Medically reviewed by
Dr. Ardalan Sayan
McLeod Orthopedics Dillon

“It is important that hip and knee replacement patients are informed of what is going to happen as they prepare for and recover from total joint replacement surgery,” says McLeod Orthopaedic Surgeon Dr. Ardalan Sayan. “Preparing for surgery can be overwhelming. Therefore, it is important for patients to ask questions, especially if they are unsure or do not understand what their doctor said.”

Medical terms are often challenging to understand. Here are some of the frequently used medical terms to help you prepare for your total joint replacement surgery.

Arthroplasty.  Describes the surgery to replace or reconstruct a joint.

Acetabulum (ahs-uh-TAB-you-lum). The “cup” part of the hip, into which the femur ball fits.

Diagnostic Imaging. This means that your doctor will take some X-rays of your joint.  Or, they may request more sophisticated imaging, such as a CT Scan or Magnetic Resonance Imaging (MRI).  A CT scan, sometimes called a “cat” scan, is an X-ray that uses computers to create a three-dimensional picture of the hip or knee.  An MRI uses magnetic pulses to cause the tissues to make signals, which are translated into a picture.  It is better at showing soft tissue.

Femur (FEE-mer). Another name for the thigh or upper part of the leg, which is connected to the hip. The femoral head is the rounded “ball” part that fits into the hip.

Nonsteroidal Anti-inflammatory Drugs (NSAIDs). (EN-saids) These non-narcotic medications include aspirin and ibuprofen and are also available at prescription strength. They are commonly used for arthritis and pain management after joint replacement.

Knee Joint Revision. This refers to the need to replace a worn joint replacement with a second one.  When people under 50 receive a hip or knee replacement, the new prosthesis can wear out over 15 to 20 years.

Osteoarthritis (OA).  It is the most common reason that a person needs a joint replacement. OA breaks down the smooth cartilage surface of a joint. Bones then rub directly against each other, causing pain and swelling.  Wear and tear over a lifetime causes OA. It can also be triggered by an accident.

Prosthesis.  The artificial joint, which may have several pieces or components.

• For a hip replacement, the parts are the stem, ball, cup and liner.  The stem goes into the femur bone.  The cup goes into the acetabulum.  The liner goes into the cup.
• For a knee replacement, the parts include the femoral component, which sits on the end of the thighbone, and the tibial component, which sits atop the lower leg bone.  These are separated by a plastic liner.  A plastic liner is often placed on the back of the kneecap (patella) as well.

Tibia. (TIHB-ya) The leg bone that runs from the knee to the ankle.

Total Hip Replacement (THR). Also called Total Hip Arthroplasty (THA).  Refers to removing the ball from the top of the thigh bone, and replacing it with metal or ceramic components, and resurfacing the cup of the hip with a metal and (usually) plastic liner.

Total Knee Replacement (TKR).  Replacing the worn top of the tibia (leg) and bottom of the femur (thigh) with metal, ceramic or plastic components.

A hospital stay of a day or two is typical for knee or hip joint replacement. Physical therapy then helps the muscles around the new joint to get strong. Like any major operation, joint replacement surgery carries the risk of possible complications.

If you have questions, find an orthopedic specialist near you.