Splints and Casts

-External immobilization is key for fracture healing and consists of splinting and casting.



  • Upper Extremity
Type of splint Common Indication Application Image
Coaptation Humeral shaft # -elbow flexed at 90
Sugar tongue Distal radius/ulna # -elbow 90-Wrist 20 extension
Posterior long arm  Distal humerus, radial head, olecranon #. -elbow 90-wrist 20 extension or neutral
Volar splint Carpal bone # -wrist extended 20
Thumb spica 1st metacarpal #, scaphoid #. Skier’s thumb (UCL tear) -wrist 20 extensions-thumb as if holding a can
Radial gutter 2nd and 3rd metacarpal # -forearm neutral-MCP 50 flexion-PIP and DIP 10 flexion
Ulnar gutter 4th and 5th (boxer’s) metacarpal # -MCP 50 flexion-PIP/DIP 10 flexion
Finger splint mallet finger, phalangeal # -DIP in hyper-extension
  • Lower extremity
Type Indication Application Image
Posterior Short leg -Distal tibia/fibula #-All foot bone #- metatarsal displaced # (Lisfranc’s) -foot 90 to tibia
Ankle Stirrups -Ankle sprains grade II/III -Splint goes up to mid tibia and fibula


  1. Put on a stockinette.
  2. Apply the cotton padding circumferentially, overlapping each layer by 50%. Generally, 5 layers.
  3. Cut plaster sheets to size, 10 sheets upper extremity and 15 sheets for lower extremity in thickness.
  4. Use cold water and soak the plaster. Mold and place on extremity. Takes ~10 min to harden.
  5. Apply elastic bandage/ACE wrap to finish off.

Video of radial gutter splint from UoT Ortho –


  1. Pressure Sores – Make sure there is enough padding, especially on bony prominences.
  2. Compartment syndrome – Any acute fracture with possibility of swelling should not be casted. Worry about 5Ps (pain, paresthesia, pulseless, pallor, paralysis).
  3. Stiffness – Make sure all other joints can mobilize. Prolonged immobilization causes stiffness specially in hands. Hand physiotherapy is key.


-Emergency medicine procedures, Eric Reichman – Chapter 91; casts and splints

Copyedited by: Kurt Ebeling, Medical Student, University of Alberta