Osteoarthritis, being the prevalent form of arthritis, takes a toll on the knee joint as it gradually erodes the cartilage that serves as a crucial buffer between the bones. As time passes and the condition progresses, the cartilage wears down to a point where the bones come into direct contact with one another, a situation known as bone-on-bone contact. This results in pain that can range from a dull ache to sharp, shooting sensations, especially when weight is placed on the knee during activities like walking or standing. Stiffness also becomes a major issue, making it difficult for individuals to bend or straighten their knees freely. Simple tasks such as getting in and out of a car or climbing stairs can turn into arduous endeavors. In its advanced stages, this combination of pain and stiffness can severely limit a person’s ability to carry out daily activities and lead to a significant decline in their quality of life.

Rheumatoid arthritis, an autoimmune disorder, sets off a chain reaction of inflammation within the knee joint. The immune system, which is supposed to protect the body, instead attacks the joint lining. This initial attack triggers a cascade of events that lead to continuous inflammation, which gradually damages both the cartilage on the surface and the underlying bone structure. Over time, the knee joint experiences progressive destruction, resulting in intense pain that can be persistent throughout the day. Mobility is greatly hampered as the knee loses its normal range of motion and flexibility. Basic movements like walking, sitting down, or rising from a seated position become challenging, and the individual’s overall ability to function independently is impaired. This not only affects physical activities but also impacts their social and emotional well-being.

When a knee suffers a fracture or endures other significant injuries that harm the joint, it becomes vulnerable to developing post-traumatic arthritis. The initial trauma disrupts the integrity of the cartilage and bone within the knee joint. Even after the visible signs of the injury have healed, the internal damage continues to have consequences. The damaged cartilage starts to break down further, and the bone surfaces may become irregular or rough. This leads to persistent pain that can be felt even during light activities or at rest. Stiffness sets in, reducing the knee’s ability to move smoothly through its normal range of motion. As a result, activities that were once routine, like walking around the neighborhood or participating in sports, become increasingly difficult or even impossible, causing a significant impact on the person’s lifestyle and mobility.

Avascular necrosis in the knee occurs when the normal blood supply to the bone is interrupted. This disruption can be caused by various factors such as trauma, certain medications, or underlying medical conditions. Without an adequate blood supply, the bone tissue begins to die off, which then triggers joint degeneration. As the bone structure deteriorates, the knee joint loses its stability and functionality. This results in significant pain that can be quite severe and is often accompanied by limitations in mobility. Simple movements like bending the knee to put on shoes or walking a short distance can become extremely painful and challenging. The individual may also experience a sense of instability in the knee, making them cautious about putting weight on it and further restricting their ability to move around freely.