The knees are the strongest joints in the human body, allowing the legs to bend and straighten while carrying almost all of the weight of the individual when they are standing. The knees are a hinge joint, but still have substantial capacity for lateral (side-to-side) motion.
As an active, weight-bearing joint, the knee is a source of pain and problems for many people. This pain may be acute or chronic, and may be a result of injury, overuse or growth. It can stem from the tendons, ligaments, bones, cartilage or any other structure within the knee. Some of the most common knee conditions include:
Meniscal or cartilage tears are common knee injuries. Athletes are at risk for meniscal tears. However, anyone at any age can tear a meniscus. When people talk about torn cartilage in the knee, they are usually referring to a torn meniscus. Many tears are related to an injury but sometimes a meniscus can tear during an activity of daily living such as squatting or getting out of a chair
There are two menisci in the knee. They are made of a rubbery cartilage and lie between the femur (thigh) and tibia (leg). The menisci cushion the joint and help provide stability.
People with meniscal tears frequently complain of pain, swelling, stiffness and locking.
The meniscus has a limited blood supply, so patients with a torn meniscus frequently require arthroscopic surgery.
The anterior cruciate ligament (ACL) works together with the other ligaments in the knee to connect the femur to the tibia and support the knee joint. A tear in the ACL is one of the most common knee injuries, causing the joint to become unstable and slide forward too much. This injury occurs most often in athletes and causes pain, swelling, tenderness and limited motion.
ACL reconstruction is usually not performed until several weeks after the injury, when swelling and inflammation have been reduced. The torn ligament is completely removed and replaced with a new ACL. Simply reconnecting the torn ends will not repair the ACL. Part of another ligament, usually in the knee or hamstring, is used to create a graft for the new ACL.
Arthroscopy offers patients many benefits over traditional surgery, including no need to cut muscles or tendons, less bleeding, smaller incisions and shorter recovery times. However, arthroscopy is not appropriate for all patients. Your doctor will decide whether or not arthroscopy is right for you.
Some knee conditions that can often be treated through arthroscopy include meniscal tears, ACL or PCL tears, synovitis, patellar misalignment, arthritis and more. During the arthroscopy procedure, a thin tube with a camera on the end (arthroscope) is inserted into the joint, along with several tiny surgical instruments so that your surgeon can adequately visualize the area while repairing any damage that is found.
Arthritis means joint inflammation. It causes pain, swelling and stiffness. Arthritis leads to destruction of cartilage and there may be inflammation of the synovial tissue that lines the joint. Once arthritis gets severe it can interfere with the following activities:
The knee is made of two joints. The “hinge” part consists of the lower end of the femur (thigh) and the upper end of the tibia (leg). The patella (kneecap) forms the second part of the joint as it glides along the femur. Individuals with knee arthritis usually have pain in the knee, thigh and leg. Sometimes there is discomfort radiating down to the ankle.
There are two broad categories of arthritis. Osteoarthritis and Inflammatory Arthritis.
Osteoarthitis is the more common of the two conditions. It is also called degenerative joint disease or “wear and tear” arthritis. The cause is unknown, but certain conditions such as previous fracture, ligament tears and obesity often lead to osteoarthitis. The condition begins with cartilage loss and results in bone deformity with spurs and cysts.
Rheumatoid arthritis is the most common type of inflammatory arthritis. It may affect multiple joints including the jaw, hands, and spine. The problem often begins with inflammation of the synovial lining of the joint that results in cartilage loss and areas of exposed bone.
People with knee arthritis often have stiffness and deformity. They are unable to straighten or bend their knees as much as they would like. Many are bow-legged, while some are knock-kneed. Sometimes they can’t tell if the problem is coming from their hip, knee or lower back.
Your orthopaedic surgeon can tell where the problem is coming from by watching you walk and examining your hips, knees and spine. X-Rays are required and in certain circumstances MRI, CT scan and blood tests may be indicated.
Initial treatment may involve medication, exercise, weight loss, activity modification, knee brace and use of a cane.
When pain gets to the point where it interferes with the activities of daily living, surgery is a good option. Young patients who have a deformity (bowlegged or knock-kneed) but minimal joint destruction may be offered an osteotomy. This is a procedure that involves straightening the leg without replacing the joint.
Usually the orthopaedic surgeon suggests either a partial or total knee replacement. Partial (unicompartmental) knee replacement is indicated for those who have arthritic disease in only a portion of their knee. Total knee replacement is best for patients with more extensive disease and people with deformity. Surgery is usually performed through a muscle sparing sub-vastus approach. This allows for a quicker recovery. Both operations involve a short hospital stay and patients usually use a walker, crutches or cane for a few weeks after surgery. The surgery almost always cures pain and improves the ability to walk.