Clinical-Radiographic Dissociation of Type II Odontoid Fracture with Complex Features: A Case Report

: Background Traumatic ground-level falls in older adults are a leading cause of emergency department visits, with a subset resulting in cervical spine injuries such as type II odontoid fractures. Although relatively uncommon, traumatic odontoid fractures are the most frequent cervical fractures in the elderly and carry significant risk due to atlantoaxial instability and potential for C2 posterior subluxation into the spinal cord. These injuries may present with minimal or absent neurological deficits, creating a dangerous clinical-radiographic dissociation that increase risk for spinal cord compression. Case Report An 80-year-old woman with osteoporosis presented after a mechanical ground-level fall with severe neck pain but no neurological deficits. Physical examination was largely unremarkable aside from midline cervical tenderness. CT imaging revealed a posteriorly displaced type II odontoid fracture with bilateral atlantoaxial rotatory subluxation and an associated anterior epidural hematoma causing mass effect at the cervicomedullary junction. MRI confirmed ligamentous injury and prevertebral hematoma. Despite cervical immobilization, the patient developed acute right upper extremity weakness after three days inpatient. Repeat imaging demonstrated worsening subluxation and spinal canal compromise, necessitating emergent surgical decompression and fusion. Why should an emergency physician be aware of this? Elderly patients presenting with neck pain and a normal neurological exam after a traumatic fall require acute stabilization given the risk of occult cervical spine injuries. Early CT imaging is essential for diagnosis, while MRI and CT angiography can identify associated soft tissue and vascular injuries. Clinical deterioration may occur rapidly, even with immobilization, making repeat imaging critical when new symptoms arise. Prompt recognition and neurosurgical consultation are vital to prevent severe complications, including quadriplegia and respiratory failure.