髓腔的动物模型,根据不同的观察时间段随机分成术后当天(0d),4,8,16周组,每组6只。使用生理测压仪,对正常和模型动物双侧股骨远端骨内压进行测量和比较。结果:32只兔均进入结果分析。①各组实验侧和对照侧骨内压比较:正常组双侧股骨远端骨内压比较无差异性;造模后0d,4,8,16周实验侧骨内压明显比对照侧增高[(4.6±0.5)比(3.1±0.4)kPa,(4.8±0.5)比(3.0±0.4)kPa,(4.7±0.4)比(3.1±0.4)kPa,(4.1±0.2)比(3.1±0.4)kPa,P<0.01)。②模型后不同观察时间段骨内压比较:造模后在不同观察时间段对照侧骨内压均无差异性;实验侧处于持续骨内高压状态,4周显著高于16周(P<0.05)。结论:骨水泥阻塞股骨近中段骨干髓腔后严重破坏了骨内和髓内的血液循环状态,引起了一系列血流动力学变化,导致股骨远端的骨内压持续升高并长期存在。

AIM： To explore the short-term and long-term effects on the distal femoral intraosseous pressure after blocking of proximal and middle femoral medullary cavity with bone cement. METHODS： The experiment was carried out in the Animal Experimental Center of Chongqing Medical University from July 2002 to April 2003. Thiry-two New Zealand rabbits were used in the experiment. Rabbit models were established whose proximal and middle femoral medullary cavity of left side was infused with polymethyl methacrylate （PMMA） while the right side served as controls. Eight rabbits were selected randomly as controis without modeling. The other twenty-six rabbits were randomly divided into 4 groups according to based on the following observational time-points： postoperative 0 day, week 4, week 8 and week 16. Physiological pressuremeasuring instrument was used to detect, analyze and compare the intraosseous pressure of bilateral distal femoral medullary cavity of the experimental and control groups. RESULTS： All the thirty-two rabbits entered the result analysis. ①Comparison of intraosseous pressure between the experimental and control sides： There was no significant difference in the intraosseous pressure between the bilateral distal femurs in normal rabbits （P 〉 0.05）. In the experimental group, the pressure of the experimental side increased notably and significantly differed from that of the control side at day 0, week 4, week 8 and week 16 after modeling[（4.6±0.5 ） vs. （3.1±0.4）kPa, （4.8 ±0.5 ）vs. （3.0±0.4）kPa, （4.7±0.4）vs. （3.1±0.4）kPa, （4.1±0.2）vs. （3.1±0.4 ）kPa, P 〈 0.01]. ②Comparison of intraosseous pressure at different time after modeling： There was no difference in the intraosseous pressure of the control side at different time after modeling. As for the experimental side, intraosseous hypertension presented continuously, which was higher at week 4 than at week 16 （P 〈 0.05）. CONCLUSION： The intraosseous and intramedullary blood circulation is severely damaged after blocking the proximal and middle femoral medullary cavity with bone cement, leading to a series of hemodynamical changes and the continuous intraosseous hypertension of a long-term existence on the distal femoral.