Arthrography as a method of diagnosing tear of the ulnar collateral ligament of the metacarpophalangeal joint of the thumb ("gamekeeper's thumb").

Arthrography of the metacarpo-phalangeal (MP) joint of the thumb was performed on 47 thumbs. The normal arthrographic appearance shows a closed joint space, whereas leakage of contrast material indicates tear of the joint capsule with or without an associated tear of a stabilizing ligament. Arthrographic demonstration of the heads of the adductor pollicis muscle was found to be specific for tear of the ulnar collateral ligament (UCL) of the MP joint, a tear which is commonly responsible for its instability. Arthrography is suggested as a safe and accurate diagnostic examination for the early detection of tears of the UCL of the MP joint.