PROSTHETIC MOCK EXAM Flashcards
The Ertl procedure is known as an osteomyoplastic amputation reconstruction that perfroms a bone bridge between what:
A. Tibia bridged with the fibula
B. Distal end of the radius and ulna
C. Distal end of femur bridged with the tibia
D. Humerus bridged with the ulna
A. The Ertl procedure uses an osteoperiosteal graft which is used for an arthrodesis of the tibia to the fibula. This offers improved weight distribution and is thought to aid in pain control.
A below knee amputee is seen in your clinic for a follow up appointment and states he feel anterior/distal discomfort in his prosthetic socket. Choose all correct answer(s) to address this problem:
A. extend the prosthetic socket
B. flex the prosthetic socket
C. add pretibial pads to the prosthetic socket
D. lower the posterior socket brim
A. Extending the socket moves pressure more proximal to the painful area.
C. Adding pretibial pads bridges the painful area so it receives less direct pressure
A below the knee amputee is seen in your clinic for a follow up appointment and states he has posterior knee or hamstring discomfort. Choose all correct answers(s) to address this problem:
A. lower the posterior medial brim on the prosthetic socket
B. extend the prosthetic socket
C. flex the prosthetic socket
D. Align prosthetic foot more posterior in relation to the prosthetic socket
A,C,&D
A. lowering the posterior brim relieve pressure on hamstring tendons
C. flexing the socket decreases tension on posterior knee joint and hamstring tendons
D. moving the prosthetic foot posterior decreases the toe lever whereby decreasing the extension moment at the knee
Which level(s) of amputation may lead to an equinus gait deformity:
A. Lisfranc amputation
B. Chopart amputation
C. Symes amputation
D. Transmetatarsal amputation
A,B,&D: Both the Lisfranc and Chopart amputation may result in an equinus deformity due to the dorsiflexor attachments, causing a patient to plantarflex their ankle. Transmetatarsal amputation transects the peroneus longus tendon which assists in first ray plantarflexion. This creates a muscular imbalance causing the muscles participating in supination to override muscles involved in pronation. The Symes amputation is through the articulation of the ankle and would not cause an equines deformity.
A below knee amputee presents in clinic wearing a PTB style endoskeletal prosthesis with general knee pain and distal end pressure. The patient doffs her prosthesis and liner, upon examination of her residual limb you note redness on the distal tibia and inferior aspect of the patella bone. what would be the most logical clinical action(s) you could take at this point in addressing this problem:
A. Recommend the patient be evaluated for a new liner that will provide cushioning to her residual limb.
B. Flex the prosthetic while concurrently plantar flexing the prosthetic foot
C. Add a gastroc pad to the prosthetic socket
D. Add a 1 ply prosthetic sock over liner
C&D
C. Adding a gastroc pad decreases socket volume effectively lifting the residual limb reducing patellar contact with the patellar bar and socket bottom.
D. Adding a prosthetic sock decreases socket volume effectively lifting the residual limb reducing patellar contact with the patellar bar and socket bottom.
Myodesis can be described as:
A. condition associated with calcification of muscle fibers
B. The suturing and permanent attachment of a muscle to bone
C. The suturing or permanent attachment of a muscle to another muscle
D. A muscle going through atrophy
B. Myodesis involves the attachment of a muscle to a bone.
Which of the following is not part of a symes amputation procedure:
A. removal of the malleoli “distal aspect”
B. Placement of thick heel pad
C. amputation through the articulation of the ankle
D. Transmetatarsal amputation
D. All the above are seen with a symes procedure except for amputation at the transmetatarsal level
Myoplasty can be described as;
A. A condition associated with the loss of sarcomerers
B. the suturing and permanent attachment of a muscle to a bone
The suturing or permanent attachment of a muscle to a bone
C. the suturing or permanent attachment of a muscle to another muscle
D. A muscle experiencing hypertrophy
C. Myoplasty involves the attachment of a muscle to another muscle
What are two advantages in the list below of myodesis over myoplasty with regards to amputation:
A. decreased rate of infection related revisions
B. decreased rate of muscular atrophy
C. decreased rate of antagonistic muscular imbalances
D. provides a bulbous distal residual limb for self suspending applications in TT and TF cases
B&C
B. Myodesis provides an anchor for muscle to pull against which encourages hypertrophy.
C. most joints in the body operate with the cooperation of antagonistic muscle groups, imbalances in these groups causes dysfunction in movement, myodesis try’s to maintain muscular balances.
During normal heel strike, the forward hip is how flexed:
A. neutral
B. 10 deg flexed
C. 25 deg flexed
D. 40 deg flexed
C. During normal heel strike the anterior hip is flexed to 25 degrees
Which style of muscular tissue management in an TH amputation would be of greatest advantage to a myoelectric prosthesis candidate:
A. myodesis
B. myoplasty
A. Myodesis can provide anchors for the muscles innervated by the musculocutaneous and radial nerves. This provides palpable, separable, antagonistic muscular contractions which are most likely to exhibit a strong myo-signal.
A TF patient is seen in clinic that exhibits lateral/proximal loss of contact in stance. Upon prosthetic fit examination it is noted the lateral wall is superior to the greater trochanter, the anterior wall contours to the adductor longus tendon, the posterior socket does not encompass the ischial tuberosity, the medial wall is located 65mm inferior to the perineum. What do you attribute to the cause of this deviation:
A. The posterior wall does not have ischial containment
B. the lateral wall is located too proximal for an ischial containment socket
C. the patient is causing the deviation from antalgic gait secondary to adductor longus tendon socket pressure
D. The medial wall is located too far inferior to the perineum
D. When a medial wall is located too distal, the counter force with lateral wall is lost causing the socket gap laterally, impinging the adductors, and losing optimal grasp of the ischial tuberosity.
With a Krukenberg procedure what muscle is the driver of the pincer grip:
A. Supinator
B. Pronator teres
C. Brachioradialis
D. Flexor carpi radialis
B. The Krukenburg procedure is used at times with below elbow amputations. It relies on the strength of the pronator teres for the patient to use a pincer grip between the radius and ulna which have been separated.
What would be a good quality(s) to look for in a prosthetic foot for a TT amputee who is K2 designated household ambulator that utilizes his prosthesis efficiently during the day but fatigues in the evening and buckles at the knee secondary to quadriceps weakness:
A. foot that progresses rapidly into plantar flexion during loading response
B. foot that progresses slowly into plantar flexion during loading response
C. heel should have a relatively firm durometer
D. heel should have a relatively soft durometer
A&D
A. Feet that plantar flex rapidly from heel strike to foot flat keep the ground reaction force anterior to the knee joint whereby increasing knee stability
D. feet with soft heels or plantar flexion bumper keep the ground reaction force anterior to the knee joint whereby increasing knee stability and workload across the knee extensors (quadriceps)
Today in clinic a TT patient is seen presenting with a traditional exoskeletal PTB prosthesis with a SACH foot. Patient states that she feels like the prosthesis is throwing her knee forward as soon as the heel firmly contacts the ground. She has worn this prosthesis comfortably for two years until one month ago. What should be the first clinical action you should take at this time in the appointment:
A. plantar flex the prosthetic foot
B. dorsiflex the prosthetic foot
C. check to see if the patient switched to a shoe with a higher heel height compared to what she used to wear
D. check to see if the patient switched to a shoe with a lower heel height compared to what she used to wear
C. switching to a higher heel shoe “relatively dorsiflexing the foot will induce a flexion moment about the knee. Since this is an exoskeletal prosthesis you cannot make real alignment changes to remedy the problem
The Krukenburg procedure is used at times in developing countries where expensive prosthesis are not attainable. What other patient population(s) would this be potentially used for:
A. blind patients with bilateral below elbow amputations
B. unilateral above elbow amputee
C. a patient concerned with the cosmetic appearance
D. failed prosthetic use for bilateral below elbow amputations
A&D: Krukenburg procedure is used in third world countries along with developed countries with blind patients with bilateral below elbow amputations as with the Krukenburg procedure sensation and proprioception is preserved. Also patients that have failed with use of prosthetics may consider this procedure for improved function and grip.
A TR patient is seen in your clinic. The patient is inquiring as to which terminal device would be best for picking up a small coin from a table. Which device would you recommend:
A. 555
B. #7
C. 5XA
D. a mechanical prosthetic hand
C. The 5XA has a non-symmetrical or “canted” approach which allows better vision of the object being manipulated whereby making it easier to grasp the object as opposed to the other options which can interfere with the users ability to see what they are doing
What are simple option(s) for increasing the ease of pre-positioning the prosthetic elbow in flexion, for a TH amputee utilizing a body powered prosthesis who lack glenohumeral flexion strength and biscapular abduction strength but can operate an elbow lock:
A. have the forearm lift tab located distally/anterior
B. have forearm lift tab moved proximal/anterior
C. move proximal base plate and retainer on humeral section posterior
D. check the level resistance in the cable housing
A&D
A. by moving the forearm lift tab anterior/distal you move the pull angle anterior to bridge the elbow joint where by decreasing the force necessary to move the forearm section about the humeral section.
D. This is overlooked commonly
What bony landmark is utilized for a weight bearing prosthesis in a hip disarticulation:
A. pubic rami
B. greater trochanter
C. ischial tuberosity
D. iliac crest
C. with hip disarticulations you would utilize the ischial tuberosity just as with above knee prosthesis
What is an option for pre positioning the prosthetic elbow in flexion, for a TH amputee utilizing a triple control body powered prosthesis who lacks glenohumeral flexion strength and biscapular abduction strength but can operate an elbow lock:
A. have the forearm lift tab located posterior/proximal
B. have forearm lift tab moved proximal
C. change triple control to dual control, switch split housing to single housing, utilize ballistic motion for forearm lift
D move NW ring laterally towards the prosthetic side
C. This is an option for “gathering” vs. “harnessing” energy for use as a force elsewhere.
Why is choosing a SACH foot with a firm heel durometer not advised for TT patients with poor prosthetic side knee stability:
A. it will increase knee stability
B. it will decrease knee stabiliy
C. it will increase shock absorption at heel strike
D. it will not provide enough keel resistance
B. SACH feet with firm heel hurometer moves the ground reaction force posterior to the knee inducing a flexion moment whereby decreasing knee stability
You are doing a gait assessment with your patient that has a below knee prosthesis. You notice that there is lateral trunk bending at mid stance to the prosthetic side. Choose the choice that would NOT be a potential cause of this gait deviation:
A. prosthesis too short
B. residual limb pain
C. prosthesis too long
D. weak quadriceps
D. Weak quadriceps would not account for lateral trunk bending but would contribute to abrupt knee flexion
A TF patient is seen in your clinic. It is noted that as he ambulates with a circumducted gait. Select ALL possible causes:
A. prosthesis height is longer than his sound side ischial tuberoisty to floor measurement
B. prosthetic suspension is not adequate
C. the user does not have adequate hip flexor strength
D. prosthetic foot is plantar flexed excessively
A,B,C,&D
A. if the prosthesis is too long the patient may circumduct to clear the prosthetic foot
B. if the prosthesis does not suspend well the patient may circumduct to clear the prosthetic foot
C. if the patient does not have adequate hip flexor strength other muscles may be recruited to clear the prosthetic foot
D. excessively plantar flexed feet create a relative leg length discrepancy causing the patient to circumduct to clear the prosthetic foot.
A TF patient is seen in your clinic. In stance, the prosthetic foot “smears” externally as she simultaneously abducts her prosthesis whereby advancing forward in the sagittal plane. She complains of low back pain as well. What is a prosthetic cause:
A. prosthetic keel too short
B. prosthetic knee has too little resistance to flexion
C. not enough flexion is built into the socket
D. prosthetic socket is excessively flexed
C. If inadequate flexion is built into the TF socket the patient will develop gait deviations utilizing compensatory motions for forward progression. Inadequate flexion of the socket will cause compensatory hyperlordorsis, causing discomfort for the patient over time
A patient with an above knee amputation has a prosthesis. During gait analysis you find that she has knee instability while standing and you see knee buckling with any weight shift. You suspect the cause of the instability is:
A. prosthetic knee set too far posterior to the TKA line
B. tight extension aid
C. prosthetic knee set too far anterior to the TKA line
D. weak hip flexors
C. for knee stability in a prosthesis the knee is aligned posterior to the trochanter knee ankle line. If the knee is set anterior to the TKA line the stability will be poor and can cause buckling. An extension aid helps with extension during swing phase. Weak hip flexors would influence swing through of the prosthetic limb but would not cause knee instability
TT prosthetic sockets that are excessively extended cause excessive pressure in what areas:
A. anterior/proximal
B. anterior/distal
C. posterior/distal
D. posterior/proximal
A&C
TT prostheses with excessively extended sockets concentrate pressure ant/prox, post/dist as it creates an extension moment across the knee
T/F, outsetting the prosthetic foot on a TT prosthesis socket pressure medial/distal and lateral/proximal:
A. True
B. False
A-True
This will cause a valgus moment at the knee
A forequarter amputation removes what structures:
A. femur and half of pelvis
B. femur and acetabulum
C. arm, clavicle, and scapula
D. arm and scapula
C. describes a forequarter amputation
A TT patient is seen in clinic. Upon examining gait you notice a mild extension moment at the knee in stance phase. What could be the cause? Note: alignment is proper:
A. prosthetic keel too short
B. prosthetic heel is too firm
C. prosthetic keel is too soft
D. prosthetic heel is too soft
D. soft prosthetic heels will cause the ground reaction force to be anterior to the knee whereby causing an extension moment in stance
When choosing if a prosthetic patient is a gel liner candidate, which of the following option(s) would assist you in this decision:
A. general hygiene
B. hand dexterity
C. k-level
D. allergies
A,B,C,&D
A. because a prosthetic socket does not circulate fresh air, body temperature, and the fact that gel is porous it creates an environment optimal for breeding bacteria
B. poor hand dexterity may cause donning to be difficult
C. activity level is important as gel durometer varies from model to model which may impact your decision
D. gel composition varies between manufactures and models allergies need to be considered
In a transmetatarsal amputation you would expect to see what gait deviation:
A. absent push off
B. absent heel strike
C. foot drop due to loss of dorsiflexion
D. loss of supination during gait
A. with transmetatarsal amputations gait deviations include limited push off on the affected side along with diminished stance phase. You would not expect to see any of the other gait deviations as the muscle tendinous insertions remain intact to perform dorsiflexion and supination.
Dorsiflexing the prosthetic foot is synonymous with________________:
A. flexing the prosthetic socket
B. extending the prosthetic socket
C. switching to a shoe with a lower heel height
D. switching to a shoe with a wider heel
A. dorsiflexing the prosthetic foot is the same as flexing the prosthetic socket
Why is it necessary to utilize a Berkeley alignable componentry prior to final fabrication of an exoskeletal prosthesis:
A. this will allow alignment changes in the final prosthesis
b. this will allow you to align the prosthesis properly as exoskeletal prostheses cannot be re-aligned
C. this will make the prosthesis more cosmetic
D. none of the above
B. Berkeley alignable componentry simulate endoskeletal componentry but differ in that they are only utilized prior to final fabrication for alignment purposes. This can save you time and the frustration of re-fabrication in exoskeletal applications
What muscle group would you expect to be the weakest in an above knee amputee:
A. hip flexors
B. hip abductors
C. hip extensors
D. hip adductors
D. Hip adductors would expected to be weak due to their transection. The shorter the amputation the weaker expected. Hip extension may be slightly weaker due to the loss of the adductor magnus which also aides in extension
When flexing an AK socket to accommodate a flexion contracture what concurrent alignment adjustment should also be made:
A. dorsiflex the prosthetic foot
B. plantarflex the prosthetic foot
C. move the prosthetic knee anterior
D. move the prosthetic knee posterior
D. when ever you flex an AK socket this moves the prosthesis weight line posterior to the prosthetic knee whereby decreasing knee stability. By making a linear adjustment moving the prosthetic knee posterior knee stability can be maintained. Note: always utilize manufacturer instructions for pinpointing knee location with respect to the socket
An AK patient is seen in clinic. When ambulating the patient complains of knee instability. What alignment change could possible assist in regaining knee stability:
A. flex the prosthetic foot
B. move the prosthetic knee anterior relative to the socket
C. move the prosthetic knee posterior relative to the socket
D. move the prosthetic foot posterior relative to he prosthetic knee and socket
C. by making a linear adjustment moving the prosthetic knee posterior we can decrease ground reaction forces running posterior to the knee center whereby promoting knee stability
With a knee disarticulation amputee what is a cosmetic concern:
A. knee extends too far out when sitting or kneeling
B. leg length discrepancy
C. the non amputated side extends too far past the surgical knee side
D. Knee too bulky
A. with a knee disarticulation one concern is the leg length discrepancy seen when a patient is sitting or kneeling. However the patient would not have an actual leg length discrepancy when standing and walking. The knee joints in the past, used to be more bulky but with modern prosthetics this is not as much of a concern.
An AK patient is seen in clinic. When ambulating the patient complains of knee instability. What alignment change could possible assist in regaining knee stability:
A. extend the prosthetic socket
B. move the prosthetic knee anterior relative to the socket
C. shorten the overall height of prosthesis
D. move prosthetic socket posterior in relation to the prosthetic knee
A. by making an angular adjustment moving the prosthetic socket into extension we can decrease ground reaction forces running posterior to the knee center whereby promoting knee stability. Note: extend socket with caution as to not cause hyperlordosis when range of motion at the hip is limited.
When making an angular change utilizing endoskeletal componentry it is necessary to:
A. loosen the bolt opposite the direction of desired angulation and tighten the opposing bolt on the side of desired angulation
B. loosen the bolt on the side of desired angulation and tighten the opposing bolt opposite the side of desired angulation
A. endoskeletal componentry can be counter intuitive but in general you always tighten the bolt on the side of desired angulation
Choose all the apply to the benefit of a knee disarticulation over an above knee amputation with prosthetic fit:
A. socket rotational control
B. natural weight bearing surface
C. muscular balance equalized with abductors and adductors
D. large surface area for prosthetic sockets
E. all the above
E. all the above are reasons that describe the benefits of a knee disarticulation over an above knee disarticulation in regards to prosthetic fit
When removing endoskeletal prosthetic componentry for adjustment, how do you save your original alignment:
A. completely back out two opposing bolts
B. completely back out three adjacent bolts
C. completely back out two adjacent bolts
D. completely back out all bolts
C. backing out two adjacent bolts you can then rely on the remaining two “untouched” bolts to hold the memory of the previous alignment when you re-assemble the prosthesis
In general polycentric prosthetic knees are considered inherently stable. Why is this:
A. polycentric knees have multiple linkages which increases resistance to flexion
B. polycentric knees have a theoretical knee center which is located posterior and superior
C. polycentric knees are difficult to bend manually and under body weight the resistance increases making them even more difficult to bend
D. polycentric knees utilize fluid friction which resist fast motions such as knee buckling
B. Polycentric knees have a centrode which is a projection of the linkages specific to each brand of knee. this projection is like two lines converging more superior and posterior to the actual physical knee unit which can decrease ground reaction forces running posterior to the theoretical knee center whereby promoting knee stability
Which of the following is not part of the Scarpa’s triangle:
A. rectus femoris
B. inguinal ligament
C. sartorius
D. adductor longus
A. rectus femoris is not part of the Scarpa’s triangle. Adductor longus, sartorius and inguinal ligament are the boundaries of the triangle.
Choose all answers that are considered benefits of polycentric knees:
A. they relatively shorten in swing phase of AK prosthetic gait
B. they provide increases cosmesis when sitting
C. they are inherently stable
D. They have less moving parts when compared to other prosthetic knee designs
A,B,&C
A. polycentric knees when flexed allow the linkages to work in coordination to fold relatively compact whereby decreasing the distance between the socket and foot which allows for greater prosthetic foot clearance.
B. polycentric knees when flexed allow the linkages to work in coordination to fold relatively compact which can assist in matching knee centers on longer residual limbs when sitting increasing cosmesis.
C. polycentric knees have a centrode which is a protection of the linkages specific to each brand of knee. This projection is like two lines converging more superior and posterior to the actual physical knee unit which can decrease ground reaction forces running posterior to the theoretical knee center whereby promoting knee stability.
T/F: In a TT amputation, when trying to increase the energy return of a dynamic response foot it may be necessary to increase plantarflexion:
A. True
B. False
A-True
By plantarflexing the prosthetic foot, forefoot pressures increase relatively earlier in stance which allows greater energy to build up “stored” to be released in terminal stance.
The gait cycle is composed of what:
A. heel strike on one side followed by heel strike by the same foot
B. heel strike to push off
C. heel strike on one side followed with heel strike on the other side
D. push off on one side followed by push off on the opposite side.
A. Gait cycle is heel strike followed by heel strike on the same side
A TH patient is seen in clinic. The patient is utilizing a body powered prosthesis with a Hosmer mechanical elbow and complains that he can operate it throughout its full range of motion but it requires too much effort. What could you do to remedy this:
A. dial the automatic forearm balance mechanism located proximal posterior on the forearm shell
B. install a spring lift assist
C. lengthen the forearm section 10mm
D. switch the terminal device from a 5XA hoo, to a #7 hook
B. By installing a spring lift assist you can decrease the effort required to flex the prosthetic elbow throughout its ROM
What is a simple option for pre positioning the prosthetic elbow in flexion, for a TH amputee utilizing a body powered prosthesis who lacks glenhomumeral flexion strength and biscapular abduction strength but can operate an elbow lock:
A. have the forearm lift tab located proximal and anterior
B. have forearm lift tab moved proximal and anterior
C. move the proximal base plate and retainer on humeral section anterior
D. move proximal base plate and retainer on humeral section posterior
C. by moving the control cable retainer on the humeral section anterior you move the pull angle anterior to bridge the elbow joint whereby decreasing the force necessary to move the forearm section about the humeral section.
During many amputations the surgeon will perform a myoplasty. What does this consist of:
A. surgical attachment of muscle to muscle
B. surgical attachment of the muscle to bone
C. bone bridge between two bones, artificial joint ossification
D. surgical replacement of a joint due to osteoarthritis
A. During some amputations myoplasties “muscle to muscle” are used such as with an above knee amputation with the quadriceps muscle. When possible myodesis “muscle to bone” is used as it gives the cut muscle an anchor to pull from whereby promoting hypertrophy. An arthrodesis is used in the case of the Ertl procedure with a bone bridge of the fibula to the tibial. Arthroplasty is the procedure for joint replacements.
T/F: When fabricating a TR figure of eight harness it is necessary to incorporate elastic materials in the control strap:
A. True
B. False
B-False
When fabricating a TR figure of eight harness inelastic material must be utilized to capture maximal cable excursion where as excursion will be lost within the elastic material
