The intravertebral vacuum phenomenon ("vertebral osteonecrosis"). Migration of intradiscal gas in a fractured vertebral body?

Study Design: Retrospective cohort.

Objectives: To compare the prevalence of the association between contiguous intervertebral disc and vertebral collapses with or without an intravertebral vacuum phenomenon.

Summary Of Background Data: The mechanism of occasional gas accumulation within some vertebral collapses is poorly known.

Bone mineral density in patients given oral vitamin K antagonists.

Background: Divergent results have been obtained in studies of bone mineral density in patients under oral vitamin K antagonists.

Objective: To gather prospective data on bone mineral density and bone metabolism in 70 aortic valve replacement patients.

Study Design: 49 patients who had been under oral vitamin K antagonists for at least one year after implantation of a mechanical aortic valve were compared with 21 recipients of a tissue aortic valve that did not require anticoagulant therapy.