The clinical effects of posterior C1-C2 pedicle screw-rod fixation with different crosslink modes in the treatment of atlanto-axial dislocation

English Keywords:Atlanto-axial dislocation  Posterior fixation  Crosslink

English Abstract:

  【Abstract】 Objectives: To investigate the clinical effects of posterior C1-C2 pedicle screw-rod fixation(C1-C2 PSR) with different crosslink modes in treating atlanto-axial dislocation. Methods: From January 2018 to December 2019, 32 patients with atlanto-axial dislocation who had different degrees of spinal nerve damage such as limb numbness and weakness before operation were treated with C1-C2 PSR fixation. Before operation, imaging examinations including cervical X-ray, CT and three-dimensional reconstruction, MRI, vertebral artery CTA were performed to confirm the diagnosis. 7 cases were treated with horizontal screw-screw crosslink(hS-S CL) C1-C2 PSR, including 4 males and 3 females, aged 45.57±9.05 years old(group A), 12 cases were treated with horizontal rod-rod crosslink(hR-R CL) C1-C2 PSR, including 5 males and 7 females, aged 43.58±7.35 years old(group B), and 13 cases were treated with C1-C2 PSR simply, including 6 males and 7 females, aged 42.38±6.70 years old(group C). The operative time, intraoperative blood loss and complications were recorded, and Japanese Orthopaedic Association(JOA) scores were used to evaluate the neurologic status of patients before operation and at final follow-up. Anteroposterior lateral cervical X-ray and CT were performed at half a year after operation and 1 year above to assess the fixed position and bone fusion. Results: All patients underwent operation successfully without injuring vertebral artery, spinal cord, or nerve root during operation, no poor incision healing or cardiovascular or cerebrovascular accidents during follow-up. The operative time, intraoperative blood loss, and follow-up time between the three groups of patients were with no statistical differences(P>0.05). The postoperative nerve functions of the three groups of patients all improved to different extent, the differences between final follow-up JOA scores and preoperative ones were statistically significant(P<0.05), while the improvement rates of JOA scores between the three groups were not statistically different(P>0.05). For the number of bone fusion patients at 6 months, 1 year, 2 years after operation, and final follow-up: it was respectively 4 cases, 5 cases, 6 cases, and 7 cases in group A; 5 cases, 9 cases, 10 cases, and 12 cases in group B; and 1 case, 3 cases, 5 cases and 10 cases in group C. The number of bone fusion patients in group A and group B were statistically different from that in group C at 6 months, 1 year and 2 years after operation(P<0.05), while there was no statistically significant difference between group A and group B(P>0.05), and there was no statistically significant difference between the three groups at the last follow-up(P>0.05). No internal fixation-related complications such as screw displacement, loosening, or fracture occurred during follow-up. Conclusions: Posterior C1-C2 pedicle screw-rod fixation with different crosslink modes can all achieve good clinical results in the treatment of atlantoaxial dislocation. The bone graft fusion in crosslink fixation group is earlier than that in the group without crosslink fixation. The hS-S CL group has the same clinical efficacy as the hR-R CL group, but the former is more convenient for intraoperative installation.