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 OCC – Advanced Orthopedic & Sports Medicine Specialists in Denver, Parker, or Aurora, 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

CAUSES

Risk factors that increase the possibility of arthritis of the knee include:

• Aging—normal wear and tear
• Genetics– inherited traits that affect cartilage health or joint structure.
• Joint Injury: previous knee injuries, such as fractures, ligament tears, or meniscus injuries
• Obesity–excess body weight puts additional pressure on the knee joints, accelerating cartilage wear
• Joint Overuse–repetitive stress on the knee joint from certain occupations, sports like jogging, basketball, and tennis, or activities that involve heavy lifting, squatting, or kneeling
• Weakness in the muscles surrounding the knee, particularly the quadriceps
• Inflammation–conditions like rheumatoid arthritis, can lead to the breakdown of cartilage over time and contribute to osteoarthritis.
• Bone Deformities–some people are born with malformed joints or defective cartilage

SYMPTOMS

• Difficulty straightening or flexing the affected knee joint
• Swelling
• Pain–affected joints might hurt during or after movement.
• Stiffness-joint stiffness might be most noticeable upon awakening or after being inactive.
• Tenderness– the joint might feel tender when applying light pressure to or near it.
• Grating sensation
• Bone spurs
• Creaking, clicking, grinding or snapping noises (crepitus)
• Difficulty walking
• Knee buckling
• Skin redness
• Warm skin
• The knee locks or sticks when it’s trying to move
• Deterioration of the tendons and ligaments around the knee joints
• Bow-leggedness (curved-out knees)
• Loss of independent function (activities of daily living, such as house cleaning, shopping, and doing errands)

NON-SURGICAL TREATMENTS

Non-surgical treatments for knee osteoarthritis focus on managing pain, improving function, and slowing the progression of the disease. The approach typically includes a combination of treatments:

• Medications: over-the-counter pain relievers: Acetaminophen (Tylenol) or nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (Advil) and naproxen (Aleve) can reduce pain and inflammation.
• Prescription medications: If over-the-counter options are ineffective, your doctor may prescribe stronger NSAIDs or pain relievers.
• Physical therapy: strengthening the muscles around the knee can help stabilize the joint and reduce pain. Low-impact exercises such as swimming, cycling, and walking are often recommended.
• Stretching and Flexibility Exercises: these help maintain or improve range of motion in the knee.
• Corticosteroid Injections can provide short-term pain relief by reducing inflammation in the knee joint.
• Weight loss decreases the load on the knee joint, which can reduce pain and improve function.
• Knee Braces: these can help stabilize the knee and reduce pain during movement.
• Canes or walkers: assistive devices can help reduce the weight placed on the knee
• Wearing supportive shoes or using orthotics can help with alignment and reduce knee stress.

WHEN IS SURGERY INDICATED?

As in most cases, surgery is often the last option to be considered. Surgery may be an option when more conservative measures have not significantly alleviated pain. It may be recommended if one can’t sleep through the night because of pain, or when pain prevents doing daily activities, or the pain limits mobility. Osteoarthritis is limited to one compartment of the knee, but for surgery, the remaining compartments must be well-preserved. Cruciate ligaments, especially the anterior cruciate ligament (ACL), should be functional and intact for surgery. The inflammatory changes in the synovium should be minimal. This means patients with inflammatory arthritis, like rheumatoid arthritis, are not eligible. The patient should ideally have a reasonably good range of motion preoperatively. To consider surgery, there should be absence of significant axial deformity: mild varus or valgus deformity (bowlegged or knock-kneed) is acceptable, but severe deformities are a contraindication

GETTING THE RIGHT DIAGNOSIS.  GETTING THE RIGHT DOCTOR.

Your doctor will diagnose osteoarthritis based on your medical history, physical examination, discussion of symptoms, and advanced imaging studies. X-rays should reveal the type of arthritis, any bone changes, bone spurs, and how narrow the space is between the bones. The less cartilage, the narrower the space and the greater the pain. Additional imaging such as CT scans and MRIs can offer more detailed information. At Advanced Orthopedics in Denver, Parker, or Aurora, Colorado, their highly-trained experts are renowned in their field having performed a high volume of this type of replacement with unparalleled expertise and successful outcomes. There are constant innovations in the field of knee replacement and you can count on the professionals at Advanced Orthopedics to be on top of it all. At Advanced Orthopedics it’s all about you. You’ll get all your questions answered with clarity and honesty and your surgeon will discuss all your options in detail. In every case, you can expect the most caring and supportive surgeons devoted to all your needs. Their main purpose is to offer you a better quality of life and improved mobility that will last for many years. If you believe you are a candidate for a unicompartmental knee replacement, schedule your appointment with Advanced Ortho today.