Peindl R D, Harrow M E, Banks D M, Bosse M J, Kellam J F
Orthopaedic Engineering Research Laboratory, Carolinas Medical Center, Charlotte, North Carolina 28232, USA.
J Orthop Trauma. 1998 Nov-Dec;12(8):531-9. doi: 10.1097/00005131-199811000-00001.
This study evaluated the mechanical loading experienced by four clinically used intramedullary reamer cutter designs to evaluate the effects of variations in speed and feed rate on reamer system performance.
Biomechanical laboratory study.
Research laboratory.
Four clinically used reamer systems with detachable cutters were tested using a computer-controlled machining system at representative reaming and drilling speeds of 250 and 750 revolutions per minute (RPM), respectively. Hard oak blocks with mechanical properties similar to cortical bone were reamed using cutter heads with diameters from nine to fourteen millimeters (in 0.5-millimeter increments) at feed rates of 1.0 and 7.6 centimeters per second. Reactive axial loads and torques were recorded and analyzed.
All systems demonstrated reduced maximal loads/torques for small reamer sizes (9 to 10.5 millimeters) at drilling speeds rather than reaming speeds. Individual systems demonstrated measurable differences in sensitivity to alterations in operating speed, indicating that some designs are not amenable to operation at increased speeds. In tests where reamer head cutting characteristics were isolated by using identical solid drive shafts, the deeply fluted design with a long lead taper and a rounded, burrlike body consistently produced significantly lower mechanical loading at all speeds and feed rates. In addition, two of the four systems tested use a larger flex shaft diameter for reamer head sizes of thirteen millimeters or greater. There was no indication of a need to use larger flex shafts for the larger reamers, based on mechanical load/torque data for those systems.
The tests performed demonstrate that appropriate control of reaming speeds (RPM) can be used to minimize mechanical loading for all systems. Caution should be exercised, however, so that any operational changes that reduce resistive loads and torques do not lead the surgeon to increased feed rates. Additional study is required to investigate the variable effects of increasing the operating speed of each system on localized thermal changes.
本研究评估了四种临床使用的髓内扩孔钻刀具设计所承受的机械负荷，以评估速度和进给速率变化对扩孔钻系统性能的影响。
生物力学实验室研究。
研究实验室。
使用计算机控制的加工系统，分别以每分钟250转和750转（RPM）的代表性扩孔和钻孔速度，对四种临床使用的带有可拆卸刀具的扩孔钻系统进行测试。使用直径从9毫米到14毫米（以0.5毫米为增量）的刀头，以每秒1.0厘米和7.6厘米的进给速率对机械性能类似于皮质骨的硬橡木块进行扩孔。记录并分析反应性轴向负荷和扭矩。
所有系统在钻孔速度而非扩孔速度下，对于小尺寸扩孔钻（9至10.5毫米）均表现出最大负荷/扭矩降低。各个系统在对操作速度变化的敏感性方面表现出可测量的差异，这表明某些设计不适合在更高速度下操作。在通过使用相同的实心驱动轴来分离扩孔钻头切削特性的测试中，具有长导程锥度和圆形、毛刺状主体的深槽设计在所有速度和进给速率下始终产生显著更低的机械负荷。此外，所测试的四个系统中有两个在扩孔钻头尺寸为13毫米或更大时使用更大直径的挠性轴。根据这些系统的机械负荷/扭矩数据，没有迹象表明对于更大尺寸的扩孔钻需要使用更大直径的挠性轴。
所进行的测试表明，适当控制扩孔速度（RPM）可用于使所有系统的机械负荷最小化。然而，应谨慎操作，以使任何降低阻力负荷和扭矩的操作变化不会导致外科医生提高进给速率。需要进一步研究以调查提高每个系统的操作速度对局部热变化的不同影响。
