- See: 
- Forces Displacing the Fracture
- Cast Brace
- Caldwell (1933) 
- for displace frx of the humeral shaft with shortening, and also for oblique and spiral fractures; 
- Indications: 
- used for comminuted humeral frx 
- disatl humeral shaft frx; 
- cast must be light wt. and must extend from at least 1 inch proximal to the fracture site to wrist, w/ elbow at right angle & forearm in neutral rotation; 
- arm must lie dependent to provide a traction force; 
- patient must sleep erect or semierect to avoid supporting elbow when seated; 
- erect position is maintained during the day as much as possible; 
- there should be no support under the elbow, and nothing should compress the arm against the body (such as clothing); 
- Correction of Angulation: 
- sling must be securely fixed at the wrist by a loop made of plaster or other material; 
- to correct lateral angulation, the loop is placed on dorsum of the wrist; 
- medial angulation is corrected by placing loop on the volar side 
- anterior angulation may result from length of collar that is too long; 
- wrist drops below the horizontal plane, & distal fragment of humerus tilts posteriorly allowing anterior angulation of the fracture to result; 
- conversely a short collar and cuff will cause posterior bowing