微型钢板侧块螺钉穿透小关节面对颈椎单开门术后轴性症状的影响

EFFECT OF PENETRATION OF MINI-PLATE LATERAL MASS SCREWS INTO FACET JOINT ON AXIAL SYMPTOMS IN CERVICAL LAMINOPLASTY

目的探讨颈椎单开门椎管扩大椎板成形Centerpiece内固定术中侧块螺钉穿透小关节面对术后轴性症状的影响。方法回顾分析2009年9月-2011年12月接受后路C3~7单开门椎管扩大椎板成形Centerpiece内固定术且符合选择标准的52例患者临床资料。男42例,女10例;年龄34~83岁,平均61.2岁。单纯退行性颈椎管狭窄症17例,合并多节段颈椎间盘突出症25例,合并后纵韧带骨化症10例。病程1~120个月,中位病程11个月。采用日本骨科协会(JOA)评分法评价患者神经功能,计算神经功能改善率;疼痛视觉模拟评分(VAS)及颈椎功能障碍指数(NDI)评估患者颈肩部疼痛及颈椎功能情况。记录患者术后轴性症状及其他并发症发生情况。行颈椎X线片、CT及MRI检查,测量椎管矢状径、颈椎曲度、椎管横截面积、椎板开门角度。通过术后1周CT三维重建判断Centerpiece钢板侧块螺钉是否穿透小关节面进入小关节,并根据破坏的小关节数量将患者分为无关节破坏组(无小关节面被穿透)、少关节破坏组(1~2个小关节面被穿透)和多关节破坏组(3个及以上小关节面被穿透),对各组以上指标进行统计分析。结果术后5例发生C5神经根麻痹,2例脑脊液漏,均经相应治疗后治愈。患者均获随访,随访时间3~35个月,平均15.7个月。末次随访时,患者JOA评分、NDI、椎管矢状径以及椎管横截面积均优于术前(P<0.05)。根据术后1周CT三维重建检查,无关节破坏组16例,少关节破坏组23例,多关节破坏组13例;3组患者年龄、性别、病程、手术时间、术中出血量及随访时间比较,差异均无统计学意义(P>0.05),具有可比性。末次随访时,3组术后JOA评分、VAS评分,颈椎曲度、椎管矢状径、椎管横截面积以及神经功能改善率、开门角度比较,差异均无统计学意义(P>0.05);但3组间NDI比较差异有统计学意义(P<0.05)。术后10例发生轴性症状,无关节破坏组1例,少关节破坏组4例,多关节破坏组5例,3组间轴性症状发生率比较差异无统计学意义(χ2=4.881,P=0.087)。结论侧块螺钉穿透小关节面可能是单开门椎管扩大椎板成形Centerpiece内固定术后出现轴性症状的原因之一,且随着小关节面破坏数目的增加,发生轴性症状的风险可能增加。

Objective To investigate the effect of the penetration of mini-plate mass screws into facet joint on axial symptoms in cervical laminoplasty. Methods A retrospective analysis was made on the clinical data of 52 patients who underwent unilateral open-door cervical expansive laminoplasty fixed with Centerpiece mini-plate between September 2009 and December 2011. There were 42 males and 10 females, with a mean age of 61.2 years （range, 34-83 years）. Seventeen patients exhibited simple degeneration cervical canal stenosis, 25 patients had multilevel cervical disc protrusion, and 10 patients had ossification of posterior longitudinal ligaments. Disease duration ranged 1-120 months （median, 11 months）. The Japanese Orthopedic Association （JOA） score was used to assess neurological function, and JOA recovery rates were calculated. The visual analogue score （VAS） and the neck disability index （NDI） were used to evaluate the axial pain and neck daily activities. The axial symptoms and other complications were recorded. The cervical canal diameter, cervical curvature, cervical canal cross area, and open angle were measured according to the X-ray films, CT scans, and MRI scans. The postoperative CT three dimensional （3-D） reconstruction images were used to identify whether the screws penetrated into the facet joints. All the patients were divided into 3 groups according to involved facet joints： no joint penetrating group （no penetrated facet joint）, oligo-joint penetrating group （one or two penetrated facet joints）, and multi-ioint penetrating group （three or more penetrated facet joints）. Results Five patients suffered from C5 nerve palsy, and 2 patients had cerebrospmal nma tea^c, l ~ t~ time ranged 3-35 months （mean, 15.7 months）. At the final follow-up, the IOA scores, NDI, cervical canal diameter, and cervical canal cross area were significantly improved when compared with preoperative ones （P 〈 0.05）. At 1 week after operation, CT 3-D reconstruction showed that 16 patients had no penetrated facet joint, 23 patients had one or two penetrated facet joints, and 13 patients had three or more penetrated facet joints. There was no significant difference in age, gender, disease duration, operation time, intraoperative blood loss, and follow-up time among 3 groups （P 〉 0.05）. And at the final follow-up, there was no significant difference in JOA score, VAS score, cervical curvature, cervical canal diameter, cervical canal cross area, the JOA recovery rates, and lamiae open angle among 3 groups （P 〉 0.05）. The NDI of the multi-joint penetrated group was significantly higher than that of other 2 groups （P 〈 0.05）. Axial pain occurred in 1 case of no penetrating group, in 4 cases of oligo-joint penetrating group, and in 5 cases of multi-joint penetrating group, showing no significant difference among 3 groups （X^2=4.881, P=0.087）. Conclusion The penetrations of lateral mass screws into articular surface of facet joint may contribute to the axial symptoms after cervical laminoplasty. The risk of axial symptom raises accompany with increased penetrated facet joints.