Replacement
Arthritis
Arthritis is an inflammation of a joint. The knee can be divided into three compartments: medial (inside), lateral (outside) and patellofemoral (front). Arthritis can be present in one, two or three compartments. Over time, the loss of the smooth covering on the ends of bones (aka - articular cartilage) causes pain and stiffness. This can lead to pain with motion or rest, swelling, clicking or grinding and a loss of strength. When the cartilage is damaged or decreased, the bones rub together during joint motion, resulting in “bone-on-bone” arthritis. When arthritis becomes severe, inflammation occurs around the joint and extra bone is formed to protect the joint, resulting in limited motion and strength.
Causes
The primary cause of arthritis is osteoarthritis (aka – “wear and tear” arthritis). Trauma and other illnesses like rheumatoid arthritis, systemic lupus, septic arthritis and psoriasis can degrade a joint, leading to symptoms of pain and lack of motion.
It affects nearly 6% of all adults, but more women are affected than men.“According to several published reports, anywhere from 6% to over 13% of men, but between 7% and 19% of women, over 45 years of age are affected, resulting in a 45% less risk of incidence in men.
Age is a determining factor in the development of OA. “As the population ages in demographic terms, the prevalence of OA is expected to rise. From the age of 40, there is an increased risk of OA. Approximately 50% of the 65+ population are affected by OA in the knee, but it can also affect young people.
Symptoms
Arthritis of the knee causes pain, swelling, stiffness and loss of strength. Pain can be isolated to the medial, lateral or patellofemoral aspects of the joint or be generalized discomfort around the knee. Pain and swelling in the back of the knee may be from a Baker's Cyst, an area of the fluid collection caused by arthritis. A 'grinding', 'clicking' or 'locking' sensation may be felt. Loss of motion can become severe, and the patient may have trouble performing tasks, such as walking long distances. Patients who have arthritis of the patellofemoral joint will often complain of 'giving way' or buckling of the knee. Patients with patellofemoral arthritis have trouble using stairs, squatting, or standing after prolonged sitting.
Diagnosis
Your surgeon will perform a thorough history and physical exam, which typically includes X-rays. Your surgeon will evaluate the range of motion, stability of the ligament and strength of the muscles surrounding the knee. X-rays may demonstrate decreasing space between the bones (joint space narrowing) and bone spurs (osteophytes) in areas of arthritis. MRI may be helpful to determine if other areas of joint cartilage or the meniscus have damage.
Treatment
Non-operative
Knee arthritis is treated with physical therapy to strengthen the muscles that support the joint. The stronger the supporting muscles, the less the body will need to rely on bony architecture to stabilize the joint. This will lead to less stress across the arthritic area. Your surgeon may prescribe anti-inflammatory medication or offer an injection to reduce the inflammation. Certain nutritional supplements may be beneficial to decrease pain and inflammation.
Operative
When non-operative treatment does not relieve symptoms, your surgeon may suggest surgery. Three surgical options are available for knee arthritis. Minimally-invasive arthroscopy of the knee, or a 'knee scope', may be beneficial to "clean-out" the knee. Although not a cure, this procedure may provide relief in patients suffering mechanical symptoms, such as catching and locking. The entire knee joint, including joint cartilage, meniscus and ligaments, can be evaluated during arthroscopy. The definitive treatment for knee arthritis is joint replacement surgery. Your surgeon will resurface the bone ends where the cartilage has worn away, with metal and plastic implants. If the arthritis is localized to a single or two compartments (medial, lateral or patellofemoral), your surgeon will replace only the affected areas (unicompartmental or patellofemoral replacement). If the arthritis is present in all three compartments, a total knee replacement is required to alleviate symptoms.
Partial Knee Replacement
A partial knee replacement is an alternative to total knee replacement for some patients with osteoarthritis of the knee. This surgery can be done when the damage is confined to a particular compartment of the knee.
Only the damaged part of the knee cartilage is replaced with a prosthesis in a partial knee replacement.
Who are the candidates for partial knee replacement?
Patients with medial, or lateral, knee osteoarthritis can be considered for partial knee replacement. "Medial" refers to the joint's an inside compartment, which is nearest the opposite knee, while "lateral" refers to the outside compartment farthest from the opposite knee. Medial knee joint degeneration is the most common deformity of arthritis.
Other factors to consider:
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You may want to consider a knee replacement if your knee pain persists despite taking anti-inflammatory drugs and maintaining a healthy weight.
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Your doctor will ask you to identify the pain area in your knee and then check your range of motion and the knee's stability. An X-ray of the knee will determine your eligibility for partial knee replacement. However, your surgeon may not know for certain if you are a good candidate until the surgery has begun.
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It would be best if you had an intact anterior cruciate ligament, a good range of knee motion, damage to only one compartment, and a stable knee. The angulation of the deformity is also considered.
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In the past, a partial knee replacement was considered only in patients older than 60 years who were sedentary but younger, more active patients are increasingly being considered.