颈椎后路单开门椎管扩大成形术后门轴侧骨性融合失败的风险因素研究

Analysis of the risk factors for hinge fusion failure after cervical posterior single door laminoplasty

目的探讨颈椎后路单开门椎管扩大成形术后门轴侧骨性融合失败的风险因素。方法93例脊髓型颈椎病患者接受后路单开门椎管扩大成形术，共计330个节段。术后所有患者均获至少12个月随访，分析融合失败的风险因素，包括年龄、性别、吸烟、糖尿病、后纵韧带骨化、骨密度检查、术前颈椎曲度、门轴侧骨皮质连续性等。通过视觉模拟评分（VAS）、日本骨科学会颈痛评分法（JOA）评估术后临床疗效。结果术后12个月患者门轴侧骨性融合率为84％（78／93），术后6个月无内侧骨皮质不连续的患者术后12个月时无门轴压缩情况出现，而有骨皮质不连续的患者中有2例术后12个月时分别压缩2．5mm和2．1mm，术后6个月铰链内侧骨皮质不连续为显著风险因素（P〈0．01）。术后6、12个月融合组与未融合组患者VAS评分分别为（2．4±1．7）、（3．3±2．0）、（2．1±2．0）、（1．8±2．1）分，差异无统计学意义（P〉0．05）。术后12个月融合组与未融合组患者JOA评分分别为（13．6±4．1）分与（14．0±3．2）分，差异无统计学意义（P〉0．05）。结论颈椎后路单开门椎管扩大成形术后术后6个月时骨皮质不连续是门轴侧骨性融合失败的风险因素。虽然会有轻微移位，时间可能超过12个月，但一般能达到骨性融合。

Objective To analyze risk factors for lamina hinge fusion failure after plate - only open - door laminoplasty. Methods Ninty - three patients who underwent posterior single door lamin- oplasty （330 levels） for cervical myelopathy and who had serial computed tomography （CT） scans at 6 and 12 months were analyzed. Risk factors for fusion failure at 12 months were analyzed, including age, sex, smoking, presence of diabetes mellitus and ossification of posterior longitudinal ligament, bone mineral density, preoperative cervical curvature and presence of a ventral cortical bony continuity. Clinical out- comes were assessed with neck pain score using visual analog scale and Japanese Orthopedic Association score. Results Hinge fusion occurred in 84% （78/93） of patients at 12 months. A significant risk factor for fusion failure was the absence of a ventral cortical bony continuity at 6 months （ P 〈 0. 01 ）. No lamina with ventral cortical bony continuity at 6 months showed depression at 12 months, but two lamina without continuity showed depression of 2. 5 and 2. 1 mm, respectively, at 12 months. Clinical outcomes were not different between patients with and without hinge fusion. The visual analogue scale （VAS） scores for hinge fusion group and no hinge fusion group at 6 months and 12 months were 2.4 _＋ 1.7, 3.3 -＋ 2. 0, 2. 1 ＋ 2. 0 and 1.8 -＋ 2. 1 respectively, there was no statistically significant difference （ P 〉 0. 05 ）. The VAS scores for hinge fusion group and no hinge fusion group at 12 months were 13.6 ＋4. 1 and 14. 0 ＋3.2 respective- ly, there was no statistically significant difference （P 〉 0. 05 ）. Conclusion Absence of a ventral cortical bony continuity at 6 months is a risk factor for fusion failure at 12 months. However, bicortically defective laminae usually heal with minimal displacement, although it may take longer than 12 months.