Symptomatic gas-containing disc herniation. Report of four cases.

Intradiscal gas collection, causing the radiographic vacuum phenomenon, is a common finding on radiographic studies of the lumbar spine. Four cases of radiographically documented and surgically confirmed cases of herniated discs containing gas are presented. All four patients presented with radicular symptoms secondary to the gas-containing herniations. Minimal nuclear material was found at surgery; however, all patients experienced relief after the operation.