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