Traumatic pneumorrhachis is the presence of air in the spinal canal, as visualized in a CT or MRI.
Synonyms: aeroarrachy, spinal emphysema, pneumomyelon, spinal pneumatosis, intraspinal air)
Key finding: localized or generalized air in the spinal canal, most often epidural
Risk factors:
(1) penetrating trauma (including iatrogenic)
(2) serial rib fractures
(3) pneumothorax
(4) vertebral body fracture
(5) pelvic ring fracture
(6) skull fracture with pneumocephalus
(7) sudden increase in intra-thoracic pressure
(8) air embolism into mediastinal veins
Typically, the patient is asymptomatic with the finding seen incidentally on imaging studies. In most cases the air is gone within a few days.
Rarely a patient may develop spondylodiscitis at the same level weeks or months later. If the patient has signs of systemic infection, then prophylactic antibiotics may be given.
If air is seen in the subdural space, then the skull should be scanned for evidence of a skull fracture.
Differential diagnosis:
(1) spontaneous pneumorrhachis
(2) paraspinal infection with gas-forming bacteria
