O-arm Navigation Assisted Internal Fixation In The Treatment Of Unstable Clinical Study On Injury Of Posterior Pelvic Ring

objective:Investigate the efficacy and safety of sacroiliac joint cannulated screws in the treatment of unstable posterior pelvic ring injury guided by O-arm navigation system.Method:From September 2015 to January 2017,a total of 40 patients with posterior pelvic ring injuries were admitted to our hospital.19 cases were guided by O-arm navigation system to guide cannulated screw insertion of sacroiliac joint.21 cases underwent conventional C-arm fluoroscopy closure to guide the placement of cannulated lag screws in the sacroiliac joint.The two groups were compared with operative time,intraoperative blood loss,insertion time,reduction quality,function after the operation.According to Tile fracture classification,O-arm navigation group include 7 cases of B1.2,8 cases of B2.2,2 cases of C1.2,1 cases of C1.3,1 cases of C2.3.C arm fluoroscopy group: 9cases of B1.2,7 cases of B2.2,2 cases of C1.2,2 cases of C1.3,1 cases of C2.3.Result : In the O-arm navigation group,23 sacroiliac screws were implanted,with 18 excellent cases,4 good cases and 1 poor case,and the Excellent rate is 95.7%.In the C arm fluoroscopy group,23 sacroiliac screws were implanted,with 14 excellent cases,7 good cases and 5 poor cases,and the Excellent rate is 80.8%.O-arm navigation group screw placement took 18 ~27min,the average(24.19±3.14)min;the amount of bleeding was 11 ~ 25 ml,the average(19±5.26)ml.C-arm fluoroscopy group screw placement time 26 ~38min,the average(25.35±4.38)min;the amount of bleeding was 13~27ml,the average(20±6.36)ml.Two groups of 1 cases lost follow-up.Two cases of wound were healed without wound infection complications.No complications occurred in O-arm navigation group after surgery.There were 2 cases of lower extremity numbness occurred in C arm fluoroscopy group,both healed after being treamed with dehydration,application of hormone,nerve nutrition and other symptomatic treatment after 3 months.The Matta score was used to evaluate the reduction of fracture.There were 13 excellent cases,5 good cases,1 poor cases in O-arm navigation group and the excellent rate was 94%.There were 12 excellent cases,7 good cases,2 poor cases in C-arm group,and the excellent rate was 90.5%.The Majeed function score of O-arm navigation group was higher than C arm fluoroscopy group at 1 months and 3 months after operation.Conclusion : O-arm navigation assisted percutaneous sacroiliac screw fixation for treatment of pelvic posterior ring injuries,can reduce the operation time and the intraoperative inspection of screw position is good.It has good maneuverability,higher security and more conducive to the postoperative functional recovery.