The impact of dynamic factors on surgical outcomes after double-door laminoplasty for ossification of the posterior longitudinal ligament of the cervical spine
The impact of dynamic factors on surgical outcomes after double-door laminoplasty for ossification of the posterior longitudinal ligament of the cervical spine
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DOI：
10.3171/2014.8.spine131197
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发表时间：
2014-12-01
影响因子：
2.8
通讯作者：
Yoshiya, Shinichi
中科院分区：
文献类型：
--
作者：
Maruo, Keishi;Moriyama, Tokuhide;Yoshiya, Shinichi
Object.椎板成形术是大多数颈椎病患者由于多节段后纵韧带骨化（OPLL）的首选手术。最近的研究表明，椎板成形术后临床结局不良的几个重要风险因素，包括年龄较大、术前日本矫形协会（乔亚）评分较低、术后颈椎对线变化、颈椎后凸和OPLL占用率较高（即，侧位图像上OPLL的最大前后厚度与同一节段椎管前后直径的比值）.然而，动态因素对临床结局的影响尚不清楚。本研究的目的是评估动态因素对OPLL所致颈椎病椎板成形术后临床结果的影响。回顾性分析了2003年至2009年间因OPLL而接受颈椎病椎板成形术的连续患者系列。作者所在医院的椎板成形术适应症包括术前颈椎直线或前凸对线，OPLL占用率低于60%。采用乔亚评分和痊愈率评价临床疗效。不良临床结局定义为恢复率低于50%。沿着检查的患者因素包括年龄、术前乔亚评分、术前体感诱发电位、术前肌力诱发电位、体重指数和MRI高信号。影像学指标包括术前C2-7前凸角、术前C2-7活动度（ROM）、术前脊髓病节段ROM和OPLL占位率。共45例患者（男性33例，女性12例）。平均随访时间为4年（范围2-6.8年）。患者平均年龄为66.9岁（范围50-85岁）。平均乔亚评分从术前的9.1显著增加至最终随访时的13.1。平均回收率为51.2%。19例患者（42%）的恢复率低于50%。患者因素与手术结果无关。只有手术结果较差组的术前C2-7 ROM显著更大（23.1度vs 14.1度）。受试者工作特征曲线分析显示，最佳术前C2-7 ROM临界值为20度。Logistic回归分析显示，术前C2-7 ROM大于20度的患者临床结局不良的风险高4.6倍（p = 0.021），表明动态因素可能对椎板成形术的手术结局有影响。对于术前颈椎过度活动的患者，融合手术可能是一种有用的策略。
Object. Laminoplasty is the preferred operation for most patients with cervical myelopathy due to multilevel ossification of the posterior longitudinal ligament (OPLL). Recent studies have demonstrated several significant risk factors for poor clinical outcomes after laminoplasty, including older age, lower preoperative Japanese Orthopaedic Association (JOA) score, postoperative change in cervical alignment, cervical kyphosis, and high occupying ratio of the OPLL (that is, the ratio of the greatest anteroposterior thickness of the OPLL to the anteroposterior diameter of the spinal canal at the same level on a lateral image). However, the impact of dynamic factors on clinical outcomes is unclear. The purpose of this study is to assess the impact of dynamic factors on the clinical outcome after laminoplasty for cervical myelopathy due to OPLL.Methods. A consecutive series of patients who underwent laminoplasty for cervical myelopathy due to OPLL between 2003 and 2009 was retrospectively reviewed. The indication for laminoplasty at the authors' hospital included preoperative straight or lordotic alignment of the cervical spine and an occupying ratio of OPLL less than 60%. The JOA score and recovery rate were used to evaluate clinical outcomes. A poor clinical outcome was defined as a recovery rate of less than 50%. Patient factors examined along with outcome included age, preoperative JOA score, preoperative somatosensory evoked potentials, preoperative inotor evoked potentials, body mass index, and presence of high intensity on MRI. Radiographic measures included the preoperative C2-7 lordotic angle, preoperative C2-7 range of motion (ROM), preoperative segmental ROM at the level of myelopathy, and the occupying ratio of OPLL.Results. There were 45 patients (33 males and 12 females). The mean follow-up period was 4 years (range 2-6.8 years). The mean patient age was 66.9 years (range 50-85 years). The mean JOA score significantly increased from 9.1 before surgery to 13.1 at the final follow-up. The mean recovery rate was 51.2%. Nineteen patients (42%) had a recovery rate of less than 50%. Patient factors were not associated with surgical outcomes. Only the preoperative C2-7 ROM was significantly greater in the poor surgical outcome group (23.1 degrees vs 14.1 degrees). Receiver operating characteristic curve analysis showed that the optimal preoperative C2-7 ROM cutoff was 20 degrees. Logistic regression analysis revealed that patients with a preoperative C2-7 ROM of greater than 20 degrees had a 4.6 times higher risk (p = 0.021) of a poor clinical outcome, indicating that dynamic factors may have an impact on the surgical outcome of laminoplasty.Conclusions. Fusion surgery may be a useful strategy in patients with preoperative hypermobility of the cervical spine.