A preclinical and clinical study of ankle arthrography for chronic ankle instability was performed. In the first study, ankle arthrograms were done on 50 cadaver ankles to demonstrate the limits of the normal ankle joint, and it was demonstrated that contrast in tendon sheaths is not a sign of a torn ankle ligament. The second study consisted of investigating ten cases of chronic ankle instability utilizing ankle arthrography. It was concluded that ankle arthrography is helpful in diagnosing torn ankle ligaments if all remaining investigative procedures are negative. A positive ankle arthrogram is proof that a torn capsule and ligament has occurred. However, in this small series a negative arthrogram and a normal talar tilt was still associated with a torn ligament of the ankle.