RESUMEN
Objective: This study evaluated the effectiveness and safety of C1-C2 transarticular screw fixation (transarticular screw fixation com-bined with bone grafting) and C1 lateral mass-C2 pedicle screw fixation (modified Harms technique) in patients with C1-C2 instability. Materials and methods: This prospective, self-controlled, single-center study evaluated two fixation techniques for the treatment of atlantoaxial instability injury. From June 2006 to February 2017, 118 patients were admitted to our hospital because of atlantoaxial instability injury. These patients were divided into two groups: group 1, including 52 patients who underwent C1-C2 transarticular screw fixation (C1C2-TAS group), and group 2, including 66 patients who underwent C1 lateral mass-C2 pedicle screw fixation (C1LM-C2PS group). Results: There were significant differences in the operation time, blood loss amount, and hospital stay length between the groups (p<0.001). The mean operation time (78.94 vs. 110.91 min; p=0.0003) and hospital stay length (5.31 vs. 8.34 days; p=0.0003) were shorter, and the mean blood loss amount during surgery (122.31 vs. 258.33 mL; p<0.0001) was smaller in the C1C2-TAS group than in the C1LM-C2PS group. The surgical complication rate was low and no vertebral artery injury was observed. After surgery, the clinical presentations were significantly reduced in both groups. The patients showed sati-sfactory internal fixation on postoperative radiography and computed tomography. Conclusion: Both C1-C2 transarticular screw fixation and C1 lateral mass-C2 pedicle screw fixation are effective and safe in treat-ing atlantoaxial instability injury. Notably, C1-C2 transarticular screw fixation yields a shorter operation time and hospital stay length and a smaller intraoperative blood loss amount than does C1 lateral mass-C2 pedicle screw fixation.