Comparison of outcomes after atlantoaxial fusion with C1 lateral mass-C2 pedicle screws and C1-C2 transarticular screws

To compare the clinical and radiological outcomes of posterior atlantoaxial fixation and fusion using C1 lateral mass-C2 pedicle screws (screw-rod constructs, SRC) with C1-C2 transarticular screws (TAS). A retrospective review was conducted of 105 patients with atlantoaxial instability who underwent posterior C1-C2 fixation and fusion by SRC group (60 pt) and TAS group (45 pt). The follow-up period was minimum 2 years. Clinical outcomes measurements included the Numeric Rating Scale (NRS) for pain assessment, the Neck Disability Index (NDI), the Japanese Orthopedic Association (JOA) score and the American Spinal Injury Association (ASIA) impairment scale for the functional and neurological outcomes that were assessed. Radiological outcomes were assessed by evaluating the fusion rate and proper screws position. Both outcomes were evaluated in the early postoperative period, 3, 6, 12 and 24 months after surgery. Operative time, estimated blood loss, complications and length of stay were also reviewed. The majority of cases were caused by trauma and presented with axial neck pain. The improvement of NRS, NDI, JOA score and ASIA impairment scale were not different between the two groups. Proper screw position and fusion rate were also observed similarly between the two groups. Estimated blood loss was lesser and operative time was shorter in TAS group than SRC group (p = 0.047, p = 0.001, respectively). Operative complications and the length of hospital stay were also not different between the two groups. Both SRC and TAS produced excellent outcomes for atlantoaxial stabilization. But the volume of bleeding and operation time tended to be better in TAS group compared to SRC group.