后路腰椎椎体间融合术后cage移位的危险因素分析及处理策略

Risk factors and treatment strategies for cage migration following posterior lumbar interbody fusion

中文关键词:  腰椎椎间融合术  椎间融合器  并发症  翻修术

英文关键词:Lumbar interbody fusion  Cage  Complication  Revision surgery

中文摘要:

  【摘要】 目的：探讨开放后路腰椎椎体间融合术后cage移位的发生率、相关危险因素及其处理对策。方法：回顾性分析2016年1月～2017年12月在我院骨科腰椎专业组行开放后路腰椎椎体间融合手术的970例患者，男423例，女547例；年龄14～87岁（56.8±12.5岁）。随访时腰椎侧位X线片上cage后缘标记线位置较术后首次测量时移动大于3mm判定为cage移位，纳入cage移位组。在无cage移位的患者中随机抽取100例作为对照组。统计并比较两组患者的一般资料[年龄、性别、体重指数（body mass index，BMI）]、皮下腰椎指数（subcutaneous lumbar spine index，SLSI）、术中出血量、术前和术后腰椎前凸角（lumbar lordosis，LL）、术前和术后平均椎间高度（mean disc hight，MDH）、术前和术后椎间隙后缘高度（posterior disc height，PHD）、术前和术后椎间隙活动度（range of motion，ROM）、有无终板损伤、有无骨质疏松、螺钉置入深度、椎间隙形态、有无螺钉松动、cage置入深度等。对单因素分析有统计学意义的参数进行Logistic回归分析以寻找cage移位的独立危险因素。结果：随访6~66个月（43.4±18.2个月），共21例（2.16%）患者22枚cage术后出现移位。cage移位组的年龄、术前及术后MDH、术后ROM、男性患者比例、骨质疏松患者比例、合并螺钉松动比例、梨形椎间隙比例均大于对照组（P<0.05），其余指标两组间无显著性差异（P>0.05）。Logistic回归分析显示螺钉松动（OR=5.020，95%CI 1.026~24.564，P=0.046）、骨质疏松（OR=8.116，95%CI 1.503~43.841，P=0.015）及梨形椎间隙（OR=28.031，95%CI 1.850~424.748，P=0.016）是cage移位的独立危险因素。cage移位患者中有12例（1.24%）cage后移进入椎管，其中8例无明显症状，行保守治疗，末次随访（平均52.4±7.6个月）时椎体间已融合，3例（0.31%）伴明显腰痛和（或）下肢痛，保守治疗无效，行翻修手术后症状缓解，1例有腰痛及臀部疼痛，建议行翻修手术但患者拒绝，随访55个月，cage移位未进展且椎间已融合。结论：骨质疏松、梨形椎间隙及螺钉松动是后路腰椎椎体间融合术后cage移位的独立危险因素；对于cage移位但无明显症状患者可行保守治疗及密切随访，对于有明显神经症状或不稳定者应行翻修手术治疗。

英文摘要:

  【Abstract】 Objectives: To investigate the incidence of cage migration(CM) and its related risk factors and corresponding management strategies after open posterior lumbar interbody fusion(PLIF). Methods: A retrospective analysis was conducted on 970 patients(423 males and 547 females) underwent PLIF in the lumbar spine group of our hospital from January 2016 to December 2017. CM was defined as the posterior edge marking line on lumbar lateral X-ray moved more than 3mm compared with the first postoperative measurement, and the CM group was then screened out. A control group of 100 patients without CM was randomly selected. Parameters were compared between the two groups, including: general data [age, sex, body mass index(BMI)], subcutaneous lumbar spine index(SLSI), estimated blood loss, preoperative and postoperative lumbar lordosis, preoperative and postoperative mean disc height, preoperative and postoperative posterior disc height, preoperative and postoperative range of motion of the disc space, endplate injury, osteoporosis, depth of screw, shape of disc space, and cage depth. The parameters of univariate analysis with statistical significance were analyzed by Logistic regression to find the independent risk factors for CM. Results: The mean follow-up time was 43.4±18.2 months(6-66 months). 22 cages in 21 patients(2.16%) had CMs. The age, preoperative and postoperative mean disc height, postoperative intervertebral range of motion, the proportion of male patients, the proportion of osteoporosis patients, the proportion of screw loosening, and the proportion of pear-shaped disc space in the CM group were all higher than those without CM(P<0.05), while other factors showed no significant difference between the two groups(P>0.05). Logistic regression analysis showed screw loosening (OR=5.020, 95%CI 1.026-24.564, P=0.046), osteoporosis(OR=8.116, 95%CI 1.503-43.841, P=0.015), and pear-shaped disc space(OR=28.031, 95%CI 1.850-424.748, P=0.016) were independent risk factors for CM. Among the patients with CM, 12 cases(1.24%) had cage retropulsion(CR) which was defined as the movement of the posterior margin of the cage into the spinal canal. Among the 12 CR patients, 8 cases were asymptomatic and received conservative treatment, and successful fusion were acquired at the last follow-up(mean 52.4±7.6 months); 3 cases(0.31%) had significant low back pain and/or lower limb pain and failed to conservative treatment, whose symptoms were relieved after revision surgery; 1 case had the indication of revision surgery but the patient refused, and CM did not progress and successful fusion was acquired at the last follow-up(55 months). Conclusions: Osteoporosis, pear-shaped disc space, and screw loosening were independent risk factors for CM. Conservative treatment and close follow-up were feasible for patients with CM without obvious symptoms, and revision surgery should be performed for those with obvious neurological symptoms or instability.