腰椎融合术前相邻节段存在退变因素对术后早期临床疗效的影响

Effect of pre-existing adjacent segment degeneration on short-term effectiveness after lumbar fusion surgery

目的探讨腰椎拟融合节段的相邻节段术前存在的椎管狭窄因素对术后早期临床疗效的影响。方法采用前瞻性对比研究,将2015年7月-2017年12月收治的符合选择标准的183例L4~S1腰椎管狭窄症患者,根据术前椎间盘退变情况及椎管狭窄情况判断的相邻节段退变(adjacent segment degeneration,ASD)状态不同分成两组,A组98例(术前相邻节段无退变),B组85例(术前相邻节段已退变)。两组患者性别、美国麻醉医师协会(ASA)分级、体质量指数(body mass index,BMI)、合并滑脱状态及术前腰、腿痛疼痛视觉模拟评分(VAS)、日本骨科协会(JOA)评分、Oswestry功能障碍指数(ODI)等一般资料比较差异无统计学意义(P>0.05);A组患者年龄显著小于B组(t=-3.560,P=0.000)。记录并比较两组患者手术时间、术中出血量、住院时间、围术期并发症;末次随访时采用腰、腿痛VAS评分、JOA评分、ODI评分评价疗效。比较两组间末次随访时ASD发生情况,采用logistic回归分析影响患者术后出现ASD的独立危险因素。结果两组患者手术时间、术中出血量及住院时间比较差异均无统计学意义(P>0.05)。A、B组围术期并发症发生率分别为13.3%和20.0%,比较差异无统计学意义(χ^2=1.506,P=0.220)。两组患者均获随访,A、B组随访时间分别为(24.9±8.8)个月和(24.8±7.8)个月,差异无统计学意义(t=0.050,P=0.960)。至末次随访时,两组患者均未出现相邻节段病变。两组患者末次随访时椎间盘Pfirrmann分级与术前比较差异均无统计学意义(P>0.05);术前及末次随访时两组间Pfirrmann分级差异均有统计学意义(P<0.001)。至末次随访时A、B组分别有21例(21.4%)和53例(62.4%)出现ASD,比较差异有统计学意义(χ^2=31.652,P=0.000);术后相邻节段椎管狭窄程度加重是术后发生ASD的主要原因。两组患者末次随访时各临床评分均较术前显著改善(P<0.05),末次随访时A组JOA评分显著高于B组(P<0.05)。B组患者中术后出现ASD患者末次随访时的腰痛VAS评分、ODI评分显著高于非ASD患者(P<0.05)。logistic回归分析显示,术前相邻节段存在退变因素与BMI是影响患者术后出现ASD的独立危险因素(P<0.05)。结论术前相邻节段存在退变因素,会显著影响患者术后早期临床疗效及增加术后出现ASD的风险,相邻节段椎管狭窄程度加重是术后早期ASD主要的病理类型。应根据术前相邻节段椎管的整体退变情况评估术前相邻节段的退变状态。

Objective To analyze the prospective effect of pre-existing spinal stenosis of adjacent segment on the short-term effectiveness after lumbar fusion surgery. Methods A prospective comparative study was conducted to divide183 patients with L4-S1 lumbar spinal stenosis who met the selection criteria between July 2015 and December 2017 into two groups according to the status of adjacent segment degeneration(ASD) judged by preoperative disc degeneration and spinal stenosis. There were 98 patients in group A(no degeneration of adjacent segments before operation) and 85 patients in group B(adjacent segments degenerated before operation). There was no significant difference in gender,American Society of Anesthesiologists(ASA) grade, body mass index(BMI), combined spondylolisthesis, and preoperative visual analogue scale(VAS) score of low back pain and leg pain, Japanese Orthopaedic Association(JOA)score, and Oswestry disability index(ODI) score between the two groups(P>0.05);the age of group A was significantly younger than that of group B(t=-3.560, P=0.000). The operation time, intraoperative blood loss, hospitalization stay, and perioperative complications were recorded and compared. The VAS score of low back pain and leg pain, JOA score, and ODI score at last follow-up were used to evaluate the effectiveness. The incidence of ASD after operation was compared between the two groups, and logistic regression was used to analyze the independent risk factors affecting the occurrence of ASD after operation. Results There was no significant difference in operation time, intraoperative blood loss, and hospitalization stay between the two groups(P>0.05). The incidence of perioperative complications in groups A and B was13.3% and 20.0%, respectively, with no significant difference(χ^2=1.506, P=0.220). Two groups of patients were followed up, the follow-up time of groups A and B was(24.9±8.8) months and(24.8±7.8) months, respectively, there was no significant difference(t=0.050, P=0.960). At last follow-up, no adjacent segment disease was found in either group. There was no significant difference in Pfirrmann grade between the two groups at last follow-up(P>0.05), and there was significant difference in Pfirrmann grade between the two groups before operation and at last follow-up(P<0.001). At last follow-up, 21 cases(21.4%) in group A and 53 cases(62.4%) in group B had ASD, with significant difference(χ^2=31.652,P=0.000). The main cause of ASD was the severity of adjacent spinal canal stenosis. The clinical scores of the two groups at last follow-up were significantly improved when compared with those before operation(P<0.05). The JOA score of group A was significantly higher than that of group B at last follow-up(P<0.05). In group B, the VAS score of low back pain and ODI score in patients with ASD after operation at last follow-up were significantly higher than those in patients without ASD(P<0.05). logistic regression analysis showed that preoperative pre-existing degeneration and BMI were independent risk factors for ASD after operation(P<0.05). Conclusion Pre-existing mild spinal stenosis in adjacent segment can significantly affect the effectiveness, and can significantly increase the risk of ASD early after operation. The main pathological type of ASD was the severity of adjacent segment spinal stenosis. For preoperative assessment of pre-existing degeneration, we should evaluate the overall degeneration of the adjacent segment of the spinal canal, rather than simply evaluating the degeneration of the adjacent disc and facet joints.