The Regan “shuck” test is used to test for wrist instability in someone complaining of pain along the ulnar border (little finger side) of the wrist. The examiner moves the lunate wrist bone up and down while moving the rest of the wrist in the opposite direction.
To do this, place your thumb and index finger of one hand on the triquetrum and pisiform bones located at the distal end (bottom) of the ulna bone at the wrist. Now use the thumb and index finger of the other hand on either side of the lunate (in the middle of the wrist) between the triquetrum and the scaphoid bones.
By moving your two hands in opposite directions, you are creating stress across the lunotriquetral (LT) joint. Any excess motion here may be an indication of instability from injury and damage to the lunotriquetral ligament holding these bones together.
This test is considered a “provocative” maneuver because it will reproduce the patient’s painful symptoms when there is a problem at the LT joint. The diagnosis is usually made based on the patient’s history, clinical presentation, results of special tests like the Regan shuck test, and imaging studies.
Magnetic resonance arthrography (MRA)may provide the most accurate information. MRA involves injection of a dye into the joint(s) to look for any place where the dye leaks out (a sign of ligamentous tear). MRI, multidetector CT, and ultrasound are also available for some situations.