Wang Michael Y, Levi Allan D O
Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles 90033, USA.
Neurosurgery. 2006 May;58(5):907-12; discussion 907-12. doi: 10.1227/01.NEU.0000209929.38213.72.
Lateral mass screw fixation of the subaxial cervical spine has been a major advancement for spinal surgeons. This technique provides excellent three-dimensional fixation from C3 to C7. However, exposure of the dorsal spinal musculature can produce significant postoperative neck pain. The incorporation of a minimal access approach using tubular dilator retractors can potentially overcome the drawbacks associated with the extensive muscle stripping needed for traditional surgical exposures.
A retrospective analysis was performed on the first 18 patients treated using lateral mass screws placed in a minimally invasive fashion. All patients, except 2 who were lost to follow-up, had a 2-year minimum clinical follow-up. All patients had a computed tomography (CT) scan in the immediate postoperative period to check the positioning of implanted hardware. Operative time, blood loss, and complications were ascertained. Fusion was assessed radiographically with dynamic radiographs and CT scans.
Sixteen of the 18 patients underwent successful screw placement. Two patients had the minimal access procedure converted to an open surgery because radiographic visualization was not adequate in the lower cervical spine. Six cases involved unilateral instrumentation and 10 had bilateral screws. A total of 39 levels were instrumented. There were no intraoperative complications, and follow-up CT scans demonstrated no bony violations except in cases where bicortical purchase was achieved. All patients achieved bony fusion.
A minimally invasive approach using tubular dilator retractors can be a safe and effective means for placing lateral mass screws in the subaxial cervical spine. Up to two levels can be treated in this manner. This approach preserves the integrity of the muscles and ligaments that maintain the posterior tension band of the cervical spine but requires adequate intraoperative imaging.
颈椎下颈椎侧块螺钉固定术是脊柱外科医生的一项重大进展。该技术可实现从C3至C7的出色三维固定。然而，显露背侧脊柱肌肉组织会导致术后颈部疼痛明显。采用管状扩张器牵开器的微创入路可能会克服传统手术显露所需广泛肌肉剥离带来的缺点。
对首批18例采用微创方式置入侧块螺钉治疗的患者进行回顾性分析。除2例失访患者外，所有患者均有至少2年的临床随访。所有患者术后即刻均行计算机断层扫描（CT）以检查植入器械的位置。确定手术时间、失血量及并发症情况。通过动态X线片和CT扫描对融合情况进行影像学评估。
18例患者中有16例成功置入螺钉。2例患者因下颈椎的影像学视野不佳而将微创手术改为开放手术。6例为单侧器械置入，10例为双侧螺钉置入。共置入39个节段。术中无并发症，随访CT扫描显示除实现双侧皮质骨固定的病例外无骨质破坏。所有患者均实现了骨融合。
采用管状扩张器牵开器的微创入路可作为在下颈椎置入侧块螺钉的一种安全有效的方法。以此方式可治疗多达两个节段。该方法保留了维持颈椎后张力带的肌肉和韧带的完整性，但需要术中充分的影像学检查。
