| ObjectiveTo design an individualized 3D printing guide template using computer software and 3D printing technology, auxiliary on upper cervical pedicle screw implantation,and evaluate the security, accuracy and validity of the guide template.MethodsUsing three kinds of computer software(Mimics15.0,Geomagic Studio 2013,NX8.5) design out of screw guide template of atlas and axis pedicle, and the use of 3D printing technology to print a proportion of entity model of the cervical spine, screw guide template.Each case cervical spine model were printed 2 copies with 3D printing,divided into 2 groups.Using guide template pace atlas and axial pedicle screws in the experimental group; Using imaging X-ray method implant atlas and axial pedicle screws in the control group.Two groups of upper cervical pedicle screws were placed by same director of spinal surgery in our hospital.On the basis of the screw place in the pedicle cortex in sagittal and transverse planes and the need for revision operation are divided into 3 levels.LevelⅠ:screw in pedicle completely;Level Ⅱ:screw penetrating pedicle cortex less than 1mm or equal to 1mm and internal fixation stably,need not revision;Level Ⅲ:screw penetrated pedicle cortex more than 1 mm, or internal fixation poorly, need to remove the screw and revise.If there is a discrepency in the grade of deviation between sagittal and transverse planes,the worse finding is adopted.LevelⅠand Level Ⅱscrews are acceptable implanted screws,Level Ⅲ screws are unacceptable implanted screws.ResultsThe experimental group: 19 blocks of upper cervical 3D printing screw guide templates were designed and printed,37 pedicle screws of atlas and axis were implanted.The results of all screws placement are as follows:LevelⅠ:32 screws(86.49%);Level Ⅱ:3 screws(8.11%);Level Ⅲ:2 screws(5.40%).The mean time ofimplanting a screw into upper cervical pedicle was 10.73 minutes.The average number of X-ray machine fluoroscopy of placing a screw was 10.95 times.The control group: a total of 37 upper cervical pedicle screws were implanted with the method of C- arm X ray fluoroscopy.The results of 37 screws placement are as follows:LevelⅠ:23 screws(62.16%);Level Ⅱ:3 screws(8.11%);Level Ⅲ:11screws(29.73%).The mean time of implanting a screw into upper cervical pedicle was27.70 minutes.The average number of X-ray machine fluoroscopy of place a screw was 40.35 times.Result of implanted screws based on the screws out of the pedicle cortex and the need for revision operation was that rate of acceptable placed screws of experimental group and the control group were 94.60% and 70.27%, rate of unacceptable placed screws were 5.40%and 29.73%.The result of statistical analysis was significant(P =0.021, < 0.05).Rate of acceptable implanted screws of control group was lower than the experimental group.ConclusionThe best planting screw channel of atlas and axis pedicle can be probed intuitively and accurately by computer software of Mimics15.0,Geomagic Studio 2013,NX8.5.The screw guide templates with bilateral pedicle screw implant guide hole of atlas and axis were designed.Equal proportion cervical models,screw guide templates of upper cervical pedicle were printed out using 3D printing technology.Experiments show that the guide template which assisted upper cervical implant screws was safe and accurate. Screw guide template system is reliable and applicable to the upper cervical pedicle screw implantation, even severe deformity of upper cervical vertebral body and pedicle.It is feasible to simulate surgical implantation of cervical pedicle screws by printing cervical spine model,and the success rate of upper cervical pedicle screw fixation with 3D printing guide template is high. This method of implanting cervical pedicle screw is simple,without needs of too much operation experience for surgeon. Individualized principle was embodied in this 3D printing on cervical pedicle screw guide template system.The method is safe, effective and feasible!... |
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