CTO Device Fitting & Adjustment 2 — Questions and Answers
Question 1: When fitting a supramalleolar orthosis (SMO), which anatomical landmark is most critical to check for adequate clearance?
- Tibial crest
- Medial malleolus (Correct answer)
- Fibular head
- Calcaneal tuberosity
Correct answer: Medial malleolus
The medial malleolus is a prominent bony prominence that requires adequate clearance in an SMO to prevent pressure sores.
Question 2: A patient reports their TLSO feels too tight after wearing it for two hours. Which initial assessment step is most appropriate?
- Replace the orthosis immediately
- Check for erythema and assess trim lines at pressure points (Correct answer)
- Add more padding throughout the interior
- Refer the patient back to the orthotist without adjustment
Correct answer: Check for erythema and assess trim lines at pressure points
Checking for erythema and evaluating trim lines at pressure points helps identify the specific cause of discomfort before making targeted adjustments.
Question 3: Which type of ankle joint allows dorsiflexion but blocks plantarflexion in an AFO?
- Free motion joint
- Posterior stop joint (Correct answer)
- Anterior stop joint
- Dorsiflexion assist joint
Correct answer: Posterior stop joint
A posterior stop joint in an AFO limits plantarflexion while allowing dorsiflexion, commonly used for dropfoot with spasticity concerns.
Question 4: During dynamic alignment of a prosthetic-orthotic device, excessive heel rise at toe-off most likely indicates:
- Too much dorsiflexion resistance (Correct answer)
- Insufficient plantarflexion resistance
- Correct alignment
- Excessive knee flexion
Correct answer: Too much dorsiflexion resistance
Excessive heel rise at toe-off suggests that dorsiflexion resistance is too great, preventing the heel from staying down through mid-stance.
Question 5: A child fitted with a KAFO for myelomeningocele is observed with medial knee thrust during stance. The MOST likely cause is:
- Excessive varus adjustment at the knee joint
- Insufficient medial upright length
- Valgus malalignment of the knee joint (Correct answer)
- Shoe heel that is too high
Correct answer: Valgus malalignment of the knee joint
Valgus malalignment of the knee joint axis causes the knee to shift medially during weight-bearing, producing a medial thrust.
Question 6: When adjusting a wrist-hand orthosis (WHO) for a patient with rheumatoid arthritis, wrist position should typically be set at:
- 20-30 degrees flexion
- Neutral (0 degrees)
- 10-20 degrees extension (Correct answer)
- Full extension (60 degrees)
Correct answer: 10-20 degrees extension
A functional wrist position of 10-20 degrees extension is optimal for hand function and reduces joint stress in rheumatoid arthritis patients.
Question 7: Which padding material is MOST appropriate for lining bony prominences in a rigid orthosis to distribute pressure?
- Closed-cell polyethylene foam (Correct answer)
- Open-cell foam
- Cotton stockinette
- Silicone gel sheet
Correct answer: Closed-cell polyethylene foam
Closed-cell polyethylene foam (e.g., Plastazote) distributes pressure effectively over bony prominences because it conforms and resists bottoming out.
CTO Device Fitting & Adjustment 2
When fitting a supramalleolar orthosis (SMO), which anatomical landmark is most critical to check for adequate clearance?