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Clenched Fist AP


- See:
      - PA View of the Wrist
      - X-ray findings: in scapholunate dislocation

- Discussion:
     - used to evaluate widening of scapholunate interval;
     - those pts suspected of having SLD should have compression stress view, which is performed by having pt clench his fist for AP film;
     - clenching first draws capitate proximally & emphasizes any widening of scapho-lunate interval;
     - should get companion views of the opposite side for comparison;
     - best taken: w/ supinated clenched fist view w/ wrist in ulnar deviation;
     - AP x-rays made w/ wrist in ulnar deviation (increases gap), in radial deviation (decreases gap), & w/ application of longitudinal compressive load (clenched fist) may also show widened scapholunate gap in wrist w/ SLD;

- Technique:
    - same technique as PA view of wrist except patient clenches fist as tightly as possible during exposure;
    - proper technique: for visualizing scapholunate interval;
          - gap is more noticeable on AP View that is made w/ wrist supinated than it is on more usual PA view (made w/ wrist pronated);

- Findings in Scapholunate Dissociation
     - scapholunate interval > 2-3 mm (Terry Thomas sign);
     - cortical ring sign:
            - produced by cortex of distal pole of palmar flexed scaphoid;
            - produced by cortical outline of the distal pole of scaphoid;
     - scaphoid is foreshortened;
            - distance between scaphoid ring & proximal pole is < 7 mm;
     - negative ulnar variance:
     - misc:
            - ulnar deviation, increases scapholunate gap;
            - radial deviation, closes gap

The “clenched pencil” view: A modified clenched fist scapholunate stress view