后路经椎间隙脊髓环形减压治疗严重胸椎后纵韧带骨化症

Treatment of posterior longitudinal ligament ossification of thoracic spine with posterior transforaminal spinal decompression

目的探讨后路经椎间隙脊髓环形减压治疗严重胸椎后纵韧带骨化症的安全性、有效性及其疗效。方法自2010年05月至2016年05月，21例严重胸椎后纵韧带骨化症（即椎管侵占率〉50%）患者行后路环形减压术，男12例，女9例；年龄42～71岁，平均（63.3±1.6）岁。术前均有严重脊髓压迫症状。手术取后正中入路，首先在需要减压的上、下两个节段置入椎弓根螺钉，然后分段采用＂揭盖法＂去除椎管的后壁完成后部减压；经上、下关节突关节处切除关节，向外侧推开肋间神经，显露椎体外间隙及椎间盘组织，切除椎间盘及后纵韧带骨化下椎体松质骨；分离硬膜囊前方粘连，应用自主研制手术工具切除后纵韧带上、下边缘，压塌，取出后纵韧带骨化块，经一侧或两侧完成脊髓前方的减压；最后椎间植骨，完成椎弓根钉棒固定。术后随访（平均38.5个月）行CT及MR扫描观察椎管通畅情况及内固定物状态。Frankel分级评价脊髓功能恢复情况，日本骨科协会（Japanese Orthopaedic Association Scores，JOA）评分（11分法）评估脊髓神经功能，Otani评价系统评估手术疗效并计算临床优良率。结果19例术后即有恢复，1例术后即刻出现单侧下肢肌力一过性下降，经脱水、神经营养支持治疗后恢复正常；1例于术后当日出现双侧下肢运动、感觉一过性丧失，6 h后感觉恢复，48 h后运动恢复。手术时间180～300 min，平均（240±23）min；术中出血量150～270 ml，平均（168±12）ml。术后脊髓功能明显恢复，至末次随访时Frankel分级D级8例，E级13例。术前的平均JOA评分3.5，末次随访JOA评分由术前平均（3.5±0.98）分提高至（9.0±0.9）分，JOA评分改善率优14例，良5例，可2例。根据Otani评评价系统，优14例、良6例、可1例，优良率为95.24%。3例术后发生脑脊液漏，经对症处理后痊愈。术后随访期间均未发生胸椎失稳，内固定松动、断裂。结论后路经椎间隙脊髓环形减压治疗严重胸椎后纵韧带骨化症，可在较小的显露范围内应用自主研制手术工具安全完成前方后纵韧带骨化块的切除、脊髓减压充分，术后疗效肯定。

ObjectiveTo explore the safety, efficacy and outcomes of posterior transforaminal spinal cord reduction in the treatment of severe thoracic ossification of the posterior longitudinal ligament.MethodsSince May 2010 to May 2016, 21 patients with thoracic spinal stenosis with ossification of the posterior longitudinal ligament and embedding rate of more than 50% underwent posterior circular decompression, 12 males and 9 females; age 42-71 years old, with an average of 63.3±1.6 years old. There were severe spinal cord compression symptoms before surgery. The operation was from the posterior median approach. First, the pedicle screw tract was preset in the upper and lower segments where decompression was required, and then the posterior wall of the spinal canal was removed by the ＂uncovering method＂ to complete the posterior decompression. Through the superior and inferior articular joints, the joints were removed, the intercostal nerves were pushed outward, the extracorporeal intervertebral space and intervertebral disc tissue were revealed, and the vertebral cancellous bone of the lower vertebral body was removed. Separate the adhesion of the dura mater, use the special tool to cut the upper and lower edges of the posterior longitudinal ligament, collapse, remove the posterior longitudinal ligament ossification block, and complete the decompression of the front of the spinal cord through one or both sides. Finally, the pedicle screw fixation and the intervertebral bone graft were completed. Postoperative follow-up （mean 38.5 months） CT and MRI scans were performed to observe the patency of the spinal canal and the state of the internal fixation. The Frankel graded evaluation function was restored, the JOA score was used to evaluate the neurological function, the Otani evaluation system was used to evaluate the surgical outcome, the clinical excellent rate was calculated, and the treatment effect was evaluated.ResultsNineteen cases recovered after operation, and 1 case showed a transient decrease in unilateral lower extremity motor function on the second day after surgery. It returned to normal after dehydration and neurotrophic support treatment, and 1 case had bilateral lower limbs on the day after surgery. Muscle strength was transiently lost, feeling recovered after 6 hours, and exercise resumed after 48 hours. The operation time was 180-300 min, with an average of 240±23 min. The intraoperative blood loss was 168±12 ml. Postoperative spinal cord function recovered significantly. At the last follow-up, Frankel graded F in 8 cases and grade E in 13 cases. Preoperative average JOA score was 3.5, and the JOA score of the follow-up was increased from 3.5±0.98 points to 9.0±0.9 points. The improvement rate of JOA score was excellent in 14 cases, good in 5 cases, and fair in 2 cases. According to Otani system there was excellent in 14 cases, good in 6 cases, and fair in 1 case. The excellent and good rate was 95.24%. Cerebrospinal fluid leakage occurred in 3 cases and healed after symptomatic treatment. No chest occurred during the follow-up period. The vertebral instability, internal fixation loose, broken.ConclusionPosterior transforaminal spinal decompression of posterior longitudinal ligament ossification of thoracic spine can be finished using self-developed special surgical tools, which is safe, effective and can achieve full decompression of spinal cord.