腰椎融合术后症状性相邻节段退变原因及再手术治疗

目的分析腰椎融合术后症状性相邻节段退变的原因及再手术治疗效果。方法自2011年1月至2012年5月我科共收治的15例腰椎融合术后相邻节段退变病例，自初次融合手术至再次手术平均时间6.7（6.1～8.3）年，临床表现为初次手术后症状缓解，2次手术前6～12个月再次出现腰痛伴下肢放射痛、麻木，间歇性跛行。影像学表现为融合节段的上位或下位运动节段出现椎间盘突出，椎管狭窄，退变性节段不稳定。经保守治疗效果差。须再次手术。其中10例经 CT 重建发现融合节段骨性融合，拆除初次内固定，进行相邻节段椎板减压，并咬除间盘突出侧的部分或全部关节突，切除间盘，进行椎间植骨融合内固定。4例发现融合节段融合欠佳，保留原有内固定，向上扩大椎板减压，椎间植骨融合并延长内固定。1例融合不确实，行原有内固定取出，改用 Dynesys 动态椎弓根内固定并延长至上位相邻节段。手术时间平均160 min，术中出血量平均560 ml。术后随访6～18个月。采用 VAS 评价腰腿痛改善情况，ODI 评价术后生活能力改善状况。结果15例患者手术均顺利完成。有1例因硬膜粘连出现硬膜撕裂，术后出现脑脊液漏，经伤口加密缝合，脑脊液漏愈合。所有病例未出现神经功能恶化。术后腰腿痛 VAS 由术前的平均6.5分降至术后的1.6分。ODI 指数由术前的35%降至术后11%。结论腰椎融合术后相邻节段退变再手术，在去除部分或全部关节突，谨慎分离粘连组织，充分减压的基础上，根据具体情况采用不同的内固定方式，能够取得满意的效果。

Cause analysis and reoperations of symptomatic adjacent segment degeneration after lumbar fusion surgery

Objective To analyze the causes and operation results of symptomatic adjacent segment degeneration （ ASD ） after lumbar fusion surgery. Methods 15 patients with ASD after lumbar fusion surgery were treated in our department from January 20l 1 to May 2012. The interval from primary operation to revision surgery was 6.7 years on average （ range; 6.1-8.3 years ）. When the symptoms were relieved after the primary operation, clinical manifestations were back pain, radiating pain of lower limps, numbness and intermittent clandication from 6 to 12 months before the second operation. The imaging findings were disc herniation, spinal stenosis and instability of degenerative segments in the proximal or distal adjacent motion segments. The revision surgery was needed, due to the poor conservative treatment results. Bony fusion in fused segments was confirmed in 10 patients by CT reconstruction. The primary internal fixator was removed, and laminectomy was performed in adjacent segments. Partial disc herniation sides or the whole articular process was taken out, and the disc was resected. Intervertebral body fusion and internal fixation were carried out. Fusion failure in fused segments was found in 4 cases, and the primary internal fixator was reserved. Laminectorny was expanded upwards, and extended implantation was used, with intervertebral body fusion. 1 patient had unconfirmed fusion, and the primary internal fixator was taken out. The Dynesys dynamic pedicle screws were fixed, which were then extended to the proximal adjacent segments. The average operation time was 160 minutes, and the average blood loss during the surgery was 560ml. All patients were followed up for 6-18 months postoperatively. The visual analogue scale （ VAS ） was used to evaluate the relief of back and leg pain, and the oswestry disability index （ ODI ） was used to assess the living ability of the patients after the surgery. Results All patients had successful operations. 1 patient developed dural laceration due to epidural adhesion, and leakage of cerebrospinal fluid （ CSF ） occurred after the surgery. After more intensive suturing was done in incisions, this condition got improved. There was no neurologic function deterioration in all cases. The VAS score of back and leg pain got decreased from 6.5 points on average preoperatively to 1.6 points postoperatively, and the ODI from 35% to 11%. Conclusions Spondylolisthesis may be a risk factor for ASD. The revision surgery for ASD after lumbar fusion is difficulty and risky. Partial or total removal of the articular process should be done, and adhesion tissues should be separated carefully. On the basis of full decompression, different methods of internal fixation can be chosen in accordance with specific conditions, and satisfactory clinical results can be achieved.