OBJECTIVETo evaluate the therapeutic effects of atlantoaxial pedicle screw in treating odontoid process fracture by location through inferior and inner wall of atlas and superior and inner wall of axis.

METHODSFrom June 2006 to September 2010, 12 patients with odontoid process fracture were treated with the atlantoaxial pedicle screw fixation by location through inferior and inner wall of atlas and superior and inner wall of axis. There were 8 males and 4 females, ranging in age from 18 to 62 years, with an average of 37.9 years. According to classification of Anderson, type II was in 10 cases and type III was in 2 cases. Fresh fracture was in 9 cases and old fracture was in 3 cases. All patients had symptoms such as cervical pain, stiffness and limitation of activity and 9 cases with symptoms were found physical signs of cervical spinal injury. According to grade of ASIA, grade C was in 4 cases and grade D was in 5 cases.

RESULTSThere were no severe complications such as injuries of vertebral artery, nerve root and spinal cord during operation. The mean time of follow-up was 14 months (6 to 24 months). The X-ray film and CT scanning showed that all patients had steady bony union and all screws were in the proper position, no screws loosening or breaking were found. Clinical symptoms of all patients improved significantly. Nine patients with spinal injury before operation, of which nerve function obtained improvement, grade C was in 1 case, grade D was in 2 cases and grade E was in 6 cases according to grade of ASIA.

CONCLUSIONLocation through inferior and inner wall of atlas and superior and inner wall of axis is an effective method for the atlantoaxial pedicle screw implantation; atlantoaxial pedicle screw could be accurately and safely implanted thought this way.