CTO Patient Evaluation & Measurement 2 — Questions and Answers
Question 1: When measuring a patient for a supramalleolar orthosis (SMO), which anatomical landmark is used to determine the proximal trim line height?
- Fibular head
- Medial malleolus
- Just above the malleoli (Correct answer)
- Mid-shaft tibia
Correct answer: Just above the malleoli
The proximal trim line of an SMO is positioned just above the malleoli to provide medial-lateral ankle stability without restricting tibiotalar motion.
Question 2: A patient presents with a limb length discrepancy of 1.8 cm. Which evaluation tool provides the most clinically accurate measurement?
- Tape measure from ASIS to medial malleolus
- Standing block test
- Scanogram (orthoroentgenogram) (Correct answer)
- Visual gait observation
Correct answer: Scanogram (orthoroentgenogram)
Scanogram provides the most accurate measurement of limb length discrepancy by using serial radiographic exposures of the hip, knee, and ankle on a single film with a ruler for reference.
Question 3: During gait analysis, a patient exhibits excessive lateral trunk lean toward the right stance limb. This compensatory pattern most likely indicates:
- Right hip flexion contracture
- Right hip abductor weakness (Correct answer)
- Left ankle plantar flexor weakness
- Right knee hyperextension
Correct answer: Right hip abductor weakness
Lateral trunk lean (Trendelenburg compensation) toward the stance limb reduces the external abductor moment demand when hip abductors are weak.
Question 4: A certified orthotic technician is fitting a patient with a rigid AFO. The patient reports pressure over the navicular tuberosity. Which measurement step was most likely inadequate?
- Ankle circumference at the malleoli
- Identification of bony prominences prior to casting (Correct answer)
- Measurement of foot length
- Assessment of hallux dorsiflexion range
Correct answer: Identification of bony prominences prior to casting
Failure to identify and mark bony prominences such as the navicular tuberosity before casting leads to pressure areas in the finished orthosis.
Question 5: When evaluating a patient's knee for an KAFO prescription, which measurement most directly determines the mechanical joint axis placement?
- Thigh circumference at mid-femur
- Medial joint line height from the floor (Correct answer)
- Patellar tendon length
- Posterior tibial declination angle
Correct answer: Medial joint line height from the floor
Medial joint line height from the floor is the primary measurement used to align the KAFO mechanical knee joint with the anatomical axis.
Question 6: Spasticity assessment using the Modified Ashworth Scale records a score of 3 for a patient's plantar flexors. This means:
- No increase in muscle tone
- Slight increase with catch and release
- Considerable increase limiting full PROM (Correct answer)
- Affected part is rigid in flexion or extension
Correct answer: Considerable increase limiting full PROM
A Modified Ashworth Scale score of 3 indicates considerable increase in muscle tone, making passive movement difficult but still possible.
Question 7: Which measurement is essential when fitting a thoracolumbosacral orthosis (TLSO) to ensure proper load transfer through the pelvis?
- Waist circumference
- Iliac crest height and inter-ASIS distance (Correct answer)
- Shoulder width
- Sternal notch to pubic symphysis distance
Correct answer: Iliac crest height and inter-ASIS distance
Iliac crest height and inter-ASIS distance are critical for positioning the TLSO pelvic section to achieve proper pelvic purchase and load transfer.
CTO Patient Evaluation & Measurement 2
When measuring a patient for a supramalleolar orthosis (SMO), which anatomical landmark is used to determine the proximal trim line height?