强直性脊柱炎合并寰枢椎脱位的影像学特点及手术疗效

Atlantoaxial subluxation in ankylosing spondylitis patients: radiographic characteristics and surgical treatment

中文关键词:  强直性脊柱炎  寰枢椎脱位  影像学特点  手术疗效

英文关键词:Ankylosing spondylitis  Atlantoaxial subluxation  Radiographic characteristic  Clinical outcome

中文摘要:

  【摘要】 目的：分析强直性脊柱炎（ankylosing spondylitis，AS）合并寰枢椎脱位（atlantoaxial subluxation，AAS）的影像学特点，评估手术治疗的临床疗效。方法：回顾性分析2001年11月~2019年2月于我院接受颈枕融合或上颈椎融合术治疗的AS合并AAS的患者资料8例，均为男性，年龄15~59岁，平均39.9±16.2岁。术前颈椎侧位X线片示所有患者均存在寰枢椎脱位，寰齿前间隙（anterior atlantodental interval，AADI）平均为10.4±7.0mm（2~17mm）；其中5例为前脱位，AADI平均为15.2±2.7mm（11~17mm），另3例为后脱位合并齿状突骨折。3例患者术前伴不全瘫（Frankel D级2例，Frankel C级1例）。在术前、术后即刻及末次随访的颈椎侧位X线片上测量C0-C2角、C1-C2角、C2-C7角、C2-C7矢状面偏移（sagittal vertical axis，SVA）和AADI。采用Frankel分级评估术前及术后出院前的神经功能状态。应用配对样本t检验比较术前、术后影像学参数。记录手术并发症情况。结果：7例获得随访，随访时间3~96个月，平均37.9±38.5个月。C0-C2角术前为18.9°±16.8°，术后改善至22.6°±15.4°，末次随访时为20.4°±11.4°；C1-C2角术前为19.6°±18.7°，术后改善至28.5°±10.1°，末次随访时为24.6°±8.1°；术前C2-C7角平均为-6.4°±25.2°，术后改善至6.6°±19.7°，末次随访时为9.0°±18.8°；C2-C7 SVA术前为46.0±36.5mm，术后改善至39.4±26.4mm，末次随访时为39.6±18.9mm，C0-C2角、C1-C2角、C2-C7角及C2-C7 SVA术前、术后的差异均无统计学意义（P>0.05）。AADI术前为10.4±7.0mm，术后显著改善至6.4±4.1mm（P<0.05），差异具有统计学意义，末次随访时为6.9±4.6mm。3例术前不全性瘫痪者，术后神经功能均有一定程度的恢复，其中2例术前Frankel D级者恢复至E级；另1例由术前Frankel C级改善至D级。所有患者均未发生神经并发症及浅表、深部感染，且无断钉、断棒、螺钉松动等内固定并发症发生。结论：AS合并AAS在影像学上多表现为前脱位，手术治疗AS合并AAS可取得良好的疗效。术前伴神经损害者需行后路C1后弓切除减压。后路颈椎/颈胸段截骨矫形适用于明显颈椎/颈胸段后凸畸形患者。

英文摘要:

  【Abstract】 Objectives: To explore the clinical and radiographic characteristics of atlantoaxial subluxation(AAS) in ankylosing spondylitis(AS) patients and to assess the clinical efficacy of surgical intervention. Methods: The medical records of eight AS patients with AAS who underwent occipitocervical fusion or upper cervical fusion in our hospital between November 2001 and February 2019 were retrospectively reviewed. All patients were male, aged 15-59 years, with an average of 39.9±16.2 years. Three patients presented with preoperative incomplete paraplegia (two presented with Frankel D and one with Frankel C). Preoperative lateral X-rays of the cervical spine showed that all patients presented with AAS, with an average of 10.4±7.0mm (range 2-17mm) in anterior atlantodental interval(AADI), among whom five were with anterior AAS, with an average AADI of 15.2±2.7mm (11-17mm), and the other three patients presented with posterior AAS and odontoid fracture. C0-C2 angle, C1-C2 angle, C2-C7 angle, C2-C7 sagittal vertical axis(SVA), and AADI were measured on lateral X-rays of the cervical spine before surgery, immediately after surgery, and at the final follow-up. The neurological function was assessed by Frankel grading before operation and before discharge, respectively. Paired samples t test was used to compare the preoperative and postoperative radiographic parameters. The surgical complications were recorded. Results: Seven of the eight patients were followed up for 37.9±38.5 months (range, 3-96 months). C0-C2 angle was improved from preoperative 18.9°±16.7° to 22.6°±15.4° immediately after surgery, and it was 20.4°±11.4° at the final follow-up. C1-C2 angle was corrected from preoperative 19.6°±18.7° to 28.5°±10.1° immediately after surgery, and it was 24.6°±8.1° at the final follow-up; C2-C7 angle was improved from preoperative -6.4°±25.2° to 6.6°±19.7° immediately after surgery, and it was 9.0°±18.8° at the final follow-up. C2-C7 SVA was corrected from preoperative 46.0±36.5mm to 39.4±26.4mm immediately after surgery, and it was 39.6±18.9mm at final follow-up. A significant improvement of AADI from preoperative 10.4±7.0mm to 6.4±4.1mm immediately after surgery was observed(P<0.05), and the AADI was 6.9±4.6mm at final follow-up. There was no significant difference between preoperative and postoperative radiographic parameters including C0-C2 angle, C1-C2 angle, C2-C7 angle, and C2-C7 SVA(P>0.05). The neurological functions of the three patients with preoperative incomplete paraplegia were restored to varying degrees after surgery. Two of them improved from Frankel grade D to grade E. The other one was improved from Frankel grade C to grade D. There were no neurological complications, superficial or deep infection, or implant related complications including screw breakage, rod fracture, and screw loosening. Conclusions: AAS in AS patients predominantly manifests as anterior AAS. Favorable clinical outcomes can be obtained by surgical treatment in AS patients with AAS. Resection of the C1 posterior arch and posterior decompression should be performed in patients with neurological compromise. Posterior cervical/cervicothoracic osteotomy is indicated for patients with obvious cervical/cervicothoracic kyphosis.