ABSTRACT
Objective To explore the clinical effect of the trans-atlantoaxial pedicle screw-rod internal fixation and fusion in treatment of old odontoid fracture combined with atlantoaxial instability.Methods The study involved 48 patients with old odontoid fractures combined with atlantoaxial instability treated with trans-atlantoaxial pedicle screw-rod internal fixation and fusion from January 2005 to January 2010.There were 30 males and 18 females,at average age of 45.1 years old(19-56 years).All the patients underwent the skull traction preoperatively.Results A total of 192 pedicle screws(96 screws for the atlas and another 96 for the axis)were implanted in all the 48 patients who obtained satisfactory atlantoaxial reduction,with no spinal cord injuries.The operation lasted for average 155 min,with blood loss for average 370 ml.There were three patients with vertebral artery injury and three with inferior posterior arch fracture of the atlas during operation.All the patients were followed up for average of 46.6 months(range,9-64 months),which showed bone fusion at 6 months after operation,with no loosening,displacement,instability or breakage of the screws.The JOA score was improved from preoperative 7.1 ±2.8 to postoperative 13.3 ± 2.1(P ＜ 0.05).Conclusion Atlantoaxial pedicle screw fixation is a reliable and effective method for the treatment of the atlantoaxial instability.