Does Radiographic Union Matter? Clinical Outcomes After Anterior Odontoid Screw Fixation in Elderly Patients

Type II odontoid fractures in elderly patients are associated with high rates of nonunion and substantial morbidity. However, the clinical relevance of radiographic nonunion following anterior odontoid screw fixation remains unclear. This study aimed to evaluate long-term functional outcomes and health-related quality of life, with particular focus on the impact of fracture healing.

This retrospective single-center study included 82 patients (mean age 75.7 years) treated with anterior odontoid screw fixation between 2011 and 2019. Radiographic union was assessed using postoperative imaging. Patient-reported outcome measures (PROMs), including Visual Analog Scale (VAS), Neck Disability Index (NDI), EQ-5D-5L, and SF-36, were obtained at long-term follow-up. Outcomes were compared between patients with and without radiographic union.

Radiographic nonunion was observed in 44% of patients. A total of 27 patients completed follow-up assessments. Overall outcomes were favorable, with low pain levels (mean VAS score of 2), minimal disability (NDI mean 7), and good quality of life (EQ-5D-5L mean 0.79). Patients with nonunion demonstrated consistently worse PROMs; however, differences did not reach statistical significance. A significant difference was observed in the EQ-5D-5L anxiety/depression domain (p=0.018), indicating increased psychological burden in the nonunion group.

Anterior odontoid screw fixation provides satisfactory long-term clinical outcomes in elderly patients with type II odontoid fractures. Despite a high rate of radiographic nonunion, functional outcomes and quality of life were not significantly impaired. These findings suggest that mechanical stability may be more clinically relevant than complete osseous union. Larger prospective studies are required to confirm these results.