Abstract: Background Chiari malformation type Ⅰ(CM-Ⅰ) is one of the soft tissue anomalies in craniovertebral junction (CVJ). This kind of soft tissue anomaly usually develops with bone anomaly, such as atlantoaxial subluxation, basilar invagination, platybasia, C1 assimilation, etc. For these complex combined anomalies, the treatment remains unaddressed. This study was performed to evaluate the effect of posterior reduction and internal fixation with posterior cranial fossa cranioectomy decompression for Chiari malformation type Ⅰ with basilar invagination, atlantoaxial subluxation, and syringomyelia. Methods Patients with basilar invagination and atlantoaxial subluxation treated from July 2004 to September 2011 were reviewed. Including criterions were made to screen matching patients. Including patients were retrospectively analyzed on both clinical outcomes and radiographical results. Japanese Orthopaedic Association (JOA) score was used to evaluate the clinical outcomes, while the syrinx maximum size was measured on transverse view of MRI T2 image. The results were analyzed by SPSS 17.0 using t -text. Significant difference was considered when P ≤ 0.05. Results Fourteen patients met the including criterions, including 4 male patients and 10 female patients, with a mean age of 31.86 ± 11.36 (standard deviation, range: 17-51) years. Mean JOA score preoperatively of 14 patients was 13.07 ± 1.59 (standard deviation), while that was 15.57 ± 1.02 (standard deviation) postoperatively (t = 9.946, P = 0.000). The mean syrinx size was (7.05 ± 1.98) mm (standard deviation), while that was (2.21 ± 1.91) mm (standard deviation) postoperatively (t = 7.271, P = 0.000). There were no procedure-related morbidity or mortality happened. Conclusion Direct posterior reduction and internal fixation with posterior cranial fossa cranioectomy decompression can obviously improve the clinical outcomes and shrink syrinx for patients suffered from Chiari malformation typeⅠ with basilar invagination, atlantoaxial subluxation, and syringomyelia.

Key words: Internal fixation (not in MeSH), Dislocations, Atlanto-axial joint, Platybasia, Syringomyelia, Cranial fossa, posterior

摘要： 研究背景  ChiariⅠ型畸形为颅颈交界区软组织畸形，可合并其他复杂骨性畸形如寰枢椎脱位、颅底凹陷、扁平颅底及寰枕融合等。对这些复杂畸形，目前尚无成熟的治疗方法。本文探讨颅后窝小骨窗减压并Ⅰ期经后路复位内固定术治疗合并颅底凹陷、寰枢椎脱位和脊髓空洞症的ChiariⅠ型畸形的临床疗效。方法  回顾分析2004 年7 月-2011 年9 月治疗的寰枢椎脱位和颅底凹陷患者临床资料，分别采用日本骨科协会（JOA）17 分评分系统和MRI 影像学数据评价颈脊髓功能和脊髓空洞改善程度。结果  根据纳入标准，共筛选14 例符合入组条件的患者，男性4 例，女性10 例；平均年龄为（31.86 ±11.36）岁。术前JOA 评分平均为13.07 ± 1.59，术后增加至15.57 ± 1.02，二者比较差异具有统计学意义（t = 9.946，P = 0.000）；术前脊髓空洞大小平均为（7.05 ± 1.98）mm，术后缩小至（2.21 ± 1.91）mm，手术前后比较差异亦有统计学意义（t = 7.271，P = 0.000）。手术后无一例发生并发症或死亡。结论  经后路复位内固定联合颅后窝小骨窗减压术治疗合并脊髓空洞症、寰枢椎脱位及颅底凹陷的ChiariⅠ型畸形能够显著改善患者预后、缩小脊髓空洞。

关键词: 内固定术（非MeSH 词）, 脱位, 寰枢关节, 扁颅底, 脊髓空洞症, 颅窝, 后