Hanging Cast

Indications

1.     For displace fracture of the humeral shaft with shortening, and also for oblique and spiral fractures –(Caldwell, 1933) 

2.    Used for comminuted humeral fracture, distal humeral shaft fracture.

·     Cast must be lightweight and must extend from at least 1 inch proximal to the fracture site to wrist, with elbow at right angle & forearm in neutral rotation.

·       Arm must lie dependent to provide a traction force.

·       Patient must sleep erect or semi-erect 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).

It is frequently exchanged for functional bracing 1 to 2 weeks after injury.

Correction Of Angulation:

1.     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.

2.     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.

3.     Conversely a short collar and cuff will cause posterior bowing.

·       These casts are routinely used to treat humeral diaphyseal fractures in the acute phase.

·       The arm is placed over the lower chest with the elbow at 90 degrees.

·       A collar and cuff support can be used to maintain the position.

·     A cast is then applied, so that the top of the humeral component of the cast is above the humeral fracture.

·  Gravity is used to regain humeral length and the alignment of the fracture can be theoretically adjusted by altering the length of the cast between the neck and forearm.

·       The shorter the cuff the more varus is applied to the fracture.

·       An alternative to the hanging cast is the U-slab or sugar-tong splint, in which a plaster is placed from just below the axilla on the medial side of the arm down and around the elbow and then upwards to just below the shoulder.

·       The slab is then bandaged into position.

·       In proximal humeral fractures the slab can be extended above the shoulder but surgeons should be aware that this will negate any beneficial reduction effects of gravity.

·       These casts are often replaced at 2 to 4 weeks by a functional brace.