Wu Ji, Ding Yiyang, Xu Zhenji, Chen Fei, Lu Xuhua, Ni Bin, Zhang Qi, Bi Xiaoda, Guo Qunfeng
Department of Orthopedics, 905th Hospital of PLA Navy, Shanghai, China.
Department of Orthopedics, Shanghai Changzheng Hospital, Shanghai, China.
Eur J Orthop Surg Traumatol. 2025 Sep 9;35(1):385. doi: 10.1007/s00590-025-04505-z.
To investigate the images and treatment differences for Type IIIa atlantoaxial rotary dislocation (AARD) by comparing the imaging characteristics of patients with Type III and Type IIIa AARD.
The present study retrospectively analyzed a cohort of 35 patients who underwent posterior C1-C2 intra-articular fusion due to AARD from our hospital database. Among them, 23 patients were diagnosed with Type III AARD, while the remaining 12 patients were diagnosed with Type IIIa AARD. The imaging characteristics and clinical data were reviewed and compared.
Type III AARD demonstrated significantly greater traction reducibility than Type IIIa (18/23 vs. 4/12 cases, P < 0.05), with longer operative times required for Type IIIa (P < 0.05). All patients achieved successful fusion without complications, showing significant Visual Analog Scale Score for Neck Pain (VASSNP) improvement (P < 0.05) but unchanged Japanese Orthopedic Association (JOA) scores. Radiographically, Type IIIa exhibited higher C2 facet deformity rates (10/12 vs. 9/23), more severe Ishii Grade III involvement, and larger C1-C2 separation angle (SEA)/lateral inclination angle (LIA) measurements (P < 0.05), while atlanto-dens interval (ADI), C2-C7 angle, and T1-slope (T1S) showed no intergroup differences. The SEA has a significant positive correlation with the LIA (r = 0.711, P < 0.001).
In conclusion, compared to Type III AARD, Type IIIa AARD exhibits a larger SEA and LIA, rendering it more susceptible to C2 facet joint deformities and consequently posing greater challenges during surgical reduction of the atlantoaxial joint.
通过比较III型和IIIa型寰枢椎旋转性半脱位（AARD）患者的影像学特征，探讨IIIa型AARD的影像学表现及治疗差异。
本研究回顾性分析了我院数据库中35例因AARD接受C1-C2关节内后路融合术的患者队列。其中，23例患者被诊断为III型AARD，其余12例患者被诊断为IIIa型AARD。对影像学特征和临床资料进行回顾和比较。
III型AARD的牵引复位率显著高于IIIa型（18/23对4/12例，P < 0.05），IIIa型所需手术时间更长（P < 0.05）。所有患者均成功融合且无并发症，颈部疼痛视觉模拟量表评分（VASSNP）显著改善（P < 0.05），但日本骨科协会（JOA）评分未变。影像学上，IIIa型C2关节面畸形率更高（10/12对9/23），石井III级受累更严重，C1-C2分离角（SEA）/侧倾角（LIA）测量值更大（P < 0.05），而寰齿间距（ADI）、C2-C7角和T1斜率（T1S）组间无差异。SEA与LIA呈显著正相关（r = 0.711，P < 0.001）。
总之，与III型AARD相比，IIIa型AARD的SEA和LIA更大，使其更容易发生C2关节面畸形，因此在寰枢关节手术复位过程中面临更大挑战。
