Total joint replacement, medically also known as total joint “arthroplasty,” is a surgical procedure that involves removing a damaged or an arthritic (worn out and inflamed) joint surface, and replacing it with a metal or ceramic artificial implant called a joint “prosthesis.” The prosthesis functions much like a normal, healthy joint surface, but because it has no nerve supply, typically does so without the pain that was present prior to surgery.
Total joint replacement is typically done for severely damaged and inflamed hip and knee joints that have failed to respond to medical and lifestyle therapies. It is one of the most common and cost-effective procedures in orthopedic surgery, typically carried out with great success. The results of both the hip and knee replacement surgeries have shown to be favorable in terms of pain relief, restoration of activity, complication rates, and quality of life. In general, the level of patient satisfaction with their outcome has been shown to be slightly higher for hip replacement patients (92%) than for knee replacements (86%). Nevertheless, both types of replacement provides reliable outcomes for patients suffering from end-stage degenerative diseases of their joint.
How is the Total Joint Replacement done?
Total Knee Replacement
After the necessary preparations, the steps of this procedure include:
- With the knee in the bent position, a vertical incision is made on the skin right over the middle of your kneecap. The joint is then entered from the side for “minimally-invasive” technique.
- The kneecap is then elevated and carefully moved to the side to get a clearer view.
- The diseased/damaged cartilage surfaces at the ends of the thigh and shin bones are removed along with a thin layer of the underlying bones.
- The removed cartilage and bone are then covered with metallic parts. These metal parts are most commonly “cemented” to the bone, or sometimes “press-fit” into the natural bone snugly, that then knits to the bone biologically. Sometimes, a combination of both types are used to replace the various removed parts.
- After resurfacing the damaged surfaces, the surface of the kneecap is most often cut from underneath and resurfaced with a plastic button. The decision to resurface the kneecap varies with the individual case.
- A durable, smooth, high-density plastic pad is next locked into position between the metal components so that the resurfaced parts of the knee joint can easily glide over each other as the knee bends and straightens.
- The knee is finally checked for its range of motion and stability. Proper alignment is essential to enable load distribution through the prosthesis.
Total Hip Replacement
After the necessary preparations, the total hip replacement can be carried out from:
- the front of the hip, referred to as an “anterior approach”
- the side of the hip (“lateral approach”), or
- behind the hip (“posterior approach”)
The anterior approach is minimally invasive, is the most common approach used by our surgeons, and done by working between the muscles, rather than by cutting through muscles, as follows:
- After making a small cut on the skin from the front of the hip, the surgeon retracts (pulls away) the muscles to reach your hip joint. No muscles are cut.
- Your hip is a ball-and-socket joint. The rounded head of the femur (thighbone) forms the ball, which fits into the cup-like socket of the pelvis. The surgeon takes out the bony ball and replaces it with a hip prosthesis, designed in a way similar to your natural “ball-and-socket” hip joint. It is made up of a metallic stem that goes into the marrow canal of your thighbone, the head (ball) attached to the stem, and a metallic cup with a durable plastic liner that is inserted into the socket of your pelvis.
- Unlike knee replacement parts, these implants are almost always “press fit,” in that the bone grows into the implant surface over weeks to months for permanent fixation. This is due to the different mechanics involved with the prosthesis-bone connection during walking. However, one can usually walk on both knee and hip replacements on the same day as the surgery.
Being a muscle-sparing surgery, the anterior approach for hip replacement enables faster recovery, excellent functional outcome, less muscle trauma and reduced post-surgical pain, as well as a shorter surgical facility stay (many patients are even going home now on the same day as the surgery!)
How long do joint replacements last?
Recent data polling worldwide data registries show that 82% of knee replacements are functioning well at 25 years post replacement. Thus, while not a perfect solution for a very young patient, most older patients can reasonably expect that their joint replacement will last the rest of their life.
What are the complications of Total Joint Replacement?
Knee joint replacement
The complication rate is low with serious complications observed in fewer than 2% of cases with the knee joint replacements. These include:
- Infection
- Fractures occurring around the implanted parts of the joint (called periprosthetic fractures)
- Loosening of the attachment between the implant and bone
- Nerve and blood vessel damage
- Blood clots in the limb
Total hip replacement
When done through the anterior approach, total hip replacement is a relatively safe procedure. However, just like any other surgery, it does carry a few risks, such as:
- Infection
- Fractures occurring around the implanted parts of the joint (called periprosthetic fractures)
- Loosening of the attachment between the implant and bone
- Nerve and blood vessel damage
- Blood clots in the limb
Complications are less likely following a total joint replacement when performed by highly specialized surgeons like Dr. Charlie Peterson. Dr. Peterson trained for 5 years of residency in Orthopedic Surgery at the Mayo Clinic in Rochester Minnesota. Mayo has one of the most highly-regarded joint replacement programs in the world, and Dr. Peterson trained with, and operated under many leaders in the field. He also co-authored several international papers on joint replacement and reconstructive surgery while there. He also now has 23 years of experience in expertly, caringly, and successfully performing hip, knee, and shoulder replacement surgeries in all manner of patients just like you.
Contact Orthopedic Specialists of Seattle to set up an appointment today.
