Clinical analysis of posterior lamina internal fixation for the treatment of atlantoaxial dislocation with craniovertebral junction region malformation

Abstract

Objective To study the efficacy of posterior lamina internal fixation for the treatment of atlantoaxial dislocation with craniovertebral junction region malformation. Methods In April 2010 to November 2011, 12 patients suffered from atlantoaxial dislocation complicated with craniovertebral junction region malformation were treated at our department. All patients underwent posterior decompressed reduction and screw ⁃ titanium rod (plate) system internal fixation. CT thin layer scanning and 3D CT reconstruction were performed. Pre⁃ and post⁃operative atlanto⁃dental interval (ADI), Chamberlain's line (CL) distance and McRae's line (ML) distance were measured. The degree of spinal cord compression was evaluated by cervicomedullary angle (CMA). Japanese Orthopaedic Association (JOA) score was used to assess the improvement of cervical medullary function. Electroneurophysiology was applied to detect nerve conduction function. Clinical effect of this surgical procedure was analysed. Results All patients were followed up for 4-20 months (mean 13 months). The differences of preoperative and postoperative ADI [(4.42 ± 2.91) mm vs (2.96 ± 2.08) mm], CL [(10.31 ± 3.80) mm vs (7.16 ± 3.19) mm], ML [(3.24 ± 2.92) mm vs (0.29 ± 2.36) mm], CMA [(127.83 ± 8.75)° vs (134.10 ± 8.38)°] and JOA [(9.75 ± 2.59) scores vs (14.83 ± 2.94) scores] were all statistically significant. In electroneurophysiological examination, preoperative waveform was abnormal in 10 cases, while 7 cases recovered to normal. Imaging examination showed bony fusion at bone grafting area, and no abnormal appearances after internal fixation. In follow⁃up period no complication occurred. Conclusion Posterior lamina internal fixation for the treatment of craniovertebral junction region malformation with atlantoaxial dislocation is safe, feasible and effective. DOI：10.3969/j.issn.1672⁃6731.2012.04.014