Traumatic pneumorrhachis: systematic review and an illustrative case

Pneumorrhachis (PR) refers to free air in the spinal canal. We aim to describe a case report and conduct a systematic review focused on the clinical presentation, diagnosis, and management of traumatic PR. We conducted a language-restricted PubMed, SciELO, Scopus, and Ovid database search for traumatic PR cases published till June 2019. Categorical variables were assessed by Fisher's exact test. In addition to our reported index case, there were 82 articles (96 individual cases) eligible for meta-analysis according to our inclusion/exclusion criteria. Eighty per cent of patients had blunt trauma, while 17% had penetrating injuries. Thirty-four per cent of cases were extradural PR, 21% intradural PR, and unreported PR type in 43%. Nine per cent of patients presented with symptoms directly attributed to PR: sensory radiculopathy (2%), motor radiculopathy (1%), and myelopathy (6%). CT had a 100% sensitivity for diagnosing PR, MRI 60%, and plain radiograph 48%. Concurrent injuries reported include pneumocephalus (42%), pneumothorax (36%), spine fracture (27%), skull fracture (27%), pneumomediastinum (24%), and cerebrospinal fluid leak (14%). PR was managed conservatively in every case, with spontaneous resolution in 96% on follow-up (median = 10 days). Prophylactic antibiotics for meningitis were given in 13% PR cases, but there was no association with the incidence of meningitis (overall incidence: 3%; prophylaxis group (0%) vs non-prophylaxis group (4%) (p = 1)). Occasionally, traumatic PR may present with radiculopathy or myelopathy. Traumatic PR is almost always associated with further air distributions and/or underlying injuries. There is insufficient evidence to support the use of prophylactic antibiotic in preventing meningitis in traumatic PR patients.