寰枢椎脱位术后翻修的手术策略分析

Operative strategies for atlanto-axial dislocation revision surgery

中文关键词:  寰枢椎脱位  翻修手术  手术策略

英文关键词:Atlantoaxial dislocation  Revision surgery  Operative strategies

中文摘要:

  【摘要】 目的：分析寰枢椎脱位（atlanto-axial dislocation，AAD）手术后翻修的手术策略。方法：回顾性分析2016年1月~2019年8月在我院行寰枢椎翻修手术的12例患者。其中男3例，女9例，翻修时年龄7~62岁[45.5（34.25，52.50）岁]。初次手术距翻修手术间隔3~360个月[30（5，93）个月]。翻修术中有内固定首先进行内固定及植骨取出，根据1/6体重牵引情况评估是否行前路松解术；根据术前影像结合术中探查，个性化选择原位钉道-增粗增长螺钉、更换螺钉钉道、延长固定节段增加整体内固定强度，选择寰枢侧块关节松解植骨增加植骨融合。翻修后随访12~50个月[24.0（17.25，34.00）个月]。术后3d及末次随访时测量寰齿间距（atlantodental interval，ADI）、枢椎斜坡角（clivus-axial angle，CAA）、延髓脊髓角（cervico-medullary angle，CMA）评价寰枢椎复位情况，日本骨科学会（Japanese Orthopaedic Association，JOA）评分评价神经功能恢复情况；术后3d、3个月、6个月、12个月及末次随访行CT检查评价植骨融合情况。结果：12例翻修手术中，8例先进行原内固定及植骨取出，根据牵引情况，4例行前路松解联合后路复位固定融合术，8例行后路复位固定融合术。其中枕骨螺钉翻修4例，均更换螺钉钉道；C1螺钉翻修4例，2例选择增粗、增长螺钉固定，2例选择更换螺钉钉道；C2螺钉翻修8例，5例选择增粗、增长螺钉固定，3例选择更换螺钉钉道；延长固定节段3例；12例患者均进行寰枢侧块植骨。所有患者翻修术后均获得解剖复位，术后3d及末次随访ADI均较术前明显减少（P<0.05），CCA、CMA较术前明显增加（P<0.05）。所有患者术后3d及末次随访时的JOA评分均较术前明显改善；所有病例骨性融合，融合率100%，融合时间为3~7个月[3.5（3.0，6.0）个月]。结论：前路松解术适用于拆除初次内固定后大重量牵引下寰枢椎仍未复位的患者。在进行后路翻修手术时，枕骨螺钉需更换钉道以维持内固定牢固，更换更粗、更长螺钉，更换螺钉钉道适用于C1、C2螺钉，延长固定节段适用于C1或C2无法置钉的患者。寰枢侧块关节植骨适用于所有寰枢椎翻修手术患者。

英文摘要:

  【Abstract】 Objectives: To explore the operative strategies of revision surgery after atlanto-axial dislocation(AAD) surgery. Methods: 12 patients undergone AAD revision surgery in our hospital between January 2016 and August 2019 were analyzed in this retrospective study, including 3 males and 9 females, aged 7-62 years[45.5(34.25, 52.50) years]. The interval of initial operation and revision operation was 3-360 months[30(5, 93) months]. Internal fixation and bone graft were removed before revision surgery. The patients were assessed to receive anterior release according to the conditions of 1/6 body weight dose skull traction. According to preoperative imaging and intraoperative exploration, larger diameter and longer screws, new screw track, and extended fixed segments were performed optionally to increase the overall internal fixation strength, and the lateral atlantoaxial joint release and grafting were performed to increase bone graft fusion. The follow-up period ranged 12-50 months [24.0(17.25, 34.00)months]. The atlanto-dental interval(ADI), clivus-axial angle(CAA), cervico-medullary angle(CMA) and Japanese Orthopaedic Association(JOA) score were assessed at 3 days after surgery and final follow-up, the CT examination was performed at 3 days, 3 months, 6 months, 12months and final follow-up after surgery to evaluate the bone graft fusion. Results: There were 8 patients receiving internal fixation and bone graft removing before revision surgery. Among the patients, 4 received anterior releasing combined with posterior reduction and internal fixation and fusion, the other 8 patients underwent posterior reduction and internal fixation and fusion. Of all the patients, occipital screw revision was performed in 4 with new screw track; C1 screw revision was performed in 4, of which 2 patients were fixed with larger diameter and longer screws, and 2 patients were fixed with new screw track; C2 screw revision was performed in 8, of which 5 patients were fixed with larger diameter and longer screws, and 3 patients were fixed with new screw track; extended fixed segments were preformed in 3 patients; the lateral atlantoaxial bone grafting was performed in all 12 patients. Anatomical reduction was obtained in all the patients. The postoperative 3d and final follow-up ADI were significantly reduced compared with pre-operative ADI, and the CCA and CMA were significantly increased than those at pre-operation(P<0.05). The JOA at 3 days after surgery and final follow-up were significantly improved than that at pre-operation. Bony fusion was achieved in all the patients, with a bone fusion rate of 100%, and the bone fusion time ranged 3-7 months[3.5(3.0, 6.0) months]. Conclusions: Anterior release is suitable for the patients with un-reduced atlantoaxial dislocation after removal of primary internal fixation under heavy traction. During posterior revision surgery, occipital screws need to change trajectory to maintain firm internal fixation, and larger diameter and longer screw is suitable for C1, and C2 screws, while extended fixed segments are suitable for patients whose C1 or C2 screws cannot be inserted. The lateral atlantoaxial joint bone grafting is suitable for all AAD revision.