Knee Osteoarthritis is a degenerative joint disease and is the most common form of arthritis. The source of pain is the result of wear and tear on a joint in the knee and inflammation.
Osteoarthritis of the Knee (Knee OA), occurs when the cartilage that covers and cushions the end of the bone breaks down, causing pain and loss of movement, as bone begins to rub against bone. The knee is not a single joint but is made up of three joints, the medial and lateral compartments between the femur (thigh one) and tibia (shin bone) and the joint under the knee cap in the patella groove. People who have had a previous injury, or who have overused their joints will start to get early onset arthritis, a condition which will eventually come to all of us as we age.
Osteoarthritis occurs as the articulating cartilage within any of the smooth gliding parts of the joint becomes rough and thinner. Initially there’s pain as the cartilage wears away and the area becomes sore. Once the bone surface has worn away completely, it can change the mechanics of the knee and cause the joint to be stiff, painful and it may become misaligned.
If the Knee Osteoarthritis is advanced, the cartilage erodes to the point where the bone is exposed and the two bones of the knee joint – the femur and tibia – rub together. The bone at the edge of the joint then thickens and begins to grow outwards, causing bony spurs to form called osteophytes which change the shape and thicken the width of your knee.
What are the symptoms of Knee Osteoarthritis?
- JOINT PAIN: People often find themselves cutting back on their activities or work due to the high level of discomfort and pain. The pain increases when active and reduces slightly when resting. Often people complain of night pain (similar to a tooth ache type of pain) which can keep them awake.
- STIFFNESS: During the early stages of Knee Osteoarthritis, the articular cartilage becomes pitted, causing stiffness in the knee especially after you have been sitting for longer periods of time. Starting to move again after sitting or in the morning getting up can be difficult as the knee resists ‘getting going’ due to the sore worn parts sticking together.
- GRINDING SENSATION: When you move you often hear and/or feel a grinding sensation, this is known as crepitus.
- DECREASE IN MOBILITY: Your knee may give way when you put any weight on it, decreasing your mobility and resulting in weakened muscles and it may just be stiff and painful to move.
- SWELLING: Soft or hard swellings may form around the knee and change its shape as the body reacts and tries to protect the painful joint.