Endoscopic transcervical anterior release and posterior fixation in the treatment of irreducible vertical atlantoaxial dislocation

English Keywords:Atlantoaxial joint  Dislocation  Basilar invagination  Endoscopy

English Abstract:

  【Abstract】 Objectives: To describe the effect of endoscopic transcervical anterior release and posterior fixation in treating patients with irreducible vertical atlantoaxial dislocation. Methods: Five consecutive patients with vertical atlantoaxial dislocation and upper cervical spinal cord compression underwent endoscopic transcervical anterior release and posterior fixation. The pathologies were rheumatoid arthritis(2 patients) and primary basilar invagination(3 patients). The McRae line was chosen to evaluate the reduction, the cervicomedullary angle(CMA) was measured to evaluate the degree of upper cervical spinal cord compression, and the JOA score and VAS were used to evaluate the pre- and post-operative neurological function. Results: All patients had an uneventful recovery with significant improvement in neurological function and radiographic parameters with an averange 25.8-month follow-up. No complications were seen. In all cases, anatomic reduction was achieved, the mean value of distance between odontoid process and the McRae was 5.79mm preoperatively(range: 5.02-7.02mm), and -3.18mm postoperatively(range: -9.89-1.53mm). The CMA was improved from average 127.2°(range: 105°-139°) to 152.8°(range: 141°-164°) averagely. The average preoperative and postoperative JOA score was 9.2(range: 7-12) and 15.3(range: 13-17) with an 80.5% overall improvement rate. The mean VAS improved from 5.4(preoperative, range: 4-7) to 1.6(postoperative, range: 1-2) in average. Conclusions: Endoscopic transcervical anterior release and posterior fixation appears to be a viable and interesting alternative for the treatment of vertical atlantoaxial dislocation in properly selected individuals.