Sasagawa Takeshi
Department of Orthopaedic Surgery, Toyama Prefectural Central Hospital, Toyama, Japan.
Spine Surg Relat Res. 2022 Oct 13;7(2):155-160. doi: 10.22603/ssrr.2022-0133. eCollection 2023 Mar 27.
Thoracic percutaneous pedicle screw (PPS) fixation is technically challenging because of the complexity of the spinal anatomy involved. Furthermore, owing to the proximity of critical neurovascular structures, serious complications have been reported because of misplaced thoracic pedicle screws. Therefore, it is important to know the factors associated with the misplacement of thoracic PPS, but there have been few reports to date.
The present study included 663 PPSs inserted from T4 to T12 in 127 patients. The accuracy of pedicle screw placement was assessed using computed tomography (CT) scans conducted within two weeks postoperatively. We compared the screws in the misplaced group (Group M) and the optimal placed group (Group O) for sex, age, body mass index, the consecutive surgery numbers, type of disease, instrumented level, laterality, the pedicle diameter, the inclination angle of the transverse process, and Hounsfield units (HU) at the base of the transverse processes of the instrumented vertebrae.
Screw misplacement was observed in 28 (4%) of 663 screws on CTs conducted within two weeks postoperatively. In univariate analysis, there was a statistically significant difference between Group M (n=25) and Group O (n=638) for insertion level, the pedicle diameter, and the HU value of the transverse process. In multivariate logistic regression analysis, T4-6 level (T4-6; odds ratio [OR]=12.083, 95% confidence interval [CI]: 3.219-45.355) and greater HU value at the transverse process (OR=1.009, 95% CI: 1.004-1.014) were identified as independent factors associated with the misplacement of thoracic PPS.
The misplacement of thoracic PPS was observed in 28 (4%) of 663 screws. The vertebral level (T4-6) and greater HU values at the base of the transverse process were identified as independent factors associated with the misplacement of thoracic PPS.
由于所涉及的脊柱解剖结构复杂，胸椎经皮椎弓根螺钉（PPS）固定在技术上具有挑战性。此外，由于关键神经血管结构位置临近，已有报道称胸椎椎弓根螺钉位置不当会导致严重并发症。因此，了解与胸椎PPS位置不当相关的因素很重要，但迄今为止相关报道较少。
本研究纳入了127例患者中从T4至T12置入的663枚PPS。使用术后两周内进行的计算机断层扫描（CT）评估椎弓根螺钉置入的准确性。我们比较了位置不当组（M组）和最佳置入组（O组）在性别、年龄、体重指数、连续手术次数、疾病类型、固定节段、侧别、椎弓根直径、横突倾斜角度以及固定椎体横突基部的亨氏单位（HU）方面的差异。
术后两周内的CT检查发现663枚螺钉中有28枚（4%）位置不当。在单因素分析中，M组（n = 25）和O组（n = 638）在置入节段、椎弓根直径和横突的HU值方面存在统计学显著差异。在多因素逻辑回归分析中，T4 - 6节段（T4 - 6；比值比[OR] = 12.083，95%置信区间[CI]：3.219 - 45.355）以及横突更高的HU值（OR = 1.009，95% CI：1.004 - 1.014）被确定为与胸椎PPS位置不当相关的独立因素。
663枚螺钉中有28枚（4%）出现胸椎PPS位置不当。椎体节段（T4 - 6）和横突基部更高的HU值被确定为与胸椎PPS位置不当相关的独立因素。
