Post-traumatic spinal hygroma causing cord compression in type III odontoid fracture with vertical atlantoaxial instability

STUDY DESIGN: Case report.

OBJECTIVE: To report the first case in the literature of a traumatic cervical spine subdural cerebrospinal fluid (CSF) collection (hygroma) under tension causing cord compression. We suggest etiopathogenesis and modality of treatment.

SUMMARY OF BACKGROUND DATA: Hygromas are subdural cranial CSF collection. A literature review showed no previous published case of post-traumatic spinal hygroma. This was a potential life-threatening sequelae of a high cervical injury that warranted early diagnosis and emergency treatment.

METHODS: We present a case of a young adult who sustained a traumatic vertical atlantoaxial dislocation associated with a type III odontoid fracture. He was initially scored C6 ASIA D. Magnetic resonance imaging (MRI) demonstrated cord contusion at the craniocervical junction and a small fluid collection anterior to the cervical cord. On day 5 after his injury he developed complete paraplegia and priapism. An urgent MRI of his spine revealed expansion of the intraspinal fluid collection with distortion of the cord. He was treated with an emergency surgical decompression. The cervical fluid collection was found to be subdural extra-arachnoidal CSF. A subdural-pleural shunt was inserted. The atlantoaxial injury was reduced and fixed with posterior instrumentation.

RESULTS: At 1 year from the injury the patient was independent and fully ambulant. MRI and computed tomography images of his spine demonstrated complete resolution of the cervical hygroma, appropriate placement of the cervical-pleural shunt, and stability of the atlantoaxial injury.

CONCLUSION: We describe a unique case of post-traumatic spinal hygroma causing cord compression in a patient with an unstable craniocervical injury. The early recognition and correction of this dangerous complication is of paramount importance to savage cord function.

LEVEL OF EVIDENCE: 5.