Complete remodelling of a displaced odontoid synchondrosis fracture managed conservatively: a case report

Odontoid synchondrosis fractures are the most common cervical fracture in young children, although their overall incidence is rare. Various strategies have been proposed in the management of injuries with significant displacement or angulation. In this report, we present the long-term functional and radiological outcomes following nonoperative treatment of such a fracture in a 5-year-old female. The patient was referred to our tertiary centre with radiological progression of angulation from 10° to 35° within 5 weeks of the injury, despite wearing a rigid collar. She had no neurological compromise. Although we examined the fracture under general anaesthetic, and subsequently applied halo traction, there was no effect on alignment. The halo device was removed after 11 days and a rigid collar was fitted again. The patient had no pain or neurological symptoms out of the collar at 12 weeks after injury (6 weeks after removal of halo), and a computed tomography scan at 15 weeks confirmed that the fracture had united in malalignment. However, serial radiographs and MRI subsequently have shown that the axis has remodelled completely. At 7 years follow-up, there has been no impact on the patient's functional range of movement or quality of life. This case highlights the preservation of the motion segment and the remarkable remodelling potential of the paediatric cervical spine.