Despite the publication of numerous studies, controversy regarding the non- operative treatment of type II dens fractures remains. The halo-thoracic vest (HTV) and cervical collar are the most commonly used devices. We sought to compare the outcomes of patients managed with these devices in terms of non-union risk factors and associated complication rates.

This study was a retrospective review of adult patients with type II dens fractures treated non-operatively at a level one trauma centre between 2001 and 2007. The patients were identified using a hospital trauma database. Each patient included in the study had a minimum follow up of six months. Patient medical records and imaging studies were reviewed. Union was defined as stable fibrous union or bony union, measured at three months. A p-value of < 0.05 was considered statistically significant.

Sixty-seven patients were included. Thirty-five patients were treated using a HTV and 32 with a collar. Non-union was found to be associated with increased time in HTV or collar (p = 0.011) and with a mechanism of injury involving a low fall (p = 0.008). In addition, the proportion of patients with stable union at three months was 60% for the HVT group versus 35% for the cervical collar group (p = 0.10). There were trends to support an increased risk of non-union with a patient age of greater than or equal to 65 years at the time of presentation (p = 0.13) as well as with a fracture displacement of greater than or equal to 2 mm at time of presentation (p = 0.17). Clinically significant complications of the HTV were of greater prevalence than those experienced by collar patients. Sixty percent of HTV patients suffered one or more complications compared with 6% of collar patients.

We were unable to demonstrate any clear advantage or disadvantage of either device. Further investigation of mortality would be beneficial, particularly in the patient group injured with a mechanism involving a low fall (which tends to include more elderly patients).