The Clinical Application Of Freehand Placement Atlantoaxial Pedicle Screw Internal Fixation Under Direct Visualization For The Treatment Of Atlantoaxial Instability

Objectives:To discuss and analyze the clinical efficacy and safety of freehand placement atlantoaxial pedicle screw internal fixation under direct visualization for the treatment of atlantoaxial instability,In order to promote the application of the technology in clinical practice.Methods:60 cases of patients with atlantoaxial instability who were admitted from April 2014 to October 2020 were treated,in the Sixth Affiliated Hospital of Kunming Medical University,which were treated by freehand placement atlantoaxial pedicle screw internal fixation under direct visualization.Statistics of patients’ intraoperative and postoperative related indicators.At the same time,the Japanese orthopaedic association to evaluate treatment method of cervical score(JOA),visual analogue scale(VAS)and neck disaility index(NDI)were contrasted association during the preoperative and three months postoperative follow-up.And calculating the postoperative improvement of superior rate in the three months after operation were assessed.Observe the imaging manifestations of the atlantoaxial postoperative X-ray、computed tomographic and so on,and according to the relationship between screw and pedicle,the position of pedicle screw was graded and evaluated,and the rate of atlantoaxial screw accuracy was calculated.In addition,the occurrence of postoperative adverse reactions were observed.Results:The operation time of the enrolled patients was 86～165 min,with an average of(130.82± 17.22)min;intraoperative blood loss was 70～420 ml,with an average of(148.37±65.65)ml;postoperative suction drainage volume was 15～400 ml,with an average of(108.67±78.50)ml.The JOA score(14.42±1.56)points in the three months postoperative follow-up was significantly higher than that before surgery(8.38±1.70)points,while the VAS(1.97±0.76)points and NDI(13.93±3.86)%in the three months postoperative follow-up were significantly lower than those before surgery(6.93±1.01)points and NDI(41.45±8.44)%,and the difference was statistically significant(P<0.05).The patients’ postoperative improvement of superior rate in the three months after operation was 81.67%(49/60).A total of 240 pedicle screws were inserted in the enrolled patients,including 179 Grade 0 screws,42 Grade 1 screws,and 19 Grade 2 screws,1 Grade 3 screws were found,the accuracy of calculating the atlantoaxial pedicle screw is 92.08%(221/240).Postoperative X-ray,CT scans and other examinations were performed to show the stability of atlantoaxial vertebra was reliable,the position of the pedicle screw was good,and there were no loosening and prolapse,fatigue fracture and displacement of internal fixation,most of them had achieved osseous fusion.No postoperative spinal cord,nerve roots,blood vessel injury and other adverse reactions in all patients.Conclusion:The clinical curative effect of freehand placement atlantoaxial pedicle screw internal fixation under direct visualization for the treatment of atlantoaxial instability is significant,the safety of screw implant is high,which is worth popularization and application in clinic.