Types of Cast for a Broken Arm: What to Know

A splint leaves room for early swelling and can be easier to adjust. A full cast surrounds the arm more completely and helps limit movement while bone healing begins. Plaster moulds closely to the limb and is often useful when a clinician needs a precise shape. Fiberglass is lighter, firm, and usually more resistant to everyday moisture, although it still needs protection unless your care team says otherwise.

The cast may cover the wrist and forearm, the forearm and elbow, or more of the arm depending on the fracture. A distal radius fracture, also called a broken wrist, may be managed with casting after the bones are aligned. Read more about [Distal Radius Fracture](/conditions/distal-radius-fracture/) and [Fracture Casting](/treatments/trauma-and-fracture-care/fracture-casting/).

Keep the arm raised when it is swollen, move the fingers regularly, and keep the cast clean and dry. Do not push objects inside it or trim its edges. Check the fingers for normal colour, warmth, movement, and sensation. Use only the pain plan given by your clinician. If the fracture needed alignment before casting, [Closed Reduction](/treatments/trauma-and-fracture-care/closed-reduction/) may be discussed; some unstable fractures need [Fracture Fixation Surgery](/treatments/trauma-and-fracture-care/fracture-fixation-surgery/). After removal, [Hand Therapy](/treatments/physiotherapy-and-rehabilitation/hand-therapy/) can help restore movement and function.

Contact the treating service promptly if pain or tightness is increasing, fingers become pale or blue, swelling keeps worsening, or you develop numbness, tingling, or difficulty moving the fingers. A wet, cracked, loose, foul-smelling, or rubbing cast also needs assessment. New [Hand Swelling](/symptoms/hand-swelling/) or severe [Wrist Pain](/symptoms/wrist-pain/) should not be dismissed as ordinary healing.

Ask which bone and level are fractured, whether a splint or full cast is planned, how long the cast should stay on, and how to protect it during washing. Ask when follow-up imaging is needed, which finger movements are encouraged, and what changes mean the cast should be checked sooner.