Amputations
Braces
Prosthetics
Complications
Equipment
100
You are rounding on an 82 year-old female with a past medical history of uncontrolled diabetes mellitus with severe physical deconditioning secondary to multiple bouts of pneumonia. She is status-post right transtibial amputation due to complications from diabetes. She asks you which type of lower extremity prosthesis you are planning to prescribe for her. You are of the opinion that she will remain nonambulatory for the rest of her life. Which of the following best describes her K-level of ambulation?
A. K3
B. K2
C. K1
D. K0
D.K0
K levels describe how functional of an ambulator a patient is projected to be K0 = nonambulatory - “zero prosthesis” K1 = limited household ambulator, fixed cadence K2 = unlimited household; limited community ambulator; fixed cadence K3 = unlimited community ambulator, variable cadence K4 = high impact activities; sports, variable cadence
100
What is the minimal number of points of contact that an orthosis must have in order to exert rotational control?
A. One
B. Two
C. Three
D. Four
C. Three
Rotational control forces or moments across a joint are not effective unless there are at least 3 points of contact between the device and the limb segment.
100
At what developmental stage should a child with congenital transverse radial limb deficiency be fitted for an initial prosthesis?
A. At the time of starting kindergarten
B. As soon as possible after birth
C. At the time of first sitting independently
D. At the time of initially walking
C. At the time of first sitting independently
Children with unilateral transverse radial limb deficiency should be “fit to sit,” meaning fitted by 6 months of age with an initial prosthesis that has a passive terminal device.
100
Which of the following is a risk factor associated with increased incidence of phantom pain?
A. Younger age
B. Upper extremity amputation
C. Early prosthesis fitting
D. Proximal amputation
D. Proximal amputation
The pathophysiology of phantom pain is not entirely understood. Postulated mechanisms include changes in the central nervous system, such as cortical reorganization in the primary somatosensory cortex, and alterations in the peripheral nervous system, such as increased sodium channel expression in nerves causing spontaneous evoked potentials and increased presence of substance P in dorsal horns. Regardless of cause, phantom pain is experienced in the majority of patients following amputation. It is more commonly seen in patients with proximal amputations, shorter residual limbs (D), lower extremity amputation, bilateral amputees, patients with history of infection, and patient with pain in the amputated limb prior to amputation. Phantom pain is not common in children or congenital amputees. In adults, etiology of amputation, age, gender, and laterality of amputation do not have a correlation with occurrence of phantom pain.
100
What is the primary disadvantage of moving the rear axle of a wheelchair forward?
A. Wheelies become easier
B. It takes more muscle effort to propel the wheelchair
C. More strokes are required to propel the wheelchair
D. Ascending a ramp becomes more difficult
D. Ascending a ramp becomes more difficult
Moving a wheelchair's rear axle forward enables the user to propel the chair with less muscle effort and fewer strokes. Because the modification causes more weight to be centered over the rear wheels, it is easier to pop a wheelie, negotiate obstacles and ascend or descend curbs. However, moving the axle forward can also make the wheelchair more likely to tip backwards thus making it more difficult to propel the chair up a ramp.
200
In preparation for the residual limb to accept a prosthesis, which of the following is the ideal shape of the residual limb following a transfemoral amputation?
A. Cylindrical
B. Ovoid
C. Conical
D. Rhomboid
A. Cylindrical
Cylindrical is the ideal shape for a transtibial residual limb. Conical is the ideal shape of a transfemoral residual limb.
200
When looking at spinal orthoses effects on normal cervical motions from the occiput to the first thoracic vertebra, which device limits the most in all areas of flexion, extension, lateral side bending and rotation?
A. Philadelphia collar
B. Soft collar
C. Four poster brace
D. Halo device
D. Halo device
The Halo device limits the most movement in all areas, followed by the four-poster brace, and then Philadelphia collar. The soft collar allows for the most movement.
200
What is the primary advantage of a soft insert or liner fitted into the socket of a transtibial prosthesis?
A. Perspiration resistant
B. Easy to keep clean
C. Skin protection
D. Very durable
C. Skin protection
Soft inserts are fabricated to fit inside the socket. They are recommended for patients with thin, sensitive, or scarred skin, or peripheral vascular disease (PVD). They are easily modified. Hard sockets also have their advantages. They are perspiration resistant, less bulky than sockets fitted with a soft insert, easy to keep clean, and durable. Further, reliefs or modifications can be located with precision in the hard socket.
200
A 7-year-old child undergoes a right transtibial amputation for a mangled limb after his leg was caught underneath a push lawnmower. What is the most common complication following an acquired amputation in a child?
A. Phantom limb pain
B. Neuroma
C. Infection at site of incision
D. Terminal Overgrowth
D. Terminal Overgrowth
In a child with an acquired amputation, terminal overgrowth at the transected end of a long bone is the most common complication. This typically requires surgical revision. For this reason, disarticulations are often considered in growing children when determining the level of amputation; disarticulations maintain the growth centers of long bones in a growing child. The other complications are possible but not as common as terminal overgrowth. In general, the risk of phantom limb pain following amputation is decreased with younger age.
200
What is the ideal grip height of a rolling or standard walker?
A. Permits full weight bearing through the arms
B. Positioned with the elbow at least 40° of flexion
C. Level with the greater trochanter of the hip
D. May vary depending on the underlying condition requiring its use
C. Level with the greater trochanter of the hip
When properly fit, the height of the grips of a walker or cane should be near the level of the greater trochanter of the hip; this permits a 20° flexion in the elbow. This also corresponds to the position of the ulnar styloid with the arms in a comfortable position. A rolling or standard walker, in use for normal ambulation, is not meant to permit full weight bearing, but rather improve balance by providing a larger base of support. The proper height of an assistive ambulatory device does not change based upon its intended use.
300
Which of the following accurately describes a Lisfranc amputation?
A. Occurs between the tarsal and metatarsal bones
B. Plantar flexion contractures are a common complication
C. Requires a “stovepipe” design prosthetic socket
D. Occurs more proximal than a Chopart amputation
A. Occurs between the tarsal and metatarsal bones
A Lisfranc partial foot amputation occurs in the midfoot, between the tarsal and metatarsals, essentially a disarticulation of all metatarsals. The length of the foot that remains is insufficient to wear a normal shoe alone, but a normal shoe can be worn with an appropriate AFO or full-length shoe insert with distal padding. Plantarflexion contractures occur after Chopart amputations from unopposed plantarflexion in view of the loss of dorsiflexor insertions. A stovepipe socket is a design associated with Syme's amputation. A Lisfranc amputation is more distal than a Chopart amputation.
300
A resting wrist-hand-orthosis (WHO) has which of the following characteristics?
A. Distal and proximal interphalangeal joint extension
B. Thumb in maximum radial abduction
C. Wrist in neutral position
D. Metacarpal phalangeal joint extension
A. Distal and proximal interphalangeal joint extension
A resting hand orthosis is commonly prescribed for the hemiparetic, or mildly spastic distal upper extremity to maintain the hand in a functional position. This position includes the wrist slightly/moderately “cocked-up” between 10-30° hyperextension, the metacarpal phalangeal joints mildly flexed, the proximal and distal interphangeal joints in extension, and the thumb halfway between palmar and radial abduction. This position (commonly referred to as a Functional “C” position) reduces the stress on the respective joints, reduces hypertonicity, and permits greater opportunity for functional restoration.
300
Which of the following is true regarding the pylon of a lower extremity prosthesis?
A. Exoskeletal is less durable
B. Endoskeletal tends to require less maintenance
C. Exoskeletal is easily adjusted after fabrication
D. Endoskeletal tends to weigh less
D. Endoskeletal tends to weigh less
Exoskeletal prostheses are more rugged, require less maintenance, cannot be adjusted for alignment after fabrication, and can accommodate only a restricted number of foot and knee units. Furthermore, these prostheses tend to weigh more than the equivalent endoskeletal prostheses. For these reasons, exoskeletal prostheses are prescribed less often than endoskeletal prostheses. Endoskeletal prostheses are modular in design, allowing relative ease of adjustment of alignment and replacement of parts. They are also easier to suspend by virtue of their relatively lighter weight.
300
A 57 year-old female presents for follow-up after receiving her definitive left transtibial prosthesis. She has been undergoing prosthetic gait training at your facility. Today she tells you that her left distal residual limb has been hurting while she ambulates using her prosthesis. She denies numbness or tingling. On physical examination, you detect red and firm skin at the distal residual limb. You diagnose venous choke syndrome. Which of the following is the most likely cause of this presentation in this patient?
A. Excessive residual limb sweating
B. The patient is walking too often
C. Excessive knee flexion during gait
D. The socket is too tight
D. The socket is too tight
Too tight of a prosthetic socket can cause venous choke syndrome: impaired venous outflow in the residual limb due to an ill-fitting (too tight) socket constricting blood flow; this can lead to red and firm/indurated skin at the residual limb. If left untreated, verrucous hyperplasia (warts) and venous stasis ulcers may develop. Treatment involves improving socket fit by adjusting sock ply or by fabricating a new total-contact fit socket.
300
Prescribing power mobility in young children has been shown to:
A. increase receptive language level.
B. decrease social functional skills.
C. increase level of caregiver assistance.
D. negatively impact self-care abilities.
A. increase receptive language level.
In children who are typically developing, the ability to move independently has been shown to influence self-awareness, emotional attachment, spatial orientation, fear of heights and visual/vestibular integration as well as personality traits such as motivation and initiation. Children who have restricted mobility tend to have passive, dependent behavior and this can have long lasting cognitive, emotional, and social consequences. When children use great effort to move short distances, they will not be able to engage in play or have the same psycho-social experiences as their peers. For these reasons, therapists have begun to emphasize meaningful participation rather than exclusively focusing on development of normal movement patterns. No longer is power mobility only considered for older children, as a last resort, once all other forms of mobility had been found to be ineffective.
400
In children, which of the following is an advantage of a through-joint disarticulation compared to a transection amputation?
A. Reduced rotational control in the prosthesis
B. Absence of terminal overgrowth
C. Lower incidence of phantom pain
D. Reduced epiphyseal growth
B. Absence of terminal overgrowth
Terminal overgrowth is avoided in through-joint disarticulation. The most common surgical complication among traumatic juvenile amputees is terminal osseous overgrowth of the transected bone. In below-knee amputations overgrowth involves the fibula more often than the tibia. The phenomenon is best explained by high osteogenic activity of the child's periosteum-perhaps further stimulated by weight bearing within the prosthesis-resulting in a cartilaginous spike that slowly ossifies.With regards to phantom pain there is no difference between a through-joint disarticulation versus a transection. Rotational control in the prosthesis is supplemented in through-joint disarticulation. Epiphyseal growth is preserved in through-joint disarticulation.
400
What is the primary goal of treatment with orthotic bracing for scoliosis from neuromuscular disease?
A. Improve sitting posture in wheelchair
B. Arrest spinal curve progression
C. Improve respiratory function
D. Decrease falls in ambulatory patients
A. Improve sitting posture in wheelchair
Scoliosis in neuromuscular disease is very common and can begin early and progress quickly. Neuromuscular curve progression is rarely slowed by bracing. Orthoses may be beneficial because they can stabilize a weak trunk, and improve sitting posture in those using wheelchairs. Bracing may cause instability for ambulatory patients however, increasing the risk for falls. Rigid spinal bracing has a negative effect on vital capacity
400
What is the primary advantage of an ischial containment socket over a quadrilateral socket in a transfemoral amputee?
A. A narrower anterior–posterior dimension that contains the pubic ramus and ischial tuberosity
B. A flat ischial seat, which provides a primary weight bearing surface for the ischium and gluteal muscles
C. Promotion of femoral adduction by distributing the pressure through the socket along the shaft of the femur
D. Allowance of the gluteus medius to contract and force the femur into the distal-lateral wall of the socket
C. Promotion of femoral adduction by distributing the pressure through the socket along the shaft of the femur
An ischial containment socket is designed to stabilize the socket on the residual limb and to control socket rotation by containing the ischial tuberosity and the pubic ramus within the contours of the socket with a snug medio-lateral dimension. This socket has a sub-trochanteric contour that holds the femur in adduction and distributes the pressure through the socket along the shaft of the femur. Option A is incorrect because its anterior-posterior dimension is wider than the quadrilateral socket. Options B &D describe the quadrilateral socket.
400
A 28-year-old patient with a transradial amputation due to trauma presents two days after initial fitting of his prosthesis with complaints of discomfort. Your exam reveals that the discomfort arises over a bony prominence of the distal radius. Your initial recommendation is to:
A. Add padding to the inner wall
B. Line the inner wall with silicone
C. Reshape the socket's inner wall
D. Replace the socket
C. Reshape the socket's inner wall
A poorly fitting upper limb prosthetic socket can cause local irritation or discomfort. Bony prominences such as the radial and ulnar styloid processes and the humeral condyles are particularly vulnerable. Skillful reshaping of the socket's inner wall usually provides relief. Socket modification must redistribute pressure while maintaining a secure fit that can resist slippage and rotary forces. Adding padding or other materials in the area of irritation is not usually indicated, because the padding creates additional pressure. Lining the socket with silicone can reduce friction if shear is the culprit. If the prosthetist cannot relieve these areas by grinding or reshaping the socket, socket replacement is indicated.
400
Which of the following would typically be specified in a shoe prescription for a patient with a Charcot foot?
A. Lace stays sown to the base of the throat (Balmoral throat)
B. Rocker-bottom sole
C. Laced closure across the throat
D. Flexible heel counter
B. Rocker-bottom sole
The purpose of custom shoe prescription in someone with a Charcot foot is to minimize the forces the foot sees during standing/ambulatory activity. When entering the shoe, a large, wide throat assists in reducing trauma to the forefoot and heel by shearing forces. This can be done by prescribing that the shoe has a Blucher opening, where the bottom of the lace stays are not sewn together across the base of the throat (as is the case with a Balmoral opening). Using a Velcro strap in place of lacing across the throat reduced the static pressure the upper of the shoe places on the dorsal surface of the foot. A high and wide toe box reduces pressure around the toes and metatarsal heads (particularly #1 & #5), while a firm heel counter captures the heel to reduce movement of the foot within the shoe, and aids in controlling the shoe during activity. A custom insert to further relieve static pressure along the plantar surface of the foot and support the longitudinal and mediolateral arches can reduce further orthopedic injury. Finally, incorporating a rocker bottom into the rubber sole of the shoe will significantly reduce the dynamic pressure experienced by the foot during stance phase by minimizing the plantar area in contact with the ground at any one time.
500
How much pronation/supination can occur in the residual limb of a wrist disarticulation?
A. 0 degrees
B. 60 degrees
C. 120 degrees
D. 180 degrees
C. 120 degrees
A patient with a wrist disarticulation can commonly perform up to 120 degrees of pronation/supination. Supination and pronation is largely preserved.
500
A 37-year-old male with Becker Muscular Dystrophy presents for a bracing evaluation. He is noted to have full passive range of motion in all lower extremity joints. Manual muscle testing shows 4/5 initial strength in hip flexors/extensors and knee flexors; 3/5 knee extensors, and flaccid dorsiflexors. The patient ambulates without assistive device for 20 feet with a hyperextended trunk, reciprocal gait pattern, and increased step height. Initial contact occurs through bilateral forefeet, with moderately severe bilateral knee hyperextension at midstance. Which bilateral AFO design will minimize weight, maximize compliance and prevent genu recurvatum?
A. Carbon fiber ground force reaction spiral AFOs
B. Molded articulated thermoplastic AFO with a plantarflexion stop set in slight dorsiflexion
C. Solid thermoplastic AFO with anterior malleolar trim lines aligned in dorsiflexion
D. Posterior leaf spring thermoplastic AFO aligned in a neutral ankle position
B. Molded articulated thermoplastic AFO with a plantarflexion stop set in slight dorsiflexion
Although a knee-ankle-foot orthotic would be the ideal choice, most patients with moderate to severe lower extremity weakness find them too heavy, and contribute to overall fatigue. Remembering closed chain kinetics, knee extension will be encouraged by plantarflexion of the ankle, and discouraged by dorsiflexion. The flexibility of a posterior Leaf Spring thermoplastic AFO or spiral AFO, though lightweight and assisting with foot drop, will not prevent this patient's knee hyperextension (genu recurvatum). An AFO set in slight dorsiflexion would help to inhibit knee hyperextension by promoting knee flexion. However, if too much dorsiflexion is permitted, his knee might buckle due to knee extensor weakness. An articulated AFO would allow the flexibility to adjust the degree of dorsiflexion appropriately, whereas a solid AFO would not.
500
Which of the following methods of controlling a myoelectric hook on a transradial prosthesis is the easiest to learn to operate functionally?
A. Two-site/two-function with the electrodes placed over the flexors/extensors of the arm
B. Two-site/two-function with the electrodes placed over the flexors/extensors of the forearm
C. One-site/one-function with the electrode placed over the flexors of the arm
D. One-site/one-function with the electrode placed over the flexors of the forearm
B. Two-site/two-function with the electrodes placed over the flexors/extensors of the forearm
There are three ways to control a myoelectric terminal device in an upper extremity prosthesis. One-site/two-function controls are typically difficult to control as each function is generated through different levels of muscular contraction for operation. For example, strong contraction of the residual flexor digitorum superficialis may close the terminal device, while a weaker contraction will open the device. A two-site/two-function control system can potentially utilize the appropriate physiologic muscles to control corresponding functional activity of the terminal device. Placing the voluntary opening electrode over the forearm extensors and the voluntary closing electrode over the forearm flexors will result in natural functional movement of the terminal device. Using the two-site/two-function control system with the arm flexor and extensor muscles of the residual limb would be more difficult to learn. This requires the patient to learn to isolate a portion of each muscle for device control, without flexing or extending the elbow- the normal function of the muscle groups.
500
Which of the following adjustments would correct the lateral whip observed in a transfemoral amputee as swing phase begins?
A. Internally rotating the knee bolt
B. Externally rotating the knee bolt
C. Tightening the suspension socket
D. Increasing the length of the prosthesis
B. Externally rotating the knee bolt
In a lateral whip the heel of the prosthetic foot moves in a lateral arc as swing phase begins. This is often caused by excessive internal rotation of the knee bolt, thus externally rotating the knee bolt should correct this gait deviation. Option A is incorrect as internally rotating the knee bolt will worsen the lateral whip. Option C is incorrect because making a too tight suspension socket increases the pressure from contracting muscle bellies which causes the prosthesis to rotate around its long axis worsening the whip. Option D is incorrect since a long prosthesis causes vaulting and circumduction gait deviations.
500
How are mobility devices paid for through Medicare?
A. The patient must make a 50% down payment, with the rest covered by Medicare upon delivery of the device.
B. Medicare part A pays 80% of the allowed purchase price and Medicare part B pays the remaining 20%.
C. Medicare will pay for purchase but not rental of mobility devices.
D. Medicare part B pays 80% of the allowed purchase price in one lump sum.
D. Medicare part B pays 80% of the allowed purchase price in one lump sum.
Medicare Part B pays 80% of the allowed purchase price in one lump sum payment if the patient chooses to purchase the device. The patient is required to pay 20% of the allowed purchase price. If the patient chooses to rent a wheelchair, Medicare part B will pay 80% of the allowed rental price for months 1 through 10 and the patient will pay 20% of the allowed rental charge.