Wrist XRay

Aka: Wrist XRay, Wrist Imaging, Radial Inclination, Radial Height, Volar Tilt

1. Imaging: Views
   1. Standard
      1. Anterior-Posterior XRay (or Posterior-Anterior XRay)
         1. True AP View needed to isolate the two rows of Carpal Bones (oblique view obscures Fractures)
         2. Evaluate for Scaphoid Fracture, Scapholunate Dissociation and other Carpal BoneFractures
      2. Lateral XRay
         1. True lateral xray is needed to assess Lunate-Capitate alignment
         2. Check alignment: Radius, Lunate/Scaphoid, Capitate
            1. Perilunate Dislocation
            2. Lunate Dislocation
   2. Special
      1. Scaphoid Fracture suspected
         1. Scaphoid View
      2. Pisiform Fracture or hook of hamate Fracture suspected
         1. Carpal Tunnel view
         2. Supinated oblique view
      3. Scapholunate Dissociation
         1. Clenched-fist view
         2. Supinated wrist with ulnar deviation
2. Imaging: Other imaging modalities
   1. Wrist Ultrasound
      1. Evaluates soft tissue (tendon, synovium)
      2. Variable efficacy based on operator
   2. Bone scan
      1. Finds occult Fractures (Scaphoid), Stress Fractures
      2. Highly sensitive but not specific for Fracture
   3. Wrist CT Scan
      1. Identifies Fractures and articular subluxations
   4. Wrist MRI
      1. Identifies Fractures and soft tissue injuries
      2. Expensive, but most sensitive and specific study
3. Evaluation: Interpretation
   1. Post-Reduction Wrist XRay confirms normal radius length
   2. Images
      1. 
      2. 
   3. AP View
      1. Landmarks on AP View at distal radius
         1. Distal line (line 1)
            1. Draw a horizontal line at the level of the radial styloid at the distal radius (point A)
            2. Represents the distal most point of the radial articular surface
         2. Proximal line (line 2)
            1. Draw a horizontal line at the level of the ulnar articulation of the medial distal radius (point B)
            2. Represents the distal most point of the radial-ulnar articular surface
            3. Radial length (Radial Height) represents the distance between distal line 1 and proximal line 2
         3. Articular plane (line 3)
            1. Draw a line between the points A and B above (between ulnar aspect of radius and ulnar styloid)
            2. Radial Inclination represents the angle between Line 1 (proximal transverse) and this oblique Line 3
      2. Normal anatomic relationships
         1. Radial Inclination (normal measurements are for adults)
            1. Angle formed between the articular plane and the proximal line (see above)
            2. Normal Radial Inclination: 23.6 +/- 2.5 degrees
            3. Acceptable inclination: 13-30 degrees
         2. Radial Height (radial length) shortening (normal measurements are for adults)
            1. Distance between the proximal and distal lines (see above)
            2. Normal Radial Height: 11-12 mm
            3. Acceptable Radial Height: 8-18 mm
   4. Lateral View
      1. Landmarks on Lateral View at distal radius
         1. Distal dorsal rim
            1. Point on the distal radius at the dorsal aspect
         2. Distal volar rim
            1. Point on the distal radius at the volar aspect
         3. Vertical line at distal radius
            1. Perpendicular to the long axis of the radius
         4. Volar Tilt Line
            1. Line drawn between distal dorsal rim and distal volar rim
      2. Normal anatomic relationships
         1. Volar Tilt angle: 11.2 +/- 4.6 degrees
            1. Angle formed between Volar Tilt line and vertical line at distal radius
         2. Radius articular surface directed down, forward, in
         3. Appearance of tea cup and saucer
4. References
   1. Medoff (2005) Hand Clin 21(3): 279-88 [PubMed]