Casts are supportive devices used to help keep an injured bone in place while it heals. Splints, sometimes called half casts, are a less supportive, less restrictive version of a cast.

Casts and splints may be used to help treat broken bones and injured joints and tendons, or after surgery involving bones, joints, or tendons. The purpose of a cast or splint is to immobilize a bone or joint while it heals from injury. This helps to restrict movement and protect the area from further injury.

Doctors sometimes use casts and splints together. For example, they might stabilize a fracture with a splint first and replace it with a full case after the initial swelling goes down. Other fractures might need just a cast or just a splint.

Read on to learn more about the different types of casts and splints, including the pros and cons of each.

Until the 1970s, the most common type of cast was made with plaster of paris. This involves mixing white powder with water to form a thick paste.

Before applying a plaster cast, a doctor will place a stockinette made out of thin, webbed material over the inured area. Next, they’ll wrap several layers of soft cotton around the area before applying the paste. Eventually, the paste hardens into a protective case.

Plaster cast pros

While they aren’t as popular as they used to be, plaster casts still have some advantages. Compared to other cast types, plaster casts are:

  • less expensive
  • easier to mold around certain areas

Plaster cast cons

Plaster casts require more care than other types of casts. For one, they can’t get wet, as this can cause the plaster to crack or disintegrate. To bathe with a plaster cast, you’ll need to wrap it in several layers of plastic.

They also take several days to fully harden, so you’ll need to limit your activities for a few days after getting the cast.

Plaster casts tend to be heavier as well, so they can pose a challenge to small children.

Today, synthetic casts are used more often than plaster casts. They’re usually made out of a material called fiberglass, a type of moldable plastic.

Fiberglass casts are applied in a similar manner to plaster casts. A stockinette is placed on the injured area, then wrapped in soft cotton padding. The fiberglass is then soaked in water and wrapped around the area in several layers. Fiberglass casts dry within a few hours.

Synthetic cast pros

Synthetic casts offer a lot of advantages over plaster casts for both doctors and the people wearing them.

They’re more porous than plaster casts, which allows your doctor to take X-rays of the injured area without removing the cast. This also means that fiberglass casts are more breathable, making them much more comfortable to wear. This makes the skin underneath the cast less vulnerable to irritation.

As an added bonus, fiberglass casts weigh less than plaster casts do, and the come in a range of colors.

Synthetic cast cons

Fiberglass casts are much more waterproof than plaster casts, but not completely. While the outer layer is waterproof, the soft padding underneath is not. In some cases, your doctor may be able to put a waterproof liner under the cast, which makes the entire cast waterproof.

Waterproofing the cast will likely cost more and take more time, but it may be worth discussing with your doctor if you feel a waterproof cast will best fit your lifestyle.

Splints are often called half casts because they don’t fully surround an injured area. They typically have a hard, supportive surface made of plaster, plastic, metal, or fiberglass. This material is usually lined with padding, and Velcro straps hold everything in place.

Many injuries requiring casts initially cause swelling. Splints are easily adjustable, so they’re often used to help stabilize the area until the swelling goes down. Once the swelling subsides, your doctor can get a better look at the injury and decide if a more supportive cast is needed.

Some splints can be purchased ready-made, but others are custom made to fit a specific area.

If you have a broken bone or an injured joint or tendon, or are recovering from bone surgery, you may need a cast, splint, or both. Your doctor will take a number of factors into consideration when choosing the type of cast or splint to use in your treatment. Some of these factors include:

  • the type of fracture or injury
  • the location of your injury
  • your age
  • how swollen the area is
  • whether you’re likely to need surgery
  • your activity level and lifestyle

Regardless of what your doctor recommends, they’ll give you a list of instructions to help you take care of your cast or splint and ensure a smooth recovery process.