Casts and Splints Overview

Casts and splints are used to stabilize and protect bones and soft tissues while they heal. 

‍A cast encircles the arm or leg completely and is custom-made for the patient, requiring a special saw for removal. Splints, often off-the-shelf and made from fabric, Velcro, and plastic or metal, generally cover only part of the limb and accommodate swelling better than casts. The choice between a cast and a splint depends on the injury type and the amount of swelling.

Both casts and splints also protect wounds after surgery, which is crucial for young children who might disturb their wounds. A cast is often a good option for protecting a surgical site during healing.

Types

Most custom casts and splints are made from plaster or fiberglass:

• Plaster: Traditional and white, plaster casts are heavier and take longer to dry but are less expensive and more moldable than fiberglass.
• Fiberglass: Lightweight and available in various colors, fiberglass casts are better for x-ray visibility but are less flexible in shaping compared to plaster.

For information specific to hip spica casts, please refer to the Spica Cast page in our library.

Applying the Cast/Splint

A protective padding, typically cotton or synthetic material like rayon, is placed between the cast material and the skin. A cotton stocking may also be used to keep the padding in place.

Fiberglass or plaster must be wet to mold properly. The doctor or cast technician will immerse the material in water before applying it over the padding. The cast needs to extend past both joints above and below the injury for optimal support.

In cases of significant swelling, the cast may need to be split to accommodate it. Plastic spacers can help keep the cast open, and it might need to be adjusted as swelling decreases over the following weeks.

After the Cast is Applied

Swelling is common after an injury, and it is important to keep the limb elevated for 2 to 3 days, particularly if a cast or splint has been applied. While some snugness is normal, contact your doctor if pain or swelling persists despite elevation.

Tips for Reducing Swelling

• Elevation: Keep the injured limb above heart level to promote drainage. For arm casts, keep fingers above the elbow, elbow above the shoulder, and shoulder above the heart. For leg casts, use pillows to elevate the leg, but avoid placing them under the heel to prevent sores.
• Movement: Gently wiggle toes and fingers to help reduce swelling and prevent stiffness.
• Ice: Apply a cold pack to the cast or splint to reduce swelling, ensuring a layer of absorbent material separates the ice from the cast to keep it dry. A large plastic bag with space around the cast is preferable to a rigid ice pack.

Warning Signs

Severe swelling can lead to circulation issues or nerve damage. Contact your doctor immediately if you notice:

• Increased pain or swelling that doesn’t improve with elevation
• Numbness or tingling in fingers or toes
• Burning or stinging sensations
• Loss of motion in fingers or toes

If these symptoms occur outside office hours, visit either our Urgent Care Center or a local emergency room.

Caring for the Cast/Splint

Follow your doctor’s specific care instructions for your cast or splint. To maintain cast integrity:

• Keep plaster casts dry to prevent damage and skin issues.
• Avoid inserting objects under the cast for scratching.
• Keep the cast free of powders, dirt, and sand.
• Do not trim or remove cast edges yourself; contact your doctor if adjustments are needed.

Cast Removal

Do not attempt to remove the cast yourself to avoid injury or misalignment. A specialized cast saw will be used, which vibrates but does not rotate, minimizing risk. The saw may be noisy and warm, and although rare, it might cause a superficial burn that usually heals without long-term issues.

After Cast Removal

Expect some stiffness and soreness, which should improve over time. Dry, flaky skin is common and can be removed with baths or showers. Excess hair may also grow under the cast but will eventually fall out. Regaining muscle strength and mobility is important, and your doctor will advise on exercises to help with recovery.

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