The first ball-and-socket hip joint was made of stainless steel and plastic. Over the years, the materials used to create these life-changing devices have been improved to provide greater function and durability. One of the most important changes is the design of the device itself. The man-made joints we have today are much more similar to the joints they are replacing than the devices first used. Likewise, the material used in these man-made joints is much stronger than older versions.

Today, artificial joints are made by using ultra high Molecular Weight Polyethylene (UHMWPE) to create a plastic bearing surface which is attached to one bone of the joint. A metal replacement surface is attached to the other bone. Therefore, bone is not rubbing against bone and ,consequently, pain is decreased. This type of procedure can replace joints such as the hip, knee, shoulder, wrist, finger, or toe.

These artificial joints can function for up to 20 years. The materials may then begin to break down and cause damage to the surrounding tissue. When this happens, the artificial joint needs to be repaired or replaced. Doctors and scientists are constantly researching new materials that will increase the strength and longevity of artificial joints.

Hip replacement

When a Total Hip Joint Replacement is performed, the acetabulum or “shelf” of the pelvis is rounded out and a new cap implant is put into place. The femoral component is round like a femoral head and has a stem on the other end.  The rounded end is placed in the new cup where it will rotate for hip movement.

The stem is placed inside the shaft of the femur where new bone tissue will grow into the surface of the implant.
Knee replacement

During Knee Joint Replacement surgery, the diseased portions of the femur, tibia, and patella are removed.  Both ends of a hinge-shaped implant are then inserted into the center area of the lower femur and upper tibia.  The implant is cemented into place and becomes the new knee.

Shoulder replacement

In Shoulder Joint Replacement surgery, the scapula is shaped into a cup-like shelf in order to hold the new implant.  The implant is rounded on one end like the end of the humerus bone.  The other end has a stem, which is placed inside the humerus bone.

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