Objective: To assess the clinical impact of direct two-step distraction reduction (TSDR) for basilar invagination (BI) with atlantoaxial dislocation (AAD). Methods: Retrospective analysis was conducted on the clinical data of patients who underwent TSDR and occipitocervical fusion in West China Hospital between October 2013 and March 2021. Depending on whether the preoperative decrease was greater than 50% on preoperative hyperextension X-rays, the patients were split into two groups. The neurological function [Japanese Orthopedic Association (JOA) score], atlantodens interval (ADI), the distance of odontoid process beyond McRae Line (ML) and Wackenheim Line (WL), cervicomedullary angle (CMA), O-C2 angle (OC2A), and complications incidence were compared between two groups preoperatively and postoperatively. Results: There were 12 men and 23 women among the 35 patients with BI and AAD, and the age ranged from 28 to 71 years, with an mean age of (52.0±13.4) years. In the preoperative reduction ≥50% group, there were 4 males and 9 females with an average age of (54.0±13.8) years; in the preoperative reduction <50% group, there were 8 males and 14 females with a mean age of (50.9±13.4) years. All the patients were followed-up for a mean time of (23.3±13.4) months. There was no significant difference in age, gender, bleeding, length of hospital stay and follow-up time between the two groups (all P>0.05). The JOA score, ADI, WL, ML and CMA of 35 patients were significantly improved when compared with those before operation (all P<0.05). The reduction degree of ADI, ML and WL was more than 80% in 31 cases (88.57%), 30 cases (85.71%) and 31 cases (88.57%), respectively. There was no significant difference in postoperative ADI, ML and WL between the two groups (all P>0.05). All patients had no incision infection, no loosening or breakage of the internal fixators. Dysphagia occurred in 3 patients, non-fusion happened in 1 patient, but no instability in X-ray of cervical dynamic position was found, no loosening or displacement occurred in internal fixators, and partial spontaneous fusion occurred between atlantoaxial lateral mass joints. Conclusions: For BI with AAD without atlantoaxial bony connection or serious atlantoaxial facet joint inclination, TSDR could obtain satisfactory reduction degree. The reduction degree on preoperative hyperextension X-ray doesn't affect the degree of intraoperative reduction.
目的： 探索术中两步撑开复位技术（TSDR）对颅底凹陷合并寰枢椎脱位的疗效。 方法： 回顾性分析2013年10月至2021年3月因颅底凹陷合并寰枢椎脱位于四川大学华西医院接受TSDR治疗的患者临床资料。根据患者术前过伸位X线片横向脱位复位程度，分为术前复位≥50%组和<50%组。观测35例患者手术前后日本骨科学会（JOA）评分评价神经功能、影像学指标［寰齿间距（ADI）、McRae线（ML）、Wackenheim线（WL）、颈延髓角（CMA）、枕颈角（OC2A）］及并发症的发生。比较术前复位≥50%组和<50%组一般情况及术后复位效果（ADI、ML、WL及CMA）。 结果： 本研究35例颅底凹陷合并寰枢椎脱位患者中，男12例，女23例，年龄（52.0±13.4）岁（28~71岁）。其中术前复位≥50%组13例，男4例，女9例，年龄（54.0±13.8）岁；术前复位<50%组22例，男8例，女14例，年龄（50.9±13.4）岁。所有患者随访（23.3±13.4）个月。两组患者年龄、性别、出血量、住院时间、随访时间差异均无统计学意义（均P>0.05）。35例患者末次随访时JOA评分、ADI、WL、ML及CMA与术前相比差异均有统计学意义（均P<0.05）。ADI、ML、WL复位超过80%分别为31例（88.57%）、30例（85.71%）、31例（88.57%）。术前复位≥50%组和术前复位<50%组比较，术后ADI、ML、WL差异均无统计学意义（均P>0.05）。所有患者无切口感染、内固定松动、断裂。3例患者存在吞咽困难，1例患者后方植骨未融合，颈椎动力位X线片未见不稳，内固定无松动、移位，寰枢椎侧块关节间部分自发融合。 结论： 对于寰枢间无骨性连接、寰枢小关节无严重倾斜的颅底凹陷合并寰枢椎脱位患者，应用TSDR术中直接复位可获得满意的复位效果。术前过伸位X线片复位程度不影响术中复位效果。.