PROSTHETIC CPM COMPREHENSIVE EXAM 2026
QUESTIONS AND ANSWERS GRADED A+
✔✔What are the disadvantages to a hydraulic/pneumatic knee - ✔✔Costly, more
expensive
✔✔What are the advantages to an MPK - ✔✔Varied resistances depending on
situation/speed/incline, various different modes for different situations, most natural gait
✔✔What are the disadvantages to a an MPK - ✔✔Heavy/bulky, expensive, not always
covered by insurance
✔✔What are the measurement that will be given for a the TF bench alignment task -
✔✔KC-floor, IT to floor, heel height, flexion contracture.
Note whether KC-floor and IT-floor include shoe or not
✔✔What is the bench alignment for a TF prosthesis - ✔✔Sagittal= 5 degrees of socket
flexion plus contracture, 5-15 mm (1/4"-1/2") TKA anterior to knee center
Coronal= foot(center of heel) 30-50mm outset from ischium, socket adducted 6-8
degrees, 2-4" base of support
Transverse= Knee externally rotated 3-5 degrees, foot externally rotated 5-7 degrees,
medial wall in line of progression
✔✔What are some questions to always ask during the trouble shooting section -
✔✔Gained lost weight?
Activity level changed?
Limb volume change?
Changed shoes?
Donning liner/prosthesis correctly
Did the problem start at delivery or a time period after
Wearing socks
Is the patient a child/have they grown
Are there any gait deviation
Are they washing the liner
Are they wearing a shrinker
Do they feel like they are falling medially or laterally
Do they feel like the are walking up or down hill
✔✔What is the cause and solution to a patient with discoloration/blistering on distal limb
with appropriate socket fit - ✔✔Limb is being milked due to inappropriate liner donning
Solution: educate patient on how to properly don liner
, ✔✔What is the cause and solution to an upper limb patient with the TD opening with
elbow flexion - ✔✔Too much force/not enough excursion in system
Solution: Move EFA (Elbow Flexion attachment) distal, move Proximal Baseplate
Retainer(PBPR) Lateral, Anterior, Proximally, Add forearm lift assist, check housing
clearance, add rubber band
✔✔What is the cause and solution to an upper limb patient with a TD that will not open
all the way - ✔✔Too much excursion with in the system
Solution: Move EFA proximal, Move PBPR Distal, Medial Posterior, remove rubber
band, check housing clearance, add z strap, tighten CAS, add dual NW ring
✔✔What is the cause and solution to a patient with - ✔✔Lack of ischial containment,
lack of proximal control causing femur to adduct in socket
Solution- pad medially, until ischium is contained and if this is not possible, re make
socket
✔✔What is the cause and solution to a patient with - ✔✔Pushing through narrow
socket, add a window door
Solution" pad proximal to malleoli to offload, remake socket
✔✔What is the cause and solution to a patient with transtibial pain/redness on bottom,
distal Patel, and fibular head - ✔✔Bottoming out- solution add sock, pad pretibial and
popliteal area
✔✔What is the cause and solution to a knee disarticulation with pain on very
bottom/condyles - ✔✔Using too many socks/ not reaching the bottom
✔✔What is the cause of anterior proximal redness with a BK and solution - ✔✔Socket is
too extended , flex socket
Shoes were changed to lower heel height
✔✔What is the cause of anterior distal redness - ✔✔Socket too flexed- extend socket
Socket to anterior to foot- use offset plate to reverse
Shoe heel to height
AP too large- pad popliteal
✔✔What is the cause of tibial tubercle/proximal fibular head redness - ✔✔Too many
socks- reduce sock ply
QUESTIONS AND ANSWERS GRADED A+
✔✔What are the disadvantages to a hydraulic/pneumatic knee - ✔✔Costly, more
expensive
✔✔What are the advantages to an MPK - ✔✔Varied resistances depending on
situation/speed/incline, various different modes for different situations, most natural gait
✔✔What are the disadvantages to a an MPK - ✔✔Heavy/bulky, expensive, not always
covered by insurance
✔✔What are the measurement that will be given for a the TF bench alignment task -
✔✔KC-floor, IT to floor, heel height, flexion contracture.
Note whether KC-floor and IT-floor include shoe or not
✔✔What is the bench alignment for a TF prosthesis - ✔✔Sagittal= 5 degrees of socket
flexion plus contracture, 5-15 mm (1/4"-1/2") TKA anterior to knee center
Coronal= foot(center of heel) 30-50mm outset from ischium, socket adducted 6-8
degrees, 2-4" base of support
Transverse= Knee externally rotated 3-5 degrees, foot externally rotated 5-7 degrees,
medial wall in line of progression
✔✔What are some questions to always ask during the trouble shooting section -
✔✔Gained lost weight?
Activity level changed?
Limb volume change?
Changed shoes?
Donning liner/prosthesis correctly
Did the problem start at delivery or a time period after
Wearing socks
Is the patient a child/have they grown
Are there any gait deviation
Are they washing the liner
Are they wearing a shrinker
Do they feel like they are falling medially or laterally
Do they feel like the are walking up or down hill
✔✔What is the cause and solution to a patient with discoloration/blistering on distal limb
with appropriate socket fit - ✔✔Limb is being milked due to inappropriate liner donning
Solution: educate patient on how to properly don liner
, ✔✔What is the cause and solution to an upper limb patient with the TD opening with
elbow flexion - ✔✔Too much force/not enough excursion in system
Solution: Move EFA (Elbow Flexion attachment) distal, move Proximal Baseplate
Retainer(PBPR) Lateral, Anterior, Proximally, Add forearm lift assist, check housing
clearance, add rubber band
✔✔What is the cause and solution to an upper limb patient with a TD that will not open
all the way - ✔✔Too much excursion with in the system
Solution: Move EFA proximal, Move PBPR Distal, Medial Posterior, remove rubber
band, check housing clearance, add z strap, tighten CAS, add dual NW ring
✔✔What is the cause and solution to a patient with - ✔✔Lack of ischial containment,
lack of proximal control causing femur to adduct in socket
Solution- pad medially, until ischium is contained and if this is not possible, re make
socket
✔✔What is the cause and solution to a patient with - ✔✔Pushing through narrow
socket, add a window door
Solution" pad proximal to malleoli to offload, remake socket
✔✔What is the cause and solution to a patient with transtibial pain/redness on bottom,
distal Patel, and fibular head - ✔✔Bottoming out- solution add sock, pad pretibial and
popliteal area
✔✔What is the cause and solution to a knee disarticulation with pain on very
bottom/condyles - ✔✔Using too many socks/ not reaching the bottom
✔✔What is the cause of anterior proximal redness with a BK and solution - ✔✔Socket is
too extended , flex socket
Shoes were changed to lower heel height
✔✔What is the cause of anterior distal redness - ✔✔Socket too flexed- extend socket
Socket to anterior to foot- use offset plate to reverse
Shoe heel to height
AP too large- pad popliteal
✔✔What is the cause of tibial tubercle/proximal fibular head redness - ✔✔Too many
socks- reduce sock ply
