胸腰椎爆裂骨折内固定术后伤椎相邻椎间盘及上邻节段椎间盘的转归

The fate of intervertebral discs and segments adjacent to injured vertebra following pedicle screw fixation with transpedicular bone grafting for acute thoracolumbar burst fractures

目的研究胸腰椎爆裂骨折经椎弓根植骨结合椎弓根螺钉内固定术后伤椎相邻椎间盘及相邻节段椎间盘的转归。方法随机选取60例胸腰椎爆裂骨折病例,55例(62椎体)得到随访,合并椎间盘损伤38例。所有患者均接受了经伤椎椎弓根椎体内植骨结合椎弓根螺钉内固定手术,观察指标包括术前术后椎间盘的退变程度(于MRI T2加权像上按Pearce分级标准)、Cobb角改变、VAS疼痛评分改变等。结果术前未合并椎间盘损伤的患者与合并椎间盘损伤的患者相比,伤椎相邻椎间盘的退变差异有显著性意义(P<0.05),中央终板骨折粉碎严重或复位不佳的患者与术前未合并椎间盘损伤的患者差异更加显著(P<0.01),术前未合并椎间盘损伤的患者与合并椎间盘损伤的患者相邻节段椎间盘的退变差异无显著性意义(P>0.05)。术前未合并椎间盘损伤组及中央终板骨折复位良好组与中央终板骨折粉碎严重或复位不佳组相比,术前术后VAS评分改变差异均有显著性意义(P<0.05)。结论经伤椎椎弓根椎体内植骨结合椎弓根螺钉内固定能很好地避免术后后凸畸形的复发,明显改善患者的疼痛症状。术前应尽可能行MRI检查明确椎间盘的情况,术中尽可能复位中央终板骨折,尤其是术前合并椎间盘损伤的患者,必要时可切除损伤椎间盘,行椎间融合术。由于坚强固定及融合术的相关副作用,新的固定方式需要进一步研究探讨。

Objective To evaluate the fate of the intervertebral discs and segments adjacent to injured vertebra following pedicle screw fixation with transpedicular bone grafting for acute thoracolumbar burst fractures. Methods A grading system for lumbar disc degeneration was used on the basis of the literature. An algorithm to assess the grading was performed by reviewing lumbar MRI examinations. The intervertebral disc degeneration was tested on the MRI of 62 lumbar intervertebral discs in39 men and 16 women whose mean age was 33.5 years, aged from 21 to 67. The patients were followed up for 50 to 97 months （60.8 months in average）. Thirty-eight of them had intervertebral disc injury accompanied with thoracolumbar burst fractures. All patients underwent pedicle screw fixation with transpedicular bone grafting. The degree of degeneration before and after the surgery was observed through the weighted imaging of T2 on MRI which was graded by Pearce standards. In addition, the change of Cobb＇s angle and the VAS score were examined. Results The patients who had intervertebral disc injury accompanied with thoracolumbar burst fractures were more likely to sustain disc degeneration than patients without （P〈0.05）, especially for the patients with central endplate fracture or poor reduction（P〈0.01）. For the adjacent segment degeneration, there was no significant difference between two groups（P〉0.05）. Conclusions Pedicle screw fixation with transpedicular bone grafting can reduce the incidence of post-operative scoliosis, and relieve pain. MRI scans should be performed pre-operatively to check the condition of the intervertebral body, The central endplate should be restored during the operation. For the patient with disc injury, discectomy and intervertebral fusion are necessary. Further studies for new patterns of fixation are needed due to the side-effects of fixation and fusion.