Transpedicular screw fixation system for treatment of unstable fractures of atlas vertebra

Objective To study the clinical outcomes of transpedicular screw fixation system for treatment of unstable fractures of the atlas vertebra.Methods From March 2007 to April 2010,transpedicular fixation was employed to treat 23 patients with unstable fractures of the atlas vertebra;the patients included 15 males and 8 females.Eight patients had posterior 3/4 Jefferson fracture,12 had 1/2 ring Jefferson fracture and 3 had posterior 1/2 Jefferson fracture.The preoperative Japanese Orthopaedic Association(JOA)score was 7-12,with an average of 9.5.All patients were treated by single transpedicular fixation via the posterior approach.Results The patients were followed up for 12-39 months,with a mean of 18.8 months.The operative time ranged 30-60 min.Intraoperative blood loss ranged from 50-200 mL.Postoperative roentgenoghaph and CT scan showed that 1 screw was inserted so medially and penetrated the spinal canal,and 1 screw was directly inserted into the lateral mass of the atlas due to posterior atlas arch breakage caused by repeated drilling,but with no nervous system symptom.The postoperative JOA scores were 13-17,with an average of 14.7.There were no spinal cord injuries,and no loosening or breakage of screw after surgery.Bony fusion was achieved in all patients and the atlantoaxial rotational function was satisfactorily restored.Conclusion The transpedicular fixation technique is an effective method for the treatment of unstable fractures of the atlas vertebra.