This document discusses lower limb prosthetics. It defines key terms like prosthesis, residual limb, and orthosis. It then describes the ideal characteristics of a prosthesis and factors considered in prescribing one, like amputation level and activity level. The major components of a lower limb prosthesis are also outlined, including the suspension system, socket, knee joint (for transfemoral prosthetics), pylon, and terminal device. Different types of each component are explained. Complications from prosthetics are noted.

1. LOWER LIMB PROSTHESIS
Dr Thileebphan

2. INTRODUCTION
Prosthesis
Device to replace part of the limb or missing limb
Prosthetist
Person skilled in prosthetics and its application
Residual limb
Part of the limb that remains after an amputation
Orthosis
Externally applied mechanical devices to Support weakened
injured, paralyzed, diseased part as supplementation.

3. TO THINK…..
If lower limb amputation done in
FOUR patient
how many will die with in ONE
MONTH?

4. IDEAL PROSTHESIS
1. Provide Posture , Balance, Stability
2. Provide Comfortable mobilization
3. Performing desired activity
4. Pleasing cosmetically
5. Protect & accommodate residual limb

5. PRESCRIBING THE PROSTHESIS
1.Level of amputation , 2.State of residual limb, 3.Activity level
K-rating scale
US Department of Health and Human Services’ Centerfor Medicare and Medicaid
Services.
K-0 – Non-ambulator requires assist with transfers
K-1 - Household ambulator
K-2 – Limited community ambulation
K-3 - Unlimited community ambulation
K-4 - Exceeds basic use

6. LEVEL OF AMPUTATION IN LOWER LIMB

9. LOWER LIMB PROSTHESIS
1.Trans-femoral prosthesis
2.Trans-tibial prosthesis
3.Foot prosthesis

10. MAJOR COMPONENT OF THE LOWER LIMB PROSTHESIS
1. The control system
2. Suspension mechanism
3. Socket
4. Knee joint
5. Pylon
6. Terminal device

11. Suspension system

12. CONTROLLING SYSTEM
Simple prosthesis - largely through gravity
The most sophisticated (and expensive) prosthesis - myo
electric
Electrodes to sense muscular impulses in the residual
limb

14. SUSPENSION
Attaches the prosthesis to the residual limb.
It actually-
1. Prevent pistoning.
2. Holding and prevent slippage during stance.

15. TO THINK…..
What if not bother about
pistoning of socket?

16. Types
1. Straps & Belts- Selesian belt, Thigh corset – For AK
2. Cuff – Supra-condylar cuff, Supra-patellar cuff – For BK
(cautious with PVD patients.)
3. Suspension sleeve – Elastomer material rolling into stump and
holding by negative pressure- For BK & AK
4. Suction System – Socket itself attaching to stump by negative
pressure, not suitable in tibia
5. Shuttle lock system – More advanced - For BK & AK
6. Combined

17. Selesian Belt

18. Supra condylar cuff

19. Suspension Sleeve & Suction system
..DownloadsSuction system.mp4

20. Shuttle lock system
..Downloadssuttle locksystem 3.mp4

21. SOCKET
The connection between the residual limb
and the prosthesis;
It needs to
1. Accommodate & protect the residual limb.
2. Transmit the forces evenly through a greater surface
area.
3. Decrease pressures to any constant area.
4. Not allow distal pooling of fluid within the residual limb.

22. Types
1. Trans-Tibial Sockets – 1. PTB socket
2. Hydrostatic
1. Trans-Femoral Sockets 1. Cylinder
2. Quadrilaeral
3. Ischial containment
4.Flexible socket
Advancement and more comfortable

23. Patellar tendon bearing socket

24. Ischial containment trans femoral socket

25. Flexible trans femoral socket

26. KNEE
In case of the trans femoral prosthesis –it is wanted.
It is available
1. Single axis
2. Multiaxis

27. Types
1.Fixed cadence knee – Fixed resistance in the knee unit to control the
pendulum action of the prosthesis.
Rate of swing is set by the prosthetist.
For K1 & K2 patients
2. Variable cadence knee – Accomodates user’s walking speed and
adopt the gait.
1. Hydraulics or pneumatic – for control
and set rate range. For K3
2. Intelligent knee – Combining the
micro processor with above mechanism.
For K4

29. TO THINK…..
Roughly how much it will cost to
purchase a intelligent knee?

30. PYLON
A simple tube or shell that attaches the
socket to the terminal device.
It evolved
From simple static shells to dynamic devices that allow
axial rotation and absorb, store, and release energy.

31. Types
Exo skeleton Composed of a solid piece of wood or rigid
polyurethane covered with plastic laminate and
fashioned into the shape of a leg.
Endo skeleton Internal metal frame with aesthetic soft covering.
Made of - lightweight nylon, aluminum, or carbon/graphite.
Completely interchangeable & prosthesis easily repairable.

33. TO THINK…..
During prosthetic prescription ,
does weight of prosthesis matter?

34. TERMINAL DEVICE
Typically a foot and ankle.
It is expected to
1. Give push off
2. Ankle function mainly dorsi flexion
3. Shock absorbtion.

35. Types
Non dynamic response foot – More conventional
Great ground reaction force
SACH(Solid ankle/cushioned heel )
For K1 & K2
Dynamic response foot More advanced
Push off, ankle function and
shock absorption.
For K3 & K4

36. SACH Foot

37. Dynamic response foot

38. COMPLICATIONS DUE TO PROSTHESIS
1. Choke syndrome
2. Dermatologic problems
3. Painful residual limb
4. Ineffective suspension system
5. Poor socket fit
6. Stump volume changes

39. REFERENCE
1. Componentry for Lower Extremity Prostheses
Friel, Karen PT, DHS JAAOS - Journal of the American Academy of Orthopaedic
Surgeons: September 2005 - Volume 13 - Issue 5 - p 326–335 Articles
2. AAOS 2nd edition.