Design, Biomechanical Evaluation And Clinical Research Of SCHANZ Atlantoaxial Fixation With Direct Reduction System

Objective:Design and manufacture a SCHANZ atlantoaxial internal fixation with direct reduction system. To evaluate the immediate three-dimensional stability of and observe the effect of reduction of this new atlantoaxial fixation system.Methods:Design, manufacture a SCHANZ atlantoaxial internal fixation with direct reduction system:First, understand sprinciple of this new atlantoaxial fixation system. Second, draw the blueprint by author with help of tutor. Third, manufacture this new atlantoaxial fixation system. Biomechanical trail:seven fresh ligamentous human cervical spine specimens were harvested from cadavers. Atlantoaxial instability was produced by dissection of all the ligaments (cruciate, alar and ligaments) surroundingthe dens with asurgical blade through the spinal canal and part of capsula articularis was dissected. The specimens were biomechanical tested (range of motion in flexion-extension and lateral bending and axial rotation) sequentially in the intact state group (three specimens from the seven specimens with no destroy and fixation) and pedicle screw group (three instability specimens fixed with C1-C2 pedicle screw) and SCHANZ group (three instability specimens fixed with). With SPSS 16.0, the range of motion date was analysed to evaluation Biomechanical stability of SCHANZ atlantoaxial internal fixation and reduction system. During the fixation, to observe the the effect of reduct with SCHANZ atlantoaxial system. Clinical research:23 cases of atlantoaxial luxation and subluxation divided into 2groups, the conservative treatment group (traction+ herbal washing+ manipulative reduction) and the surgery group (use of C1-C2 pedicle screw). All cases of the two groups take X-ray to observe ADI and movement of C1 lateral mass before and afrer therapy.Results:The vitro study suggest that the SCHANZ atlantoaxial internal fixation with direct reduction system have better stability in flexionandextension compare with the C1-C2 pedicle screw(P=0.05), but have equal stability in rotation and lateroflexion(P=0.127, P=0.275). During Biomechanical trail, this new atlantoaxial internal fixation system could easily obtain reduction of atlantoaxial joint. Conservative treatment could obtain reduction of atlantoaxial join too.Conclusions:It is stable of atlantoaxia fixed with the SCHANZ atlantoaxia internal fixation with direct reduction system. Biomechanical trail suggest this new fixation system have better stability in flexionandextension compare with the C1-C2 pedicle screw, but have equal stability in rotation and lateroflexion. During Biomechanical trail, this new atlantoaxial internal fixation system could easily obtain reduction of atlantoaxial joint. Conservative treatment could obtain reduction of atlantoaxial join too,...