OTC Orthopaedic Technologist Certified Spinal and Pelvic Immobilization 3 — Questions and Answers
Question 1: What is the recommended torque for tightening halo skull pins in an adult patient?
- 2 in-lb
- 4 in-lb
- 8 in-lb (Correct answer)
- 12 in-lb
Correct answer: 8 in-lb
Standard adult halo pin torque is 8 in-lb; over-tightening risks bone penetration and under-tightening risks loosening.
Question 2: Which spinal orthosis provides the greatest restriction of cervical rotation?
- Soft foam collar
- Philadelphia collar
- Sterno-occipital-mandibular immobilizer (SOMI)
- Four-poster brace (Correct answer)
Correct answer: Four-poster brace
The four-poster brace provides superior restriction of all cervical motions including rotation due to its rigid anterior and posterior uprights.
Question 3: During spinal board immobilization, padding is placed beneath the occiput of an adult patient primarily to:
- Increase patient comfort only
- Maintain neutral cervical alignment (Correct answer)
- Prevent skin breakdown at the sacrum
- Facilitate airway suctioning
Correct answer: Maintain neutral cervical alignment
Occipital padding offsets the protuberance of the head to keep the cervical spine in neutral alignment on a flat board.
Question 4: Which pelvic fracture pattern is most commonly associated with a need for emergent external fixation?
- Isolated pubic rami fracture
- Open book (APC-II/III) pelvic ring disruption (Correct answer)
- Posterior acetabular wall fracture
- Avulsion fracture of the ischial tuberosity
Correct answer: Open book (APC-II/III) pelvic ring disruption
Open book injuries cause significant pelvic volume expansion and hemorrhage, requiring emergent fixation to control bleeding.
Question 5: A thoracolumbosacral orthosis (TLSO) is contraindicated as a primary treatment in which of the following injuries?
- Stable compression fracture at T12
- Chance fracture (flexion-distraction injury) (Correct answer)
- Minor transverse process fracture at L2
- Scheuermann's kyphosis
Correct answer: Chance fracture (flexion-distraction injury)
Chance fractures are unstable three-column injuries that typically require surgical stabilization, not bracing alone.
Question 6: The occiput-C1-C2 complex is responsible for what percentage of total cervical rotation?
- 15%
- 35%
- 50% (Correct answer)
- 70%
Correct answer: 50%
Approximately 50% of cervical rotation occurs at the atlantoaxial (C1-C2) joint, making this level critical to immobilize.
Question 7: Which measurement is used to determine the correct height of a rigid cervical collar?
- Head circumference
- Chin-to-sternal notch distance (Correct answer)
- Neck circumference
- Ear-to-shoulder distance
Correct answer: Chin-to-sternal notch distance
The chin-to-sternal notch distance determines collar height to ensure proper fit without causing flexion or extension.
OTC Orthopaedic Technologist Certified Spinal and Pelvic Immobilization 3
What is the recommended torque for tightening halo skull pins in an adult patient?