Clinical Analysis Of O-arm Multi-Dimensional Imaging System Combined With Cevical Pedicle Fixation In Landells Type Ⅲ Atlas Fracture

Objective:To explore the clinical effect of O-arm multidimensional imaging system combined with personalized 3D printing model in the treatment of Landells type Ⅲ atlas fracture.Methods:A retrospective analysis was performed on 11 patients with Landells type Ⅲ atlanto fracture treated in the Second Hospital of Shanxi Medical University from January 2019 to January 2022,including 6 males and 5 females,aged 26～63 years,with an average age of(48.55±13.18)years.All patients should undergo preoperative computed tomography angiography(CTA)examination and make personalized 3D printing model,and use personalized 3 D printing model for preoperative planning.During the operation,O-arm multidimensional imaging technology and model assistance were used.Atlantoaxial pedicle fixation was used for Landells type Ⅲ atlantoaxial fractures with atlantoaxial joint instability,and single body pedicle fixation was used for atlantoaxial joint stability.Clinical efficacy was evaluated by comparing preoperative and last follow-up pain visual analogue scale(VAS),Japanese Orthopaedic Association Evaluation Treatment score(JOA score),cervical spine dysfunction index(NDI score),atlas lateral mass displacement distance(LMD value),and statistical statistics of operative time and intraoperative blood loss.Fracture reduction and screw placement were evaluated by6 4-slice spiral CT scan after surgery,and the CT images were graded according to the correctness of screw placement.Level 0(G0): Position correct.Level 1(G1): Incorrect placement of less than half of the screw diameter.Level 2(G2): Incorrect placement of more than half the diameter of the screw(Figure 1),to evaluate screw accuracy.Results:All patients successfully completed the operation and received a complete follow-up.The average follow-up time was 18.45±5.65 months,the average operation time was 85± 8.06 min(range 70-100)min,and the intraoperative blood loss was 85.45 ± 13.69ml(60-100)m L.The incisions of all patients were healed in one stage,and no neurovascular complications occurred during follow-up.Significant improvement in symptoms was observed in all patients at the last follow-up,and all patients showed imaging evidence of bone fusion by X-ray and CT.VAS score decreased from 6.27 ± 1.35 points before surgery to 2.09±1.04 points at the last follow-up,and the difference was significant(P<0.05);The JOA score evaluated by the Japanese Orthopaedic Association was significantly different from 7.45 ± 0.93 before surgery to 14.82 ± 1.54 at the last follow-up(P <0.05);The cervical dysfunction index decreased from 76.36 ± 2.50 points before surgery to 11.27±4.32 points at the last follow-up,and the difference was significant(P <0.05);The LMD value decreased from 8.18±2.71 mm before surgery to 2.64± 1.12 mm at the last follow-up,and the difference was significant(P <0.05);Thirty-six upper cervical pedicle screws were inserted.The accuracy of cervical pedicle screws was 94.4%(32/34).Two(5.6%)of the screws broke through the cervical pedicle and were evaluated as grade I.ConclusionThe O-arm multidimensional imaging system combined with personalized 3D printing model is safe,feasible and has unique advantages in the treatment of Landells type Ⅲ unstable atlas fractures.