Types of Plaster Casts and their Uses

A cast is one of the immobilisation techniques that is applied over the injured musculoskeletal parts. This is done to help quick healing of injured musculoskeletal parts. Orthopaedic doctors also apply casts after orthopaedic surgery to ensure immobility.

Generally, there are two types of casts, plaster cast and synthetic cast. Both casts are effective in preventing movement and helping in healing. However, there are pros and cons for both.

Plaster Casts

The most common type of plaster cast for fracture is made from the Plaster of Paris. Plaster of Paris is a soft material that is malleable when wet but becomes hard when dry. It is available as rolls of crinoline (a stiff fabric made of cotton, nylon or polyester) impregnated with Plaster of Paris. 
It can be easily wound around the hand or leg when wet. The cast will set very quickly but takes a long time to dry. During this time, one should not move the body part where the cast is put because that could result in cracks on the cast. 
Plaster casts are used to keep a person's body part immobilised in case of a fracture. 

1. They help keep the bones or joints together and allow them to heal. 
2. They are also used to prevent or correct a deformity in the bones or joints. 
3. Casts restrict movement and help reduce pain and muscle spasms.

Making The Plaster Cast

1. Plaster casts cannot be applied directly to the skin and hence need another material to cover the skin.
2. A stockinette is used for this purpose. 
3. It is a soft knit material available in rolls of different widths. 
4. This material protects the skin and the edges of the cast.
5. A thick layer of cotton is placed on the stockinette before the cast is applied. 
6. The padding helps protect the bony projections of the body from the rigid cast. 
7. In all types of plaster cast, this padding is applied. 
8. The plaster rolls are saturated with water between thirty-five and forty degrees temperature. 
9. The specialists change the water a few times to prevent loose particles from attaching to the fresh plaster being dipped in the water. 
10. All fracture plaster types need two days to dry and utmost care must be taken during the drying period.

Advantages of Plaster Casts

1. They are very economical and affordable for everyone.
2. Plaster casts are easier to mould around certain areas of the body.

Disadvantages of Plaster Casts

1. Plaster casts are heavier and can be uncomfortable for children
2. One cannot bathe with this cast unless he/she wrap it in several layers of plastic.
3. They take more time to dry and require more care during this period. 

Synthetic Cast

The synthetic casts are made using fibreglass.

Applying The Synthetic Cast

1. All steps in the making of a synthetic cast are similar to those of the plaster cast.
2. In the last step, the fibreglass roll is dipped in water and wrapped around the padding.
3. Synthetic casts dry within a few hours.

Advantages of Synthetic Casts

1. They allow doctors to take X-rays of the part without removing them.
2. Fibreglass casts weigh much less than plaster casts.
3. These casts are more breathable, making them more comfortable to wear.

Disadvantages of Synthetic Casts

1. They are much more expensive than plaster casts

Splints

Splints are also cast that help keep the broken bones together and reduce pain. They are generally used before applying a plaster cast or when there is swelling in the area.

1. They are placed at the part with broken bones and held in place using bandages or other materials. 
2. They don’t provide as much support as casts because they don’t wrap around the part. 

Apart from classifying them by the materials, casts are categorised by size and usage. 

1. Short Arm Cast
   This plaster cast is used to treat the fracture of the bones in hand or dislocation of the wrist joint. The short arm cast extends from below the elbow to the palm. This cast allows free movement of the fingers and improves blood circulation. 
2. Long Arm Cast
   It is one of the plaster casts used to treat fractures of either one or both bones of the forearm. The model is also used to correct the dislocation of the elbow joint. The elbow joint is kept straight in this cast. It starts from below the shoulder and extends up to the palm. 
3. Short Leg Cast
   The short leg cast is used to treat fractures of the bones in the feet. It is also used to correct dislocation or sprain of the ankle. This cast can be made either as a weight-bearing or non-weight-bearing type. If it has to bear the weight of the person during movement, then it is fitted with a walking heel. A fracture plaster starts below the knee and extends to the feet. The toes remain free in this cast. 
4. Long Leg Cast
   This plaster cast for fracture is used to treat fractures involving the lower leg. It is also used to treat knee dislocations. The model starts from below the groin area and ends at the feet. 
5. Spica Cast
   1. This cast is used to treat fractures or other problems related to the hip or shoulder joints.
   2. The shoulder spica cast is used to treat shoulder girdle fractures, shoulder dislocation and fractures of the bone of the upper limb.  The shoulder spica cast combines a long arm cast and a body jacket.
   3. The hip spica cast is a plaster cast used for treating dislocation of the pelvis or hip joint. It also helps treat fractures of the pelvic or thigh bones. The hip spica cast extends from below the nipples to the entire length of the leg on the affected side. It has openings around the buttocks and perineal region for urine and stool passage.
6. Body Cast
   There are two types of body casts - the Minerva Jacket and the Body Jacket.
   1. Minerva Jacket: This plaster cast for fracture covers the front and back of the skull, chest, abdomen, back and hips. The face and ears are kept exposed in this plaster cast. 
   2. Body Jacket: It extends from the upper chest to the pelvis. The buttocks and the perineal area are kept exposed. Some types of body jackets also include the thighs. 
      Both body casts are used to keep the spine from moving. These are used after spinal surgery or injury. Body casts are sometimes applied, so the spine remains in an extended position. It helps treat compression fractures. 
7. Bivalved Cast
   It is one of the fracture plaster types with two halves that can be separated. This cast is used when tissue swelling is expected. This cast allows the doctors to perform skin care without causing movement to the affected part. 

A person must also take care once the cast is in place. Below mentioned are some of the cast care tips that one should follow while the cast is on.

1. The plaster cast must be kept dry at all times. 
2. Check for any cracks or breaks in the cast.
3. Paddings can be added to rough edges to prevent them from scratching the skin.
4. Cool air can be blown beneath the cast to relieve hot and itchy skin. 
5. One must not put powder or lotion under the cast.
6. Swellings can be avoided by raising the cast above the heart level. 
7. It is wise to cover the cast while eating to prevent it from spoilage. 

1. Skin Trauma
   This is caused by ridges formed on the inner side of the cast. This can happen if the limb is allowed to move while casting. These ridges form pressure points on the skin that can cause pain or burning. The solution to the problem is to open, inspect the skin and then apply the cast again. 
2. Swelling
   Most casts constrict the portion under them. But if the constriction is in excess, it can compress the veins leading to swelling. This causes pain and discomfort. Blue colour will be seen on the skin or under the nails. The cast must be removed and applied again in such conditions. 
3. Plaster Sores
   Plaster sores are mostly caused by the pressure of the cast on the skin. This happens due to the poor technique used while applying the cast. Inadequate padding can also cause sores. Sores also occur when there is a foreign particle between the cast and the skin. Sores can be detected by swelling of the digits, odour from the cast or staining because of pus. The plaster needs to be removed and examined. 
4. Joint Stiffness
   The use of casts can result in joint stiffness. This is because there is no movement of the part. This can be resolved by exercises and stretching after the cast is removed. But if the cast is present longer, the stiffness may become a long-term or chronic issue. This is why it is best to apply a cast only for the shortest time. 
5. Infection
   Infection is more likely if there is an open wound inside the cast. But even in cases with no open wounds, the condition may occur. This is because of the warm environment inside the form which is an ideal breeding environment for bacteria.

A cast saw is generally used to remove a plaster cast. It is a powerful tool with small, sharp teeth that move back and forth to cut the cast. The orthopaedic surgeon ensures that the teeth don’t touch the patient’s skin.

The article aims to tell people about plaster cast types for different musculoskeletal injuries or conditions. Casts help in the quick healing of broken bones or joints. The report has dealt in detail with the other cast types used for various needs. One must also understand that taking care of the cast and the complications that can occur while applying casts are equally important. 

To enquire about the best hospitals and doctors to get a cast applied, you can visit the HexaHealth website. We help you with all the formalities, from counselling and sourcing the best doctor to hospital admission and medical insurance claim settlement.