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50 Cards in this Set
- Front
- Back
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technical goals
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articular congruity
radial alignment and length motion (functional) stability |
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which ligaments are stronger
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volar
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primary stabilizer of DRUJ
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TFCC
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TFCC attachments
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ulnar aspect of lunate facet distal radius
base of ulnar styloid blend into dorsal and volar radioulnar ligaments |
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columns of wrist
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lateral
intermediate medial (ulnar) |
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lateral (radial) column
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radial styloid
scaphoid facet |
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radial styloid importance
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important stabilizer:
bony buttress attachments for extrinsic carpal ligaments |
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intermediate column
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lunate facet
sigmoid notch |
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primary load bearing column
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intermediate
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medial (ulnar) column
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distal ulna
TFCC radio-ulnar ligaments |
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importance of ulnar column
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restore normal rotation of forearm
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oblique xray
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~10-15 degree oblique to capture lunate facet and remove overlap of radial styloid
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PA xray
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shoulder abducted to 90
elbow flexed to 90 forearm and palm flat on cassette wrist in neutral flexion with neutral radioulnar deviation |
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good PA?
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can see:
groove of ECU, sigmoid notch |
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how to measure radial inclination
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angle formed by line drawn from tip of radial styloid to ulnar corner of lunate facet and line drawn perpendicular to longitudinal axis of radius
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normal radial inclination
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22-33 degrees
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why is loss of radial inclination bad?
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carpus shifts ulnarly
increases load on TFCC and ulna correlated with decreased wrist strength |
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how to measure radial height
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first line intersects tip of radial styloid
second line intersects distal articular surface of ulnar head distance between in call radial length/height |
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normal radial height
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11-12 mm
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why is loss of radial height bad?
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ulnar variance
ulnar impaction syndrome instability loss of pronation, supination, strength |
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measurement most highly correlated with significant changes in kinematics
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radial shortening
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how to measure ulnar variance
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distance between distal ulnar articular surface and ulnar aspect of distal radius articular surface
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normal ulnar variance
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0.75 mm
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negative ulnar variance associated with
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Kienbock's
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positive ulnar variance associated with
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schapholunate instability
ulnar impaction syndrome tears of TFCC |
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how to measure scapholunate interval
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on PA
midportion of the articulation |
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normal scapholunate interval
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3 mm
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Terry Thomas sign
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clenched PA radiograph
when scapholunate interval is >2-3 mm compared to contralateral |
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assessment of Gilula's lines
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3 lines
should be smooth lines |
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adequate lateral
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pisiform sits between distal pole of scaphoid (volar) and volar aspect of capitate (dorsally)
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how to take a lateral xray
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shoulder at patient's side 0 degrees abduction
elbow flexed to 90 wrist in neutral |
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normal tilt
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11-12 palmar tilt
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how to measure scapholunate angle
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angle between axis of scaphoid and axis of lunate
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normal scapholunate angle
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30-70 degrees
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signs of DRUJ disruption
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radial shortening >5 mm on PA
DRUJ widening on PA dorsal ulnar subluxation on lat ulnar styloid base fracture |
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how to measure AP distance
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on facet lateral view
distance between distal apex of dorsal and volar rims of lunate facet |
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normal AP distance
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20 mm males
18 mm females |
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abnormal AP distance indicates
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impaction
articular split |
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what is teardrop
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volar projection of lunate facet of distal radius
serves as mechanical buttress to prevent subluxation of lunate |
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how to measure teardrop angle
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one line drawn tangent to subchondral bone of articular surface through tip of teardrop
second line down longitudinal axis of radius |
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normal teardrop angle
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70 degrees
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acceptable reduction parameters
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radial inclination: <5 degree loss
radial height: within 2-3 mm of contralateral palmar tilt: 0-10 degrees dorsal AP distance: ~20 mm males, ~18 mm females teardrop angle: ~70 degrees articular stepoff: <2 mm |
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Chauffer's fracture
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shear fracture with displacement of carpus and avulsion of attached radial styloid
notorious for concomitant injuries to intercarpal and extrinsic radiocarpal ligaments |
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Colles fracture
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dorsal comminution
dorsal angulation dorsal displacement radial shortening associated ulnar styloid initially defined as extraarticular |
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Smith's fracture
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any volar angulation fracture
reverse Colles |
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Barton's fracture
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displaced, unstable, articular fracture
subluxation of distal radius with displacement of carpus with articular fragment may be dorsal or volar |
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Frykman classification
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I: extraarticular
II: I + ulna fracture III: intraarticular involving radiocarpal joint IV: III + ulna fracture V: intraarticular involving DRUJ VI: V + ulna fracture VII: intraarticular involving radiocarpal joint and DRUJ VIII: VII + ulna fracture |
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Melone classification basis
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based on fracture fragments:
radial styloid volar medial dorsal medial radial shaft |
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Melone classification
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I: stable without comminution
II: unstable die-punch, dorsal or volar IIa: reducible IIb: irreducible III: spike fracture, conused volar structures IV: split fracture, medial complex fracture with dorsal and palmar fragments displaced separately V: explosion fracture, severe comminution with major soft tissue injury |
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Fernandez classification
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mechanism based
I: metaphyseal bending II: shearing fracture III: compression without characteristic fragmentation IV: avulsion fracture or radiocarpal fracture dislocation V: combined injury with significant soft tissue involvement, high energy |
