ObjectiveTo compare the clinical results of pedicle screw fixation via the injured vertebra versus across the injured vertebra for thoracolumbar spine fracture.MethodsThe study reviewed 56 patients (41 males and 15 females,at age range of 21-66 years,mean 41.5 years) with thoracolumbar spine fractures managed with the two fixation methods from June 2005 to December 2008.The fracture segment included T12 in 13 patients,L1 in 27 and L2 in 16.According to the AO classification,there were six patients with type A1.2,29 with type A3.1,nine with type A3.2 and 12 with type A3.3.McCormack load score was 5-8 points (average 6.3 points). The spinal cord injury was classified as grade A in three patients,grade B in four,grade C in eight,grade D in 17 and grade E in 24 according to Frankel scale.The patients were divided into two groups,ie,across vertebral fixation group (27 patients) and via the vertebral fixation group (29 patients).All patients were selectively treated with monosegment bone graft simultaneously.The Cobb' s angle,restoration of the anterior height of the injured vertebra,improvement of spinal canal stenosis rate and Denis scale in local pain and work status were compared between the two groups.The bone graft fusion and spinal cord recovery of both groups were observed during follow-up.ResultsAll patients were followed up for 12-48 months (average 25.8 months).Implantation loosening occurred in one patient 1.5 month after operation in across vertebral fixation group.There were no significant differences in aspects of correction of Cobb' s angle,restoration of the anteriorheight of injured vertebra and improvement of spinal canal stenosis rate postoperatively as well as in aspects of restoration of anterior height of injured vertebra and improvement of spinal canal stenosis rate at the latest follow-up between the two groups ( P ＞ 0.05).The postoperative loss of correction rate of Cobb's angle of both groups existed,with significant difference (P ＜0.05). The differences of the Cobb's angle at the latest follow-up and after operation were significant in the across vertebral fixation group ( P ＜ 0.05) but insignificant in the via vertebral fixation group (P ＞ 0.05 ).Bone graft fusion occurred in 21 patients (78％) in the across vertebral fixation group and in 27 patients (93％) in the via vertebral fixation group ( P ＜ 0.05 ).Denis scale indicated a better recovery in the local pain of via vertebral fixation group compared with the across vertebral fixation group ( P ＜ 0.05 ),but showed no significant differenc e in work status between the two groups ( P ＞ 0.05 ).ConclusionsCompared with across vertebral fixation,the pedicle screw fixation via the vertebra has the advantages of higher fusion rate and better correction rate of Cobb' s angle and is a better choice for thoracolumbar spine fracture with posterior approach.

ObjectiveTo investigate safety and efficacy of one-stage pedicle screw fixation plus 360° spinal canal decompression and reconstruction in treatment of severe thoracolumbar burst fractures.MethodsThe study reviewed 11 patients (8 males and 3 females, at age range of 19-59 years, mean 34.4 years) with severe thoracolumbar burst fracture, who underwent one-stage posterior pedicle screw fixation, 360° spinal canal decompression and reconstruction. The injury location was at T12 in one patient, at L1 in three, at L2 in two, at L3 in three and at L4 in two. According to AO classification, all patients were with type A 3.3 fractures. McCormack load score was 7-9 points ( average 8.2 points). Based on the Frankel' s scale, the spinal cord function was classified as grade A in one patient, grade B in one,grade C in five and grade D in four. ResultsAll the operations accomplished successfully, with operation duration for 3.5-4.5 hours ( mean 4.1 hours) , blood loss for 900-2 800 ml ( mean 1 750 ml) and allogeneic blood transfusion for 400-1 200 ml ( average 760 ml). There was no complication either during or after operation. The loss rate of the anterior vertebrae column height was 48％ -85％ ( average 64.2％ )before operation and recovered to 95％ -100％ (average 98.6％ ) of the normal. The kyphotic Cobb angle was at -12°-35 ° ( average 12.1 ° ) before operation and recovered to - 30°-7 ° ( average - 8.1 ° ) after operation. The spinal canal stenosis rate was improved remarkably. The patients were followed up for 10-18 months (average 14. 5 months), which showed solid bone fusion, with no implant failure. The spinal cord function was improved Ⅰ to Ⅲ degrees in all patients except for one patient at grade A. One patient had mild lower back pain.ConclusionsOne-stage pedicle screw fixation plus 360° spinal canal decompression and reconstruction is a good alternative for severe thoracolumbar burst fracture, but it is essential for choosing strictly the surgical indications.

Objective To investigate the feasibility and efficiency of unilateral pedicle screw combined with contralateral translaminar facet screw fixation by percutaneous and interbody fusion to treat low lumbar vertebra diseases. Methods Thirty patients with low lumbar vertebra diseases were entered into the study, including 8 males and 22 females with an average age of 53.7 years. All patients underwent discectomy, spinal canal decompression, cage implantation and lumbar fixation by unilateral pedicle screw combined with contralateral translaminar facet screw under gunsight guiding by percutaneous. Clinical outcomes were assed by JOA questionnaires before and after operation. Operative time, blood loss, and postoperative draiming were recorded. Radiological examination was obtained to assess position of translaminar facet screw.Results Mean operation time was 89 min with a blood loss of 285 ml. Position of translaminar facet screw grade Ⅰ were 24 cases, and grade 11 were 6. Mean follow-up was 22.5 months. 29 cases got bony fusion, and the fusion rate was 96.7%. There were no instability and evidence instrument failure during follow-up. The JOA grades improved from 13.0 preoperation to 25.2 at final follow-up, with the excellent and good rate of 72.5 %. Conclusion Unilateral pedicle screw combined with contralateral translaminar facet screw fixation by percutaneous and interbody fusion provide simple procedure, little trauma, forceful fixation, high fusion rate, and less complication, etc. Therefore, the surgical maneuver is a good choice for partial low lumbar vertebra diseases.