IDS ::: Prosthetics ::: Exoskeletal

Exoskeletal means having an external framework. A crab is therefore exoskeletal. This is different from a human for example, as a human skeleton is effectively an internal framework A human is therefore endoskeletal.

Modern exoskeletal prostheses are normally of a laminated construction where layers of fabric such as glass fibre and carbon fibre are incorporated into a resin under vacuum. Older designs of exoskeletal construction include shaped sheet aluminium alloy and wood. Some alloy prostheses still are made but wooden prostheses are now extremely rare in Ireland. Exoskeletal prosthesis are often prescribed for children because Endoskeletal prostheses are never fully waterproof and are often not damage resistant enough.

An exoskeletal transradial prosthesis at fitting stage, showing the body powered hand and operating cable.

Showing the same hand in the open position.

A conventional exoskeletal ankle disarticulation prosthesis with steel side bars, leather socket and wooden foot. This type is now almost obsolete.

An example of a metal exoskeletal prosthesis. This is a transtibial prosthesis known as a No. 8 Metal. It has a wooden foot, duralumin shin, a leather socket, external knee joints and a leather lacing thigh corset. The No. 8 refers to the amputation level. Metal exoskeletal prostheses are normally made from duralumin with steel joints. While some are still made they are not common, especially for more recent amputees. These prostheses have some disadvantages. They are not modular and are therefore difficult to repair or even adjust. Cosmetically they can be very unsatisfactory also.

A laminated myoelectric transradial exoskeletal prosthesis

A young soccer player with bilateral transtibial prostheses. These are laminated and very hard wearing. Laminated lower limb prostheses can often be made waterproof and are very damage resistant. However, they cannot easily be lengthened or shortened.

The alignment cannot be easily changed. A structural failure will require a complete remanufacture. While it is difficult to achieve a very good cosmetic result with this method of construction, it does allow for a wide variety of textiles to be used as a final outer layer. Instead of being flesh coloured, the prosthesis can display sports logos or cartoons, for example.

Use the links below to find out more information on 'Construction':

Endoskeletal ::: Exoskeletal ::: Conventional ::: Solely Cosmetic ::: Silicone ::: Cosmetic Covers