{'fraction_non_alphanumeric': 0.02055137844611529, 'fraction_numerical': 0.0015037593984962407, 'mean_word_length': 5.030211480362538, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Post-traumatic Spinal Hygroma Causing Cord Compression in type III Odontoid fracture with Vertical Atlanto-Axial 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 etio-pathogenesis 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.


METHOD
We present a case of a young adult who sustained a traumatic vertical atlanto-axial dislocation associated with a type III odontoid fracture. He was initially scored C6 ASIA D. MRI demonstrated cord contusion at the cranio-cervical junction and a small fluid collection anterior to the cervical cord. On day 5 following 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 atlanto-axial injury was reduced and fixed with posterior instrumentation.


RESULTS
At one year from the injury the patient was independent and fully ambulant. MRI and CT images of his spine demonstrated complete resolution of the cervical hygroma, appropriate placement of the cervical-pleural shunt and stability of the atlanto-axial injury.


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


LEVEL OF EVIDENCE
5.