Cases of snapping finger originating in tendovaginitis of extensor digiti quinti proprius tendon.

Snapping finger is frequently encountered in orthopeidic diagnosis a:r:d treatment, and frequently experienced as cases of minor surgical operation of the hand. Cases of snapping finger generally are broadly classified into infantile cases and adult cases by their operative findings. The former is caused by formation of tumor by the flexor pollicis longus tendon itself at the entrance of the tendon sheath at the MP joint and the latter is caused when tendovaginitis of flexor tendon developing in the thumb, middle finger or ring finger disturbs the gliding at the tendon sheath entrance. These are very regular conditions, and it would be no exaggeration to say it is not the custom to look for another cause when snapping of finger is observed clinically. However, very rare as it is, it is a fact also that snapping fingers exist which are not attributable to the above-described general causes. Their cause can be attributed to the structure of the PIP joint or to the extensor tendon and not to the flexor tendon. The authors recently experienced three cases of snapping of the little finger originating in tendovaginitis of the extensor digiti quinti proprius tendon, which they will