Osteoarthritis is the most prevalent form of arthritis in the knee. It is a degenerative joint disease, often referred to as “wear-and-tear” arthritis. OA occurs when the cartilage that cushions the ends of bones in your knee gradually deteriorates. As cartilage wears down, the bones begin to rub against each other, resulting in pain, swelling, and reduced joint function.

The symptoms of osteoarthritis in the knee often include persistent pain, which tends to worsen after activity or later in the day. Joint stiffness is common, particularly in the morning or after periods of inactivity. Many patients experience swelling and tenderness around the knee, especially during or following movement. As the condition progresses and the joint wears down, the range of motion becomes limited, making it difficult to fully bend or straighten the knee. Additionally, a grinding or crunching sensation, known as crepitus, is often reported during movement, as the cartilage continues to deteriorate.

The causes of osteoarthritis in the knee include several contributing factors. Aging plays a significant role, as cartilage naturally becomes less resilient and wears down over time. Previous knee injuries, such as fractures, ligament tears, or meniscal injuries, can increase the risk of developing osteoarthritis later in life. Obesity is another important factor, as excess weight places additional stress on the knee joint, which can accelerate cartilage breakdown. Genetics also play a role, with a family history of osteoarthritis making some individuals more susceptible to the condition. Repetitive stress from jobs or sports that require frequent use of the knee joint can also lead to increased wear and tear over time.

The treatment for osteoarthritis depends on the severity of the condition and may involve both non-surgical and surgical options to help manage symptoms and improve joint function.

Inflammatory arthritis involves the body’s immune system mistakenly attacking healthy joint tissue, causing inflammation in the knee joint. Unlike osteoarthritis, which results from mechanical wear and tear, inflammatory arthritis is driven by autoimmune responses, often leading to faster joint damage.

Rheumatoid Arthritis (RA):Rheumatoid Arthritis (RA) is a chronic autoimmune disease that primarily affects the lining of your joints (the synovium), causing inflammation and pain. Over time, this inflammation can lead to the destruction of the cartilage and bone within the joint. RA is systemic, meaning it can affect other parts of the body beyond the joints, including the skin, eyes, lungs, and heart. Unlike osteoarthritis, which is due to wear and tear, RA is the result of the immune system mistakenly attacking the body’s healthy joint tissues. It often begins with small joints, such as those in the hands and feet, but can affect larger joints like the knees, shoulders, and hips.

Gout:Gout is a type of inflammatory arthritis caused by the accumulation of uric acid in the bloodstream, which forms sharp crystals in the joints, leading to sudden and severe pain. Uric acid is a byproduct of the breakdown of purines, which are found in certain foods and in your body. When the body produces too much uric acid, or if the kidneys cannot remove it efficiently, uric acid can crystallise in the joints, most commonly in the big toe, but it can also affect the knees, ankles, and other joints.Gout is characterised by sudden, intense flare-ups of pain, often waking patients at night. These flares can be excruciating, with the affected joint becoming red, swollen, and hot to the touch. Gout is more common in men than women, and certain factors like diet (high in red meat, seafood, and alcohol), obesity, and certain medications can increase the risk of developing gout.

Systemic Lupus Erythematosus (SLE):Systemic Lupus Erythematosus (SLE), commonly known as lupus, is a complex autoimmune disease in which the body’s immune system mistakenly attacks its own tissues, including the joints, skin, kidneys, heart, lungs, and other organs. This widespread inflammation can lead to a wide range of symptoms, making lupus a highly variable condition, as it affects each person differently. In the context of arthritis, lupus can cause joint pain, swelling, and stiffness, often affecting the knees, hands, wrists, and other joints.

Lupus-related arthritis tends to be less destructive to the joints than rheumatoid arthritis, but the pain and swelling can be quite similar. One distinguishing feature is that lupus can affect multiple body systems at once, with symptoms ranging from mild to severe. Patients with lupus may experience periods of flare-ups where symptoms worsen, followed by times of remission.