Knee Replacement Surgery

As the largest weight-bearing joint in the body, a properly functioning knee is required for almost all activities. Any damage to the knee joint can result in pain during simple everyday activities, such as walking, or even during resting periods, such as sitting. The knee joint is comprised of three main components: the thighbone (femur), the shinbone (tibia), and the kneecap (patella).

Providing stability and strength, four ligaments surround the knee: the anterior cruciate ligament (ACL), medial collateral ligament (MCL), posterior cruciate ligament (PCL), and lateral collateral ligament (LCL). The posterior cruciate ligament is located at the back of the knee, and its function is to keep the knee from rolling backwards during bending. The meniscus, a soft cartilage disc located between the thighbone and shinbone, acts as a cushion when pressure is put on the knee joint during movement.

The meniscus, a soft disc of cartilage located between the femur and tibia, prevents friction between the bones and balances the weight and tension placed on the knee during movement. Surrounding the knee joint is the synovium, a thin tissue that produces a fluid to reduce friction between the bones.

Osteoarthritis of the Knee

The leading cause of knee pain is osteoarthritis, a degenerative joint disease that is most commonly found in patients over the age of 50 or who have experienced trauma or injury. During the progression of osteoarthritis, the cartilage thins, exposing the ends of the bones. As the exposed ends of the femur and tibia rub against each other, the patient will experience stiffness, pain, and a decrease in the knee’s range of motion.

Several factors can increase a patient’s risk of developing osteoarthritis, including weight, age, and repetitive use. Excessive weight, or pressure, on the knee joint can cause the condition to progress more quickly. Osteoarthritis is more common in patients over the age of 50 because the ability of cartilage to heal itself decreases later in life and the increased wear of repetitive motion over a long period of time. Osteoarthritis can also develop after trauma or injury because of strain on the joint caused by fractures or ligament tears.

Osteoarthritis Treatment

Based on the stage of the disease and the patient’s needs, Dr. Pritchett will develop an individualized treatment plan. During the early stages of osteoarthritis, Dr. Pritchett may recommend a more conservative course of treatment to decrease pain and slow the progression of the disease, such as physical therapy, weight loss, non-steroidal pain medications, and exercise.

Invasive procedures are commonly recommended for patients who experience severe pain during daily activities, suffer from joint stiffness, and those who do not benefit from more conservative treatments. If only one section of the knee joint has been damaged by osteoarthritis, Dr. Pritchett may recommend partial knee replacement, in which only the damaged or diseased area of the knee joint is replaced with a prosthesis. If the entire or majority of the knee joint has been damaged, total knee replacement is typically recommended.

Knee Replacement Procedures

For knee replacement procedures, Dr. Pritchett will use a minimally invasive approach whenever possible. Using an incision at the front of the knee, Dr. Pritchett will remove the damaged bone and cartilage. After the damaged area is removed, the bone surfaces will be shaped to accept the artificial joint. The prosthesis is composed of three pieces designed to recreate the natural pain-free movement of the knee joint: the metal femoral component (covers the end of the thigh bone), the metal and plastic tibial component (covers the end of the shin bone), and the plastic patellar component (fitted to the kneecap).

During the procedure, there are several different techniques and technologies that Dr. Pritchett may use to provide the best possible results for the patient’s needs and to improve the recovery process.

Minimally Invasive Knee Replacement

For patients suffering from osteoarthritis or rheumatoid arthritis, and have damage to only one compartment of the knee joint, partial knee replacement is often the best treatment option to relieve pain symptoms.

During partial knee replacement surgery, also known as unicompartmental knee replacement, Dr. Pritchett will frequently use minimally invasive surgical techniques to remove the damaged areas from the affected compartment.

Using specialized instruments, he will then cover the ends of the shinbone and thighbone with a metal prosthesis, and place a plastic component in between to allow for smooth movement.

Machine Assisted (Computer and Robotic Knee) Replacement

Over recent decades, there have been significant advancements in the realm of orthopedic diagnostics and damage repair. Navigation tools and systems are being applied for the correction of knee injuries and disease. Dr. Pritchett and his team are consistently working to master and apply these surgical offerings, providing the highest quality care and treatment to the benefit of patients.

Modern knee surgery offers a less invasive option for the removal of diseased bone and cartilage, requiring less cutting than a traditional operative approach. As a result, patients undergoing treatment for cartilage or ligament injuries may experience an expedited return to physical activities. Likewise, for those requiring a partial replacement effort, machine based tools may allow for a more precise prosthetic positioning, which may provide improved mechanical alignment and balance.

Potential benefits of contemporary knee surgery include, but are not limited to:

• Reduced cutting and associated bleeding
• Faster recovery times
• “More natural” post-op knee performance and feeling
• Potential increases in prosthetic longevity

Cruciate Retaining Knee Implants

The amount of damage to the knee’s components varies for each patient. If the anterior and posterior cruciate ligaments (ACL and PCL) are still healthy and strong, Dr. Pritchett may use a cruciate retaining knee implant. The cruciate retaining knee implant does not require the removal of ACL and PCL for attachment. Using a cruciate retaining knee implant during a total knee replacement procedure allows for less disruption to the surrounding areas during surgery, a more natural movement after surgery, and allows patients to maintain the full stability of the joint after surgery.

Recovering from Knee Replacement Surgery

In many cases, knee replacement surgery can be done an outpatient procedure. This has resulted in an even lower infection and blood clot risk.

Before undertaking any knee surgery, Dr. Pritchett will prepare the patient for expected outcomes and associated timelines. With a combination of physical therapy and exercise, patients can expect to return to their normal everyday activities 2 to 6 weeks after surgery.

While modern techniques, there are still risks associated with any knee surgery procedure. Any extended discomfort, fever, abnormal bleeding, or other symptoms of concern should be reported for immediate medical attention. In addition, should re-injury or further degeneration occur, a later revision surgery may be required to either expand repair efforts or replace any prosthetic components.

Total Knee Replacement in Seattle, WA

James W. Pritchett, MD, is a board-certified orthopedic surgeon who is renowned for his experience in total knee replacement, including the use of minimally invasive techniques, robotic surgery, and cruciate retaining knee implants. For an evaluation with Dr. Pritchett regarding knee pain and treatment options, schedule an appointment at his office (206) 323-1900.