| Question | Answer |
| Types of Prostheses | Post-Operative;
Temporary;
Definitive |
| Post-Operative Prostheses | Eliminates contracture potential;
Reduces time to fitting of preparatory prosthesis;
Restricted use on vascular/diabetic pt due to skin abrasion & inability to monitor residual limb |
| Preparatory Prosthesis | Basic- socket, pylon, foot;
Allows early ambulation, promotes residual limb shrinkage;
~4-8 months
Adjustable socket/interface
Adjustable/interchangeable components;
No cosmetic finish;
2nd socket req'd w/ extreme edema/rapid limb reduction |
| Definitive Prosthesis | Fit once limb stabilizes shape/size;
Typically 3-5 yrs;
Cosmetic & finished;
Replace PRN |
| Endoskeletal Design | Modular; Anatomically shaped foam w/ soft cover;
Pylon- aluminum, stainless steel, titanium, carbon;
Adjustable, lightweight |
| Exoskeletal Design | Hard outer covering-laminated;
Durable- pts in construction/farming;
Not easily adjusted |
| Conventional Fabrication | Cast residual limb (- impression);
Fill w/ plaster (+ mold)
Add- tibial tub & crest, distal tib/fib, fib head, hams
Remove- patella tendon, tib flare, popliteal area, calf mm
Dx socket- static & dynamic alignments;
Definitive socket laminated, foam s |
| Computer-Aided Fabrication (CAD/CAM) | Cast/scan residual limb;
Converted to computer;
Modified on computer;
Sent to carver, + mold created out of foam;
Same as conventional fabrication |
| Prosthetic Feet | Used on 90% pts |
| Foot Failure- Alignment | Socket & components not set in appropriate alignment;
Forces improperly interacting with foot components & causing pre-mature wear |
| Foot Failure- Pt. Selection | Pt's activity level doesn't correspond to foot design;
Pt's weight/activity has increased since initial fitting |
| Foot Failure- Proper Use | Pt abuses foot: walking w/o shoes; improper heel height; water damage; dust/dirt damage; lack of maintenance |
| Foot Failure- Shoe Selection | Pt has change heel height;
Shoes old & in disrepair;
Shoes don't provide adequate support for prosthetic foot |
| Choosing Appropriate Foot- Physical | Pt. height, weight & functional age;
Knee disarticulation; trans-femoral; hip disarticulation; hemi-pelvectomy; bilateral; pediatric; adult; geriatric |
| Choosing Appropriate Foot- Functional- FL 0 | No ability or potential to ambulate or transfer |
| Choosing Appropriate Foot- Functional- FL 1 | Ability/potential to transfer or ambulate on level surfaces at fixed cadence |
| Choosing Appropriate Foot- Functional- FL 2 | Ability or potential for ambulation with ability to traverse low level barriers |
| Choosing Appropriate Foot- Functional- FL 3 | Ability/potential to ambulate with variable cadence |
| Choosing Appropriate Foot- Functional- FL 4 | Ability-potential to ambulate which exceeds basic ambulation skills |
| Choosing appropriate Foot- Financial | Initial investment; Maintenance; Replacement parts; Long-term replacement; Future insurance status |
| Choosing Appropriate Foot- Functional | Stability factor;
Maintenance;
Durability |
| Choosing Appropriate Foot- Patient Priorities | Function;
Durability;
Cosmetics;
Comfort |
| Prosthetic Feet Functions | Joint stimulation;
Shock absorption;
Stable WB BoS;
Muscle simulation;
Cosmetically pleasing |
| Prosthetic Feet- Conventional | Solid-ankle cushioned heel (SACH);
Stationary-attachment flexible endoskeletal (SAFE);
Single-axis;
Multi-axial;
If not conventional, dynamic response/energy storing |
| SACH Foot | Solid Ankle Cushion Heel
Simple design, low cost, lowest fxn;
Cushion heel compresses on heel strike, rigid keel provides resistance during mid-stance; flexible forefoot provides rollover capabilities |
| SAFE Foot | Stationary Attachment Flexible Endoskeleton;
Flexible internal keel permits tri-planar mvmt & easy "rollover";
Foot stiff & stable during stance |
| Single-Axis Foot | Provides PF & DF motion;
Very stable at heel strike for AK amputees;
Can adjust & exchange bumpers to modify foot response |
| Multi-Axis Foot | Multi-axial foot mvmt (PF/DF; Ev/Inv; IR/ER);
Preferred for uneven terrain;
Absorbs gait torque to reduce shearing forces on residual limb |
| Energy Storing/Dynamic Response | Internal keel structure "absorbs" energy during mid-stance & temrinal stance;
"Releases" energy at pre-swing (toe off) to provide smoother/more energy efficient gait;
Extremely lightweight & durable |
| Special Activity Foot | Accomodates unique & specific demands of athlete & sport;
Typically customized foot can only be used for 1 specific activity or sport |
| Foot Enhancements- Vertical Shock Absorber | Built into foot or attached as separate component;
Reduces impact forces during stance/heel strike;
Reduces shear within socket;
Improves rotational forces at heel strike |
| Foot Enhancements- Rotational Torque Absorber | Built into foot or attached separately;
Absorbs gait torque to reduce shearing forces on residual limb;
Provides rotation mobility for standing & twisting mvmts |
| Specialty Foot Considerations- Heel height adjustable foot | Pt can make adjustment to foot to accommodate various shoe heel heights while maintaining uniform distance from heel to the knee center |
| Socket Design | Patellar Tendon Bearing (PTB)
Total Surface Bearing (TSB) |
| PTB- Areas of WB | Patellar tendon, medial tibial flare, fibular midshaft |
| PTB- Areas of Relief | Lateral tibia, head & distal end of fibula, tibial crest, distal end of tibia |
| PTB- Functions | Medial/lateral control rotation & provide ML stability;
Posterior wall applies anterior force to PTB |
| Total Surface Bearing | Same areas of relief & WB as PTB, just not as aggressive;
Idea is total global reduction;
Distribute weight & pressure equally throughout limb |
| Liners | No liner;
Pelite liner (custom);
OTS gel liner;
Custom gel liner |
| No liner | Hard socket- no liner, just sock or soft interface |
| Advantages & Disadvantages to No Liner | A: Less bulk, easier cleaning, fewer perspiration issues
D: More difficult to fit, less comfortable |
| Advantages & Disadvantages to a Liner | A: Total contact= decreased edema; Modifications to liner
D: Deterioration over time; Sanitation due to perspiration absorption; Increased weight; Difficulty donning |
| Pelite Liner | Commonly used with PTB socket;
Distal end pad- plastazote or formed form |
| OTS Gel Liner | Even pressure distribution;
Minimal shear forces;
High shock absorption;
Most limbs;
Various thicknesses |
| Custom liner | Used with "problem" pts;
Otto Bock TEC liner;
Can vary in thickness;
Increased cost with better fit |
| Types of Suspension | Supracondylar cuff; Supracondylar system; Supracondylar/suprapatellar system; Thigh corset; Waist belt; Suspension sleeve; Locking liner |
| Supracondylar Cuff | Cuff suspended above femoral condyles & proximal patella;
Resists hyperextension |
| Supracondylar System | Wedge suspension on medial wall;
Removable for donning & doffing;
Wedge holds over femoral condyle |
| Supracondylar/Suprapatellar System (PTB SC/SP) | High walls encompass femoral condyles & patella;
Used for extremely short limbs or ML instability |
| Thigh Corset | Leather lacer or laminate around thigh;
Provides max ML stability;
Controls hyperextension (check strap);
Atrophies thigh |
| Waist Belt | Used most often in temporary;
2" webbing around waist attaches to supracondylar cuff;
Inverted "Y" design |
| Suspension Sleeve | Gel liner next to skin;
Sleeve over prosthesis pulled up over thigh sealing against skin;
Creates sealed chamber & suspends leg |
| Locking Liner | Gel liner with locking mechanism;
Pin attached to bottom;
Slide into socket-locks;
Press button to release |
| Vacuum System | Lower- mechanical pump out; expulsion valve; negative vacuum;
Upper- higher vacuum with electric pump; sucks air out |
| Exam/Checkout Procedure | Static (standing);
Static (sitting);
Dynamic (walking) |
| Standing Exam | Foot flat on floor (with shoe);
Correct height;
No leaning pylon |
| Sitting Exam | Adequate hamstring relief;
Liner pulled up;
When donning- invert liner completely to avoid any excess air |
| Walking Exam | Gait deviations noted;
Pistoning minimal;
No leaning pylon |
| Sock Wear | As limb shrinks inside socket- replaces lost volume to maintain total contact;
Different thickness "ply";
Add cushioning;
Reduce friction |
| Liner Care | Wipe, wash, rinse well daily;
Allow to dry thoroughly;
Don't invert;
Inspect for cracks |
| Socket Care | Wash with soap & water;
Allow to dry thoroughly |
