Efficacy Of Lateral Mass Fusion Device In The Treatment Of Irreducible Atlantoaxial Dislocation With Basilar Invagination

BackgroundThe important surgical methods for the treatment of refractory atlantoaxial dislocation(I-AAD)with basilar invagination(BI)include trans-oral anterior plate,trans-oral release and reduction combined with posterior occipitocervical fusion or posterior occipitocervical fusion.Its clinical effectiveness has been proved in years of practice and application,but the rate of non-fusion and recurrence is high.However,there are few reports on the treatment of refractory atlantoaxial dislocation with basilar invagination with lateral mass fusion in atlantoaxial joint space.PurposeTo explore the effect of atlantoaxial lateral mass fusion cage in the treatment of difficult atlantoaxial dislocation with basilar invagination.MethodRetrospective analysis was performed on the data of 26 patients with I-AAD who received transoral release and reduction combined with posterior occipitocervical fusion or direct posterior occipitocervical fusion in the Department of Orthopedics of the First Affiliated Hospital of Zhengzhou University from June 2016 to January 2020.There were 11 males and 15 females.Age:30-62 years old,average 44.1 years old;The data of 26 patients were divided into two groups according to whether or not a lateral block fusion device was used,namely,the group without the fusion device and the group with the lateral block fusion device.Visual analog scale(VAS),Japanese Orthopaedic Association(JOA)score and quality of life score(SF-12),American Spinal Cord Injury Association(ASIA)grade,atlanto-tooth spacing(ADI),spinal effective space(SAC),C2-7 Cobb Angle and cerviomedullary spinal cord Angle(CMA)were compared between 2 groups before and 1 year after surgery.ResultThere were no statistical differences in preoperative VAS score,JOA score,SF-12 score,ASIA grade,ADI,SAC and CMA between 2 groups,and the above indexes were significantly improved after surgery compared with preoperative(P<0.05).One year after surgery,the VAS score,ADI,non-fusion rate and recurrence rate in the group with the lateral mass fusion were lower than those in the group without the lateral mass fusion device(P<0.05).Joa score,SF-12,SAC,CMA and C2-7 Cobb Angle were higher than those in the non-implanted fusion group,with statistical significance(P<0.05).In terms of Asia classification,the lateral block fusion group was superior to the unimplanted fusion group,and the difference was statistically significant(P<0.05).Conclusion:In the treatment of refractory atlantoaxial dislocation with basilar indentation,atlantoaxial lateral mass fusion device showed good results in nerve decompression and atlantoaxial joint reduction with a 1-year follow-up,and low non-fusion rate and recurrence rate.This is a technique worthy of clinical promotion.