Chen Taiyong, Yang Xi, Xiu Peng, Song Yueming
Department of Orthopedics, West China Hospital, Sichuan University, Chengdu Sichuan, 610041, P.R.China.
Department of Orthopedics, the Second Affiliated Hospital of Zunyi Medical University, Zunyi Guizhou, 563006, P.R.China.
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2021 Apr 15;35(4):453-457. doi: 10.7507/1002-1892.202011057.
To investigate the relationship between O-EA angle and lower cervical curvature in patients with anterior atlantoaxial dislocation undergoing occipitocervical fusion, and to analyze the effect of O-EA angle on lower cervical curvature.
The clinical data of 61 patients with anterior atlantoaxial dislocation undergoing occipitocervical fusion who were admitted between April 2010 and July 2018 and met the selection criteria were retrospectively analyzed. There were 32 males and 29 females, with an age of 14-76 years (mean, 50.7 years). The fixed segment included 19 cases of C -C , 27 cases of C -C , 14 cases of C -C , and 1 case of C -C . The O-EA angle, C Cobb angle, and T tilt angle were measured before operation and at last follow-up. According to the O-EA angle measured at last follow-up, the patients were divided into <95° group (group A), 95°-105° group (group B), and >105° group (group C), and compared the differences of gender, age, fixed segment (short segment was at C and above, long segment was beyond C ), and C Cobb angle. Correlation analysis between the O-EA angle and C Cobb angle before operation and at last follow-up, as well as the changes of O-EA angle and C Cobb angle between before operation and at last follow-up were analyzed.
All 61 patients were followed up 12-24 months, with an average of 22.4 months. There was no significant difference in O-EA angle, C Cobb angle, and T tilt angle before operation and at last follow-up ( >0.05). According to the last follow-up O-EA angle grouping, there were 14 cases in group A, 29 cases in group B, and 18 cases in group C. There was no significant difference in age, gender composition, and fixed segment composition among the three groups ( >0.05); the differences in C Cobb angles among the three groups were significant ( <0.05), groups A, B, and C showed a gradually increasing trend. The O-EA angle was positively correlated with C Cobb angle before operation and at last follow-up ( =0.572, =0.000; =0.618, =0.000); O-EA angle change at last follow-up was also positively correlated with C Cobb change ( =0.446, =0.000).
The O-EA angle of patients with anterior atlantoaxial dislocation is positively correlated with C Cobb angle. Too large O-EA angle should be avoided during occipitocervical fixation, otherwise it may accelerate the degeneration of the lower cervical spine.
探讨枕颈融合术治疗寰枢椎前脱位患者的枕骨-耳轴角（O-EA角）与下颈椎曲度的关系，并分析O-EA角对下颈椎曲度的影响。
回顾性分析2010年4月至2018年7月收治的61例符合入选标准的寰枢椎前脱位行枕颈融合术患者的临床资料。其中男32例，女29例，年龄14～76岁（平均50.7岁）。固定节段包括C2-C3 19例、C3-C4 27例、C4-C5 14例、C5-C6 1例。分别于术前及末次随访时测量O-EA角、C2 Cobb角及T1倾斜角。根据末次随访时测量的O-EA角将患者分为<95°组（A组）、95°-105°组（B组）和>105°组（C组），比较三组患者的性别、年龄、固定节段（短节段为C2及以上，长节段为C2以下）及C2 Cobb角的差异。分析术前及末次随访时O-EA角与C2 Cobb角的相关性，以及术前至末次随访时O-EA角和C2 Cobb角的变化情况。
61例患者均获随访12～24个月，平均22.4个月。术前与末次随访时O-EA角、C2 Cobb角及T1倾斜角比较，差异均无统计学意义（P>0.05）。根据末次随访O-EA角分组，A组14例，B组29例，C组18例。三组患者年龄、性别构成及固定节段构成比较，差异均无统计学意义（P>0.05）；三组C2 Cobb角比较，差异有统计学意义（P<0.05），A、B、C组呈逐渐增大趋势。术前及末次随访时O-EA角与C2 Cobb角均呈正相关（r=0.572，P=0.000；r=0.618，P=0.000）；末次随访时O-EA角变化与C2 Cobb角变化也呈正相关（r=0.446，P=0.000）。
寰枢椎前脱位患者的O-EA角与C2 Cobb角呈正相关。枕颈固定时应避免O-EA角过大，否则可能加速下颈椎退变。
