Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China; Nanfang Neurology Research Institution, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, China.
World Neurosurg. 2022 Aug;164:e724-e740. doi: 10.1016/j.wneu.2022.05.045. Epub 2022 May 17.
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.
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 between 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.
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 position, and asymmetric displacement of atlantoaxial facets was observed. Seventeen CM + II-BI patients underwent surgical treatment with atlantoaxial distraction and occipitocervical fusion. The syringomyelia width and tonsillar herniation decreased significantly, and functional scores indicated symptom relief and good outcomes.
CVJ instability, especially the ultramovement 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.
Chiari 畸形（CM）的治疗存在争议，尤其是当它与“稳定”或 II 型颅底凹陷症（CM+II-BI）共存时。在这些患者中，精确评估颅颈交界区（CVJ）的稳定性至关重要；然而，这一点从未得到验证。本研究旨在通过运动学计算机断层扫描（CT）动态评估寰枢关节和寰枢关节的稳定性，并报告其手术治疗方法。
该研究纳入了 101 名患者（对照组、CM 组和 CM+II-BI 组：48、34 和 19 名患者）。在运动学 CT 检查期间，测量并比较了 3 组患者 CVJ 稳定性相关参数。CM+II-BI 患者的手术策略基于这些结果。获取术前和术后图像，并使用功能评分评估结果。
在 3 组患者中，CM+II-BI 组患者的斜坡长度和髁突高度最短，寰椎和寰枢关节面在颈椎屈伸运动时旋转最大。此外，在这些患者中，Chamberlain 基线侵犯增加表明齿状突在屈曲位的整体内陷，并且观察到寰枢关节面的不对称移位。17 例 CM+II-BI 患者接受了寰枢关节牵开和枕颈融合术治疗。脊髓空洞症宽度和扁桃体疝明显减小，功能评分表明症状缓解和良好的结果。
使用运动学 CT 评估，II-BI 中普遍存在 CVJ 不稳定，特别是寰枢关节面的超活动。应考虑采用寰枢关节牵开和枕颈融合术的手术策略来治疗此类患者。
