What Is a Hip Replacement?
Hip replacement, or arthroplasty, is a surgical procedure in which the diseased parts of the hip joint are removed and replaced with new, artificial parts. These artificial parts are called the prosthesis. The goals of hip replacement surgery include increasing mobility, improving the function of the hip joint, and relieving pain. According to the Centers for Disease Control and Prevention (CDC), 332,000 total hip replacements are performed in the United States each year.
Why Do People Have Hip Replacement Surgery?
For the majority of people who have hip replacement surgery, the procedure results in:
- a decrease in pain
- increased mobility
- improvements in activities of daily living
- improved quality of life.
What Does Hip Replacement Surgery Involve?
The hip joint is located where the upper end of the femur, or thigh bone, meets the pelvis, or hip bone. A ball at the end of the femur, called the femoral head, fits in a socket (the acetabulum) in the pelvis to allow a wide range of motion.
During a traditional hip replacement, which lasts from 1 to 2 hours, the surgeon makes a 6- to 8-inch incision over the side of the hip through the muscles and removes the diseased bone tissue and cartilage from the hip joint, while leaving the healthy parts of the joint intact. Then the surgeon replaces the head of the femur and acetabulum with new, artificial parts. The new hip is made of materials that allow a natural gliding motion of the joint.
Some surgeons perform what is called a minimally invasive, or mini-incision, hip replacement, which requires smaller incisions and a shorter recovery time than traditional hip replacement. Candidates for this type of surgery are usually age 50 or younger, of normal weight based on body mass index, and healthier than candidates for traditional surgery. Joint resurfacing is also being used.
Regardless of whether you have traditional or minimally invasive surgery, the parts used to replace the joint are the same and come in two general varieties: cemented and uncemented.
Cemented parts are fastened to existing, healthy bone with a special glue or cement. Hip replacement using these parts is referred to as a “cemented” procedure. Uncemented parts rely on a process called biologic fixation, which holds them in place. This means that the parts are made with a porous surface that allows your own bone to grow into the pores and hold the new parts in place. Sometimes a doctor will use a cemented femur part and uncemented acetabular part. This combination is referred to as a hybrid replacement.