Posterior Fixation with C1 Lateral Mass Screws and C2 Pars Screws for Type II Odontoid Fracture in the Elderly: Long-Term Follow-Up

OBJECTIVE: We sought to evaluate the long-term C1-C2 fusion rates, fracture healing, and functional outcomes in geriatric patients with type II odontoid fracture treated with posterior fixation with polyaxial C1 lateral mass screws and C2 pars screws. METHODS: Twenty-one consecutive patients between 2005 and 2011 with Anderson and D'Alonzo type II odontoid fracture underwent a posterior atlantoaxial fixation with polyaxial C1 lateral mass screws and C2 pars screws. A long-term clinical and radiologic follow-up was achieved in all patients with a mean follow-up period of 53.28 +/- 15.41 months (range 38 - 91 months). RESULTS: All 21 patients had bilateral C1 lateral mass screws and bilateral C2 pars screws. Correct positioning of the C1 lateral mass screws and C2 pars screws was observed in all 42 placements by postoperative computed tomography scans. No vascular or neurologic complication was noted. At the last follow-up, 20 patients (95.24%) had a solid fusion (defined as Lenke fusion grade A or B) while 1 patient (4.76%) had a partial fusion (Lenke fusion grade C). Overall, no hardware failures occurred in any patient. Odontoid fracture healing was achieved in 18 patients out of 21 (85.71%). The mean postoperative Neck Disability Index score was 12.73%, and neck motion was within normal physiologic limits at 12 months. CONCLUSIONS: This study adds to the evidence that posterior atlantoaxial fixation with polyaxial C1 lateral mass screws and C2 pars screws is a safe and effective surgical option in the treatment of odontoid fractures including long-term stability.