后路寰枢椎固定非融合术治疗新鲜Ⅱ型齿状突骨折的远期疗效观察

Observation on the long-term efficacy of posterior atlantoaxial fixation without fusion for the treatment of fresh type Ⅱ odontoid fractures

中文关键词:  齿状突骨折  寰枢椎固定  非融合  远期疗效  寰枢关节活动度

英文关键词:Odontoid fracture  Atlantoaxial fixation  Without fusion  Long-term efficacy  Range of motion of the atlantoaxial joint

中文摘要:

  【摘要】 目的：观察后路寰枢椎固定非融合术治疗新鲜Ⅱ型齿状突骨折的远期疗效。方法：回顾性分析2006年6月~2017年12月在西南医科大学附属医院采用经后路寰枢椎固定非融合术治疗且随访5年及以上的22例新鲜Ⅱ型齿状突骨折患者的临床资料，男性19例，女性3例，骨折时年龄19~58岁（40.9±10.5岁）；骨折无移位或轻度移位（移位≤2mm）17例，明显移位（移位＞2mm）5例。比较患者寰枢椎固定手术前、取出内固定前及末次随访时的颈部疼痛视觉模拟（visual analog scale，VAS）评分、颈椎功能障碍指数（neck disability index，NDI）、美国脊髓损伤协会（American Spinal Injury Association，ASIA）脊髓损伤严重程度分级；根据Landells等的方法评估患者取出内固定前与末次随访时颈部僵硬程度。末次随访时采用X线片、多平面重建CT及功能位CT评估患者骨折愈合情况、寰枢关节稳定性、寰齿和寰枢侧块关节退变分级及寰枢关节活动度，并通过相关性分析探讨影响患者末次随访时寰枢关节旋转活动度的相关因素。结果：22例患者取出内固定时间为内固定术后11.0±2.7个月，随访7.9±2.0年。患者术前、取出内固定前及末次随访时的VAS评分分别为6.5（6.0，7.0）分、1.0（1.0，2.0）分及1.0（1.0，1.0）分，取出内固定前VAS评分较术前明显降低（P＜0.05），与末次随访时比较无统计学差异（P＞0.05）。患者术前、取出内固定前及末次随访时的NDI分别为28.5（26.5，32.0）、3.5（3.0，5.0）及2.0（2.0，3.0）；取出内固定前NDI较术前显著性降低（P＜0.05），末次随访时进一步降低（P＜0.05）。3例术前存在脊髓损伤患者ASIA分级取出内固定前及末次随访时均较术前改善1级，术前、取出内固定前及末次随访比较无统计学差异（P＞0.05）。末次随访时严重颈部僵硬不适患者占比显著性低于取出内固定前（36.4% vs. 77.3%，P＜0.05）。所有患者取出内固定前骨折均愈合，未见钉棒断裂与内固定移位；末次随访时未见寰枢椎不稳，寰齿关节退变较取出内固定前加重（P＜0.05），侧块关节退变分级与取出内固定前比较无统计学差异（P＞0.05）。末次随访时寰枢关节屈伸和旋转活动度分别为2.0°（0.93°，3.0°）和5.4°（3.7°，9.5°）。相关性分析结果显示骨折移位程度和寰齿关节退变分级与患者远期随访时寰枢关节旋转活动度均呈负相关（r=-0.381，P=0.038；r=-0.584，P=0.001）。结论：后路寰枢椎固定非融合术治疗新鲜Ⅱ型齿状突骨折可获得满意的远期临床疗效，但寰枢关节活动度保留不佳，与骨折严重移位及随访中进行性加重的寰齿关节退变有关。

英文摘要:

  【Abstract】 Objectives: To observe the long-term efficacy of posterior atlantoaxial fixation without fusion for the treatment of fresh type II odontoid fractures. Methods: Retrospective analysis of the clinical data of 22 patients with fresh type II odontoid fractures who underwent posterior atlantoaxial fixation without fusion at the Affiliated Hospital of Southwest Medical University from June 2006 to December 2017 and were followed up for more than 5 years was conducted. Among the patients, there were 19 males and 3 females, aged 19-58 years old(average of 40.9±10.5 years old) at the time of fracture; 17 cases were with no displacement or mild displacement(displacement≤2mm), and 5 cases were with obvious displacement(displacement>2mm). The visual analog scale(VAS) of neck pain, neck disability index(NDI), and grade of American Spinal Injury Association(ASIA) were compared between before operation, before removal of fixations, and at final follow-up, respectively. The neck stiffness severity of the patients was compared between before removal of fixations and at final follow-up using the method proposed by Landells et al. X-ray, multiplanar reconstruction CT, and functional CT were used to evaluate postoperative fracture healing, stability of atlantoaxial joint, degeneration grade of atlanto-odontoid and lateral atlantoaxial joints, and range of motion of the atlantoaxial joint. Correlation analysis was further performed to explore the factors that affect the rotational motion of atlantoaxial joint at final follow-up. Results: All the patients were removed for implants at 11.0±2.7 months after fixation surgery, and were followed up for 7.9±2.0 years. The median VAS scores before surgery, before removal of fixations, and at final follow-up were 6.5(6.0, 7.0) points, 1.0(1.0, 2.0) points, and 1.0(1.0, 1.0) points, respectively. The VAS score before the removal of fixations was significantly lower than that before surgery(P<0.05), which was not statistically different from that at the final follow-up(P>0.05). The median NDI before surgery, before the removal of fixations, and at final follow-up were 28.5(26.5, 32.0), 3.5(3.0, 5.0), and 2.0(2.0, 3.0), respectively. The NDI before the removal of fixations was significantly reduced compared with before surgery(P<0.05), and it further decreased at the final follow-up(P<0.05). Before the removal of fixations and at final follow-up, 3 patients who had spinal cord injury achieved 1 level improvement of ASIA grade compared to before surgery. There was no statistically significant difference in ASIA grade between before surgery, before the removal of fixations, and at final follow-up(P>0.05). At final follow-up, the proportion of patients with severe neck stiffness was significantly lower than that before the removal of fixations(36.4% vs. 77.3%, P<0.05). All the patients had fracture healing before the removal of fixations, and no implants breakage or fixation displacement was found. And at the final follow-up, no atlantoaxial instability was observed. At the final follow-up, the degeneration of the atlanto-odontoid joint worsened compared with before removal of fixations(P<0.05), and there was no statistically significant difference in the degeneration grade of the lateral atlantoaxial joints compared with before removal of fixations(P>0.05). At the final follow-up, the range of motions in flexion-extension and rotation of the atlantoaxial joint were 2.0°(0.9°, 3.0°) and 5.4°(3.7°, 9.5°), respectively. The correlation analysis showed that there was negative correlations between the degree of fracture displacement and the degeneration grade of the atlanto-odontoid joint and the rotational activity of the atlantoaxial joint in long-term follow-up(r=-0.381, P=0.038; r=-0.584, P=0.001). Conclusions: The treatment of fresh type II odontoid process fractures using posterior atlantoaxial fixation without fusion can achieve satisfactory long-term clinical results, but the range of motion of the atlantoaxial joint cannot be preserved well in the long term, which is related to the severe fracture displacement and progressive degeneration of the atlanto-odontoid joint.