OBJECTIVETo explore the clinical outcomes of atlanto-axial screw-plate fixation and bone fusion for the treatment of atlanto-axial instability.

METHODSFrom June 2003 to June 2008,15 cases with atlanto-axial instability were treated with atlanto-axial lateral mass screw-plate fixation and self-cancellous bone graft fusion. There were 10 males and 5 females with the mean age of 41.7 years (range, from 19 to 72 years). Six cases were old odontoid fracture, 3 cases rheumatoid arthritis, 6 cases odontoid developmental deformity. All patients had symptoms and signs of upper cervical myelopathy and the imaging displayed atlanto-axial instability. JOA scores before operation were from 6 to 11 with an average of 7.4.

RESULTSAll patients were followed up with the mean of 28 months (range, from 9 to 40 months). The follow-up data indicated solid fusion in all patients, posterior reductions were satisfactory, no loosening or screw-plate broken was found. There were 10 cases which spinal cord function improved obviously, 4 cases improved slightly, 1 case no changed in the study. The postoperative JOA scores were from 13 to 17 with an average of 15.6.

CONCLUSIONAtlanto-axial screw-plate fixation and self-cancellous bone graft can stabilize atlas and axis, and promote fusion of atlanto-axial joint, which is an effective method for the treatment of atlanto-axial instability.