CPT Treatment Protocols & Procedures 2 — Questions and Answers
Question 1: During initial socket fitting for a transtibial amputee, which clinical sign most urgently requires immediate socket modification?
- Mild redness resolving within 20 minutes
- Persistent blanching over the fibular head (Correct answer)
- Slight pistoning during swing phase
- Minor discomfort at the distal pad
Correct answer: Persistent blanching over the fibular head
Persistent blanching over bony prominences like the fibular head indicates excessive pressure that can rapidly lead to tissue breakdown and requires immediate modification.
Question 2: A transfemoral prosthetic user reports the prosthetic knee flexes too easily during loading response. Which adjustment addresses this issue?
- Decrease stance flexion resistance
- Increase stance extension assist
- Increase stance flexion resistance (Correct answer)
- Adjust the toe break angle
Correct answer: Increase stance flexion resistance
Increasing stance flexion resistance in the prosthetic knee prevents unwanted knee flexion during the loading response phase of gait.
Question 3: Which suspension system for a transtibial prosthesis requires the least amount of residual limb volume stability to function effectively?
- Locking liner pin system
- Elevated vacuum suspension (Correct answer)
- Supracondylar suspension with wedge
- Simple sleeve suspension
Correct answer: Elevated vacuum suspension
Elevated vacuum suspension actively compensates for volume fluctuation by maintaining negative pressure within the socket, making it most tolerant of volume changes.
Question 4: When fabricating a check socket for a new amputee, what is the primary purpose of using a transparent material?
- To reduce fabrication costs
- To assess skin contact and pressure distribution visually (Correct answer)
- To improve patient psychological acceptance
- To test the durability of the socket design
Correct answer: To assess skin contact and pressure distribution visually
Transparent check sockets allow the clinician to visually assess areas of contact, air gaps, and pressure distribution while the patient is weight-bearing.
Question 5: A patient with a transtibial amputation experiences pistoning during ambulation. Which of the following is the LEAST likely cause?
- Volume loss in the residual limb
- Liner degradation
- Incorrect socket shape at patellar tendon bar (Correct answer)
- Worn or loose suspension sleeve
Correct answer: Incorrect socket shape at patellar tendon bar
Patellar tendon bar shape primarily affects pressure distribution and comfort, not pistoning, which is primarily a suspension-related problem.
Question 6: For a dysvascular amputee returning for a follow-up fitting visit, which assessment should be performed FIRST before any socket modifications?
- Gait analysis on parallel bars
- Inspection of the residual limb skin integrity (Correct answer)
- Measurement of prosthetic alignment
- Evaluation of prosthetic foot rollover
Correct answer: Inspection of the residual limb skin integrity
Dysvascular patients are at high risk for pressure injuries, so skin integrity inspection must be performed first to detect any early signs of breakdown before stressing the tissue further.
Question 7: Which thermoforming temperature range is typically used for low-temperature thermoplastics (LTTPs) used in check socket fabrication?
- 150–180°F (65–82°C) (Correct answer)
- 250–300°F (121–149°C)
- 350–400°F (177–204°C)
- 450–500°F (232–260°C)
Correct answer: 150–180°F (65–82°C)
Low-temperature thermoplastics soften and become formable between approximately 150–180°F, allowing safe draping directly over a plaster model or the patient.
CPT Treatment Protocols & Procedures 2
During initial socket fitting for a transtibial amputee, which clinical sign most urgently requires immediate socket modification?