The Long-term Clinical Outcomes of Magerl's Technique Combined with Single Laminar Clamp Internal Fixation in Treatment of Reducible Atlantoaxial Dislocation

Abstract Background. To evaluate the long⁃term clinical outcomes of Magerl's technique combined with single laminar clamp internal fixation in treatment of reducible atlantoaxial dislocation. Methods. Data of 21 patients diagnosed with reducible atlantoaxial dislocation underwent Magerl’s technique(C1-2 posterior transarticular screw fixation) combined with single laminar clamp internal fixation and fusion were retrospectively reviewed from January 2004 to September 2015.The clinical and radiological outcomes were investigated according to the Symonand Lavender clinical standard, the score of Japanese Orthopaedic Association (JOA), and the imaging index space available for the cord (SAC), the atlas⁃dens interval (ADI), respectively. The perioperative complications, operative data, and status of bony fusion were also collected and analyzed. Results. All the patients were followed up successfully. All the patients achieved substantially bone fusion according to the X-ray and CT scan. There were no intra-operative complications observed. The ADI was corrected significantly with the mean preoperative 6.13±1.84 mm, initial postoperative 1.62±0.77 mm, and the final follow-up 2.02±1.01 mm respectively(P<0.05).The SAC was also improved significantly with the mean preoperative 10.42±2.53 mm, initial postoperative 17.83±2.41 mm, and the final follow-up 16.91±2.02 mm respectively (P<0.05).The clinical recovery rate according to the Symonand Lavender clinical standard and the JOA recovery rate was 90.5% and 81.2% respectively, which showed significantly improved following surgery (P<0.05). Conclusions. This study demonstrates that Magerl’s technique combined with single laminar clamp internal fixation is effective and reliable in management of reducible atlantoaxial dislocation, which can simplify the operative manipulation and decrease the risk of iatrogenic spinal cord injury.