The Effect Of Intermediate Screw Fixation On Kyphosis Recurrence And Degeneration Of Adjacent Intervertebral Discs After Thoracolumbar Fracture

Aim:To evaluate the validity and safety of intermediate screw fixation in preventing kyphosis recurrence and degeneration of adjacent intervertebral disc after thoracolumbar fracture.Material and methods:1. Study population:From January1st2008to November1st201,41cases of thoracolumbar spinal burst fracture had been treated in Jinan Central Hospital by transpedicular screw internal fixation,among which intermediate screw fixation23cases, and transpedicular screw internal fixation through the adjacent vertebral bodies18cases. In these41cases, the fracture vertebral bodies were from T11to L3, T11:4cases,T12:15cases,Ll:18cases,L2:3cases,L3:1case.2. Methods:In all these cases, posterior approach and restoration of injury vertebral body was use. In intermediate screw fixation group, transpedicular screws were set in the injured vertebral body and adjacent vertebral bodies inferior and superior, while in the other group, the transpedicular screws were merely set in the adjacent vertebral bodies. Before surgery, after surgery and followed-up till the instrumentation were removed, the X-ray and MRI were taken to evaluate the the kyphosis of the spine and the degeneration of the superior adjacent intervertebral discs. The kyphosis was studied and calculated using the Cobb angle, while the intervertebral disc degeneration using the Pfirrmann standard.3. Statistical methods:student t test was used to evaluate the validity of transpedicular screw internal fixation in injured vertebral body, p<0.05is considered as statistically different. The entire set of data was processed by SPSS18.0(for windows) statistical software.Results:All patients with an average follow-up of13.4months, sagittal Cobb angle of the In intermediate screw fixation group of patients lost5.82±1.33°with no significant degeneration in adjacent intervertebral discs compared with the preoperative sagittal Cobb angle of the cross-segment fixation group of patients lost12.1±4.57°, while the adjacent superior and inferior intervertebral discs degenerated2.13±0.93and2.41±1.07levels compared to the preoperative, with a significant statistical difference.(p<0.05)Conclusions:Transpedicular screw internal fixation in injured vertebral body has better efficiency for the prevention of postoperative kyphosis and degeneration of the adjacent intervertebral discs. It is a safe and effective surgical procedure for the treatment of thoracolumbar fractures.