Biomechanics Final SG - Davis portion

Leading causes of amputation

• 1 in ____ people in the US have one or more amputations.

• Most occur in patients how old?

• Leading causes? (3)

Leading Causes of Amputation

• 1 in 200 people in the US have one or more amputations

• Most occur in patients 60 years-old and over

• Causes:

  • Complications of diabetes and PVD (82%)

  • Trauma (16%) - young male population

  • Tumors & Congenital Malformation (2% each)

Amputation terms

• Trans

• Disarticulation

• Partial

• Sound limb

• Residual limb

• Trans: When amputation crosses the axis of the long bone

  • EX: TTA transtibial amputation; TFA transfemoral amputation, TRA transradial amputation, THA transhumeral amputation

• Disarticulation: When amputation is between long bones, through center of a joint

  • EX: Knee disartic → amputation of the knee but still keeping femoral condyles

• Partial: Amputation of foot distal to ankle joint and of the hand distal to the wrist joint

• Sound limb: Intact limb, healthy limb

• Residual limb: The stump limb

Causes of amputation in the USA pie chart: Fill in the blank

Proper nomenclature for the Lower Limb (ISO)

For the following what is the proper naming for each

• Ankle disarticulation

• Below knee amputation BKA

• Knee disarticulation (?)

• Above knee amputation AKA

• Hip disarticulation (?)

• Transpelvic amputation (?)

• Ankle (Syme) Disarticulation

  • All bones distal to the mortise joint

• Transtibial Amputation (previous BKA)

  • Conventional, ETRL procedure (bony bridge between tib and fib). Takes a bit of healthy bone and puts it wire between 2 joints. This procedure delays prosthetic fitting.

• Knee Disarticulation

  • amputation of the knee but still keeping femoral condyles

• Transfemoral Amputation (previous AKA)

  • Ideal length is about 4 inches or 10 cm. Proximal to knee joint, allows femoral condyles to be excised with enough room to accommodate prosthetic knees.

• Hip Disarticulation

  • removes the entire leg through the hip joint

• Transpelvic Amputation

  • Removes the leg, hip joint, and portion of the pelvis

Proper Nomenclature for the Upper Limb (ISO)

• Wrist Disarticulation

• below elbow amputation

• Elbow Disarticulation

• above elbow amputation

• Shoulder Disarticulation

• Forequarter Amputation

• Wrist Disarticulation

• Transradial Amputation (previous below elbow)

• Elbow Disarticulation

• Transhumeral Amputation (previous above elbow)

• Shoulder Disarticulation

• Forequarter Amputation

(?)

Osseointegration

• What is it?

• What are the two steps?

Attachment of prosthesis directly to the body

• 2 step surgery

  • Implant placement within the end of the bone

  • Placement of external protruding connector

Postoperative compression dressing help with? (4) How long can it be used for post surgery?

• Control Edema

• Shape the limb

• Protection of the residual limb

• Fosters healing

• May be used for weeks after surgery

Shrinkers

• For TTA and TFA, the advantage of using a shrinker sock compared to wrapping methods are? What about for semirigid and rigid dressing?

• Positive effects with use of volume management?

Condie et al (1996) found that both TTA and TFA using a shrinker sock within 10 days after amputation demonstrated a significantly reduced time from amputation to prosthetic casting from those amputees using wrapping methods.

• Moreover, TTA’s who received semirigid and rigid dressing demonstrated increased time until prosthetic casting

Positive effects with use of volume management: (7)

• decrease edema

• increase circulation

• assist in shaping

• provide skin protection

• reduce redundant tissue problems

• reduce phantom limb pain sensations

• desensitize the residual limb (important for first 3 months)

Partial foot amputation levels

• Transmetatarsal

• Lisfranc’s

• Chopart

• Transmetatarsal: through all metatarsals

• Lisfranc’s (Tarsal-metatarsal): disarticulation of metatarsals

• Chopart (Midtarsal): disarticulation of tarsal bones

Syme’s Amputation

• What is it? What bones are amputated? What is attached to the distal tibia?

Ankle Disarticulation

• All bones distal to the mortise joint

• Heel pad and inferior calc are attached to distal tibia

Post surgical dressing (Advantages and disadvantages)

• Compressible soft dressing

• Shrinker

• Semirigid dressing

• IPOP (Immediate Post-Operative Prosthesis)

Phases of Amputee Rehab

• What are the three phases? When does it take place and how long does each last?

Phases of Amputee Rehab

• Healing

  • Immediately following surgery

  • Postoperative phase

  • Pre-prosthetic phase

  • Lasts up to 4–8 weeks

• Maturation (Prosthetic phase)

  • Temporary prosthesis is given

  • Definitive prosthesis given when limb is stable

  • Gait training and prosthetic management

  • Around 4 to 6 months post surgery

• Definitive

  • Long-term follow up

  • Learning to return to sport/return to work

The “K” levels: Medicare Functional Index

• What are the 5 levels and what does each entail?

• K0 = not a potential user for ambulation or transfers / no feet allowed / no knees allowed. Insurance wont cover and pt will not get prothesis or socket.

• K1 = a potential household ambulatory including minimal transfers / SACH or single-axis foot / single-axis knee or safety/lock (Given the most minimal foot and knee, pt only moves a bit around the house (barely active).

• K2 = a potential limited community ambulatory / flexible keel foot / multi-axial foot / same knees as level 1. Pt is moving well at home and performs limited ambulation in community.

• K3 = community ambulatory using variable cadence including therapeutic exercise or vocation / energy story feet / pneumatic and hydraulic knees. The sweet spot → pt will get approved. Can do everything such as play sport, go to work, etc)

• K4 = high activity user who exceeds normal ambulation / all feet / all knees. Paralympian → running blades not covered by insurance usually sponsored

Phantom pain and sensation

• Phantom pain is?

• What do people that have had a limb remove sometimes report?

• Does this get better overtime without treatment?

• Phantom pain is pain that feels like it's coming from a body part that's no longer there.

• Most people who've had a limb removed report that it sometimes feels as if the amputated limb is still there. This painless phenomenon, known as phantom limb sensation

• Phantom pain often gets better over time without treatment, for some patients managing phantom pain can be challenging.

Phantom pain and sensation - The specifics of each

• Phantom sensation

• Phantom pain

• Residual limb pain

• Phantom Sensation: A nonpainful sensation or awareness experienced that gives form to a body part with specific dimensions, weight or range of motion.

• Phantom Pain: A painful sensation-experienced below the residual limb

• Residual Limb Pain: Pain arising in the residual limb from a specific anatomical structure that can be identified.

Upper extremity surgeries

• Surgery play a role in the management of children with? Associated with?

• Reconstructions may be performed in infants to allow? What three professionals must work closely together?

• Prosthetic fitting are generally ____ ____ dependent and have a variety of options. What are they? (4)

• Families tend to prefer a ______ device that resembles what?

• Benefits to early prosthetic fitting? (2)

• Surgery plays a major role in the management of children with longitudinal upper arm or forearm deficiencies.

  • Associated with nonfunctional hands, polydactyl (extra fingers or toes), or other deformities.

• Reconstructions may be performed in infants to allow for normal development in manual tasks

  • Surgeon, prosthetist, and PT/OT staff need to work closely together, making sure children are monitored throughout the developmental stages.

• Prosthetic fitting are generally limb level dependent and have a variety of options.

  • Opposition, body powered, externally powered devices with hands, hooks with various shapes

• Families tend to prefer terminal device that resembles a hand

• Benefits to early prosthetic fitting

  • Encouraging bi manual tasks

  • Facilitating symmetric crawling

Lower extremity surgeries

• Reconstruction surgery is often delayed for what reason?

• Maintenance of long bone growth plants allows for?

• Severe deformities that interfere with early fitting or with function require? What is a important to prevent? What can be down to provide the child with a functional residual limb?

• Reconstructive surgery is often delayed to allow greatest amount of bone growth.

• Maintenance of long bone growth plates allows for greatest development of limb length.

• Severe deformities that interfere with early fitting or with function require early surgical intervention

  • It is important to prevent progressive deformities that may occur as a result of muscle and nerve imbalances.

  • Surgery to increase bone length using the Ilizarov technique can be successfully performed to provide the child with a functional residual limb.

Civilian statistics (For UE)

• What is the total amount of amputees in the USA?

• How many major amputations occur annually in the USA?

• What age population does it tend to occur in?

• 95% occur below the?

• Primary reason for amputation?

• What percent of UE amputees do NOT wear a prosthesis?

• Prevalence of UL amputation: Of the 5/100,000 UE amputations in the US

  • 3.8/100,000 were _____ related.

  • 1.3/100,000 were _____ related

  • <1/100,000 were ______ or ______ related.

• total of 1.9–2.1 million amputees in the USA

• 185,000–200,000 major amputations occur annually in USA

• Tends to occur in younger patients

• 95% occur below the elbow

• Primarily due to trauma

• 50% of upper extremity amputees do not wear a prosthesis

Prevalence of UL amputation

• Of the 5/100,000 UE amputations in the US

  • 3.8/100,000 were trauma related.

  • 1.3/100,000 were dysvascular related

  • <1/100,000 were congenital or cancer related.

UE classifications

• Partial hand

• Wrist disarticulation

• Transradial (below elbow)

• Elbow disarticulation

• Transhumeral (above elbow)

• Shoulder disarticulation

• Forequarter

six prosthetic options for UE

• Body powered prosthesis

  • How does it work? Basic requirements?

• Electrically powered prosthesis

  • How does it work?

• Hybrid prosthesis

  • What is it?

• Passive prosthesis

  • What is it used for?

• What are the last two options?

Body powered prosthesis / cable operated

• Body motion/strength is captured to operate terminal device (hook, hand, etc)

• Basic Requirements: AROM, ability to generate force associated with those motions. Muscles are required to use it.

Electrically powered prosthesis

• Electrical signal on the surface of the skin is used to communicate to the terminal device and power is supplied by an external battery

Hybrid prosthesis

• Both body and electrical

Passive prosthesis

• Cosmetic purposes

Activity specific prosthesis

Non-prosthetic user

Body powered control system

• For each what is the terminal device, elbow flexion, elbow lock:

  • Shoulder disarticulation

  • Transhumeral

  • Transradial

• Most important motions for UE?

• Shoulder disarticulation

  • Terminal device: Biscapular abduction and latissimus dorsi

  • Elbow flexion: Biscpaular abduction and latissimus dorsi

  • Elbow lock: Scapular elevation

• Transhumeral

  • Terminal device: Biscapular abduction and humeral flexion

  • Elbow flexion: Biscapular abduction and humeral flexion

  • Elbow lock: Shoulder depression and humeral abduction and extension

• Transradial

  • Terminal device: Biscapular abduction and humeral flexion

  • Elbow flexion: NA

  • Elbow lock: NA

• Most important motions for UE

  • Glenohumeral flexion

  • Shoulder elevation/depression

  • Scapular abduction (protraction)

For the following picture label:

Ring or cross of post straps is near what spinal level and on what side?

Ring or cross of post straps is near C7 on the sound side

Upper extremity prosthetic comparisons

• For the following (Passive, body-powered, battery powered) state its:

  • Weight level (Lightest, moderate, or heaviest)

  • Cosmesis (Better cosmesis, moderate cosmesis, or worst cosmesis)

  • Sensory (Best sensory feedback, limited sensory feedback, or minimal sensory)

  • Harnessing (Most harnessing, less or no harnessing, or no harnessing)

  • Function level (functional or passive)

  • Energy expenditure (No energy expenditure, less energy expenditure, or most energy expenditure)

  • Maintenance/durability level (Most durable, may stain easily, or most maintenance required)

  • Choice of terminal devices (choice of terminal devices or choice of terminal devices and elbows)

  • Movement required (No body movement required, least body movement to operate, or most body movement to operate)

  • grasp level (Stronger grasp (active), weaker grasp (VC), or no grasp)

  • Which one might have possible longer training time?

LE prosthetic - The components

• What does each of the following do:

  • Socket (and what is it critical for)

  • Suspension

  • Knee

  • Shank (and what are its two types with differences)

  • Foot

• Socket

  • Interface between residual limb and prosthesis

  • Critical to comfort and function

• Suspension

  • Maintains the socket on the residual limb (how they wear it without falling out)

• Knee

  • Knee/Shank/Foot move as a unit

• Shank

  • Connects socket or knee to the foot. Where the tib fib would be.

    • transmits forces and restores limb shape. Can be endo skeletal (internal skeleton supporting load. lighter and covered with cosmetic foam) or exoskeletal (hard laminate; outer structure provides support. Hallow and strong)

• Foot

  • Impacts energy return and gait quality

Types of prosthetic feet? (8)

Types of Prosthetic Feet

• SACH

• Single Axis

• Elastic keel

• Multi-axial

• Dynamic response

• Hybrid

• Microprocessor Ankles

• Running Feet

more on individual ones in later card

Which foot is most appropriate? (Energy returns for the following)

• SACH foot

• Seattle foot

• Flex foot

• Human foot

• SACH foot: 39% energy return

• Seattle foot: 71% energy return

• Flex foot: 89% energy return

• Human foot: 246% energy return

Non-articulated foot/ankle assemblies

• Have continuous ______ ______ from the _____ __ ____ _____ to the _____ __ ___ ______.

• What is the solid ankle cushion heel (SACH) foot?

  • Articulated joint?

  • At heel strike, the heel wedge does what? Keel is made from?

  • Avantages? Disavantages?

  • Variations? (3)

  • Used by what K level patients?

Have continuous external surfaces from the sole of the foot to the shank of the prosthesis

Solid Ankle Cushion Heel (SACH) Foot:

• A molded heel cushion made of a high-density foam rubber forms the foot and ankle into one component-cushion heel acts as a posterior bumper

• No articulated joint

• At heel strike, the heel wedge compresses to create a DF movement; keel is made of hardwood or aluminum

  • Advantages: inexpensive, light weight, durable, reliable, no moving parts, good absorption of ground reaction forces, more stability than single or multi-axis feet, child sizes available

  • Disadvantages: no adjustment on DF/PF, walking up hill is difficult, limited motion for active people, energy consuming, rigid

  • Variations: symes foot, sculptured toe foot, high heel for women

  • Used by limited or household ambulators (K1 level)

Tru-step foot or college park

• What does it allow the pt to do? designed to mimic? First foot to do what? How does it decrease GRF and increase stability? What can be changed to provide correct resistance?

Elastic keel foot

• Made form what type of material? Helps with what and has no what? Forefoot can do what? Remains ______ and _____ during standing and walking → a _____ response

Hybrid prosthetic feet

• What material does it use and allows for what? Combination of what two things? Positive? Negative? Goal?

Dynamic response feet

• What does it do? Is there moving parts? Comes in? Allows for easier what due to the carbon fiber? Functions as what and when does it cushion, store energy, and return energy?

Tru-step foot or college park

• Allows pt to walk on dynamic surfaces

• Designed to mimic anatomical foot and ankle

• First foot to do 8 motions PF/DF, INV,EVR, ABD/ADD, SUP/PRO

• 3 part weight transfer system and shock absorbing heel to decrease GRF and increase stability.

• 3 bumpers can easily be changed to provide correct resistance

Elastic keel foot

• Made of flexible material

• Helps with push off movements → no moveable ankle joints

• Forefoot can conform to uneven terrain, remains supportive and stable during standing and walking → dynamic response

Hybrid prosthetic feet

• Using carbon fiber and allow certain moving parts

• Combination of multi axis and dynamic response

• + would be accommodation to various surfaces

• - would be increased weight cost and maintenance

• goal: decrease cost and allow K2 level users to be able to get dynamic response foot

Dynamic response feet (more on another slide)

• store (at heel strike) and release (at toe off) energy, no moving part

• comes in different shapes and sizes for adults and peds

• easier to walk, run → carbon fiber does all the work

• Functions as a spring

  • cushion (at IC) → stores energy (through midstance) → return energy (pre swing)

Dynamic response feet

• What does it do?

• Functions as a? _____ at initial contact, ______ ______ through midstance and _____ _____ at pre-swing

• Variation depend on?

• Secured inside a?

• Assists as a _____ _____ at midstance

• Keel is made of?

• Ankle joint mobility? What may it have?

• Store and release energy

• Function as a “spring”

  • Cushion at initial contact, store energy through mid-stance and return energy at pre-swing

• Many variation depending upon length of the residual limb

• Secured inside a cosmetic shell

• Assist as a ankle rocker at midstance

• Keel is made of a spring-like material

• No moveable ankle joint

  • May have split toe design or urethane molded within keel

Below knee amputation (Amputation level: Transtibial)

• What is it? Ideal length being from the?

• Long transtibial is more than _____ of the tibial length.

• Short transtibial is less than _____ of the tibial length. Just distal to the?

• Advantages (Vs transfemoral) (3)

• Energy expenditure (Unilateral and Bilateral)

Amputation Level: Transtibial: Below-knee amputation (BKA)

• Resection through the tibia and fibula with the ideal length being from the proximal 1/3 to the middle of the limb

• Long transtibial is more than 50% of the tibial length

• Short transtibial is less than 20% of the tibial length

• Just distal to the tibial tuberosity

Advantages (vs. transfemoral):

• Mortality is lower

• Better prospect for prosthetic rehab

• Decreased phantom pain

Energy Expenditure:

• Unilateral 10–20%

• Bilateral 20–40%

Below knee amputation (Amputation level: Transtibial) continued:

• Fibula is transected how much shorter than the tibia? Why?

• If the fibula is transected the same length as the tibia, what can happen?

• If the fibula is cut too short this results in?

• What shape is ideal for prosthetic fitting techniques?

• A bevel is placed on the _____ _____ _____. This is to minimize?

• To avoid painful neuroma, what should be done?

• Fibula is transected 1 to 2 cm shorter than the tibia to avoid distal fibula pain

• If the fibula is transected at the same length as the tibia, the patient senses that the fibula is too long, which may cause pain over the distal fibula

• If the fibula is cut too short this results in a more conical shape, rather than the desired cylindrical-shape residual limb

• A cylindrical shape is better suited for total contact prosthetic fitting techniques

• A bevel is placed on the anterior distal tibia to minimize tibial pain on weight bearing

• To avoid a painful neuroma, a collection of axons and fibrous tissue, nerves should be identified, drawn down, severed and allowed to retract at least 3 to 5 cm away from the areas of weight-bearing pressure

Diagnostic test sockets (DTS)

• Made with?

• Assess fit both ______ and ______.

• Ensures?

• For transtibial:

  • Patients may be sent out with DTS on a?

  • Allows for what adjustments?

  • Helps ensure that the prothesis will?

• Thermal plastic used with casting tech

• Assess fit both statically and dynamically

• Ensures proper fit and function of the prosthesis

• Transtibial:

  • On a case-by-case scenario, patients may be sent out with DTS

  • Allows for custom socket adjustments

  • Helps ensure the laminated prosthesis will provide the patient with the best possible outcome.

Transtibial sockets

• What are the types of TTA sockets?

Types of TTA sockets

• Plug Fit Socket

• Patella Tendon Bearing Socket (PTB)

  • Supracondylar

  • Suprapatellar

• Total Surface Bearing Socket (TSB)

• Hybrid Sockets

Patella tendon bearing socket

• This socket is the?

• increases _____ or ____ _____ in the area of the patella tendon, ______ to the patella

• Patellar tendon bar: what percent of weight is born here when standing and walking? contouring is? This allows for what two things?

• most common

• Increase contact or weight bearing in the area of the patella tendon, inferior to the patella

• Patella tendon bar: 30% of the weight is born here when standing and walking

  • pressure related contouring

    • interfaces pressures in socket

    • Distributes pressure to RL

socket design for PTB

• What does this prevent?

• The top of the anterior wall bisects what?

• The posterior wall trim line is (higher or lower) or?

  • What if the pt has too high of a post wall?

  • What direction of force does a posterior wall apply and why?

  • Why is it contoured?

• The medial and lateral walls are slightly higher or lower than the anterior wall? Why?

  • Tibial flares still do what?

  • Pt with high medial and lateral walls typically have a what? Why?

• prevents skin problems, choke syndrome, ulceration

• The anterior wall = top of anterior wall bisects patella

• The posterior wall = trim line higher or bisects patella tendon bar

  • If pt has too high post wall → decrease knee flexion and carbon fiver digging into back when firing

  • Applies an anterior directed force to maintain the patellar tendon on the PTB bar

  • Contoured to prevent increased pressure on the HS.

• The medial and lateral walls slightly higher than the anterior wall adding stability.

  • Tibial flares still take weight

  • Pt with high med and lat walls = shorter RL for increased valgus/varus stability.

What are the pressure tolerant areas vs pressure sensitive areas of a transtibial amputee? What do pressure tolerant areas use compared to pressure sensitive areas?

Pressure tolerant: Use build-ups (convexities) in socket (presses into these areas)

• Patellar tendon

• Pre-tibial muscles and lateral fibular shaft/surface

• Medial tibial flare

• Popliteal fossa and gastroc soleus

Pressure sensitive: Use reliefs (concavities) in socket (pushes away from these areas)

• Fibular head, distal fibula

• tibial condyles

• tibial tubercle, crest and distal tibia

• Patella

• hamstring tendons

• Peroneal nerve

Transtibial socket interface materials

• What type of inserts are used for hard fit vs soft fit?

• Silicone/gel liners are good for? three types?

• Prosthetic socks (ply? accommodates? How much ply before pt needs a new prosthesis?)

• What are the other two materials?

• Hard Fit – no insert used

• Soft Inserts: Pelite inserts

• Silicone/Gel liners: Most widely used now, good cushion and pressure distribution, decreases shear, good for sensitive/adherent skin

  • Silicone Elastomers

  • Silicone Gels

  • Polyurethanes

• Prosthetic socks

  • Ply (1 ply ~2 mm)

  • Accommodate limb volume changes

  • Once pt gets to 15 - 20 ply then its time for a new prosthesis

• Nylon sheaths

• Flexible thermoplastic inner

More on gel liners

• Pt will be given how many at a time? Why? Is it covered by insurance?

• When putting on a gel liner what are the three steps?

• Signs of bacteria?

• PT will be given 2 at a time (wear 1 while the other is getting cleaned), Covered by insurance

• When putting on a gel liner:

  • Place inside/out and squeeze bottom

  • Make sure its not placed inward to avoid hickey

  • Mare sure limb reaches the end, then roll up liner

• Signs of bacteria: Fabric separation, discoloration, gel cracks and disintegration

Transtibial socket suspension

• What is suspension?

• Types

  • Corset

    • How common? Seen is pts with long or short RLs? Used for?

    • Positives? Negatives?

  • Straps/Velcro cuff

    • Common for pt undergoing what changes (and what type of atheletes)

    • what does it look like?

    • positives? negatives?

  • Anatomical

    • For long or short RL and what type of instabilities?

    • Positives? Negatives?

  • Silicone suction suspension

    • Pin is attached to? Allows for?

    • Positives? Negatives?

    • Avoid if? What K levels is this for?

  • seal in liner

    • What type of system?

    • Each rink provides what?

    • Positives? Negatives?

  • external suspension sleeve (Nothing on this)

  • vacuum assisted socket system

    • How does this socket work? Increased _____ with decreased _____ on RL

    • Positives? Negatives?

• Suspension is the method by which the prosthesis is held on the residual limb

• Types

  • Corset

    • Uncommon; seen with short RL. Used for knee stability and hypersensitive stages. Max med and lat support → unloads RL by 30%. Heavy, bulky, pistoning

  • Straps/Velcro Cuff

    • Supracondylar cuff. Common for pt undergoing increased leg volume changes (for triathletes). Inverted v strap with waist belt

    • + easy to adjust, cheap, effective

    • - slight pistoning, not for short RL

  • Anatomical

    • PTB-SC & PTB SC/SP Socket. For short RL and ligamentous instability.

    • + resists genu recurvatum

    • - kneeling difficulties, cosmetic appearance with sitting

  • Silicone suction suspension (3-S)

    • Pin attached to sleeve liner. Always volume fluctuations

    • + increase cosmesis, decrease need for straps, decrease shear, decrease pistoning

    • - irritation from sleeve, costly, elongates distal tissues, increase sweat.

    • Avoid if neuromas present on distal RL. K2-K4

  • Seal-in liner

    • Vacuum system → hypobaric sealing membrane. Each ring provides increased suction/vacuum

    • + decrease need for straps, prevent elongation of distal tissue, check for hypersensitivity

    • - irritation, costly, allows limited volume fluctuations with proximal ½ socks

  • External Suspension Sleeve

  • Vacuum assisted socket system (VASS)

    • Battery powered pulling air out of liner to make sure it stays on. Increase suction with decrease pressure on RL

    • + increase RL volume control, decrease friction and pistoning, increase comfort

    • - heavy, costly, needs good hand function to turn on and off.

Transfemoral amputees - Above the knee amputation TFA:

• The ideal length is ______ proximal to the _____ _____. What does this allow for?

• Femoral length percentages for long, transfemoral, short transfemoral?

• Advantages? Disadvantages?

• Energy expenditure?

• Surgical concerns?

Transfemoral Amputees

• Above knee amputation (TFA): The ideal length is 8 cm proximal to the knee joint, which allows femoral condyles to be excised with adequate room to accommodate prosthetic knees

• Long = more than 60% femoral length

• Transfemoral = between 35%–60%

• Short transfemoral = less than 35%

Advantages:

• the healing rate is greater than more distal amputations, the residual limb in many cases is easier to fit

Disadvantages:

• mortality is greater

• more surgical complications

• cut muscle bellies retract

• muscle atrophy and loss of function

• longer to shape the residual limb

• rehab for prosthetic walking is less successful

Energy Expenditure:

• Unilateral 60–70%

• bilateral >200%

Surgical concerns:

• Loss of adductor strength (ALABAM)

  • Adductor longus

  • Adductor brevis

  • Adductor Magnus

Transfemoral socket design

• Types

  • Bilateral TFA stubbies or shorties

    • This socket is very what? Pts have to learn how to?

    • Very challenging to learn what two things?

    • Lower to the ground = what?

    • Worn by using what?

    • What gait pattern do you need when wearing this?

  • Plug socket

    • Shape?

    • Tissue tends to displace which direction? Causes what type of rolls

    • Pressure distribution is?

    • Typically made from what?

    • How is it suspended?

    • The end bearing is very _____, causes what?

  • Quadrilateral socket

    • What does scarpas bulge do? Made for patients to? Involved with?

    • Posterior wall: flat slanting anterior for flexion of how many degrees? This puts what on a stretch and maintains what?

    • Medial brim: slightly higher or lower than the posterior brim? Does NOT press on what? Inward indentation near what muscle, pushing what what two directions for increased what?

  • Ischial Ramal containment socket

    • IC and CAT - CAM socket → what?

    • Anterior walls significantly reduces what? Why?

  • Hybrid socket

    • Mix of what two?

  • Marlo anatomical socket

    • Focuses on what?

    • Contained within socket without impeding what muscle?

    • Posterior trim line are below what?

    • Increase ROM with hip _____ ____ is ______

  • Elevated vacuum sockets (Brimless or sub ischial socket)

    • How many inches below the ischial trim lines?

    • Roll on liner contains what muscles?

    • Paired with what type of suspensions?

    • Positives? For pt with what three things?

• Many sockets designs/used these days are a?

• Types:

  • Bilateral TFA stubbies or shorties

    • Very functional, Pt learning how to walk

    • Very challenging to learn core activation and a balance

    • Lower to the ground = easier weight transfer

    • Worn by using their knee joints

    • Circumduction gait

  • Plug Socket

    • Larger at top, tapered to bottom

    • Tissue tends to displace upward - fleshy rolls

    • Poor pressure distribution

    • Typically made from carved wood

    • pelvic band and suspenders for suspension

    • poor ending bearing = increased tissue breakdown

  • Quadrilateral Socket

    • Scarpa bulge: maintains ischial tuberosity on ischial seat by providing counter pressure against post wall

    • Made for pt to stand and walk comfortably

    • Involved with pushing anterior to posterior

      • Posterior wall = flat slanting ant for flex of 15 degrees (glute and hamstrings on stretch. Maintains knee extension

      • Medial brim = slightly lower than post brim, not pressing on pubic ramus. Inward indentation near psoas, pushing anterior to posterior for increased stability and assurance

  • Ischial-Ramal Containment Socket

    • IC and CAT CAM socket → flexible inner brim with in solid outer frame

    • anterior wall = scarpas bulge is significantly reduced due to forces being applied medially and laterally

  • Hybrid Socket

    • Mix of both quadrilateral socket and ischial ramal containment socket

  • MAS Marlo anatomical socket

    • MAS design focuses on skeletal support with ischium and ramus contained within socket without impeding glute max.

    • Posterior trim line below gluteal fold

    • Increase ROM with hip ER is unrestricted.

  • Brimless (elevated vacuum sockets)

    • brimless or sub ischial socket. 2-4 inches below ischial trim lines

    • Roll on liner contains the add muscles

    • Paired with vacuum assisted suspensions

    • + increase ROM and comfort

    • for higher level, longer RL, strong hip muscles

• Many sockets designed/used these days are a combination of two types

Side by side comparisons of ischial containment design VS quadrilateral design

• Ischium location

• Shape

• Indication

Which ones increase and decrease scarpas bulge? Which one has narrow medial and lateral dimensions and which one has narrow anterior and posterior dimensions?

TFA suspension systems

• It is?

• Bands?

• Suspension is?

• Traditional suction?

• 3-S silicone suction suspension is composed of what three things?

• The vacuum is? Higher or lower levels?

TFA Suspension Systems

• Anatomical

• Bands: Silesian Band, Pelvic Band with external hip joint

• Total Elastic Suspension

• Traditional Suction: Pull in, Wet fit

• 3-S Silicone Suction Suspension

  • Pin Locking

  • Lanyard System

  • Seal-in Liner

• Elevated Vacuum → higher levels

Prosthetic knees

• Manual locking knee (single axis)

  • Knee of ____ ____. PAPA ROACH

  • For what K levels?

  • Negatives?

  • Locks in what motions? Unlocks (manually) in what motion?

• Weight activated stance control (single axis)

  • Temp depends on?

  • Swing control: swing control by what? Can add what motion assistance?

  • Stance control: (Low, moderate, or high) mechanical?

  • How does it work?

• Polycentric Knees (Multi axis)

  • Usually the ____ prosthesis but is kept for?

  • Multi axis: What is it? No what?

  • Swing control: Assists what motion? Can have what add ons?

  • Stance control: (Low, moderate, or high) alignment?

  • How does it work?

  • Indications? K levels?

  • Negatives?

• Fluid controlled knee (hydraulic)

  • Regulation of what phase by fluid filled cylinder.

  • Swing control is mechanical or muscular with resistance to what two motions?

  • Stance control is mechanical or muscular?

  • How does it work?

  • Indications? K levels?

• What are the other two?

Types:

• Manual lock single axis

  • knee of last resort

  • weak and limited ambulator, K1 - K2

  • (-) abnormal gait, decreased cosmesis, cable failure, no ability to control knee

  • locks in ext, unlocks in flexion manually.

• Weight-activated/stance control single axis

  • Temp depends on air chamber pressure

  • swing control; swing control by friction, can add ext assistance

  • stance control: mod mechanical

  • Works by mechanical friction brake activated in weight bearing 20 degrees ext. Brake sensitivity adjustable

  • Needs full unweighting for it to bend

• Polycentric multi axis

  • Usually 1st prosthesis but is kept for back up

  • Multi axis: 4+ bar linkages (no hydraulics)

  • Swing control: ext assist or hydraulic add ons

  • Stance control: mod alignment

  • Works with 4 bar knee: knee bends → center of rotation moves and displaced posterior, increasing extension and increase stability. Axis shifts proximally to increase toe clearance

  • Indicated for needing increased stability due to short RL or weak hip ext. K1 - K2.

  • (-) heavy, costly, decrease cadence.

• Gas/fluid control single axis

  • regulation of swing phase by fluid filled cylinder

  • swing control: mechanical with fix resistance and ext resistance

  • stance control: mechanical muscular

  • Works by valves opening and closing to adjust resistance

  • Indicated for active ambulators with variable cadence. K3 or higher (sports participant)

• Micro-processor

• Constant friction

Manual locking knee (Repeat)

• Indications? (4)

• Disadvantages? (3)

• Indications:

  • Knee of last resort

  • Weak patient, limited ambulator

  • No ability to control knee

  • K level 1–2

• Disadvantages:

  • Abnormal gait

  • Poor cosmesis

  • Cable failure

Fluid controlled knee (hydraulic) (Repeat)

• Joint axis?

• Swing control?

• Stance control?

• Indications? (3)

• Joint Axis: single

• Swing Control: mechanical with flexion resistance and extension resistance

• Stance Control: mechanical, muscular

• Indications:

  • Active ambulator with variable cadence

  • Sports participation

  • K level 3 or higher

Gait deviations: what’s the cause

• Patient causes? (8)

• Prosthetic causes? (4)

• Unilateral amputees usually have a midline shift towards what and increased what support? Why?

• Shear occurs at what location and during what part of the gait cycle?

• Decreased prosthetic stance time can be the result of what three things?

• Patient causes

  • Strength issues

  • ROM restrictions

  • Volume fluctuations

  • Pain

  • Functional level

  • Habit/training

  • Balance

  • Confidence level

• Prosthetic causes

  • Prosthetic fit

  • Pain in RL

  • Componentry (broken/loose)

  • Alignment issues

Unilateral amputees usually have a midline shift towards SL and increase DL support (due to fear of being on RL)

Shear occurs at the stump/socket and between ground and the foot at IC

decrease prosthetic stance time can be the result of pain, instability, or decreased prosthetic trust.

Prosthetic gait assessment

• What do you do first?

• 90 to 95% of issues can be fixed by?

• Too much ply can cause?

• Too little ply can cause?

complete proper fitting first

90 - 95% issues can be fixed by putting sock ply

• too much ply = pelvic asymmetry

• too little ply = increase foot spins

Amputee gait deviations: TTA weight acceptance (IC to LR) (Focus on highlights)

For the following, state the prosthetic cause and the amputee cause

• Foot flat

• Foot slap

• ER of the prosthesis

• Increased flexion of knee

• Hyperextension of the knee

Amputee gait deviations: TTA single limb support (Mid-stance to TS) (No highlights)

For the following, state the prosthetic cause and the amputee cause

• Walking on the lateral border of the foot

• Walking on the medial border of the foot

• Increased DF

• Decreased Knee Flexion

Amputee gait deviations: TTA single limb support (Mid-stance to TS) (Focus on highlights)

For the following, state the prosthetic cause and the amputee cause

• Valgus moment at the knee

• Varus moment at the knee

• Abducted gait

• Pelvic drop off

• Pelvic posterior rotation

Amputee gait deviations: TTA swing phase (Pre-swing to Terminal swing) (Focus on highlights)

For the following, state the prosthetic cause and the amputee cause

• Pelvic rise

• Decreased stride length on prosthetic side

• Increased stride length on prosthetic side

• Decreased toe clearance

• Increased toe clearance

• Lateral whip (heel goes out, TFA, TTA)

• Medial whip (heel goes in, TFA, TTA)

Amputee gait deviations: TTA sound limb and arm swing (Focus on highlights)

For the following, state the prosthetic cause and the amputee cause

• Adducted limb

• Vaulting

• Uneven arm swing

• Extended rotation

• Increased stance time

Amputee gait deviations: TFA weight acceptance phase (IC to IR) (No highlights)

For the following, state the prosthetic cause and the amputee cause

• External rotation of prosthesis

• Knee flexion or instability

• Foot slap

Amputee gait deviations: TFA single limb support (Mid stance to terminal stance) (Focus on highlights)

For the following, state the prosthetic cause and the amputee cause

• Abducted gait

• Pelvic posterior rotation

• Pelvic lateral tilt

• Pelvic drop off

• Lateral bending of trunk

Amputee gait deviations: TFA single limb support (Mid stance to terminal stance) (Focus on highlights)

For the following, state the prosthetic cause and the amputee cause

• Trunk lordosis

• Trunk flexion

• Decreased stance time

• Increased stride width

Amputee gait deviations: TFA (pre swing to terminal swing) (Focus on highlights)

For the following, state the prosthetic cause and the amputee cause

• Increased knee flexion

• Increased knee extension

• Medial whip

• Lateral whip

• Circumduction TFA

Amputee gait deviations: TFA (pre swing to terminal swing) (No highlights)

For the following, state the prosthetic cause and the amputee cause

• Pelvic rise

• Pelvic posterior rotation

• Decreased stride length on prosthetic side

• Increase stride length on prosthetic side

• Decreased toe clearance

• Increased toe clearance

Amputee running

• Basic components of running? (Stride length, Stride frequency, Speed)

• Five steps for learning basic running?

• What can be seen with arm swing and trunk rotation in amputees, especially on the prosthetic side? Why?

• Basic Component of Running

  • Stride Length = Distance covered with each stride

  • Stride Frequency = The number of strides taken within a given time

  • Speed = Stride Length X Stride Frequency

• Five Steps for Learning Basic Running

  • Prosthetic Trust - reach out with prosthesis

  • Backward Extension - pull back with prosthesis

  • Sound Limb Stride - pull down and back with prosthesis, reach out with SL

  • Stride Symmetry - Relax and take equal strides

  • Arm Carriage - high hands and elbows

Arm swing and trunk rotation are decreased or absent in amputees especially on prosthetic side (for bracing)