OBJECTIVETo retrospectively analyze and evaluate the results of treatment for atlantoaxial instability or dislocation employing pedicle screws of atlas and axis.

METHODSThirty-one patients (23 male and 8 female) with atlantoaxial instability or dislocation were stabilized using pedicle screws of atlas and axis between May 2005 to January 2008. The patients ranged in age from 17 to 67 years (mean 43.5 years). Patients consisted of chronic odontoid fracture in 17, Os odontoideum in 8, fresh odontoid fracture in 4, transverse ligament rupture in 1, rheumatoid arthritis in 1. Clinical features included neck pain in 31; restricted neck movement in 28, varying degrees of spastic quadriparesis in 19. All patients underwent posterior C(1) to C(2) pedicle screw fixation. Operative time, intraoperative blood loss, complications were recorded, neurological and radiographic studies were carried.

RESULTSMean follow-up time was 13 months. Operative time averaged 2.5 h. Mean intraoperative blood loss was 300 ml. A patient had postoperative wound infection and was treated conservatively with antibiotics and local wound care. A patient developed pulmonary artery embolism and got well with anticoagulation. Satisfactory stability was achieved in all cases with no vascular and C(2) neuralgia. Average JOA score in 19 cases increased at final follow-up (P < 0.01). Solid fusion was achieved in 29 cases, fusion rate was 93.6%.

CONCLUSIONSStabilization of atlantoaxial complex via pedicle screws of atlas and axis has advantages of intraoperative restoration, easier placement of screw, solid fixation. It is a safe and effective treatment modality for posterior C(1-2) fusion.