Thigh prosthesis
A thigh prosthesis is a body replacement that is used after an amputation of the leg above the knee joint when the thigh bone is severed. Since this type of prosthesis is located outside the body, it is counted among the exoprostheses , just like the lower leg prostheses .
functionality
Thigh prostheses consist of five components:
- the socket grips the stump and transfers the force to the prosthesis. With thigh prostheses, this load transfer takes place via the ischial tuberosity ( tuber ischiadicum ) or the entire surface of the residual limb . Pressure-sensitive bone parts that have to be relieved, as in the case of the lower leg prostheses , are rarely found in the thigh prostheses. However, it is necessary to create space for the muscles to expand and to optimize the load distribution.
- the prosthetic knee can be constructed mechanically in one or more axes, with or without hydraulics, or controlled by a microprocessor
- The lower leg part usually consists of a tubular skeleton, but can also consist of two carbon fiber rods or a hard shell (made of GFK / KFK ), for example for bath prostheses. However, these only offer a limited range of functions.
- the foot section also contains a movement element that mimics ankle mobility. Currently, springs made of carbon fiber are mostly used. With sports prostheses, the lower leg section is often very short, but the foot section is often an oversized carbon fiber, which, with its very high elasticity, enables high jumping performance.
- the cosmetic cladding of the entire prosthesis, which can also be dispensed with, as with many sports prostheses
Types of prostheses
Thigh prostheses are classified in several ways. The first is the classification after attachment to the stump:
- with vacuum system (active or passive)
- with locking mechanism (shuttle lock, clutch lock or cord system)
- with static friction
- Suction socket prostheses
The second form of classification is based on the shaft system:
- transverse oval
- Hybrid form
- longitudinal oval (also called CAT-CAM shaft)
- MAS shaft
The last two shapes mentioned are part of the anatomical shaft shapes, while the transverse oval and hybrid shaft are more of a functional shape. Interim prostheses represent another form . These are used shortly after the amputation for a period of approx. 3–6 months and are then replaced by permanent prostheses. As a rule, there is no cosmetic disguise for interim prostheses.
Components
Thigh prostheses consist of a shaft that is individually manufactured for the respective patient, a purely mechanical or electronically controlled knee joint, a tube and a foot component. All components are individually tailored to the patient depending on the level of activity .
See also
literature
- René Baumgartner, Bernhard Greitemann, Peter Teutrine: Basic course in technical orthopedics . Thieme, Stuttgart 2002, ISBN 978-3131250711 .
- René Baumgartner, Pierre Botta: Amputation and prosthesis fitting of the lower extremity . Enke, Stuttgart 1989, ISBN 978-3432975016 .
