Last Updated on February 17, 2025
A fiberglass cast is a plaster cast made from fiberglass material which is a lighter, synthetic alternative plaster of Paris. Fiberglass also called glass-reinforced plastic[GRP] or glass fiber-reinforced plastic [GFRP] is a fiber-reinforced polymer made of a plastic matrix reinforced by fine fibers of glass.
The fiberglass cast is also popularly called the synthetic cast. Traditionally, the orthopedic cast has been made of plaster of Paris and is called a plaster cast.
A fiberglass cast is a lightweight and extremely strong material. Compared to the traditional plaster of Paris cast, it is light in weight and more durable. It is three times stronger but is only one-third in weight.
Casts made of this material require less maintenance than those made with plaster.
Plaster of Paris casts is white. Fiberglass casts come in many colors and some doctors even let the patient choose the color.
Fiberglass cast, like its plaster of Paris counterpart, is applied in case of fracture treatment. The fiberglass cast is less yielding to molding and to hold fracture fragments, molding is required. In contrast, the plaster of Paris provides excellent molding.
Therefore fiberglass cast is used mostly in those cases where the healing process has already begun, an acute period of injury has passed, and fractures are not displaced.
Fiberglass sets quickly, therefore experience is required to time the application well. It is hygroscopic [absorbs water] and setting time decreases with humidity and warmth.
Indications for Fiberglass Cast or Splint
The usage profile of fiberglass cast or splint is similar to that of plaster of Paris cast or splint.
The use of fiberglass cast or splint can be considered in the following situations.
- A temporary splint
- For joint immobilization in ligament injury
- Joint swelling due to disease.
- For fractures.
- Definitive treatment of fractures or ligament injury
- External splint after surgery
- Blocking splints in case of nerve, tendon or vessel repair.
- After osteotomies
- Providing rest to limb or part in case of disease
Materials for Fiberglass Cast Application
- Fiberglass Tapes/bandages of appropriate size
- Available in a range of 1 inch – 6 inches
- The width used is determined by the width of the limb or region where the synthetic cast is to be applied
- Water at room temperature
- Stockinette of an appropriate width
- Cotton wrap
- Cotton bandages for splinting
- Gloves for applier and assistance
- Protective linen for patient
Procedure of Cast Application
- Position the patient. Depending on the region where the cast is to be applied, it could be sitting or lying down supine.
- Apply the stockinette. Extend proximally and distally beyond the limits of where the extent of the cast.
- Over this, a cast padding is wrapped. Take special care to cover the bony prominences.
- Fold both ends of the stockinette sleeve over the cast padding to give attractive well-cushioned ends to the cast.
- The physician and assistants wear gloves [synthetic casting materials can create exfoliative dermatitis when exposed to bare skin or the applier may have allergic reactions to the material]
- Position the limb in the desired position. For example, in the lower limb, short leg cast, the foot is kept in the neutral position mostly but depending on the injury it may be in plantar flexion as well.
- Next, a roll of synthetic cast material is removed from its packaging while the limb is kept in the desired position by assistants.
- Some people apply it after immersing in the water while others apply it directly without immersing.
- In the latter cases, the water is sprinkled over the applied synthetic bandage.
- In very humid environments, the synthetic material, being very hygroscopic absorbs water from the surrounding,s and extra water may not be required.
- As it is applied, it should be stretched, allowed to relax, and then laid on the limb. The bandage should not be applied in tension. The desired number of bandages is applied depending on limb position, circumference, and extent of the cast.
- After some time, the cast material will begin to harden with the exothermic reaction.
Aftercare of Fiberglass Cast
All the casts in case of acute fractures should be recalled the next day to note any discomfort, bluishness, swelling, and numbness of the digits.
Here are the basic DOs and DON’Ts of the fiberglass cast
- Do not wet, cut, heat or otherwise interfere with this plaster.
- Report immediately if a problem arises
- Plaster cracks or becomes loose or uncomfortable.
- A pain that is not relieved or worsens
- Discharge or high-grade fever
- Numb fingers or toes
- Swollen or blue digits
- An unrelenting burning sensation at any point throughout the cast extent.
- Elevate the limb as instructed especially for the first 24 hours
- Move the fingers or toes continuously
- Encourages the return of the blood
- Reduces swelling
- Keep the cast clean and dry.
- Pad the rough edges to protect the skin from scratches.
- Do not scratch the skin under the cast by inserting objects inside the cast.
- Instead one can use a hairdryer placed on a cool setting to blow air under the cast
- Do not put powders or lotion inside the cast.
References
- Gillian D. Smith, Raymond G. Hart, Tsu-Min Tsai. Fiberglass cast application. The American Journal of Emergency Medicine.2005. Volume 23(3)3, 347-50. [Link]
- Kowalski, Kurtis & Pitcher, J & Bickley, Barry. Evaluation of Fiberglass versus Plaster of Paris for Immobilization of Fractures of the Arm and Leg. Military medicine.2002 167. 657-61.
