Knee Disarticulation Principles

Question 1

There are some significant benefits for the patient with a knee disarticulation amputation, which include:

Answer 1

• A greater level of muscular control of the longer lever arm
• The distal end of the residual limb remains intact including the articulation cartilage.
• The surface is already accustomed to bearing weight on the proximal end of the tibia.
• Better tolerance to partial or full weight-bearing on the distal end, decreasing the pressures in the socket over the soft tissue areas and making it possible for these individuals to ambulate without ischial weight bearing, thereby increasing their comfort.

Question 2

Due to the length of the knee disarticulation amputation, it is very difficult to place prosthetic components at the distal end of the socket and still have a cosmetic appearance of the prosthesis.

Answer 2

True

Question 3

Although phantom pain and phantom sensation are less common due to the “less traumatic” amputation, hip flexion or hip abduction contractures are common.

Answer 3

False

Question 4

If captured properly in the prosthetic socket, the bony shape of the distal residual limb in a knee disarticulation can:

Answer 4

Provide good suspension over the condyles as well as rotational control of the prosthesis.

Question 5

Which of the following is true about the Gritty-Stokes amputation?

Answer 5

• Can still allow weight bearing at the distal end of the residual limb because of the relocation of the patella.
• Since the amputation is more proximal at the level of the condylar flares the distal end of the residual limb is less bulbous, tending to be more cosmetic.
• This amputation can also allow slightly more room for different components to fit distal to the socket.
• Disadvantages include the difficulty of healing and union of the patella with the distal end of the cut femur and because of the decrease in the medio-lateral diameter at the condyles, it may not be possible to provide self suspension with this amputation.

Question 6

The Gritty-Stokes amputation preserves the articular surface of the distal femur.

Answer 6

False

Question 7

In contrast to the transtibial joints and corset prosthesis, if outside joints are used with a knee disarticulation design, a back check is not necessary.

Answer 7

False

Question 8

The knee disarticulation prosthesis is usually finished with a one-piece, full length cosmetic cover.

Answer 8

False