Explore the interactive education tool below to learn about knee conditions, treatment options and symptoms. There are animations you can view and also printable documents for your convenience. Also below are some of the most common knee conditions patients suffer from.
The medial and lateral menisci (plural of meniscus) of the knee are two crescent moon-shaped disks of tough tissue that lie between the ends of the upper leg bone and lower leg bone that form the knee joint. Meniscus tears commonly occur during sports when the knee is twisted while the foot is planted firmly on the ground. In people over the age of 40 whose menisci are worn down, a tear might occur with normal movement, minimal activity, or minor injury.
Tendinitis is inflammation of a tendon, a band of tissue that connects muscle to bone. It is most commonly the result of overuse during physical activities. Repetitive motions can stretch and irritate the tendon, causing pain and swelling. Tendinitis occurs around joints such as the elbow, shoulder, wrist, ankle, or knee.
Bursitis is inflammation of a bursa or bursae (more than one bursa), small fluid-filled sacs that cushion areas of friction around joints. Bursae contain synovial fluid that lubricates the joints. Bursitis typically occurs as a result of overuse during physical activities or infection of the synovial fluid. If a bursa becomes infected or irritated from repetitive stress, it will cause pain and limited movement. Bursitis is most common in the shoulder, knee, hip, elbow, or heel.
Torn ACL and MCL
There are four ligaments in the knee: the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL). The ACL and PCL stabilize front-to-back knee movements, while the MCL and LCL stabilize side-to-side movements. The ACL can be sprained or torn if the knee is straightened beyond its normal limits (hyperextended), twisted, or bent side-to-side. A sprained or torn ACL is common in sports and usually results from a hard stop or aggressive twisting of the knee. The PCL is the least common ligament to be injured. The MCL is injured when a force is exerted on the outside of the knee, pushing it inward, while the LCL is injured by a force exerted on the inside of the knee that pushes it outward. This type of hit is frequent in contact sports like football or hockey. A torn knee ligament is usually accompanied by feeling or hearing a pop in the knee at the time of injury, severe pain and swelling, and joint instability.
ACL reconstruction is a surgical procedure that repairs a torn anterior cruciate ligament (ACL), one of the four ligaments that help stabilize the knee. The ligament is reconstructed using a tendon that is passed through the inside of the knee joint and secured to the upper leg bone (femur) and one of the two lower leg bones (tibia). The tendon used for reconstruction is called a graft and can come from different sources. It is usually taken from the patient’s own patella, hamstring, or quadriceps, or it can come from a cadaver. ACL reconstruction is most often performed through arthroscopic surgery.
Joint Replacement Surgery
Joint replacement surgery is performed to replace an arthritic or damaged joint with a new, artificial joint called a prosthesis. The knee and hip are the most commonly replaced joints, although shoulders, elbows and ankles can also be replaced. Joints contain cartilage, a rubbery material that cushions the ends of bones and facilitates movement. Over time, or if the joint has been injured, the cartilage wears away and the bones of the joint start rubbing together. As bones rub together, bone spurs may form and the joint becomes stiff and painful. Most people have joint replacement surgery when they can no longer control the pain in their hip or knee with medication and other treatments, and the pain is significantly interfering with their lives.
How long do artificial joints last?
On average, artificial joints have a lifespan of 10 to 20 years. If you are in your 40s or 50s when you have joint replacement surgery, especially if you are very active, you are likely to need another joint replacement surgery later in life.
Who needs a knee replacement?
Knee replacements were originally designed to enable people with incapacitating knee arthritis to walk again. It has evolved in recent years to allow younger and younger people to allow resumption of normal daily activities with the exception of running and jumping.
What is a gender specific knee?
Originally, the knee replacement implants were designed and based on an anatomic averaging of male and female knees. This resulted in specific sizes that in some cases restricted available range of motion for women. Design changes have been made to accommodate the narrower anatomy of a female knee, resulting in better flexion. All manufacturers have accommodated this recent change.
Partial Knee Replacement
Knee replacement surgery is designed to replace the damaged portion of the arthritic knee. Originally, complete knee replacement was offered even if the arthritis was localized to the kneecap or the inner half of the knee. Sacrificing normal structures or parts of the knee to correct the isolated damage seems excessive, and as a result, partial knee replacements have evolved and have become more and more effective. They can be done thru smaller incisions and generally allow for larger range of motion. Medial compartment replacement with the Oxford knee has been used in Europe for 25 years, giving 10 -15 years of successful results. Knee-cap replacements are available in some areas, but long term data is lacking.
Post-traumatic (Cartilage damage due to injury), Rheumatoid (excessive synovial fluid in the joint) and osteoarthritis (wearing down of cartilage in the joint) can cause knee pain. Depending on severity, a knee replacement or non-surgical approach can alleviate your symptoms.