Cartilage control (IMAGE) Northwestern University Caption Control cartilage (stained with safranin) shown with a defect on the upper left side of the image. Credit Samuel I. Stupp/Northwestern University Usage Restrictions add credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.