A cast holds a broken bone (fracture) in place and prevents the area around it from moving as it heals. Casts also help prevent or decrease muscle contractions and help keep the injured area immobile, especially after surgery, which can also help decrease pain.
Cast materials
The hard, outer layer of a cast is made of either plaster or fiberglass. Cotton and other synthetic materials are used to line the inside of the cast to make it soft and provide padding around bony areas, such as the ankle, wrist, or elbow. This also pads nerves and blood vessels.
- Plaster casts can be molded to your child’s arm or leg. They come in one color, white.
- Fiberglass casts are more durable and lightweight than plaster casts. They come in a variety of colors and designs.
Waterproof casts
Special waterproof cast liners may be used under a fiberglass cast so the cast can get wet without falling apart. These waterproof liners can only be used after the injured area has stopped swelling, usually a week or two after the initial injury. Waterproof casts can’t be used after surgery or when pins are used because of the risk of infection.
Your child can take a bath, shower, and even swim in a pool with a waterproof cast. However, they should not sit in a hot tub, go to the beach, or swim in the ocean or a pond while wearing their waterproof cast.
Waterproof casts must get completely submerged in water daily to keep the lining of the cast in good condition. They should be removed by an experienced clinician or technician who understands the specific demands of waterproof casts.
Split (Bivalve) Casts
For some injuries, the first cast may be split in order to allow room for swelling. The sides of the bivalve cast will be taped with cloth medical tape. The cast is secured from the inside at the top and bottom, so if the tape starts to peel, the cast should not fall apart. You can buy more tape at a local pharmacy in case the tape does start to peel off. If everything looks good at a follow-up appointment, your child’s doctor may apply a new layer of casting material to close the bivalve cast and prevent it from becoming too loose as swelling comes down.
Casts for upper extremities (arms, wrists, fingers)
Short Arm Cast
- used for forearm and wrist fractures
- applied below the elbow to the hand
- also used to hold the forearm or wrist muscles and tendons in place after surgery
Long Arm Cast
- used for upper arm, elbow, or forearm fractures
- applied from the upper arm to the hand
- also used to hold the arm or elbow muscles and tendons in place after surgery
Shoulder Spica Cast
- used for shoulder dislocations, or after surgery on the shoulder area
- applied around the trunk of the body, the shoulder, arm, and hand
Casts for the lower extremities (hips, legs, knees, ankles)
Short Leg Cast
- used for lower leg fractures, ankle fractures, and severe ankle sprains and strains
- also used to hold the leg or foot muscles and tendons in place after surgery to allow for healing
- applied to the area below the knee down to the foot
- may be walked on once the fracture is stable enough to bear weight without becoming re-injured
- not appropriate for most children under the age of 3, who may kick off the short leg cast
Leg cylinder cast/long leg cast
- used for knee or lower leg fractures, knee dislocations, or after surgery on the leg or knee
- applied from the upper thigh to the ankle or foot
- usually applied with the knee bent to prevent walking on the cast
Unilateral hip spica cast (also known as single hip spica)
- used for thigh (femur) fractures
- also used to hold the hip or thigh muscles and tendons in place after surgery
- applied from the chest to the foot of the affected leg
One-and-one-half spica cast
- used for thigh (femur) fractures
- also used to hold the hip or thigh muscles and tendons in place after surgery
- applied from the chest to the foot on one leg, and to the knee on the other leg, with a bar placed between both legs to keep the hips and legs immobile
Bilateral hip spica cast (also known as double hip spica)
- used for pelvis, hip, or thigh (femur) fractures
- also used to hold the hip or thigh muscles and tendons in place after surgery
- long leg: applied from the chest to the feet, with a bar between both legs to keep the hips and legs immobile
- short leg: applied from the chest to the thighs or knees
Abduction A-frame cast
- used to hold the hip muscles and tendons in place after surgery to allow time for healing
- applied from upper thighs to the feet, with a bar placed between both legs to keep the legs and hips immobile
Clubfoot cast
- used to treat clubfoot
- applied from upper thigh to toes
- usually changed every 5-7 days
Resources
- How to care for your cast
