Objective: To investigate the effectiveness of posterior microscopic mini-open technique (MOT) decompression in patients with severe spinal canal stenosis resulting from thoracolumbar burst fractures.
Methods: The clinical data of 28 patients with severe spinal canal stenosis caused by thoracolumbar burst fractures, who were treated by posterior microscopic MOT, which performed unilateral or bilateral laminectomy, poking reduction, intervertebral bone graft via spinal canal, and percutaneous pedicle screw fixation between January 2014 and January 2016 were retrospectively analyzed. There were 21 males and 7 females with a mean age of 42.1 years (range, 16-61 years). The involved segments included T 11 in 1 case, T 12 in 4 cases, L 1 in 14 cases, and L 2 in 9 cases. According to AO classification, there were 19 cases of type A3, 9 of type A4. According to American Spinal Injury Association (ASIA) grading, 12 cases were grade C, 13 grade D, and 3 grade E. The time between injury and operation was 3-7 days (mean, 3.6 days). To evaluate effectiveness, the changes in the visual analogue scale (VAS), percentage of anterior height of injured vertebrae, Cobb angle, rate of spinal compromise (RSC), and ASIA grading were analyzed.
Results: All patients were performed procedures successfully. The operation time was 135-323 minutes (mean, 216.4 minutes). The intraoperative blood loss was 80-800 mL (mean, 197.7 mL). The hospitalization time was 10-25 days (mean, 12.5 days). The incisions healed primarily, without wound infection, cerebrospinal fluid leakage, or other early complications. All the 28 patients were followed up 12-24 months (mean, 16.5 months). No breakage or loosening of internal fixation occurred. All fractures healed, and the healing time was 3-12 months (mean, 6.5 months). Compared with preoperative ones, the percentage of anterior height of injured vertebrae, Cobb angle, and RSC at immediate after operation and at last follow-up and the VAS scores at 1 day after operation and at last-follow were significantly improved ( P<0.05). There was no significant difference in the percentage of anterior height of injured vertebrae and Cobb angle between at immediate after operation and at last follow-up ( P>0.05). But the RSC at immediate after operation and VSA score at 1 day after operation were significantly improved when compared with those at last follow-up ( P<0.05). The ASIA grading at last follow-up was 1 case of grade C, 14 grade D, and 13 grade E, which was significantly improved when compared with preoperative ones ( Z=3.860, P=0.000).
Conclusion: MOT is an effective and minimal invasive treatment for thoracolumbar AO type A3 and A4 burst fractures with severe spinal canal stenosis, and it is beneficial to early rehabilitation for patients.
目的: 探讨采用 mini-open 技术（mini-open technique，MOT）后路显微镜下椎管减压微创治疗伴重度椎管狭窄的胸腰椎爆裂性骨折的临床疗效。.
方法: 回顾分析 2014 年 1 月—2016 年 1 月，采用 MOT 后路显微镜下行单侧或双侧椎板间隙开窗减压、撬拨复位、经椎管椎体内植骨、经皮椎弓根螺钉内固定治疗的伴重度椎管狭窄的 28 例胸腰椎爆裂性骨折患者临床资料。其中男 21 例，女 7 例；年龄 16～61 岁，平均 42.1 岁。受伤节段：T 11 1 例，T 12 4 例，L 1 14 例，L 2 9 例。AO 分型：A3 型 19 例，A4 型 9 例。美国脊髓损伤协会（ASIA）神经功能分级：C 级 12 例，D 级 13 例，E 级 3 例。受伤至手术时间 3～7 d，平均 3.6 d。比较手术前后疼痛视觉模拟评分（VAS）、伤椎前缘高度百分比、Cobb 角、椎管狭窄率（rate of spinal compromise，RSC）及神经功能 ASIA 分级，评价临床疗效。.
结果: 患者均顺利完成手术，手术时间 135～323 min，平均 216.4 min；术中出血量 80～800 mL，平均 197.7 mL；住院时间 10～25 d，平均 12.5 d。术后切口均Ⅰ期愈合，无切口感染、脑脊液漏等早期并发症发生。28 例均获随访，随访时间 12～24 个月，平均 16.5 个月。无内固定物松动、断裂发生；患者骨折均愈合，愈合时间 3～12 个月，平均 6.5 个月。术后即刻及末次随访时的伤椎前缘高度百分比、Cobb 角及 RSC，以及术后 1 d 及末次随访时的 VAS 评分均较术前显著改善（ P<0.05）；与末次随访时比较，术后即刻伤椎前缘高度百分比和 Cobb 角差异无统计学意义（ P>0.05），术后即刻 RSC 及术后 1 d VAS 评分有显著改善（ P<0.05）。末次随访时神经功能 ASIA 分级为 C 级 1 例、D 级 14 例、E 级 13 例，较术前显著改善（ Z=3.860， P=0.000）。.
结论: MOT 是治疗伴重度椎管狭窄的 AO 分型 A3、A4 型胸腰椎爆裂性骨折有效、微创的方法，有利于康复治疗早期介入。.
Keywords: Thoracolumbar burst fracture; microscope; minimal invasive; severe spinal canal stenosis.