- Unstable Frx Patterns:
    - Barton's frx, Radial-styloid frx, and Smith's frx, will often be unstable;
    - dorsal angulation: > initial 20 deg implies instability;
    - radial shortening of 5 mm or more;
    - articular frxs that involve radiocarpal joint;
         - more than 2 mm of articular step off is associated w/ poor prognosis;
    - radio-carpal instability (most often DISI deformity);
    - involvement of distal radio-ulnar joint;
         - there may be dislocation of the ulna from the sigmoid notch;
    - comminution:
         - dorsal surface is frequently comminuted;
         - if comminution extends volar to midaxial plane of radius, then cast immobilization will frequently fail;
         - expect increase in comminution w/ incr in amount of dorsiflexion;
         - high-loading angles, (70-90 deg), have much more comminution than low loading angles of 20 to 40 deg;

- Clinical Consequences:
    - these frxs are assoc w/ higher rate of complications, including loss of reduction, median nerve injury, and instability of the distal radioulnar joint;

- Secondary Instability:
    - present when closed reduction & cast immobilization fails to maintain initial reduction;
    - residual dorsal angulation of > 10 deg;
    - radial shortening of 5mm