Total Hip Replacement
Total hip replacement surgery requires replacing the damaged joint surfaces with prostheses, which are metal, ceramic and plastic components.
The socket component, or acetabular, is always replaced with a cementless metal shell. Its porous surface allows bone to grow into its substance. Some shells have a plastic, metal or ceramic liner that inserts into the metal and acts as a bearing surface.
For a traditional hip replacement, the head and neck of the femur are replaced with a metal stem fixed to the bone with or without cement. For the cementless stems, we implant a tightly fitting metal stem with a porous surface that relies on bone to grow into its substance for fixation. A round metal or ceramic ball which rotates within the shell is attached to the stem. The bearing surface combinations can be metal on metal, metal on plastic, ceramic on plastic or ceramic on ceramic.
A person's age, activity level, body weight, and bone quality are all key factors in determining whether or not a patient is a candidate for hip resurfacing versus hip replacement; in hip resurfacing the bone is preserved. Rather than replacing the entire hip joint, as in a total hip replacement, hip resurfacing simply shaves and caps a few millimeters of bone within the joint. The metal implant caps the femoral head and preserves the femoral stem. This approach reduces the post-operative risks of dislocation and inaccurate leg length, and the all-metal implant has the potential to last longer than traditional hip implants. This is particularly good for high level activity patients because it more predictably allows them to return to activities they enjoyed previous to their hip problems. The FDA approved hip resurfacing in the United States in 2006. Dr. Jeffrey Lawrence has performed hip resurfacing at VMH since 2007.