Rheumatoid arthritis (RA) is a chronic autoimmune disorder that primarily affects joints, often including the knees. In the initial stage, stage 1, rheumatoid arthritis leads to swelling and inflammation in the capsule surrounding the knee joint, resulting in discomfort and stiffness. As the condition progresses to stage 2, inflammation causes damage to the knee’s cartilage, the protective cushioning between the bones.
RA is not limited to the knees; it can impact multiple joints throughout the body, including the wrists, ankles, elbows, hips, and shoulders. Typically, the symptoms manifest symmetrically, affecting the same joints on both sides of the body. Interestingly, about 40% of individuals with RA also experience symptoms unrelated to the joints.
Specifically in the knees, RA causes the swelling of the synovial membrane that lines the joint, leading to pain and stiffness. Research indicates that RA can damage not just the articular cartilage but also the knee’s menisci. Symptoms of RA are not confined to joint pain and inflammation; they can also manifest in fingers, hands, wrists, ankles, feet, and toes.
RA is characterized by an immune system malfunction where the body erroneously attacks healthy cells, causing inflammation in various body parts, primarily the joints. It commonly affects joints in the hands, wrists, and knees. The condition may also lead to the development of cysts behind the knees, which can rupture and cause pain and swelling in the lower legs. Up to 30% of people with RA develop hard bumps under the skin, known as rheumatoid nodules.
Diagnostic procedures for RA often involve blood tests to detect elevated levels of erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP), both indicative of inflammation. Additionally, tests for rheumatoid factor and anti-cyclic citrullinated peptide (anti-CCP) antibodies are common. Imaging tests are also utilized for diagnosis.
Knee pain, swelling, and inflammation typically appear in the later stages of RA. Being the largest joint in the body, the knee’s affliction by RA can significantly hinder daily activities such as walking and climbing stairs. The main symptoms of RA include joint pain, swelling, stiffness, general symptoms, and inflammation in body parts other than the joints.
For more detailed information, you can visit the following sources:
Verywell Health
WebMD
Mayo Clinic
Cleveland Clinic
CDC
MSD Manuals
