267. One stage atlantoaxial pedicle screw fixation for unstable atlas burst fracture

Abstract

BACKGROUND CONTEXT Treatment of unstable atlas fracture is controversial. Some studies showed external fixation could achieve good clinical effect. Some showed internal fixation could get initial stability and perfect reduction. PURPOSE To assess the clinical results of one stage the posterior atlantoaxial pedicle screw fixation and fusion for unstable atlas burst fracture combined with atlantoaxial instability. STUDY DESIGN/SETTING A retrospective study. PATIENT SAMPLE Twenty-eight (9 females, 19 males) patients with an average age of 41.8 (22-59) years between May 2016 and December 2018 were studied. OUTCOME MEASURES The preoperative atlanto-dens interval (ADI) and lateral mass distance (LMD) were measured. All patients were assessed clinically for neurologic recovery, atlantoaxial reduction and bone graft fusion. METHODS Twenty-eight (9 females, 19 males) patients with an average age of 41.8 (range, 22-59) years between May 2010 and December2012 were studied. The patients had various degrees of occipital neck pain, limited mobility and associated with neurological dysfunction. Degree C in 1 case and degree D in 5 cases were assessed by the ASIA impairment scale. The preoperative atlanto-dens interval (ADI) and lateral mass distance (LMD) were measured. Patients were treated with posterior atlantoaxial pedicle screw fixation and fusion. All patients were assessed clinically for neurologic recovery, atlantoaxial reduction and bone graft fusion. RESULTS All 28 patients were followed up for an average of 15.6 months (range, 10-24 months). No intraoperative vertebral artery injury and spinal cord injury were noted. Postoperative cervical spine x-ray and CT showed that the sagittal cervical spine alignment was restored and no spinal cord compression was found. At last follow-up, solid bony fusion was achieved in all patients with no loosening, displacement, instability or breakage of the screws. All patients except 1 were substantially improved neurological status. At last follow-up the ADI and LMD were statistically significant difference between pre- and postoperation. CONCLUSIONS The posterior atlantoaxial pedicle screw instead of occipitocervical fusion for unstable atlas burst fracture combined with atlantoaxial instability seems to be effective, but it is technically demanding to place screw into the lateral mass of the atlas. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.