What should you know about a hanging cast for a humerus fracture?

A hanging cast surrounds the upper arm and is arranged so the weight of the cast and arm provides gentle traction. It is intended for selected humerus fractures, based on the fracture position, skin condition, and examination findings. It should not be treated like a sling that simply holds the arm against the body. The treating team checks alignment and may use imaging during follow-up.

Cast material may be plaster of Paris or fibreglass. The choice affects weight, drying, and handling, but neither material makes the arm invulnerable. Swelling can change the fit during the early healing period, and the elbow, wrist, and fingers may become stiff without appropriate guidance.

Follow the prescribed position and keep the cast dry unless your clinician has given different instructions. Do not trim, loosen, pad, or insert objects inside it. Check the fingers for normal colour, warmth, sensation, and movement several times a day. Keep the hand elevated when advised, and move the free joints as instructed. Attend imaging and fracture reviews so the team can decide whether casting remains suitable, whether a closed reduction was needed, or whether another treatment such as fracture fixation surgery should be considered.

Contact the fracture team promptly if pain or tightness is increasing, the cast cracks, becomes wet, rubs the skin, or develops a bad smell. Seek urgent care for numbness, burning, severe swelling, fingers that become pale or blue, inability to move them, or pain that is not controlled as directed. A new fall or impact while wearing the cast also needs assessment.

Ask how your cast should hang, which joints you may move, when follow-up imaging is planned, and how long support is expected. Check how to bathe safely, what pain changes are concerning, and when physiotherapy may begin after immobilisation.