Surgical treatment for development spinal canal stenosis at atlas plane

English Keywords:Development spinal canal stenosis at atlas plane  Surgical strategy  Classification

English Abstract:

  【Abstract】 Objectives: Investigate surgical strategies for development spinal cannal stenosis at atlas plane and their clinical results. Methods: We studied 15 cases diagnosed with development spinal cannal stenosis at atlas plane from January, 2014 to December, 2018 in our hospital. According to CT thin-layer scan images of atlantoaxial, they were divided into 4 subgroups: group Ⅰ (small size atlas), group Ⅱ(posterior arch incrassation), group Ⅲ(posterior arch incurvation) and group Ⅳ(odontoid hypertrophy). Different surgical procedures were applied to different types of patients: ①posterior arch osteomy(PAO) was performed on patients in group Ⅰ/Ⅲ/Ⅳ without atlantoaxial dislocation(AAD) or instability; ②posterior arch resect and replantation(PAR) was performed on patients in group Ⅱ; ③besides previous mentioned surgical methods, occipital cervical fixation(OCF) and fusion was also performed on patients associated with atlantoaxial dislocation or instability; ④a novel method of odontoid remodeling and atlantoaxial fixation by transoral anterior reduction plate(ORTARP) were performed on patients associated with AAD in group Ⅳ. All patients underwent MRI and CT examination on cervical vertebrae after operation to evaluate the improvement of spinal medulla compression in C1 plane, and the spinal function recovery was evaluated by JOA scores. Results: Of the 15 patients, 7 in group Ⅰ, 2 in group Ⅱ, 2 in group Ⅲ, and 4 in group Ⅳ. All cases underwent surgery successfully, which included OCF+PAO 6 cases, PAO 5 cases, PAR 2 cases (1 case with atlantoaxial dislocation also underwent occipital cervical fixation and fusion) and ORTARP 2 case. There were no severe complications such as spinal cord damage and vertebrae artery injury in the 15 cases. All patients show different levels of improvement in the symptoms such as limber numbs, weak, claudication. The JOA scores improved from preoperative 10.60±0.96 to 14.10±0.37 at 3 months follow up, and 14.70±0.63 at the last follow up. The improvement rate of cervical spinal function was 64%. Conclusions: Development spinal stenosis at atlas plane could be diagnosed into 4 types, and satisfactory clinical results could be obtained if treated with appropriate surgery for each type.