- Osteoarthritis is the most common arthritis and many times affects the knees. Wear-and-tear or simple aging of the cartilage cause this condition. Persons with osteoarthritis in the knee may experience pain, swelling, and stiffness.
- Knee effusion is a buildup of fluid inside the knee joint as a result of inflammation. Any arthritis or injury can cause a knee effusion.
- A meniscal tear results from damage to the cartilage, usually as a result of twisting the knee. If the tear is large, the knee may lock.
- The anterior cruciate ligament (ACL) strain or tear makes the knee joint unstable. This condition leads to your knee ‘giving out’ and may require surgery.
- The posterior cruciate ligament (PCL) strain or tear will also cause pain, swelling, and instability. Less common than the ACL injuries, physical therapy is more effective than surgery.
The medial collateral ligament (MCL) strain or tear causes pain and instability of the inner side of the knee joint.
- Patellar subluxation occurs when the kneecap slides or dislocates along the thigh bone when you’re active. This condition results in knee pain around the kneecap.
- Patellar tendonitis is an inflammation of the tendon that connects your kneecap to your shin bone. This condition commonly occurs in athletes who jump repeatedly.
- Knee bursitis results from an injury or overuse of the knee. Bursitis will cause pain, swelling, and warmth.
- Baker’s cyst is a collection of fluid behind the knee. It is a result of persistent effusion from arthritis.
- Rheumatoid arthritis is an autoimmune condition that can affect any joint in the body. If untreated, there is often permanent joint damage.
- Gout is a type of arthritis that happens when uric acid crystals build up inside a joint. When knees are affected, there is severe pain and swelling.
- Pseudogout is another arthritis found when calcium pyrophosphate crystals collect in joints.
Septic arthritis is an emergency situation. It is a bacterial, viral, or fungal infection inside the knee. There is pain, swelling, inflammation, and difficulty moving the joint. Septic arthritis is an uncommon condition, but it must receive immediate treatment.
Your Knee Joints
The knee joints are large and complex. They need to allow standing, walking, and sitting smoothly and without pain. There are many parts in the knee structure, which, in turn, may cause many problems.
Your knee joint connects your thigh bone (femur) to the shin (tibia). It connects with smaller bone, the fibula. Those and the kneecap from the bony structure of your knee.
Your Knee and Osteoarthritis
Osteoarthritis (OA) is the most common type of arthritis. According to the Journal of the American Medical Association (JAMA), more than 30 million people in the United States have OA, most of them more than 45 years old. Aging, heavy use, obesity, and other factors make it an almost certainty that most of us will eventually suffer from this condition. Knees are a common site for OA.