Clinical and radiological Comparison of treatment of atlantoaxial instability by posterior C1-C2 transarticular screw fixation or C1 lateral mass-C2 pedicle screw fixation

We compared the clinical and radiological results of posterior atlantoaxial fixation surgery using transarticular screws to those using a polyaxial screw-rod system in 55 patients with symptomatic atlantoaxial instability Patients underwent posterior C1-C2 fixation 28 patients (group 1) underwent C1-C2 transarticular screw fixation and 27 patients (group 2) underwent C1 lateral mass-C2 pedicle screw fixation Patients were followed-up for at least 24 months The clinical and radiological results were evaluated in the early postoperative period and at 3, 6, 12 and 24 months after surgery Long-term postoperative stability and bone fusion were examined After surgery, 93% of patients in group 1 and 96% of patients in group 2 were free of neck pain The solid fusion rates were 82% for group 1 patients and 96% for group 2 patients at 12 months (p < 0.092) In group 1, three patients showed fibrous union Four patients had hardware failure due to a screw malposition (one in group 1) and pseudoarthrodesis (two in group 1 and one in group 2) One patient in group 1 had cerebrospinal fluid leakage One patient in group 2 had occipital neuralgia One vertebral artery injury occurred during the screw placement in group 1 and another in group 2 during the muscle dissection C1-C2 transarticular screw fixation and C1 lateral mass-C2 pedicle screw fixation both produced excellent results for stabilization of the atlantoaxial complex, but the radiological outcome tended to be superior in C1 lateral mass-C2 pedicle screw fixation (C) 2009 Elsevier Ltd All rights reserved