(Johner and Wruhs: Clin. Orthop. 178:7-25, 1983)
A1 A2 A3
simple frc butterfly fragment comminution
Class: A1 spiral A2 oblique A3 transverse
Activity: from skiing MVA/motorcycle soccer/MVA
Mechanism: torsion uneven bending pure bending
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B1 B2 B3
Class: B1 spiral frc wedge frag w/ many butterfly
w/ butterfly butterfly fragments
Activity: from skiing car bumper/Mcycle car bumper
Mechanism: torsion & bending + compression bending/compression
bending low speed high speed
Rx closed reduction/
long Cast
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C1 C2 C3
Class: spiral frc w/ seg. frc w/ cir- segmentally com-
many butterfly cumfirentially intact minuted w/o an
mid. segment intact mid segment
Activity: high speed ski car bumper MVA/war/industry
Mechanism: high speed 4 point bending crush/penetrating
torsion
