Oszwald Markus, Westphal Ralf, Stier Rebecca, Gaulke Ralph, Calafi Afshin, Müller Christian W, Wahl Friedrich, Krettek Christian, Gösling Thomas
Department of Trauma Surgery, Hannover Medical School, Hannover, Germany.
Technol Health Care. 2010;18(4-5):325-34. doi: 10.3233/THC-2010-0596.
Intramedullary nailing has become the gold standard in the treatment of femoral shaft fractures. This procedure involves the placement of distal interlocking bolts using the freehand technique. Accurate placement of distal interlocks can be a challenging task, especially in inexperienced hands. Misplacement of distal interlocking bolts can lead to iatrogenic fracture, instability of the bone-implant construct, or even malalignment of the extremity. Repeated drilling attempts increase radiation exposure and can cause additional bony and soft tissue trauma. We hypothesize that robot-guided placement of distal interlocks is more accurate, precise, and efficient than the freehand technique.
A custom-designed drill guide was mounted onto the arm of an industrial robot. We developed a special device to secure a generic block (Synbone, Malans, Switzerland) into which an intramedullary nail could be inserted in a standardized way. A metric scale allowed later measurements of the drillings. Digital images were taken from each side of the block for analysis of the drilling trajectories. The fluoroscope was adjusted to obtain perfect circles of the distal interlocking holes. The number of images necessary to achieve this was recorded. The axis was recognized automatically by using the differences in contrast between the matrix of the generic bone and the implant (intramedullary nail). The drill trajectories were then computed. The robot with the mounted drill-guide automatically moved onto the calculated trajectory. The surgeon then executed the drilling. We performed 40 robot assisted drillings in generic blocks. Freehand drilling served as our control group.
Analysis of the digital images revealed a mean deviation of 0.94 mm and 2.7° off the ideal trajectory using robotic assistance. In 100% of the cases (n = 40), the distal locking hole was hit. A mean of 8.8 images was acquired. After manual drilling, 92.5% of the distal interlocks were hit. A mean deviation of 3.66 mm and 10.36° was measured. A mean of 23.4 fluoroscopic images were needed. The differences between the two methods were statistically significant.
Robot-guided drilling increases the accuracy and precision of distal interlocking while reducing irradiation. Considering economical and logistical aspects, this application should be integrated with robot-guided fracture reduction.
髓内钉固定已成为股骨干骨折治疗的金标准。该手术包括使用徒手技术置入远端交锁螺栓。准确放置远端交锁螺栓可能是一项具有挑战性的任务，尤其是对于经验不足的人来说。远端交锁螺栓放置不当可能导致医源性骨折、骨-植入物结构不稳定，甚至肢体对线不良。反复钻孔会增加辐射暴露，并可能导致额外的骨和软组织创伤。我们假设机器人引导下的远端交锁放置比徒手技术更准确、精确和高效。
将定制设计的钻孔导向器安装在工业机器人的手臂上。我们开发了一种特殊装置来固定一个通用模块（瑞士马兰斯的Synbone），髓内钉可以以标准化方式插入该模块。一个公制刻度用于随后对钻孔的测量。从模块的每一侧拍摄数字图像以分析钻孔轨迹。调整荧光透视仪以获得远端交锁孔的完美圆形。记录达到此目的所需的图像数量。通过利用通用骨基质与植入物（髓内钉）之间的对比度差异自动识别轴线。然后计算钻孔轨迹。安装有钻孔导向器的机器人自动移动到计算出的轨迹上。然后外科医生进行钻孔。我们在通用模块中进行了40次机器人辅助钻孔。徒手钻孔作为我们的对照组。
对数字图像的分析显示，使用机器人辅助时，平均偏差为0.94毫米，偏离理想轨迹2.7°。在100%的病例（n = 40）中，远端锁定孔被命中。平均采集8.8张图像。徒手钻孔后，92.5%的远端交锁被命中。测量的平均偏差为3.66毫米和10.36°。平均需要23.4张荧光透视图像。两种方法之间的差异具有统计学意义。
机器人引导钻孔提高了远端交锁的准确性和精确性，同时减少了辐射。考虑到经济和后勤方面，该应用应与机器人引导的骨折复位相结合。
