Preliminary clinical application of anterior anatomical reduction plate fixation for atlantoaxial dislocation

Abstract

Objective To evaluate the preliminary clinical effect of anterior anatomical reduction plate fixation on the treatment of atlantoaxial dislocation. Methods A retrospective case series study was conducted to analyze the 13 patients with atlantoaxial dislocation admitted to the second affiliated hospital of Xi'an Jiaotong University from January 2016 to December 2017. There were eight males and five females, aged 20-57 years, with an average age of 42 years. All patients received transoropharyngeal reconstruction and atlantoaxial anterior anatomical reduction plate fixation, 12 of which underwent the surgery for the first time but one had the revision surgery. The operation time and intraoperative bleeding were recorded. The angle of the clivus axis was measured, and the reduction of the atlantoaxial spine and the fusion of bone graft were observed. The neurological function was evaluated by Japanese Orthopedic Association (JOA) score and the improvement rate of spinal cord function was calculated. The complications were also recorded. Results All patients were followed up for 10-30 months [(14.2±5.0)months]. The operation time was 150-285 minutes [(216.8±36.7)minutes]. The intraoperative blood loss was 50-130 ml [(80.5±19.7)ml]. The slope axis angle was (113.2±9.1)° before operation and (145.8±6.7)° after operation, with an average increase of 32.6° (P<0.01). Anatomical reduction was obtained in nine patients, and partial reduction in four patients. At the last follow-up, the atlantoaxial fusion was obtained in all patients, and the healing time was (4.6±1.1)months. Postoperative neurological symptoms were improved compared with those before operation. The JOA score was improved from preoperative (8.7±1.7)points to postoperative (14.3±1.2)points, with an average increase of 5.6 points (P<0.01). The average improvement rate of spinal cord function was 69%. Except for one patient with cerebrospinal fluid leakage, there were no complications such as spinal cord, nerve, blood vessel injury or wound infection after operation. Conclusions Anterior atlantoaxial anatomical reduction plate fixation can effectively restore the dislocated atlantoaxial joint, restore slope axis angle, improve bone fusion rate, and improve nerve function. It can be used as an alternative or supplement to posterior fixation. Key words: Atlas; Axis; Dislocations; Internal fixators; Anatomical plate