TFCC Tears, Ulnar Variance, Ulnocarpal Abutment

Question 1

What position is ulnar variance assessed on radiographs?

Answer 1

measured in shoulder abducted 90deg, elbow flexed 90deg, forearm neutral, hand aligned with forearm axis

Question 2

What disease processes are a/w ulnar variance?

Answer 2

1) positive ulnar variance
-ulnar abutment syndrome
-SLD (scapholunate dissociation)
-TFCC tears
-arthrosis of ulnar head, lunate or triquetrum
-lunotriquetral ligament tears
- Madelung’s
- post traumatic (gymnasts)
2) negative ulnar variance
-Kienbock’s disease
-ulnar impingement syndrome
ulna impinges on the radius proximal to the sigmoid notch

Question 3

How does radial/ulna load change with ulnar variance?

Answer 3

Neutral- 80% radius, 20% ulna
Negative- 95% radius, 5% ulna
Positive- 60% radius, 40% ulna

Question 4

What is the differential for ulnar sided wrist pain?

Answer 4

1) DRUJ instability or arthritis
2) TFCC tear
3) LT ligament tear
4) pisotriquetral arthritis
5) ECU tendonitis or instability

Question 5

What treatment options are available for ulnar positive variance?

Answer 5

1) Ulnar shortening osteotomy (contraindicated in DRUJ arthrosis)
2) Wafer procedure (bone resected under TFCC)
3) Darrach procedure (ulnar head resection)
4) Sauve-Kapandji procedure (DRUJ fused and pseduoarthrosis in ulna)

Question 6

What is the most common mechanism for a TFCC tear?

Answer 6

most common is fall on extended wrist with forearm pronation

Question 7

What structures make up the TFCC?

Answer 7

1) dorsal and volar radioulnar ligaments
2) central articular disc
3) meniscus homolog
4) ulnar collateral ligament
5) ECU subsheath
6) origin of ulnolunate and ulnotriquetral ligaments

Question 8

What symptoms identify a TFCC tear?

Answer 8

1) Positive “fovea sign”- tenderness btw FCU and ulnar styloid
2) Pain with ulnar deviation and/or radial deviation
3) Pain with knob turning

Question 9

What general statements can be made about treatment of TFCC tears?

Answer 9

1) Initial non-op with immobilization, NSAIDs and injections
2) Type 1 (traumatic tears) arthroscopically managed
3) Central tears (1A) are debrided, peripheral tears (1B-D) repair
4) Traumatic tears- Ulnar osteotomy (ulnar variance >2mm) or Wafer (Ulnar variance less than 2mm)