A Modification Of Elson's Test For The Diagnosis Of An Acute Extensor Central Slip Injury

Abstract

When testing for an extensor tendon central slip lesion at the proximal interphalangeal (PIP) joint, it is proposed that the affected finger should be compared with the non-injured finger of the other hand. In this modified Elson's test, the injured finger is flexed at about 90° in the PIP joint and pushed against the dorsal side of the midphalanx of the same finger of the non-injured hand. Once in this position, the patient is asked to extend the distal interphalangeal (DIP) joints. The finger with a central slip lesion will be able to extend the distal phalanx more than the non-injured distal phalanx. The difference between the extension at the DIP joint of the injured and non-injured hand is easily observed. Asymmetrical position of the two distal phalanges in an effort to extend the distal phalanges suggests that the central slip is not in continuity. If the two fingers remain in a symmetrical position when trying to extend the distal phalanges, a central slip lesion is highly unlikely.