Oh Byeong Ho, Kim Jee Yong, Lee Jong Beom, Hong Jae Taek, Sung Jae Hoon, Than Khoi D, Lee Ho Jin, Kim Il Sup
Department of Neurosurgery, Chungbuk National University Hospital, Cheongju, Korea.
Department of Neurosurgery, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Korea.
Neurospine. 2023 Dec;20(4):1177-1185. doi: 10.14245/ns.2346830.415. Epub 2023 Dec 31.
Achieving successful fusion during spine surgery is dependent on rigid pedicle screw fixation. To assess fixation strength, the insertional torque can be measured during intraoperative screw fixation. This study aimed to explore the technical feasibility of measuring the insertional torque of a pedicle screw, while investigating its relationship with bone density.
Thoraco-lumbar screw fixation fusion surgery was performed on 53 patients (mean age, 65.5 ± 9.8 years). The insertional torque of 284 screws was measured at the point passing through the pedicle using a calibrated torque wrench, with a specially designed connector to the spine screw system. The Hounsfield units (HU) value was determined by assessing the trabecular portion of the index vertebral body on sagittal computed tomography images. We analyzed the relationship between the measured insertional torque and the following bone strength parameters: bone mineral density (BMD) and HU of the vertebral body.
The mean insertion torque was 105.55 ± 58.08 N∙cm and T-score value (BMD) was -1.14 ± 1.49. Mean HU value was 136.37 ± 57.59. Screw insertion torque was positively correlated with BMD and HU in whole patients. However, in cases of osteopenia, all variables showed very weak correlations with insertional torque. In patients with osteoporosis, there was no statistically significant correlation between BMD and torque strength; HU showed a significant correlation.
The insertional torque of screw fixation significantly correlated with bone density (BMD and HU). HU measurements showed greater clinical significance than did BMD values in patients with osteoporosis.
脊柱手术中成功实现融合依赖于坚固的椎弓根螺钉固定。为评估固定强度，可在术中螺钉固定过程中测量插入扭矩。本研究旨在探讨测量椎弓根螺钉插入扭矩的技术可行性，并研究其与骨密度的关系。
对53例患者（平均年龄65.5±9.8岁）进行胸腰椎螺钉固定融合手术。使用校准扭矩扳手，通过一个专门设计的与脊柱螺钉系统相连的连接器，在穿过椎弓根的点测量284枚螺钉的插入扭矩。通过在矢状位计算机断层扫描图像上评估索引椎体的小梁部分来确定亨氏单位（HU）值。我们分析了测量的插入扭矩与以下骨强度参数之间的关系：椎体的骨矿物质密度（BMD）和HU。
平均插入扭矩为105.55±58.08N∙cm，T值（BMD）为-1.14±1.49。平均HU值为136.37±57.59。在所有患者中，螺钉插入扭矩与BMD和HU呈正相关。然而，在骨质减少的病例中，所有变量与插入扭矩的相关性都非常弱。在骨质疏松患者中，BMD与扭矩强度之间无统计学显著相关性；HU显示出显著相关性。
螺钉固定的插入扭矩与骨密度（BMD和HU）显著相关。在骨质疏松患者中，HU测量比BMD值具有更大的临床意义。
