Evaluating Craniovertebral Stability in Chiari Malformation Coexisting with Type II Basilar Invagination: An Observational Study Based on Kinematic Computed Tomography and Its Clinical Application
Evaluating Craniovertebral Stability in Chiari Malformation Coexisting with Type II Basilar Invagination: An Observational Study Based on Kinematic Computed Tomography and Its Clinical Application
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DOI：
10.1016/j.wneu.2022.05.045
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发表时间：
2022-08-03
影响因子：
2
通讯作者：
Lu, Yuntao
中科院分区：
文献类型：
--
作者：
Zhou, Qiang;Song, Chong;Lu, Yuntao
BACKGROUND: Treatment of Chiari malformation (CM) is controversial, especially when it coexists with "stable" or Type II basilar invagination (CM + II-BI). Precise evaluation of craniovertebral junction (CVJ) stability is crucial in such patients; however, this has never been validated. This study aimed to dynamically evaluate atlanto-condyle and atlantoaxial stability by kinematic computed tomography (CT) and report its surgical treatment.METHODS: The study recruited 101 patients (control, CM, and CM + II-BI groups: 48, 34, and 19 patients, respectively). During kinematic CT, the CVJ stability-related parameters were measured and compared be-tween the 3 groups. The surgical strategy for treating CM + II-BI was based on these results. Preoperative and postoperative images were acquired, and functional scores were used to assess the outcome.RESULTS: Among the 3 groups, the length of the clivus and the height of the condyle were the shortest in the CM + II-BI group, which was accompanied by the greatest rotation of the atlas and atlanto-condyle facet movement on cervical flexion and extension. Moreover, in such patients, increased Chamberlain's baseline violation indicated the aggregate invagination of the odontoid in the flexed posi-tion, and asymmetric displacement of atlantoaxial facets was observed. Seventeen CM + II-BI patients underwent surgical treatment with atlantoaxial distraction and occi-pitocervical fusion. The syringomyelia width and tonsillar herniation decreased significantly, and functional scores indicated symptom relief and good outcomes.CONCLUSIONS: CVJ instability, especially the ultra-movement of atlanto-condyle facets, commonly exists in II-BI as evaluated using kinematic CT. The surgical strategy of atlantoaxial distraction and occipitocervical fusion should be considered to treat such patients.
