Unicompartmental Knee Replacement
For many people, knee pain has become an unwelcome part of life. Your knees help support your weight and let your legs bend and move. Almost any movement that uses your legs relies on your knees. Osteoarthritis of the knee happens when cartilage in your knee joint breaks down. When this happens, the bones in your knee joint rub together, causing friction that makes your knees hurt, become stiff, or swell. As the disease advances, the condition can become extremely painful and debilitating, leading to immobility, loss of independence, and more. If you ignore the pain and stiffness, it will likely only get worse and lead to more serious problems. The way to avoid that happening is to see one of the highly skilled and competent orthopedic specialists at Colorado Center of Orthopaedic Excellence in Colorado Springs, Colorado.
OVERVIEW
More than 32 million people in the U.S. have osteoarthritis, with the knee being one of the most commonly affected areas. It is possible to get it in one or both knees. Women are more likely than men to develop osteoarthritis of the knee. As many as 85% of cases present with isolated single-compartment degeneration, most commonly in what is called the medial compartment. In these cases, there is an alternative to a total knee replacement. Partial knee replacement is most commonly referred to as “unicompartmental knee replacement”, but it is also known as “partial knee resurfacing surgery,” or “unicondylar knee replacement.” Colloquially, it is also sometimes called a “uni.” This procedure is most often performed on older, less active patients.
ABOUT THE KNEE JOINT
The knee joint is one of the largest and most complex joints in the human body, essentially made up of three compartments: the kneecap (patellofemoral compartment), the inner aspect of the knee (medial compartment), and the outer aspect of the knee (lateral compartment). The medial compartment is an extremely significant part of the knee joint and is located where the tibia (shinbone) and femur (thigh bone) meet.
The specific functions of the medial compartment of the knee include:
- Weight-bearing—it typically handles more load than the lateral compartment due to the body’s natural alignment, where weight tends to shift more towards the inner part of the knee.
- Joint stability– the medial compartment, supported by the medial collateral ligament (MCL) and the medial meniscus, helps prevent excessive inward (valgus) movement of the knee, which could destabilize the joint.
- Shock absorption—the medial meniscus, a C-shaped cartilage within the medial compartment, helps to absorb shock and distribute the forces that occur during activities like walking, running, or jumping. This reduces the stress on the bone surfaces and other structures within the knee.
- Smooth movement—the articular cartilage in the medial compartment allows for smooth movement of the femur over the tibia, enabling activities like flexion (bending) and extension (straightening) of the knee without friction.
- Load distribution—the medial compartment works in conjunction with the lateral compartment and patellofemoral compartment to distribute loads across the knee joint. The medial meniscus helps distribute loads across the knee, reducing concentrated pressure on the joint surfaces and protecting the cartilage from wear and tear.
WHAT IS UNICOMPARTMENTAL KNEE REPLACEMENT?
Broadly speaking, there are two types of knee replacements: total knee replacements and partial or unicompartmental replacements (UKR). A unicompartmental knee replacement is typically recommended for patients with osteoarthritis that affects only one compartment of the knee, most commonly the medial compartment. In unicompartmental knee replacement, bone, tissue, and cartilage damaged by osteoarthritis are resurfaced with metal and plastic components (prosthetics or implants). Because the bone, cartilage, and ligaments in the healthy parts of the knee are preserved, many patients report that a unicompartmental knee replacement feels more natural than a total knee replacement. A unicompartmental knee may also bend better. Unicompartmental knee replacement is less invasive than a total knee replacement, requiring limited exposure and no dislocation of the knee joint, resulting in less soft tissue damage. Operative time is shorter, blood loss is reduced, and hospital stays are decreased. Not everyone with knee arthritis is a candidate for unicompartmental knee replacement. The decision depends on factors such as the extent of arthritis, overall knee function, and the patient’s activity level. A unicompartmental knee replacement implant can last as long as 10 years or longer and provide long-term relief, but it may not last as long as a total knee replacement.
Read more about Unicompartmental Knee Replacement on our new Colorado Springs Orthopedic News Site – Colorado Springs Orthopedic News. Schedule an appointment with a knee specialist today.
