Cho Jongwon, Ryu Seungjun, Jang Hyun-Jun, Park Jeong-Yoon, Ha Yoon, Kuh Sung-Uk, Chin Dong-Kyu, Kim Keun-Su, Cho Yong-Eun, Kim Kyung-Hyun
Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Department of Neurosurgery, National Health Insurance Service Hospital, Goyang, Korea.
J Korean Neurosurg Soc. 2023 Jan;66(1):44-52. doi: 10.3340/jkns.2022.0174. Epub 2022 Sep 1.
This study aimed to investigate the efficacy of transverse process (TP) hook system at the upper instrumented vertebra (UIV) for preventing screw pullout in adult spinal deformity surgery using the pedicle Hounsfield unit (HU) stratification based on K-means clustering.
We retrospectively reviewed 74 patients who underwent deformity correction surgery between 2011 and 2020 and were followed up for >12 months. Pre- and post-operative data were used to determine the incidence of screw pullout, UIV TP hook implementation, vertebral body HU, pedicle HU, and patient outcomes. Data was then statistically analyzed for assessment of efficacy and risk prediction using stratified HU at UIV level alongside the effect of the TP hook system.
The screw pullout rate was 36.4% (27/74). Perioperative radiographic parameters were not significantly different between the pullout and non-pullout groups. The vertebral body HU and pedicle HU were significantly lower in the pullout group. K-means clustering stratified the vertebral body HU ≥205.3, <137.2, and pedicle HU ≥243.43, <156.03. The pullout rate significantly decreases in patients receiving the hook system when the pedicle HU was from ≥156.03 to < 243.43 (p<0.05), but the difference was not statistically significant in the vertebra HU stratified groups and when pedicle HU was ≥243.43 or <156.03. The postoperative clinical outcomes improved significantly with the implementation of the hook system.
The UIV hook provides better clinical outcomes and can be considered a preventative strategy for screw-pullout in the certain pedicle HU range.
本研究旨在探讨在上端椎（UIV）使用横突（TP）钩系统，基于K均值聚类的椎弓根Hounsfield单位（HU）分层，在成人脊柱畸形手术中预防螺钉拔出的疗效。
我们回顾性分析了2011年至2020年间接受畸形矫正手术且随访时间超过12个月的74例患者。术前和术后数据用于确定螺钉拔出的发生率、UIV的TP钩应用情况、椎体HU、椎弓根HU以及患者的预后。然后对数据进行统计分析，以评估在UIV水平使用分层HU时TP钩系统的疗效和风险预测。
螺钉拔出率为36.4%（27/74）。拔出组和未拔出组的围手术期影像学参数无显著差异。拔出组的椎体HU和椎弓根HU显著更低。K均值聚类将椎体HU分层为≥205.3、<137.2，椎弓根HU分层为≥243.43、<156.03。当椎弓根HU为≥156.03至<243.43时，接受钩系统的患者拔出率显著降低（p<0.05），但在椎体HU分层组以及椎弓根HU≥243.43或<156.03时，差异无统计学意义。实施钩系统后，术后临床疗效显著改善。
UIV钩可提供更好的临床疗效，在特定的椎弓根HU范围内可被视为预防螺钉拔出的一种策略。
