Anterior C2–3 fusion with internal fixation for unstable teardrop fracture of the axis: a retrospective cohort study

BACKGROUND: Teardrop fracture of the axis (TDFA) is rare in cervical injuries. The treatment for TDFA is controversial, and few prior studies exist. C2–3 fusion with internal fixation could provide anterior support and ensure immediate stability. The aim of this study was to evaluate the clinical outcome of anterior C2–3 fusion with internal fixation for unstable TDFA. METHODS: Fifteen patients with unstable TDFA were treated by anterior C2–3 fusion with internal fixation between October 2012 and June 2018. Radiological parameters, including the avulsed ratio of the inferior endplate of the axis, the average rotation angle, and the displacement of the avulsed fragment, were measured before the operation. Clinical parameters, including the visual analogue scale (VAS) and the Neck Disability Index (NDI), were assessed before the operation; 3 days, 1 month, and 3 months after the operation; and at the final follow-up. Perioperative complications were also recorded. RESULTS: The mean follow-up time was 42.4 months (24–60 months). The mean operation time was 81.0 minutes (62–104 minutes), and the intraoperative blood loss was 61.3 mL (30–100 mL). Two patients complained of mild dysphagia after the operation and recovered at postoperative 1 month. Two patients classified as American Spinal Injury Association (ASIA) impairment scale grade D both improved to ASIA grade E postoperatively. The VAS score decreased from a preoperative value of 8.2±1.2 to a postoperative value of 1.7±0.9 (P<0.001), and maintained at 1.5±0.6 at last follow-up (P=0.51). The NDI score decreased from a preoperative value of 79.3±14.1 to a postoperative value of 16.5±4.3 (P<0.001), and maintained at 17.1±4.6 at last follow-up (P=0.62). No loosening or rupture of implantation was observed during the follow-up period. Bony union and fusion were achieved in all patients. CONCLUSIONS: The clinical and radiological outcomes of anterior C2–3 fusion with internal fixation for the treatment of unstable TDFA were satisfactory. Anterior C2–3 fusion with internal fixation could be considered as a safe and effective method for managing TDFA.