Ulnar Styloid Process Frx

- Anatomy:
     - Tunnel V:
          - overlies distal ends of radioulnar articulation on dorsum of wrist, contains EDM;
    - Tunnel VI:
          - in groove between the apex of ulnar styloid process & ulnar head, contains ECU tendon which is palpable from where it passes
                   over ulnar styloid process to its insertion into the side of 5th metacarpal base;

- Exam:
    - ulnar styloid process: on the distal tip of the ulnar styloid process, you should feel small, shallow dorsal groove running longitundinally;
    - ECU tendon runs thru this groove;
    - it is most easily palpated when hand is radiallly deviated & tendon is contracted;
    - ECU is more palpable when wrist is extended & ulnarly deviated;
    - tenderness in area of ulnar styloid process may be due to either pathology w/ in process itself or to a colles frx w/ assoc frx of the
              distal end of ulnar styloid process;

- Management of Frx:
    - frxs of ulnar styloid process are assoc w/ frxs of distal radius and TFCC tears;
    - avulsion frx:
          - frxs involving lesser portions of ulnar styloid do not seen to be associated w/ significant instability of distal radioulnar joint;
          - w/ minimally displaced frx involves ulnar styloid, place upper extremity in long arm posterior splint in mid supination for 3-4 weeks;
          - supination is the normal anatomic position of the forearm and reduces subluxation of the ulnar head;
    - base frx:
          - ulnar styloid fractures at its base disrupt the major stabilizing ligaments of the distal ulna and TFCC and may lead to instability
                   of the distal RU joint;
          - see RU joint instability;
          - closed reduction and pinning: fixation is achieved with 0.035 inch K wire or with use of a cannulated screw;
          - open reduction:
                   - a displaced ulnar styloid frx which occurs along w/ a unstable distal radius frx, should be considered for ORIF;
                   - surgical approach: incision is made between the ECU and the FCU;
                   - consider intra-osseous wiring or a tension band construct

Triangular Fibrocartilage Complex Tears Associated With Symptomatic Ulnar Styloid Nonunions 

Repair of the triangular ligament in Colles' fracture. No effect in a prospective randomized study.

Effect of an Unrepaired Fracture of the Ulnar Styloid Base on Outcome After Plate-and-Screw Fixation of a Distal Radial Fracture

Comparison of united and nonunited fractures of the ulnar styloid following volar-plate fixation of distal radius fractures.

The Effects of Ulnar Styloid Fractures on Patients Sustaining Distal Radius Fractures

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Tuesday, January 27, 2015 10:37 am