Cover Image

On the Cover: Upon first entering the hip joint during arthroscopy, tiny air bubbles are often observed adhering to and defining areas of mild to moderate chondromalacia on the acetabular joint surface. When chondromalacia is not present these bubbles of air coalesce into one large pocket that rises to the dependent surface. The exact reason for the adherence is unclear, but the “bubble sign” helps to identify areas of chondral pathology along the joint surface during hip arthroscopy. Courtesy of Allston J. Stubbs, M.D., and John S. Shields, M.D.