- Discussion:
    - refers to impingement of the ulnar head against the carpi which can lead to TFCC tears and lunotriquetral ligament attrition;
    - lunotriquetral ligament attrition may occur from compression and translation shear as the lunate becomes impinged against the ulnar head;
    - causes:
           - distal radius frx w/ radial shortening (positive ulnar varience:);
           - radial head excision
           - Essex Lopresti frx
           - Galeazzi frx

- Clinical Features:
    - patients may note ulnar sided pain and swelling;

- Radiographs:
    - evaluated w/ pronated - clenched fist PA;
           - look for sclerotic changes in lunate and ulnar head;

- Treatment:
    - when ulnocarpal impaction occurs following frx either opening wedge radial osteotomy or ulnar shortening procedure is required;
           - consider an oblique ulnar shaft osteotomy if joint incongruenty is present;
           - consider resection arthroplasty strategy (Bower's or Darrach) if there is DJD in the DURJ;
    - note: TFFC tear may also occur (and can mimic ulnocarpal impaction)

The ulnar impaction syndrome: follow up note of ulnar shortening osteotomy.

Precision oblique osteotomy for shortening of the ulna.

Pre-osteotomy plate application technique for ulnar shortening.