Knee osteoarthritis is the most common form of osteoarthritis. More than 10 million Americans have knee osteoarthritis. It is also the most common cause of musculoskeletal disability in the United States. Successful management of knee osteoarthritis depends on recognizing early symptoms, an accurate diagnosis, and appropriate treatment.
Signs and Symptoms of Knee Osteoarthritis
Knee osteoarthritis is typically characterized by the insidious onset of joint pain, joint stiffness, and limited range of motion.
Unknowingly, knee osteoarthritis develops gradually over a period of years and goes unnoticed until it becomes symptomatic. It is common for people with knee osteoarthritis to initially complain of pain that occurs with walking, plus limitations with walking (e.g., distance), going from sit to stand, and stair-climbing. Other common complaints include a feeling that the knee is going to give out, the affected knee locks up, or a popping sensation in the joint.
What Is an Unloader Knee Brace for Osteoarthritis?
There is often localized swelling, but it is usually not associated with warmth or redness. With any of the aforementioned signs and symptoms, after a brief period of time to see if symptoms subside or if self-treatment helps, most people realize that they must consult their doctor for a proper diagnostic evaluation.
Pain associated with knee osteoarthritis is usually worse following activity, especially when there is overuse of the affected knee. Stiffness can worsen after sitting for prolonged periods of time. As knee osteoarthritis progresses, symptoms generally become more severe. Pain may become constant, rather than present only when weight-bearing or following activity.
Bone cartilage breaks down with osteoarthritis.
Constant and severe pain is characteristic of bone-on-bone abnormalities which occur when cartilage loss is so severe there is essentially no cartilage left covering the ends of the bones in the knee joint. Loose bodies in the joint space may also contribute to pain and stiffness. Crepitus (a grinding sensation) and an increase in symptom intensity that occurs with stormy weather are also characteristic of knee osteoarthritis—although the latter has been debated.
Deterioration of articular (joint) cartilage, which is evident on plain x-rays, is an important diagnostic clue associated with knee osteoarthritis. The cartilage loss in knee osteoarthritis can be caused by:
previous knee injury
repetitive strain on the knee
fracture, ligament tear, and meniscal injury, any of which can affect the alignment of the knee and leg, further promoting wear and tear
genetic predisposition to cartilage abnormalities and knee osteoarthritis
obesity and overweight which add stress and burden to the affected joint; adipose tissue increases proinflammatory cytokines; and leptin may play a role