Biomechanical Study Of Titanium-mesh Combine With Five Kinds Of Internal Fixation Reconstruction After The Resection Of Thoracolumbar Spinal Tumor

Objective: The incidence of Spinal tumors showed an upward trend year by year, With thoracolumbar disease more common. The treatment of spinal tumors in the past used mainly conservative treatment, Such as radiotherapy and chemotherapy. Surgery is limited to simple laminectomy of palliative. In recent years, With the improvement of surgical technique, As well as the development of spinal fixation devices, Surgical treatment has become an important means of them of spinal tumors. This test by studying biomechanical changes of the embedded Titanium-Mesh instead of the resection of L1- vertebral body combine with five kinds of internal fixation is to evaluate the therapeutic effect of internal fixation methods for clinical guidance.Methods: Selecting eighteen thoracolumbar specimens of fresh slaughtered spine of the calf,Their years of age is 6-9 months or less. Muscle and other soft tissue removed. Retaining their ligaments, facet joint capsule and Structural integrity of bone. Making use of radiography to exclude osteoporosis itself, disease, tumors and congenital malformations, etc.According to WBB staging, six spinal units (T11-L4) is a specimen. Simulate mode of L1 vertebral body tumor excision, Installation of internal fixation,and then we put the fixed specimens on a good biomechanical testing machine, Pre-load 100N is used to remove the bone creep, relaxation and other time-effect on the impact of the formal testing.Testing machine-speeding was controlled 1. 5mm/min, The specimen will be compressed in the four different loading operating conditions of the vertical compression, the anteflexion, the meta-extend and the lateral bending by grade-loading, Simulating thoracolumbar movement pattern, Pre-load 5N ? m is used to remove bone creep, relaxation and other time-effect on the impact of the formal testing. Load-speeding was controlled in 1°/ min and difference of the level was 5 N ? m, To load progressively the specimen in the condition of the torsion, Recording the data. Experimental data is analysed by the randomized block design analysis of variance of statistical software( SPSS13.0 ), The level of significance placed on 0.05.Results: In all kinds of loads, the five kinds of internal fixation in the vertical compression, anteflexion, meta-extend and lateral bending movement, the vertebral body relative scope of activities compared with the control group were significantly reduced (P <0.05).They can play a good stability and be more stable than those in the control group; The spinal stability between anterior single-screw-rod group and the control group was not statistically significant (P = 0.809> 0.05). No matter what kind of campaign mode, Through the comparison between Fixation groups,We can see that N5 (the titanium mesh implants + pairs of posterior pedicle screw-rod group + anterior plate group) is the smallest scope of activities and the strongest stability of the spine , Anterior titanium mesh implants + side in front of a single screw-rod group is a larger range of motion in the vertical compression and the torsion, but still achieve the same stability of the control group specimens.Conclusion: The variety of internal fixation after reconstruction of the line of spinal stability can all have a good immediate stability, In anteflexion, meta-extend and lateral bending movement, the relative scope of activities between the vertebral body are reduced, Shows they are a higher stability than the control group. In the vertical compression and the torsion, the range of motion between the vertebrae of Anterior of titanium mesh implants + side of the front group of a single screw-rod and The control group is no significant difference,with the same stability. The range of motion of the remaining group of interbody fixation is less than the control group and more than the stability of the control group. The comparison between groups can conclude: titanium mesh implant + pairs of posterior pedicle screw-rod group + anterior plate group have the smallest in the intervertebral range of motion, the smallest spinal activity and stability of the strongest.