Weinstein J N, Loening S, Park J B, Park S H, Oster D
Department of Biomedical Engineering, University of Iowa, Iowa City 52242.
J Appl Biomater. 1991 Fall;2(3):171-81. doi: 10.1002/jab.770020305.
The present study was conducted to compare the push-out strength of the treated and control samples obtained after implantation of intramedullary rod in canine femurs with bone cement to simulate the femoral stem implantation for 2 weeks, 3 and 6 months. Contralateral femur served as control. The result showed a significant decrease in push-out interfacial strength after shock wave treatment (average 48.4% decrease compared with control, p less than 0.0001) which is similar to the in vitro results. There was no significant difference if the shock treatment was applied and left for 2 weeks or 4 weeks compared to the ones tested immediately after sacrifice. There were some soft tissue damage immediately following shock treatment in the focal area but this returned to normal in 2 weeks. Human cadaveric femoral bone experiment results showed that results are similar for both human cadaveric femoral bones and the canine bone (the dosage level was higher for the human bone than canine). The number of impacts used to extract the bone cement plug out of a human femur segment (5-cm long) decreased about 68% at 23 and 25 kV treatment power level. These preliminary studies indicate that the shock wave can be utilized to reduce the interfacial strength of the bone and bone cement although more studies are needed to assess its efficacy in terms of cost, long-term effect on patients and the exact mechanism of the loosening before this technique can be used clinically.
本研究旨在比较在犬股骨中植入带骨水泥的髓内棒以模拟股骨干植入2周、3个月和6个月后，处理组和对照组样本的推出强度。对侧股骨作为对照。结果显示，冲击波处理后推出界面强度显著降低（与对照组相比平均降低48.4%，p<0.0001），这与体外实验结果相似。与处死动物后立即测试的样本相比，施加冲击波处理并放置2周或4周后的样本无显著差异。冲击波处理后局部区域立即出现一些软组织损伤，但2周后恢复正常。人体股骨实验结果表明，人体股骨和犬骨的结果相似（人体骨的剂量水平高于犬骨）。在23和25 kV处理功率水平下，从一段5厘米长的人体股骨中取出骨水泥塞所需的冲击次数减少了约68%。这些初步研究表明，冲击波可用于降低骨与骨水泥之间的界面强度，不过在该技术能够临床应用之前，还需要更多研究来评估其在成本、对患者的长期影响以及松动的确切机制方面的疗效。
