颈椎前路融合术后邻近节段退变性疾病的原因分析及治疗策略

 目的 探讨颈椎前路融合术后邻近节段退变性疾病的发生原因及治疗策略。方法 对2005年12月至2012年8月颈椎前路减压融合术后并发邻近节段退变性疾病的14例进行回顾性分析。男10例，女4例，初次手术年龄36~68岁，平均（52.0±11.0）岁。测量初次手术后颈椎整体曲度、手术节段局部曲度、钢板与上、下间隙的距离。二次手术时对节段数量≤2个且不伴严重后纵韧带或黄韧带骨化的9例采用颈椎前路减压融合内固定术，对节段数量≥3个且不伴明显后凸畸形、排列不稳及严重黄韧带骨化的3例采用颈椎后路减压椎管扩大成形术，对伴有明显后凸畸形、排列不稳且因技术原因无法行前路减压及合并严重黄韧带骨化的2例采用颈椎后路全椎板切除减压融合术。结果 初次术后邻近节段退变性疾病的发生时间为（9.3±4.4）年，二次手术时患者年龄（61.3±12.4）岁。初次术后颈椎整体曲度与手术节段局部曲度分别为12.4°±10.8°、1.5°±6.8°；钢板与上、下间隙的距离分别为（0.9±1.8）mm、（3.8±3.2）mm。二次术后平均随访（30.4±17.8）个月，末次随访时日本骨科学会颈椎病疗效评分改善率为73.9%±9.7%。结论钢 板与邻近间隙距离过小、手术节段局部曲度恢复不良可能是前路融合术后邻近节段退变性疾病的发生原因；二次手术方案的选择应根据病变累及节段、致压因素、颈椎曲度等因素进行综合分析。

Risk factors and treatment strategy for adjacent segment diseases after anterior cervical decompression and fusion

Objective To investigate the risk factors and treatment strategy in treating adjacent segment diseases (ASD) after anterior cervical decompression and fusion. Methods Fourteen patients with ASD after anterior cervical decompression and fusion from December 2005 to August 2012 were analyzed. The overall curvature of the cervical spine, local curvature of surgical segments, and the distances between the plate and the upper and lower intervertebral space were measured and analyzed. 10 males and 4 females, age at initial surgery was 36 to 68 years old, the mean was 52.0±11.0 years old. The secondary surgery was taken, according to the number of involved segments and other factors. Anterior decompression and fusion and internal fixation was taken to patients who segment number ≤2 without severe ossification of posterior longitudinal ligament or ossification of the ligamentum flava; posterior decompression and laminoplasty was conducted in patients whose segment number ≥3, but not accompanied with significant kyphosis, instability and serious ossification of the ligamentum flava; and posterior laminectomy and fusion was performed in patients with significant kyphosis, instability and not suitable for anterior decompression due to technical reasons, as well as patients with serious ossification of the ligamentum flava. Results The average time of occurrence of ASD after the initial surgery was 9.3±4.4 years, and the average age of reoperation was 61.3±12.4 years old. The overall curvature of the cervical spine, surgical segment local curvature after the initial surgical procedure were 12.4°±10.8 °, 1.5°±6.8°, respectively; and the distances between the plate and the upper and lower intervertebral space were: 0.9±1.8 mm, 3.8±3.2 mm. The secondary surgeries were taken as follows: 9 cases anterior decompression and fusion and internal fixation, 3 cases posterior decompression and laminoplasty, and 2 cases posterior laminectomy and fusion. All 14 patients were followed up 30.4±17.8 months, and the average improvement rate of Japanese Orthopaedic Association scores at the last follow up was 73.9%±9.7%. Conclusion The smaller distance between the plate and neighboring intervertebral space, and poorer local curvature of surgical segments might be the risk factors for ASD after anterior cervical decompression and fusion. The appropriate secondary surgery was taken after comprehensive analysis of the number of adjacent segments, compression factors, cervical curvature and other factors.