OCC Casting Materials & Techniques 1 — Questions and Answers

Question 1: What is the primary advantage of fiberglass casting material over plaster?

It sets slower
It is more flexible
It is lighter and water-resistant (Correct answer)
It is cheaper than plaster

Correct answer: It is lighter and water-resistant

Fiberglass casting material offers several advantages over plaster, most notably being significantly lighter and water-resistant. Its lighter weight enhances patient comfort and mobility, while its water-resistant property allows patients to shower or bathe with proper precautions, improving hygiene and quality of life during immobilization. These features contribute to better patient compliance and overall experience.

Question 2: Which of the following is a critical first step in cast application?

Mixing the casting material
Applying padding over bony prominences (Correct answer)
Shaping the cast edges
Choosing cast color

Correct answer: Applying padding over bony prominences

A critical first step in cast application is to apply adequate padding, especially over bony prominences. This padding protects the patient's skin and underlying tissues from pressure sores, skin breakdown, and nerve compression that can result from the rigid casting material. Proper padding ensures patient comfort and prevents complications throughout the immobilization period.

Question 3: Which technique is used to relieve pressure in a circumferential cast?

Stripping
Wrapping
Bivalving (Correct answer)
Padding

Correct answer: Bivalving

Bivalving is the technique of cutting a circumferential cast lengthwise into two halves. This procedure is performed to relieve pressure, particularly in cases of anticipated or actual swelling that could lead to compartment syndrome, or to allow for wound care and physical therapy access. It helps prevent neurovascular compromise and facilitates ongoing patient management.

Question 4: Which material is preferred for initial casting when significant swelling is expected?

Fiberglass
Plastic
Plaster (Correct answer)
Resin

Correct answer: Plaster

Plaster of Paris casts are generally preferred for initial casting when significant swelling is expected because they are more conformable and allow for slight expansion as swelling fluctuates. Unlike fiberglass, plaster can be easily molded to the limb and, if needed, removed or modified more readily in the acute phase. This flexibility helps prevent complications such as compartment syndrome in the early stages of injury.

Question 5: Which part of the body would most likely require a short arm cast?

Upper arm
Wrist and forearm (Correct answer)
Knee
Ankle

Correct answer: Wrist and forearm

A short arm cast extends from just below the elbow to the metacarpal heads, effectively immobilizing the wrist and forearm. This type of cast is commonly used for fractures of the distal radius, ulna, or carpal bones, as well as for severe sprains in this region. It allows for full elbow and finger movement while stabilizing the injured area.

Question 6: Why is it important to use gloves when handling casting material?

To improve grip strength
To avoid staining the cast
To prevent skin irritation and burns (Correct answer)
To shape the cast faster

Correct answer: To prevent skin irritation and burns

It is crucial to use gloves when handling casting material because both plaster and fiberglass resins undergo an exothermic reaction (heat-generating) during the setting process. Direct contact with these materials can cause skin irritation or thermal burns. Gloves provide a protective barrier, safeguarding the technician's skin from chemical exposure and heat.

OCC Casting Materials & Techniques 1

What is the primary advantage of fiberglass casting material over plaster?