固定至骨盆的长节段矫形手术治疗老年重度胸腰椎后凸畸形机械性并发症的危险因素分析

The risk factors analysis of the mechanical complications of long-segment orthopedic surgery with pelvic fixation for the treatment of severe kyphosis in the elderly

中文关键词:  重度胸腰椎后凸畸形  机械性并发症  S2AI螺钉固定  GAP评分

英文关键词:Severe kyphosis  Mechanical complication  S2AI screw  GAP score

中文摘要:

  【摘要】 目的：研究采用骶2骶髂（sacral-2 alar iliac，S2AI）螺钉固定至骨盆的长节段矫形手术治疗老年重度胸腰椎后凸畸形的机械性并发症的发生情况，并对其危险因素进行分析。方法：回顾性分析2015年1月~2018年12月因退行性胸腰椎重度后凸畸形于我院行长节段矫形手术且远端采用S2AI螺钉技术固定至髂骨的23例患者，其中男2例，女21例，年龄60~84岁（68.0±6.5岁）。手术节段9.1±2.4个，随访32.2±6.2个月。记录患者的并发症情况，并根据末次随访时患者是否发生机械性并发症将患者分为A组（无机械性并发症）和B组（有机械性并发症）。比较两组患者术前及末次随访腰痛视觉模拟评分（visual analogue scale，VAS）、腰椎Oswestry功能障碍指数（Oswestry disability index，ODI）。比较两组患者的一般资料和术前、术后1个月及末次随访时的骨盆投射角（pelvic incidence，PI）、骨盆倾斜角（pelvic tilt，PT）、骶骨倾斜角（sacral slope，SS）、腰椎前凸（lumbar lordosis，LL）、骨盆腰椎匹配值（PI-LL）、胸椎后凸（thoracic kyphosis，TK）、胸腰段后凸角（thoracolumbar kyphosis，TLK）、T1骨盆角（T1 pelvic angle，TPA）、矢状垂直轴（sagittal vertical axis，SVA）、冠状面侧凸角（Cobb angle，CA）、冠状面偏移距离（C7 plumb line-center sacral vertical line，C7PL-CSVL），矢状面全脊柱序列比例（global alignment and proportion，GAP）评分等。采用受试者工作特征（receiver operator characteristic，ROC）曲线分析评价术后1个月时矢状位参数对机械性并发症的预测价值，并运用Logistic回归分析判断机械性并发症的危险因素。结果：末次随访时，13例患者未出现机械性并发症（A组），10例患者出现机械性并发症（B组）；4例进行了翻修，翻修率为17.4%。两组患者性别、年龄、体质指数、骨密度、手术节段、手术时间、截骨方式、术中出血、随访时间均无统计学差异（P>0.05）。术前两组患者VAS评分和ODI无统计学差异（P>0.05）。末次随访A组患者VAS评分为2.2±0.9分，ODI为（28.6±7.8）％，B组患者VAS评分为3.3±1.2分，ODI为（49.5±9.6）％，均较术前明显改善，且两组间有统计学差异（P<0.05）。A组术后1个月时LL为39.6°±6.7°，SS为28.8°±8.5°，PI-LL为11.4°±11.3°，GAP评分为6.9±2.0分。B组术后1个月时LL为24.4°±9.9°，SS为20.2°±8.6°，PI-LL为22.7°±12.5°，GAP评分为10.9±2.4分。两组间有统计学差异（P<0.05）。末次随访时A组LL为35.2°±8.5°，PI-LL为17.3°±9.6°，B组LL为16.3°±9.8°，PI-LL为30.0°±12.1°，两组间有统计学差异，且均较术后1个月有统计学差异（P<0.05）。术后1个月时的SS、LL、PL-LL及GAP评分预测机械性并发症的曲线下面积分别为0.762（P=0.035）、0.896（P=0.001）、0.754（P=0.041）和0.885（P=0.002）。最佳临界值分别为24.1°、32.8°、12.0°和9.5。多因素Logistic回归分析显示术后1个月的LL值<32.8°是机械性并发症的独立危险因素（OR：48.0，95%CI：3.7~622.0，P=0.003）。结论：固定至骨盆的后路长节段矫形手术治疗老年重度后凸畸形术后仍存在较高的机械性并发症发生率，建议术后应使SS>24.1°、LL>32.8°、PI-LL<12.0°。GAP评分≥10提示术后机械性并发症的发生风险高。

英文摘要:

  【Abstract】 Objectives: To investigate the mechanical complications of long-segment orthopedic surgery with sacral-2 alar iliac(S2AI) screws fixed to the pelvis for the treatment of severe kyphosis in the elderly, and analyze the risk factors. Methods: Patients with severe degenerative thoracolumbar kyphosis who had been placed with S2AI screws for long segment fusion from January 2015 to December 2018 were retrospectively reviewed. A total of 23 patients were recruited, comprising 2 men and 21 women(average age: 68.0±6.5 years, range: 60-84 years). The surgical segment was 9.1±2.4, and the follow-up time was 32.2±6.2 months. The complications of the patients were recorded. Based on the occurrence of postoperative mechanical complications, the patients were divided into group A(no mechanical complications) and group B(with mechanical complications). Visual analogue scale(VAS) for back pain and the lumbar Oswestry disability index(ODI) were compared between the two groups preoperatively and at final follow-up. The pelvic incidence(PI), pelvic tilt(PT), sacral slope(SS), lumbar lordosis(LL), pelvic incidence - lumbar lordosis(PI-LL) mismatch, thoracic kyphosis(TK), thoracolumbar kyphosis(TLK), T1 pelvic angle(TPA), sagittal vertical axis(SVA), Cobb angle(CA), C7 plumb line-center sacral vertical line(C7PL-CSVL), global alignment and proportion(GAP) score were compared between the two groups preoperatively, 1 month postoperatively and at final. Receiver operator characteristic(ROC) curve analysis was used to evaluate the predictive value of sagittal parameters at 1 month postoperatively for mechanical complications, and Logistic regression analysis was performed to determine the risk factors of mechanical complications. Results: At final follow-up, 13 patients had no mechanical complications(group A), 10 patients had mechanical complications(group B), 4 patients underwent revision, and the revision rate was 17.4%. There were no significant differences in gender, age, body mass index, bone density, fixed segment, operation time, method of osteotomy, intraoperative bleeding, and follow-up period between the two groups(P>0.05). There were no significant differences in VAS score and ODI between the two groups preoperatively(P>0.05). At final follow-up, the VAS score was 2.2±0.9 and ODI was (28.6±7.8)% in group A. The VAS score was 3.3±1.2 and ODI was (49.5±9.6)% in group B. Both values of the two groups were significantly improved compared with those preoperatively, and the differences between the two groups were significant(P<0.05). In group A, LL=39.6°±6.7°, SS=28.8°±8.5°, PI-LL=11.4°±11.3°, and the GAP score was 6.9±2.0 at 1 month postoperatively. In group B, LL=24.4°±9.9°, SS=20.2°±8.6°, PI-LL=22.7°±12.5°, and the GAP score was 10.9±2.4 at 1 month postoperatively. The differences were significant between the two groups(P<0.05). At final follow-up, LL=35.2°±8.5°, PI-LL=17.3°±9.6° in group A, and LL=16.3°±9.8°, PI-LL=30.0°±12.1° in group B. The differences were significant between the two groups, and both were significantly different from 1 month postoperatively(P<0.05). The area under the curve for predicting mechanical complications of SS, LL, PL-LL and GAP scores at 1 month postoperatively were 0.762(P=0.035), 0.896(P=0.001), 0.754(P=0.041) and 0.885(P=0.002), respectively, and the best cutoff values were 24.1°, 32.8°, 12.0° and 9.5 respectively. Multivariate logistic regression analysis showed that LL<32.8° at 1 month postoperatively was an independent risk factor for mechanical complications(OR: 48.0, 95%CI: 3.7-622.0, P=0.003). Conclusions: There was still a high incidence of mechanical complications after the long-segment orthopedic surgery fixed to the pelvis for the treatment of severe kyphosis in the elderly. We recommended postoperative SS>24.1°, LL>32.8°, PI-LL<12.0°. Postoperative GAP score≥10 indicated a high risk of mechanical complications.