Replacement Parts - What You Should Know About Hip Replacement Surgery

By Lee Philips M.D.
PersonalMD.com Advisory Board

Have you noticed that daily activities like walking to the mailbox or making the bed causes excruciating pain in your hip? Medical conditions like arthritis, fractures or (death) avascular necrosis of the hip from steroid use may lead to the destruction of the hip joint and the need for hip replacement surgery. About 220,000 total hip replacements are performed in the U.S. every year and is becoming more common as the population ages. It is one of the most successful and safest surgeries preformed today.

The hip joint is a ball and socket joint. The femur or thigh bone looks like a long stem with a ball on the end and fits into the socket or acetabulum a cup shaped part of the pelvis. This “ball and socket” joint allows a wide range of motion including sitting, standing, walking. Normally, the ball and socket are lined with smooth cartilage that glide over each other.

This covering of cartilage must last a lifetime. But normal use can wear away cartilage over time or an injury can cause damage to it. When it's destroyed bone grates against bone causing pain and stiffness.

Before considering hip replacement surgery, the doctor will try non-surgical therapies first such as presribing a cane, anti-inflammatory medicine and physical therapy. These therapies are not always effective in relieving pain and improving the function of the hip joint.

The decision to go ahead with hip replacement is made when pain interferes with daily living including walking, climbing stairs, and dressing. Before a doctor recommends hip replacement joint damage should be detectable on x-rays.

During a total hip replacement, an incision about 6 to 8 in. in length is made along the hip, and the damaged hip joint is removed. The ball portion of the hip joint is replaced with an artificial ball made of metal attached to a stem that goes into the middle of the femur. In the pelvis, the worn-out socket is replaced with a strong plastic socket. The hip replacement recreates the normal function of the hip allowing a natural movement of the joint. After surgery nearly all patients have a significant decrease in the level of pain.

Cemented Implants

Hip replacements joints may be secured in one of two ways. Cemented replacements are attached to the bone using a glue like substance. The cemented procedure is used frequently in older, less active people and people with weak bones such as those who have osteoporosis. The cement forms an immediate strong bond between the bone and the artificial joint. However, the bond gradually loosens over a period of about 15-20 years might need to be replaced at that time.

Uncemented Implants

In the past, hip replacement surgery was an option primarily for people over 60 years of age. Typically, older people are less active and less likely to wear out the artificial joint material than younger, more active people. In recent years however, doctors have found that hip replacement surgery can be very successful in younger people as well. Often times, a cementless procedure is used. The prosthesis is made of a rough, porous material that allows the patient's own bone to grow into the prosthesis forming a strong permanent bond.

One disadvantage of an uncemented prosthesis is the length of the recovery period. Because it takes a long time for the natural bone to grow and attach to the prosthesis, activities should be limited for up to 3 months to protect the hip joint. During the process of natural bone growth there can also also be thigh pain for several months after the surgery. The cementless joints can last 20 years, but eventually the plastic socket will begin to wear away and the patient will need a revision surgery.

By the second day after surgery, you'll be up and about walking with the use of crutches or a walker. A therapist will teach you contracting and relaxing certain muscles to strengthen the hip. Most patients are able to go home about 5 days after the surgery. All patients remain on either crutches or a walker for about 4-6 weeks after surgery. Full recovery from the surgery takes about 3 to 6 months.

Complications following hip replacement surgery have been greatly reduced in recent years. The most common problem is dislocation. This is because the artificial ball is smaller than the original and can be easily dislodged from the socket with certain hip positions. The most dangerous position usually is pulling the knees up towards the chest.

After you have had a hip replacement, your doctor will advise you when to begin sports. Gentle exercise can reduce joint pain and stiffness and increase flexibility and muscle strength. Some recommended sports are cross-country skiing, swimming, walking, golfing and stationary bicycling. Many doctors recommend avoiding high impact sports, such as basketball, jogging and tennis because these activities can put stresses on the new hip and wear it out sooner.

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