Objective To study the efficiacy and safety of transfacet approach decompression to treat thoracic spinal stenosis caused by anterior compression.Methods Thirty-three patients with thoracic spinal stenosis caused by anterior compression were treated in our institution from April 2005 to April 2009.Nineteen patients with more than 12 months follow-up were included in this study.Among of them,10 were male and 9 were female,with the age ranged from 33 to 77 years(mean,55.9 years).The causes of compression for spinal stenosis included ossification of posterior longitudinal ligament(OPLL)in 5 cases,thoracic disc herniation(TDH)in 11 cases,OPLL with ossification of ligamentum flavum(OLF)in 2 cases and TDH with OLF in 1 case.All patients underwent anterior decompression via a transfacet approach combined with anterior fusion and posterior fixation.The modified Japanese Orthopaedic Association(JOA)score system and Nurick Myelopathy grade were used to evaluate the outcomes.Results The operation time ranged from 180 to 480 min,with an average of 299.5 min and the blood loss was varied from 250 to 2200 ml,with an average of 918.5 ml.Among 7 cases with OPLL(including combined with OLF),2 patients developed neurologic deterioration and 1 patient developed cerebrospinal fluid leakage.There were no neurologic deterioration,cerebrospinal fluid leakage and other complications occurred in 12 cases with TDH(including combined with OLF).The follow-up ranged from 12 to 54 months(mean,28.6 months).The preoperative JOA score ranged from 2 to 11(mean,6.3).The JOA score in the last follow-up ranged from 5 to 11(mean,8.6).According to Nurick Myelopathy grade,the preoperative grade was 0 in 2 cases,1 in 2,2 in 4,3 in 5,4 in 2,and 5 in 4.The number of postoperative grade was 6,6,3,3,1 and 0 respectively.Conclusion Satisfactory decompression could be achieved by using transfacet approach for thoracic spinal stenosis caused by anterior compression.The approach is a safe and promising alternative for thoracic spinal anterior decompression.

Objective To investigate the correlation of spinal canal stricture and intramedullary increased signal intensity (ISI) in patients with ossification of the posterior longitudinal ligament (OPLL). Methods 92 patients with OPLL were divided into 3 groups, those with the sagittal diameter remained ≥66.7% were as group A, 33.3%~66.7% as group B, and <33.3% as group C. The incidence of intramedullary ISI was recorded, and their neurological condition was assessed with the Japanese Orthopedics Association Assessment (JOA). Results ISI were found in 6 cases in the group A (20.7%), 17 cases in the group B (47.2%) and 19 cases in the group C (70.4%) (P<0.05). The score of JOA was (7.1±2.1) in the group A, (6.0±1.8) in the group B and (5.6±2.0) in the group C (P<0.05). Conclusion The incidence of intramedullary ISI increased with the severity of spinal canal stricture, and with more severe nerve damage in OPLL patients.