Hearn T C, Schatzker J, Wolfson N
Orthopaedic Biomechanics Research Laboratory, Sunnybrook Health Science Centre, Toronto, Ontario, Canada.
J Orthop Trauma. 1993;7(2):138-41. doi: 10.1097/00005131-199304000-00006.
The purpose of this study was to determine whether the alterations in the relative dimensions of thread and core diameter that accompany cannulation of cancellous bone screws affect their holding strength. The screws were inserted in bovine femoral cancellous bone and mounted in the load train of a materials testing system. They were then extracted under servo-hydraulic displacement control. The tests were repeated in synthetic cancellous material. From the corresponding load-displacement histories, the maximum force values attained were determined as the screws' holding strengths. The results of tests from 17 matched pairs of bovine femora, and of 15 tests of each screw in synthetic material, were recorded. No significant differences in extraction strength between 7.0-mm cannulated and 6.5-mm standard cancellous bone screws were found. Based on tests in the bovine femur and synthetic cancellous material, this study showed that the extraction strength of cancellous bone screws is not altered by the changes in thread-to-core ratio accommodating cannulation.
本研究的目的是确定松质骨螺钉插管时螺纹与芯直径相对尺寸的改变是否会影响其握持强度。将螺钉插入牛股骨松质骨中，并安装在材料测试系统的加载装置上。然后在伺服液压位移控制下将其拔出。在合成松质材料中重复进行测试。根据相应的载荷-位移历史记录，将达到的最大力值确定为螺钉的握持强度。记录了17对匹配的牛股骨的测试结果，以及每种螺钉在合成材料中的15次测试结果。未发现7.0毫米空心松质骨螺钉与6.5毫米标准松质骨螺钉在拔出强度上有显著差异。基于在牛股骨和合成松质材料中的测试，本研究表明，适应插管的螺纹与芯比率的变化不会改变松质骨螺钉的拔出强度。
