distal radioulnar joint

1. Wrist
Distal Radioulnar Joint
Dr/Mohamed Mattar
MBBH,Msc,MD
Lecturer of Radiology
Al-Azhar University

2. Wrist
Distal Radioulnar
Joint
DR/MOHAMED MATTAR
MBBH,MSC,MD
ALAZHAR UNIVERSITY HOSPITAL

3. DRUJ Stability
 Bony articulation
- sigmoid notch of radius
about 20% of the overall stability.
 soft tissues
- TFCC and others about 80% of stability

4. Bony anatomy of DRUJ
- It is a pivot joint
Sigmoid notch
 Allows radius to rotate at the convex surface of ulna which remains fixed.
Ulnar head
 Slide dorsally in pronatation and vollary in supination.
DRUJ
 8-9 mm of dorsal palmar translate when external force applied.

5. Sigmoid notch
variants
 Flat face about 40%
more liable to instability
 Ski-slope.
 C type
 S type

6. Ligamentous anatomy (volar aspect)
 Primary stabilizer
 TFC disc proper
 Volar radioulnar ligament
 Meniscal homologue
 UCL
 Extrinsic ligaments
 Volar UT and UL.
 UCL.

7. Ligamentous
anatomy(dors
al aspect)
Primary stabilizer
 TFC disc proper
 Volar radioulnar
ligament
 UCL
 ECU tendon sheath
 Meniscal homologue

8. Biomechanics
 Misnormer ulna rotates
around the distal radius.
 Ulna remains fixed.
 Distal radius rotates around it.
 Supination shortens the ulna
to radius.
 Pronation lengthens ulna to
radius

9. Assessment of DRUJ
Normal arc of rotation
 Ranges form 150 to 180 degree.
Ulnar head slides
 Supination: volary
 Pronation : dorsally
Ligaments
 Volar deep fibres of radioulnar
ligament prevent translation during
pronation
 Dorsal deep fibers prevent translation
during supination

10. Assessment of stability on CT.
 Mino method