Splint vs cast
Formal Definition
A splint (half-cast, or bivalved cast) is a non-circumferential immobilization device that allows for swelling and is used acutely or when swelling is expected; a cast is a circumferential rigid immobilization device applied after swelling has stabilized, providing superior fracture control for definitive management.
How It's Used on the Ward
"Splint them in the ED, cast them in clinic" — standard practice: splints are safe acutely (no compartment syndrome risk), casts are applied at follow-up once swelling resolves.
Example
""Buckle fracture of the distal radius in a 7-year-old: placed in a volar short-arm splint tonight, ortho clinic in 5–7 days. If alignment is maintained, we'll transition to a cast for 4 weeks.""
Clinical Context
Circumferential casting over significant swelling risks compartment syndrome — the splint-first rule exists to prevent this. Common splints by injury: sugar-tong = forearm/wrist, posterior long-arm = elbow, posterior short-leg = ankle, knee immobilizer = knee. Cast complications: skin breakdown, cast saw injury, compartment syndrome, joint stiffness. Fiberglass casts are lighter and water-resistant vs plaster (heavier, moldable).