Hess T, Hopf T, Fritsch E, Mittelmeier H
Orthopädischen Universitäts- und Poliklinik Homburg/Saar.
Z Orthop Ihre Grenzgeb. 1991 May-Jun;129(3):278-82. doi: 10.1055/s-2008-1040195.
In normal cortical screws the thread must be cut by a separate thread-cutter. So a high stability of the connection is achieved. On the other hand thread cutting needs time, which may be assumed to several minutes during a plate osteosynthesis. To avoid thread-cutting, self-tapping screws were used 20 years ago. These old self-tapping screws had a reduced stability and a lower torque at the final screw driving so that they tended to destroy the thread. By a modification of the cutting edges at the tip of the screw the tapping quality is increased decisively. The microscopic examination showed a better cutting of the new screws with little difference to a thread-cutter. In biomechanical tests the final torque and the maximum tension force of the self-tapping screws were at the same level as in usual pre-cut screws. In the practical use the new self-tapping screws have a good handling and save time during operation. In osteoporosis, they should be used carefully in order to meet the opposite corticalis' hole and not to destroy the ipsilateral corticalis' thread.
在普通皮质骨螺钉中，螺纹必须由单独的螺纹铣刀加工。这样就能实现连接的高稳定性。另一方面，螺纹加工需要时间，在接骨板骨合成过程中这可能需要几分钟。为避免螺纹加工，20年前开始使用自攻螺钉。这些老式自攻螺钉稳定性降低，在最终拧入螺钉时扭矩较小，以至于它们容易破坏螺纹。通过对螺钉尖端切削刃的改进，攻丝质量得到了显著提高。显微镜检查显示新螺钉的切削效果更好，与螺纹铣刀的差别很小。在生物力学测试中，自攻螺钉的最终扭矩和最大拉力与普通预切螺钉处于同一水平。在实际应用中，新型自攻螺钉操作方便，手术过程中节省时间。在骨质疏松症中，使用时应小心，以便对准对侧皮质骨的孔，而不破坏同侧皮质骨的螺纹。
