Preliminary Application Of O-arm-based Navigation System In Treatment Of Adolescent Idiopathic Scoliosis

Objective: In recent years,with the constant advancement in spinal surgical techniques and implants,spine surgery has greatly developed.But due to the complex anatomy of the spine along with major blood vessels and nerves nearby,the high risk of spinal surgery has become increasingly evident.O-arm navigation system is the most advanced navigation technology to achieve high-quality operative 3D CT images in a short time,directly enters into the navigation computer to get an automatic match.It can be widely used in various orthopedic surgeries.Adolescent idiopathic scoliosis is one of the most common types of scoliosis.It has a high incidence rate and can be quite harmful in adolescents.Orthopedic and surgical instruments used in the surgery are not only complex and difficult to operate but they also pose many complications.Pedicle screw is currently the most commonly used treatment methods of internal fixation.But for patients with dysplastic vertebral pedicle or rotation in heavier patients,there is still a risk of misplacement of screws.This study aims to explore the value of internal fixation by O-arm navigation system in adolescent idiopathic scoliosis.Methods:1 Forty-two cases of adolescent idiopathic scoliosis were retrospectively analysed in our hosipital from January 2013 to December 2014,which were treated by posterior total pedicle screws fixation.Of 42 patients,19 patients underwent pedicle screw fixation using the O-arm-based navigation(O-arm group),while 23 patients underwent the conventional technique with C-arm X-ray machine(C-ram group).Operation time,time of pedicle screw,operative blood loss,and postoperative complication were recorded between the two groups.2 The pedicle screw position were evaluated and classified by intraoperative CT images according to the Richter method,and the good rate of pedicle screws were calculated.3 To evaluate the effect of orthopaedic by the whole spineX-ray films(anteroposterior and lateral view)after the surgery.Results: All patients underwent the surgery successfully.There was no significant difference in gender,age,involved segment and Cobb angle of main thoracic curve between 2 groups(P > 0.05).on the upper thoracic spine(T1-4),and the middle thoracic spine(T5-8),the excellent rate of O-arm group(94.4%?95.6%)was significant higher than that of C-ram group(78.9%?85.4%).There was no significant difference on the lower thoracic spine(T9-12)and the lumber(L1-5)between 2 groups(P > 0.05).The time of pedicle screw in O-ram group(98±22min)were significantly shorter than C-ram group(125±37min).There was no significant difference in operation time and operative blood loss between 2 groups(P > 0.05).All patients had an average 16.5-month follow-up.There was no lost of the orthopedic spinal decompensation effect at the last follow-up of two groups of patients.The major curve Cobb angle of 2 groups at 1 week and last follow-up were significantly improved when compared with preoperative value(P<0.05),but there was no significant difference between 1 week an last follow-up(P>0.05).There was no significant difference in correction rate of the major curve Cobb angle between 2 groups at last follow-up.Conclusions:The O-arm-based navigation system can improve the accuracy and safety of pedicle screw implantation in patients with AIS,and can detect and amend malpositioned screws timely in surgery to protect the safety of surgery.The effects of surgery is satisfactory.