Service de chirurgie du Rachis, hôpitaux universitaires de Strasbourg, B.P. 426, 1, place de l'Hôpital, 67091 Strasbourg cedex, France; Service d'orthopédie, institut régional du Rachis, centre hospitalier Charles-Nicolle, 1, rue de Germont, 76000 Rouen, France.
Service de chirurgie du Rachis, hôpitaux universitaires de Strasbourg, B.P. 426, 1, place de l'Hôpital, 67091 Strasbourg cedex, France.
Orthop Traumatol Surg Res. 2019 Oct;105(6):1137-1141. doi: 10.1016/j.otsr.2019.06.012. Epub 2019 Aug 27.
In routine practice, it is often necessary to use shorter screws in L5 than L4. The present study measured L5 versus L4 vertebral pedicles, to guide surgical strategy.
CT or MRI scans for 95 patients were analyzed. Radiographic measurements (anteroposterior diameter (APD), pedicle length (PL) and pedicle width (PW)) were taken by a spine surgeon. Statistical analysis used R 3.4.3 software.
Ninety-five patients were included: 48 female (50.53%), 47 male (49.47%); mean age, 57 years (range, 19-85 years). Univariate analysis found a strong correlation between right and left PL values in L4 and L5. Right and left values were pooled, obtaining a mean L4 PL of 55.34mm (range, 54.23-56.45mm) and L5 PL of 51.80mm (44.81-58.80) and L4 PW of 10.48mm (10.06-10.91) and L5 PW of 9.90mm (7.43-12.39). Multivariate analysis disclosed significant effects of age and gender, with greater age and male gender associated with greater anteroposterior vertebral diameter. Mean anteroposterior vertebral length was significantly shorter in L5 than L4 by 3.57mm (range, 4.08-3.06mm).
Anteroposterior pedicle length was shorter in L5 than L4, in line with the literature. This answers the surgeon's question: "Should pedicle screws be shorter in L5 than L4?". From these results, it seems logical to use an L5 screw that is 5mm shorter than in L4, to secure good intra-body screw fixation.
在常规实践中，在 L5 中使用比 L4 更短的螺钉是很常见的。本研究通过测量 L5 与 L4 椎弓根，来指导手术策略。
对 95 例患者的 CT 或 MRI 扫描进行了分析。脊柱外科医生对影像学测量值（前后直径（APD）、椎弓根长度（PL）和椎弓根宽度（PW））进行了测量。统计分析使用 R 3.4.3 软件。
共纳入 95 例患者：女性 48 例（50.53%），男性 47 例（49.47%）；平均年龄 57 岁（范围 19-85 岁）。单因素分析发现 L4 和 L5 的右侧和左侧 PL 值之间存在很强的相关性。将右侧和左侧的值合并，得到 L4 PL 的平均值为 55.34mm（范围 54.23-56.45mm），L5 PL 的平均值为 51.80mm（范围 44.81-58.80），L4 PW 的平均值为 10.48mm（10.06-10.91），L5 PW 的平均值为 9.90mm（7.43-12.39）。多因素分析显示年龄和性别有显著影响，年龄较大和男性与前后椎体直径较大相关。L5 的前后椎体长度比 L4 短 3.57mm（范围 4.08-3.06mm），差异有统计学意义。
L5 的前后椎弓根长度比 L4 短，这与文献一致。这回答了外科医生的问题：“L5 的椎弓根螺钉是否应该比 L4 更短？”。根据这些结果，似乎使用比 L4 短 5mm 的 L5 螺钉来固定体内螺钉更合理。
