First 151 words of the document:
Prosthesis is an artificial body part used by some one with a disability to help regain some degree of normal function.
Prostheses can be used to replace whole limbs or parts of limbs e.g. artificial hip joints.
Damaged knee joints can be replaced by prosthetic joints
1. The surgeon makes an incision in the affected knee.
2. Once the patella is moved out of the way, the ends of the femur and tibia are trimmed to fit the prosthesis, taking care not to damage
3. The underneath of the patella is also trimmed so that an artificial piece can be fitted.
4. Special bone cement is used to attach the new surfaces.
5. A metal device is inserted into the knee to replace damaged cartilage and bone. Cushioning in the new joint helps to reduce the impact
on the knee.