Ankle Foot Orthoses

1. What are the three different types of plastic AFOs?
2. What are indications for using a metal AFO over a plastic AFO?
3. What are indications for an AFO?

Answers:
1. Posterior leaf spring has a plastic band behind the ankle that allows the patient to overpower the brace during push-off, used for flaccid foot drop. Semi-rigid allows less motion, providing mediolateral stability, used for foot drop with extensor tone or mediolateral instability. Rigid (or solid) is used for high level of spasticity, where complete immobilization of the ankle is necessary.
2. Risk of excessive pressure or skin breakdown on the leg or foot, insensate foot, fluctuating edema.
3. Paralysis of ankle motion, prevention and correctio of deformities, reduction of WBing, reduce energy cost of ambulation.

Orthotics

1. How many points of pressure are needed for proper control of a joint?
*2. During standing, where does the center of gravity pass with respect to the hip, knee, and ankle?
3. What are different materials used in fabrication of orthotics?
*4. What are thermoplastics?

Answers:
1. 3
2. Posterior to hip, anterior to knee and ankle.
3. Steel, aluminum, titanium, magnesium, leather, rubber, plastics.
4. Thermoplastics soften when heated and harden when cooled, so can be remolded. They can be shaped by body without need for a cast.

Problem-specific shoe modifications

1. What can be done for an insensate foot?
2. What shoe modifications are made for an arthritic foot?
3. What factors contribute to foot pain associated with running?
4. What problems are associated with a pronated foot?

Answers:
1. Soft molded insole, extra depth shoes, relief under bony prominences (metatarsal bar or rocker bar), daily foot care, daily foot soaks.
2. Wide shoe, soft upper, flexible sole, soft heel counter, extra depth, soft toe box, metatarsal pad, insole, metatarsal bar.
3. Training errors, poor flexibility, poor training surface, inadequate warm-up, biomechanical abnormalities, poor footwear, growth.
4. Associated with a pronated foot are tibial stress syndrome, patellofemoral syndrome, posterior tibial tendinitis, Achilles tendinitis, plantar fasciitis.

Shoe modifications

1. What are some internal shoe modifications and their functions?
2. What are some external shoe modifications and their functions?
3. What is a rocker bar?
4. What are heel modifications and their functions?

Answers:
1. Heel cushion (soft pad for under heel - spurs), inner sole relief (pressure relief, usu for metatarsal heads), scaphoid pads (medial long arch support), metatarsal pads (transfers pressure from metatarsal heads to shafts), internal heel wedges (promotes foot inversion for pes planus), toe crest (toe pressure relief, for hammertoe).
2. Rocker bar, metatarsal bar (posterior to metatarsal heads, transfers load to shafts), sole wedge (can promote forefoot eversion or inversion), toe wedge (assist in intoing or outtoing), sole flare (widens base of support of shoe), shank filler (supports medial or lateral arch), steel shank (prevents motion of anterior sole, used with rocker bar).
3. Rocker bar is a convex strip placed across sole just posterior to metatarsal head (longer than metatarsal bar) thatis used to relieve metatarsal pain, assist rollover during stance, assist DF or push-off.
4. Heel wedge, heel flare, heel extension (to support arch), cushioned heel (stabilizes knee), heel lift (correct LLD of more than 1/4-1/2 inch).

Walkers

1. What are indications for using a walker?
2. What are advantages of a walker?
3. What are disadvantages of a walker?

Answers:
1. Bilateral weakness or incoordination nof LEs or body, relieve weightbearing, unilateral weakness with mild general weakness, and general support to aid mobility and confidence.
2. Provides a wider and more stable base of suppport, as well as sense of security.
3. Conspicuous appearance, interferes with smooth reciprocal gait pattern, interferes with stairs, difficult to maneuver doorways.

Crutches

1. What are the advantages and disadvantages of an axillary crutch?
2. What are disadvantages and advantages of a Lofstrand crutch?
3. What are disadvantages and advantages of a platform crutch?

Answers:
1. Crutches are inexpensive, adjustable, easy to use, but need good strength and ROM in upper limbs, ties up hands. Incr cardiac demand.
2. Lightweight, easily adjustable, hands are free, but requires more skill and better trunk balance.
3. No weightbearing through wrist and hand, but are awkward and heavy.

Canes

1. What are the functions of a cane?
2. What are the different types of canes?
3. What is the difference between a crutch and a cane?
4. What is the proper height of a cane?

Answers:
1. Increases base of support, decreases loading and demand on lower limbs, provides additional sensor information, assists in accel/decel during locomotion, decreases pain.
2. C-handle (crook top) cane, adjustable metal cane, functional grip cane, quadruped (wide-based) cane.
3. Cane has one point of contact with body while crutch has 2.
4. To allow 20 degrees of elbow flexion or height of greater trochanter.

Pain in the amputee

1. What are the characteristics of incisional pain?
2. What is the etiology of phantom pain? What is the time course?
3. What are treatments for pain in amputees?

Answers:
1. Incisional pain should subside with healing and can persist if there is an unprotected neuroma (nerve ending left exposed).
2. Etiology is neuron deafferentation hyperexcitability, and it is described as cramping, aching, burning, and occ lancinating. 50-85% of amputees experience some phantom limb pain, and there is no correlation between phantom pain and time after amputation, but does not occur in congenital amputation. It usually diminishes with time.
3. Modalities, medications, psychological interventions. Procedures are generally less effective.

Skin and bone problems associated with amputation

1. What are common skin problems associated with amputation?
*2. What is choked stump syndrome?
*3. What is verrucous hyperplasia?
4. What are common bone-related causes of pain?

Answers:
1. Folliculitis, boils, abscesses, epidermoid cysts, tinea corporis, tinea cruris, hyperhydrosis, allergic dermatitis.
2. Brawny edema, induration, discoloration of stump, resulting from proximal constriction of the stump and distal edema.
3. Wartlike skin overgrowth, usually from inadequate socket wall contact. Can be a sequela of choked stump syndrome.
4. Bone spurs due to incorrect stripping of periosteum, hypermobile fibula left longer than tibia, bone overgrowth in children where skin growth does not keep up with bone.

Prosthetic Knee units

What are the different kinds of knees?

1. Constant friction knee: single walking speed, can be used in kids, inexpensive and reliable.
2. Stance control knee: single axis with stance control, used in geriatrics, short residual limb, general disability, weak hip extensors. Can't be used in B/L AKA because can't bend both knees. Can't do step over step stair descent.
3. Polycentric/4-bar knee: inherently stable, short knee use, improved cosmesis.
4. Manual locking knee: automatically locks if standing, good stability, awkward gait and sitting.
5. Fluid-controlled knee units: hydraulic or pneumatic, allows for either swing phase or swing and stance phase control. For active walkers, gives smoothest gait. Greatest cost and maintenance.

Sockets for AKA

What are the two major kinds of AKA socket designs?

1. Quadrilateral transfemoral socket (quad socket): Narrow AP and wide mediolat, prominent bulge over Scarpa's triangle for wide pressure distribution, ischial tuberosity on top of post brim. Disadvantages are discomfort while sitting, skin irritation at ischium and pubis, poor cosmesis, poor control of residual limb.

2. Narrow mediolateral/ischial containment/CAT-CAM socket: more normal anatomic alignment with ischial tuberosity contained in socket. Advantages include increased comfort in groin area, can accommodate smaller residual limb, more efficient ambulation. Disadvantages include expense.

Prosthetic feet

What are the different kinds of prosthetic feet?

1. SACH: durable, light, inexpensive. Best on flat, level surfaces.
2. Single axis: ankle movement in one plane, heavier.
3. Multi-axis: good for active amputee, greater weight and maintenance.
4. Flexible keel (SAFE, STEN): ambulation on uneven surfaces
5. Energy storing/dynamic response (flexfoot): good for running and jumping

BKA suspension

What are commonly used suspension systems for BKAs?

Answers:
1. Supracondylar cuff suspension socket: cuff wraps around thigh.
2. Supracondylar or suprapatellar brim suspension: used with short stumps.
3. Rubber or neoprene sleeve: need longer stump and stable knee, may cause perspiration.
4. Silicone suction suspension: has attached distal pin or ring, good suspension and skin protection, expensive.
5. Thigh corset: use if patellar tendon can't tolerate WBing or knee unstable.

LE Prosthesis prescription

1. What is the best prosthetic option for a hindfoot amputation?
*2. What sort of prosthetics are used with a Syme amputation?
*3. What is a patellar tendon bearing socket?
*4. What are pressure tolerant areas in the lower extremity?
5. What are pressure-sensitive areas?

Answers:
1. Custom prosthetic foot with a self-suspending split socket.
2. Canadian Syme socket with either posterior or medial opening, which requires removal of a portion of the socket wall to get the stump in, and has poor cosmesis. Available feet include a SACH, SAFE, Seattle Syme foot, Syme flex foot, carbon copy Syme foot.
3. This is the standard socket, which is a plastic custom-molded socket that distributes pressure to tolerant areas and relief to sensitive areas. Bar in anterior wall applies pressure to patellar tendon.
4. Patellar tendon, pretibial muscles, popliteal fossa, lateral shaft of fibula, medial tibial flare.
5. Tibial crest, tubercle, condyles, fibular head, distal tibia and fibula, hamstring tendons.

Residual limb management

1. What is the ideal shape for transtibial and transfemoral residual limb?
2. When should whirlpool treatments be used on wounds?
3. What is the first kind of postoperative dressing that is used on the residual limb?
4. How often should a shrinkage device be worn?
5. What behaviors should be avoided to prevent contractures?

Answers:
1. Transtibial: cylindrical. Transfemoral: conical.
2. If wound is infected. If uninfected, whirlpool causes edema.
3. A removable rigid dressing, made of plaster or fiberglass cast, which may be adjusted by adding or removing socks.
4. 24 hrs per day except for bathing.
5. Avoid lying on overly soft mattress, placing a pillow between the legs or under the knee, lying with residual limb hanging off edge of bed, sitting for prolonged periods. Crutch walking encourages good ROM and lying prone 15 min TID.

BKA and above

1. What is the reported healing rate for ischemic BKA?
2. What are advantages and disadvantages of knee disarticulation over AKA?
3. What percentage of AKAs are secondary to vascular disease?
4. What are indications for hip disarticulation or hemipelvectomy?

Answers:
1. 80-90%.
2. Knee disartic is less traumatic to tissue, minimizes blood loss, and has a long strong stump with good end-bearing quality. Disadvantages include poorer healing in dysvascular patient, and cosmesis of the prosthesis.
3. 85%.
4. Malignant tumor, extensive trauma, uncontrolled infection (gas gangrene).

Common levels of amputation

1. What are three unsatisfactory levels for leg amputation?
2. What are pros and cons of partial foot vs. toe amputations?
3. What are the advantages of transmetatarsal amputation?
*4. What is the difference betwen a Lisfranc and Chopart amputation? What is a common complication of both?
*5. What is a Syme's amputation and what are the pros/cons?

Answers:
1. Distal 2/5 of tibia (below gastrocsoleus) due to skin breakdown, very short below knee amputation due to loss of knee extension resulting in flexion contractures, and very high above-knee amputation due to flexion/abduction contractures.
2. Pros of toe amputation include improved mechanical advantage and better gait pattern. Cons include possible progression of the vascular problems in a compromised patient.
3. Preserves attachment of DFs and PFs, which gives patient good mechanical advantage.
4. A Lisfranc amputation is at the tarso-metatarsal junction. A Chopart amputation is distal to the talus and calcaneus bones. In both amputations, the foot develops a significant equinus deformity, resulting in skin breakdown. This can be prevented by DF tendon implantation with Achilles lengthening.
5. Syme's amputation is an ankle disarticulation with attachment of the distal heel pad to the end of the tibia. Pros include maintenance of limb length, excellent wt bearing, good prosthetic tolerance. Cons include poor cosmesis of prosthetic.

Lower limb amputation

1. What are the most common causes of lower extremity amputation in various age groups?
2. What is myodesis?
3. What is myoplasty?
4. What are the functions of a temporary prosthesis?
5. How often is a permanent prosthesis usually replaced?

Answers:
1. 0-5: congenital. 5-15: cancer. 15-50: trauma. 50+: vascular disease.
2. Muscles and fascia sutured directly to bone through drill holes, resulting in a more structurally stable limb.
3. Opposing muscles sutured to each other and to periosteum with minimal tension, which takes less time and better for dysvascular limbs.
4. Can be used before limb volume stabilizes, helps in shrinking and shaping, allows early prosthetic training, maybe used as a trial to test patient's success with prosthesis. It is usually used for first 3-6 months.
5. Every 3-5 years.

Prosthetic training

1. What is the basic motion for opening the terminal device on a transradial prosthetic?
2. What are activities that are important to practice for a unilateral transradial amputee?
3. How is elbow flexion and extension achieved in a transhumeral prosthetic?
4. How is the TD operated with a transhumeral prosthetic?

Answers:
1. Forward flexion of the humerus.
2. Two handed activities such as cutting food or tying shoelaces.
3. Flexion of the elbow is achieved by humeral flexion, and extension of the elbow is achieved by elbow extension back to neutral.
4. When the elbow is locked, use additional humeral flexion to open or close the TD.

Amputee care and rehab

1. What are the most important three things to consider in a clinical decision for a prosthesis?
2. What does preprosthetic therapy include?
3. What types of rotation are most seriously affected in UE amputation?

Answers:
1. Amputation level, proximal muscle strength and ROM, general health.
2. Stump shrinkage, muscle strength, ROM, postural problems, desensitization, scar mobilization, and home exercise program.
3. Humeral rotation in transhumeral amputees, and forearm rotation in transradial amputees.

Above elbow prostheses

1. What are two types of elbow joints? Which is preferred?
2. What sort of elbow locking system is used in elbow disarticulations?
*3. What harness designs are used most frequently for transhumeral prostheses?

Answers:
1. Internal and external locking elbow. Internal elbow is preferred because of greater durability and used in level of amputation 4 cm or more proximal to the level of the epicondyle. External elbow is used for longer limbs.
2. External locking.
3. Modifications of the figure-8 and chest-strap patterns used with transradial prostheses.

Below elbow amputation prostheses

1. What is the difference between a split socket and a Muenster socket?
2. What are different harness suspension and control systems?
3. What are two kinds of control-cable systems?

Answers:
1. A split socket is used with very short stumps and encases the residual limb, attempted to a separate forearm shell to which the wrist unit and terminal device are attached. The Muenster socket is self-suspended, encapsulating the olecranon and humeral epicondyle with greater ease of use.
2. A figure-8 harness is most commonly used, with an axilla loop, worn at the normal side, which acts as a reaction point to transmit body force to the terminal device. The figure-9 is often used with the Muenster socket and is used only for controlling the TD and not for suspension. The chest-strap with shoulder saddle is used if an axilla loop can't be tolerated or for heavy lifting.
3. The Bowden control cable system is used with the purpose of operating the terminal device using body power. The dual-control cable system is used with very short transradial limbs with locking elbows, so can flex the elbow with the elbow is unlocked and operate the TD whe the elbow is locked.

Terminal devices

1. What are the advantages and disadvantages of a passive TD?
2. What is a three-jaw chuck pinch?
*3. What is the difference between a voluntary-opening and voluntary-closing terminal device?
4. What are externally powered TD?
*5. What are the two types of prosthetic wrists?

Answers:
1. Lighter, but with no functional mechanism and no grasp, intended for cosmetics only. Flexible passive TD may absorb shock.
2. Grip with thumb, index, and middle fingers, which is provided by a prosthetic hand.
3. VO is most common and practical type, powered by proximal muscles to open the TD against springs. VC is most physiological, but is heavier and less durable.
4. Controlled by switches or myoelectric signals and powered with energy from external batteries.
5. Friction and locking. Friction permits pronation and supination of TD and hold it in selected position via friction. A locking wrist permits manual rotation then locks the TD in the selected position, which is an advantage in that it prevents inadvertent rotation of the TD when a heavy object is grasped.

Upper limb prosthetics

1. What is the benefit of a wrist disarticulation over a BEA?
2. What is the most common level of arm amputation?
3. What are the pros and cons of elbow disarticulation?
4. What are two methods of suspension of a transhumeral amputation?
5. What sort of prosthesis is generally used in a forequarter amputation?

Answers:
1. Spares distal radial-ulnar articulation --> full forearm supination and pronation.
2. Transradial.
3. Pros include simpler surgery, improved prosthesis self-suspension. Cons include the cosmetic appearance and inability to use an externally powered elbow.
4. Figure-8 or shoulder saddle and chest strap.
5. Passive ultralight cosmetic prosthesis due to poor outcome with functional prosthesis.

Gait pathology

1. What is the cause of foot slap?
2. What is the cause of genu recurvatum?
3. What is the cause of excessive trunk extension?
4. What is the cause of excessive knee flexion?
5. What is the cause of pelvic drop?
6. What is the cause of a waddling gait?
7. What is the cause of excessive foot pronation?
8. What is the cause of steppage gait?
9. What is the cause of hip circumduction?
10. What is the cause of hip hike?

Answers:
1. Moderately weak ankle dorsiflexors.
2. Weak, short or spastic quads, hamstring weakness, Achilles contracture, PF spasticity.
3. Weak hip extensors or flexors, hip pain, decreased knee ROM.
4. Hamstring contracture, increased ankle DF, weak PF, long limb, hip flexion contracture.
5. Contralateral gluteus medius weakness.
6. Bilateral GM weakness.
7. Compensationed forefoot or rearfoot varus deformity, uncompensated valgus deformity, pes planus, decreased ankle DF, increased tibial varum, long limb, uncompensated internal rotation of tibia or femur, weak tibialis posterior.
8. Severely weak DF, equinus deformity, PF spasticity.
9. Long limb, abductor muscle shortening or overuse.
10. Long limb, weak hamstring, quad lumborum shortening.

Energy expenditure in gait

1. What type of amputation has the greatest increase in metabolic cost for ambulation? Least increase?
*2. What is the increase in energy expenditure for wheelchair propulsion?
3. Which requires more energy: prosthesis or crutch walking?
*4. What muscles need to be strengthened for crutch walking?

Answers:
1. Greatest increase: vascular transfemoral (100%), least increase: Syme's (15%).
2. 9%.
3. Crutch.
4. Latissimus dorsi, triceps, biceps, quads, hip extensors, hip abductors.

Determinants of gait

What are the six determinants of gait?

1. Pelvic rotation: lengthens limb as it prepares to accept weight.

2. Pelvic tilt: Pelvis on the side of the swinging leg is lowered to lower COG at midstance.

3. Knee flexion in stance: lowers COG and absorbs shock of impact at heel strike.

4. Foot mechanisms: Ankle PF at heel strike smooths curve of falling pelvis.

5. Knee mechanisms: after midstance, knee extends as ankle PFs and foot supinates.

6. Lateral displacement of pelvis: toward the stance limb to make COG over base of support.

Gait characteristics

1. What is the stride length? Step length?
*2. What is the normal distribution between stance and swing phases?
3. What is the distribution between double limb and single limb support?
4. What is cadence?
5. What is a comfortable walking speed?
6. Where is the center of gravity?


Answers:
1. Stride is measured from successive points of contact of same foot. Step length is measured from points of contact of opposite feet (approx 15-20 in).
2. 60% in stance phase, 40% swing phase. Faster walking decreases time in stance phase.
3. Double support is 20% of gait cycle, single support is 80%.
4. Cadance is the number of steps per unit of time.
5. 3 MPH.
6. 5 cm anterior to the 2nd sacral vertebra.

Gait: swing phase

What are the swing phase subdivisions?

Answers:
In My Teapot

1. Initial swing: from lift of extremity off ground to maximum knee flexion

2. Midswing: from immediately following knee flexion to vertical tibia position

3. Terminal swing: from vertical tibia position just prior to initial contact.

Swing phase makes up 40% of the gait cycle.

Gait: stance phase

What are the five subdivisions of the stance phase?

Answer:
I Like My Tea Pre-sweetened

1. Initial contact: instant foot contacts ground

2. Loading response: from initial contact to lift of contralateral extremity from ground (wt shift)

3. Midstance: from lift of contralateral extremity to when ankles of both extremities are aligned.

4. Terminal stance: from ankle alignment in the frontal plane to just prior to inital contact of the contralateral (swinging) extremity.

5. Preswing: From initial contact of contralat extremity to just prior to lift off of ipsilateral extremity (wt shift)

Stance phase makes up 60% of gait cycle.

Finger deformities

1. What is the etiology of trigger finger?
*2. What is the etiology of mallet finger?
3. What is the treatment of mallet finger?

Answers:
1. Trauma to the flexor tendon, resulting in thickening and a nodule. Clicking or locking is felt when the nodule passes through the tendon sheath.
2. Rupture of the extensor tendon in the distal phalanx secondary to forceful flexion, resulting flexed DIP.
3. Splint to immobilize distal phalanx in hyperextension 6-12 wks. Surgical treatment for poor healing, volar subluxation, or avulsion > 1/3 of the bone.

Dupuytren's contracture

1. What is a Dupuytren's contracture?
2. What diseases are associated with Dupuytren's contracture?
3. What are the clinical symptoms of Dupuytren's contracture?
4. What is the treatment of Dupuytren's contracture?

Answers:
1. Fibrous contracture of the palmar fascia creating a flexion contracture at the MCP and PIP.
2. Epilepsy, pulmonary TB, alcoholism, DM.
3. Painless thickening of palmar surface and underlying fascia, most common at 4th and 5th digits.
4. Injection followed by forceful extension, rupturing skin and fascia. Modalitis. Surgical treatments including fasciotomy or amputation.