OTC Orthopaedic Technologist Certified Upper Extremity Casting 5 — Questions and Answers
Question 1: When removing a cast, the cast saw should be held at what angle relative to the cast surface to minimize injury risk?
- Parallel (0 degrees) to the cast surface
- Perpendicular (90 degrees) to the cast surface (Correct answer)
- At a 45-degree angle
- The angle does not matter with oscillating saws
Correct answer: Perpendicular (90 degrees) to the cast surface
Holding the saw blade perpendicular to the cast surface and using a plunge-and-lift technique minimizes skin contact and reduces injury risk.
Question 2: Edema management instructions for a patient with a newly applied upper extremity cast should include which primary recommendation?
- Keep the extremity dependent to promote circulation
- Elevate the extremity above the level of the heart (Correct answer)
- Apply ice directly over the cast
- Perform vigorous finger exercises only at bedtime
Correct answer: Elevate the extremity above the level of the heart
Elevating the extremity above the heart reduces hydrostatic pressure and promotes venous and lymphatic drainage, minimizing post-cast swelling.
Question 3: A cylindrical arm cast that is excessively tight will most likely first impair which structure?
- The periosteum of the radius
- Venous return from the distal extremity (Correct answer)
- Arterial inflow to the shoulder
- The lymph nodes at the elbow
Correct answer: Venous return from the distal extremity
Veins are thin-walled and low-pressure, so they are compressed before arteries when external pressure is applied, leading to venous congestion as the first sign.
Question 4: Which of the following is an absolute contraindication to fiberglass casting (as opposed to plaster)?
- Active fracture less than 24 hours old
- Known allergy to isocyanate or fiberglass resin (Correct answer)
- Pediatric patients under age 5
- Fractures requiring more than 6 weeks of immobilization
Correct answer: Known allergy to isocyanate or fiberglass resin
A known allergy to the polyurethane resin or fiberglass components is an absolute contraindication; plaster is used as an alternative.
Question 5: The purpose of applying a 'petaling' technique to a cast edge is to:
- Reinforce the structural integrity of the cast
- Prevent skin irritation and breakdown at the cast margin (Correct answer)
- Improve the waterproof properties of fiberglass
- Allow for easier cast removal
Correct answer: Prevent skin irritation and breakdown at the cast margin
Petaling involves folding small strips of moleskin or tape over the rough cast edge to prevent abrasion and skin breakdown at the proximal and distal margins.
Question 6: Intrinsic-plus position for hand immobilization places the metacarpophalangeal joints in flexion and the interphalangeal joints in:
- Full flexion
- Full extension (Correct answer)
- Slight flexion (10–15 degrees)
- Hyperextension
Correct answer: Full extension
The intrinsic-plus (safe) position places MCP joints in 70–90 degrees of flexion and IP joints in full extension to prevent collateral ligament contracture.
Question 7: A patient returns 48 hours after short arm cast application with numbness and tingling in the thumb, index, and middle fingers. Which nerve is most likely compressed?
- Ulnar nerve
- Radial nerve
- Median nerve (Correct answer)
- Musculocutaneous nerve
Correct answer: Median nerve
Numbness in the thumb, index, and middle fingers corresponds to the sensory distribution of the median nerve, which passes through the carpal tunnel.
OTC Orthopaedic Technologist Certified Upper Extremity Casting 5
When removing a cast, the cast saw should be held at what angle relative to the cast surface to minimize injury risk?