Prosthetics-P101

Prosthetic Objectives

• Amputee perspective Prosthetic process– Existing amputee v. New amputee

• Component selection criteria– Suspension– Materials– Alignment– Pr(x) Feet– Pr(x) Knees

Amputee perspective Prosthetic process• Existing Amputee– Ill fitting– Repair cost will

outweigh new socket/prosthesis

– Begin Prosthetic process

• New Amputee– Order/Call to see new

amputee for a protective dressing, shrinker and or consultation

– F/u patient to Surgeon removal of sutures/staples

– Begin Prosthetic process

Soft Removable Dressing

Amputee perspective Prosthetic process (cont’d)

• Amputee– Begin Prosthetic process– Begin Therapy process– Initial Evaluation– Functional Testing

AmpnoPro & AmpPro– PM&R Pre-prosthetic

Evaluation– Component Selection

Lower Extremity Prosthetic Evaluation• Name, age, Hgt, Wgt, Sex• Amputation Level, side• Other amputations• Ortho, neuro copathologies• Existing User• Living Status• Living Environment

– Uneven terrain, carpet, hard surfaces

• Health comorbidities• Medications/Treatments• Ambulatory Aids• Vocational Needs• Pre-amputation activities• Patient Feedback of

current device• Upper Extremity ROM,

MMT, dexterity

Lower Extremity Prosthetic Evaluation• Residual Limb Features• Amputation Level• Skin health• Boney, invaginated areas• ROM, MMT• Contractures• Functional Testing

– AmpnoPro/AmpPro

• Limb Length

• Contralateral limb Features

• Diabetic• Callused• Wounds• Toe, Foot, T.T, T.F, HD

Lower Extremity Functional TestingOutcome Measures in Lower Limb Prosthetics

K-LevelsK-Levels: K-levels are defined by Medicare based on an individual's ability or potential to ambulate and navigate their environment. Once it is determined in which K-level an individual resides, it can be determined which prosthetic components are covered by Medicare.

BilateralsGait characteristics of persons with bilateral transtibial amputations, Po-Fu Su, MS Steven A. Gard, PhD, Robert Lipschutz, CP, Todd A Kuiken, MD, PhD

AmpNoPro AmpPro K-level Description Foot/Ankle Assemblies Knee Units

0-8 n/a K0 Patient does NOT have the ability or potential to ambulate or transfer w/o assistance & prosthesis does not enhance their quality of life or

mobility

Not Eligible Not Eligible

9-20 15-26 K1 Has the ability or potential to use a prosthesis for transfers or ambulation on level surfaces at fixed cadence. Typical of the limited

and unlimited household ambulatory.

External keel, SACH feet or single axis/feet

Single-axis, constant friction knee

21-28 27-36 K2 Has the ability or potential for ambulation with the ability to traverse low level environmental barriers such as curbs, stairs or uneven

surfaces. Typical of the limited community ambulator.

Flexible-keel feet & multi-axial ankle/foot Polycentric, constant friction knee

29-36 37-42 K3 Has the ability or potential for ambulation with variable cadence. Typical of the community ambulator who has the ability to transverse most environmental barriers and may have vocational, therapeutic or

exercise activity that demands prosthetic utilization beyond simple locomotion.

Flex foot, and flex-walk systems, energy storing feet, multi-axial ankle/feet, or

dynamic response feet

Fluid & Pneumatic Control knee

37-43 43-47 K4 Has the ability or potential for prosthetic ambulation that exceeds the basic ambulation skills, exhibiting high impact, stress, or energy levels, typical of the prosthetic demands of the child, active adult, or athlete

Any ankle foot system appropriate Any knee system appropriate

Examples

BK Socket/Suspension selection• Socket Style– Patella Tendon

Bearing(PTB)– Total Surface

Bearing(TSB)

• Suspension• Liners/Sleeves• Research

– Öderberg, JPO 2003PTB Socket Style

TSB Socket Style

Suspension/Liner Selection• Cushion• Locking• Distal Locking• Suction

Fitting process1. Check Socket

2. Temporary Socket

3. Definitive1. Check

2. Temporary 3. Definitive

Foot Selection CriteriaFoot/Ankle Assemblies

K0 Not eligible for prosthesis

K1 External keel, SACH feet or single axis ankle/feet

K2 Flexible-keel feet and multi-axial ankle/feet

K3

Flex foot and flex-walk systems, energy storing feet, multi-axial ankle/feet, or dynamic response feet

K4 **Any ankle foot system appropriate

• Patient Wgt.• Activity Level• Carrying Loads• Foot size• Foot Build Hgt.

Effect of wrong category of feet• Premature failure• Delayed/Absent Energy

Return• Bumpers require more

maintenance• Gait Deviations• Skin Breakdown

The AmputeeOT

K1-Level Foot Selection• K1-ability or potential to use a prosthesis for transfers

or ambulation on level surfaces at fixed cadence

K2-Level Foot Selection• K2-Flexible-keel feet

and multi-axial ankle/feet

K3-Level Foot Selection• K3-energy storing feet,

multi-axial ankle/feet, or dynamic response feet

K4-Level Foot Selection• K4-exceeds basic

ambulation skills, exhibiting high impact, stress, or energy levels

Alignment

• Bench/Static/Dynamic• Proper Standing Balance• Easier use of foot

functions• Increased socket

comfort• Increase Energy return

Efficacy of D.R.F

AK Socket Selection• Socket Design– Quadrilateral– Ischial/ Ramal

containment• More Anatomical

QuadrilateralIschial Containment

Prosthetic Knee Selection

K1 Single Axis-Locking

• Manual Locking (K1)

• Polycentric (K2)

• Weight Activated Stance Control (K1-K2)

• Single Axis Constant Friction

• Outside Hinges

Polycentric Knee

Knee Features• Locking Mechanism• Wgt. Activated Stance

Control• Geometric Lock• Stance Phase Flexion

• Stumble Recovery=Stance Phase Control

• Stance Extension Assist• Stance Flexion Resist• Microprocessor Control– C-Leg, Rheo, Plie, Orion

References1. https://med.noridianmedicare.com/web/jddme/education/event-materials/

op-claim-qa2. Po-Fu Su, MS, Gard, S., PhD, Lipschutz, R., CP, Kuiken T., MD, PhD, 2007. Gait

characteristics of persons with bilateral transtibial amputations. JRRD Vol 44 Num 4, 491-502

3. Öderberg, B., 2003. Roentgen Stereophotogrammetric Analysis of Motion between Bone and the Socket in a Transtibial Amputation Prosthesis: A Case Study. JPO Vol 15 Num 3, 95-101

4. Atlas of Limb Prosthetics5. Sinitski, E.H., et al., 2011. Biomechanics of the ankle-foot system during stair

ambulation: Implications for design of advances ankle-foot prosthesis. Journal of Biomechanics DOI:10.1016/j.jbiomech.2011.11.007