ObjectiveTo explore the clinical efficacy of the atlantoaxial lateral mass fusion cage in the treatment of basilar invagination with atlantoaxial dislocation.

MethodsThe analysis was conducted on a total of 22 patients who underwent posterior placement of atlantoaxial lateral mass fusion cage combined with occipital cervical fusion internal fixation surgery at the First Affiliated Hospital of Zhengzhou University from March 2018 to March 2022, including 4 males and 18 females. Before and after surgery, the atlantodental interval (ADI) and cervicomedullary angle (CMA) were measured, and the Japanese Orthopaedic Association (JOA) score was used for preoperative and postoperative neurological function evaluation. Regular examinations of X-ray, CT, and MRI were carried out after surgery to evaluate reduction, internal fixation, and bone graft fusion.

ResultsTotally, 22 patients successfully completed the surgery and achieved effective reduction. The surgical time was (167.72±34.51) min. The bleeding volume was (180.45±78.65) ml. The postoperative ADI was (2.02±0.42) mm, which was significantly reduced compared to the preoperative (7.62±1.96) mm. The CMA recovered from preoperative (129.00±6.39)° to postoperative (151.00±4.73)°. The JOA score increased from preoperative (11.14±2.27) to postoperative (15.27±1.64), with statistically significant differences ( t=12.961, 19.402, 11.615, P<0.05). All patients with nerve compression symptoms were relieved, and clinical symptoms were improved to varying degrees. Postoperative follow-up was 3-18 months, with an average of (8.62±3.85) months. All patients had good internal fixation, satisfactory position of the atlantoaxial lateral mass fusion cage, and satisfactory clinical results.

ConclusionPosterior placement of the atlantoaxial lateral mass fusion cage combined with occipitocervical fusion internal fixation is an effective treatment method, with low risk of long-term complications, good atlantoaxial fusion rate, good safety and long-term efficacy.