Department of Orthopaedics, Xijing Hospital, Fourth Military Medical University, 15 Changle Western Rd, Xi'an, Shaanxi Province, China 710032.
Spine J. 2011 Sep;11(9):832-8. doi: 10.1016/j.spinee.2011.07.026. Epub 2011 Sep 3.
Spring-back complication after open-door laminoplasty as described by Hirabayashi is a well-known risk, but its definition, incidence, and associated neurologic outcome remain unclear.
To investigate the incidence and the neurologic consequence of spring-back closure after open-door laminoplasty.
A retrospective radiographic and clinical review.
Lateral cervical spine X-rays were evaluated. Anteroposterior diameters (APD) of the vertebral canal of C3-C7 were measured. Spring-back was defined as loss of APD on follow-up in comparison to immediate postoperative canal expansion. The loss of the end-on lamina silhouette with consequent reappearance of the lateral profile of the spinous processes was also assessed to verify the presence of spring-back. Spring-back closure was classified based on whether the collapse was total or partial, and whether all the operated levels or only a subset had collapsed (ie, complete vs. partial closure, segmental closure vs. total-construct closure). Neurologic status was documented using the Japanese Orthopaedic Association (JOA) score.
Thirty consecutive patients who underwent open-door laminoplasty from 1995 to 2005 at a single institution with a minimum follow-up of 2 years were assessed. They were all operated on using the classic Hirabayashi technique. Radiographic outcomes were assessed independently by two individuals.
Sixteen men and 14 women with an average follow-up of 5 years (range, 2-12 years) were included. Of these patients, 24 had cervical spondylotic myelopathy and six had ossification of the posterior longitudinal ligament. Spring-back closure was found in three patients (10%) and 7 of 117 laminae (6%) within 6 months of the operation, which was further confirmed by computed tomography and magnetic resonance imaging. All spring-back closures were partial segmental closures. Gender and age were not significant factors related to spring back (p>.05). The mean JOA score on follow-up was 12.5, with a recovery rate of 40%. All patients with spring back and available JOA data exhibited postoperative neurologic deterioration. Of the three patients with spring back, two patients underwent revision surgery, whereas one declined.
Spring-back closure occurred in 10% of our patients at or before 6 months after surgery. The incidence of spring-back by level (ie, 117 laminae) was 6%, mainly occurring at the lower cervical spine. All spring-back closures were partial segmental closures, most commonly involving C5 and C6. Postoperative neurologic deficit was associated with spring-back closure; therefore, surgeons should adopt preemptive surgical measures to prevent the occurrence of such a complication.
Hirabayashi 描述的开门式椎管扩大成形术后的回弹并发症是一种众所周知的风险，但它的定义、发生率和相关的神经学结果仍不清楚。
研究开门式椎管扩大成形术后回弹关闭的发生率和神经学后果。
回顾性影像学和临床研究。
评估了颈椎侧位 X 线片。测量 C3-C7 椎管的前后径（APD）。与术后即刻椎管扩张相比，随访时 APD 丢失定义为回弹。还评估了终板轮廓丢失与棘突侧轮廓再现，以验证回弹的存在。根据塌陷是否完全或部分，以及所有手术水平或仅部分水平（即完全或部分关闭，节段性关闭与全构建关闭），对回弹关闭进行分类。神经状态使用日本矫形协会（JOA）评分记录。
在一家机构，从 1995 年至 2005 年连续 30 例接受开门式椎管扩大成形术的患者接受评估，随访时间至少 2 年。所有患者均采用经典的 Hirabayashi 技术进行手术。两名独立的人员评估了影像学结果。
平均随访 5 年（范围，2-12 年），包括 16 名男性和 14 名女性。其中 24 例为颈椎病性脊髓病，6 例为后纵韧带骨化。术后 6 个月内发现 3 例（10%）和 7 例（117 例）椎板出现回弹关闭，进一步通过计算机断层扫描和磁共振成像证实。所有回弹关闭均为部分节段性关闭。性别和年龄与回弹无关（p>.05）。随访时平均 JOA 评分为 12.5，恢复率为 40%。所有出现回弹和可获得 JOA 数据的患者术后均出现神经功能恶化。在 3 例出现回弹的患者中，2 例患者接受了翻修手术，而 1 例患者拒绝手术。
在术后 6 个月内，我们的患者中有 10%出现回弹关闭。按水平计算（即 117 个椎板）的回弹发生率为 6%，主要发生在下颈椎。所有的回弹关闭都是部分节段性的，最常见的是 C5 和 C6。术后神经功能缺损与回弹关闭有关；因此，外科医生应采取预防性手术措施以防止这种并发症的发生。
