Knee Pain With Osteoarthritis


The knees work to support and absorb physical shock from the rest of the body. The bones in the knee joint are protected and cushioned by cartilage and a special fluid called synovial fluid. The cartilage can wear down, causing the bones in the knee to grind against each other, leading to significant knee pain.


Osteoarthritis of the knee is caused by the gradual breakdown of the cartilage that serves to protect and support the knee joint. This loss of cartilage occurs over time. The cartilage gets damaged due to undue stress being put on the knee joint and, according to, is more common in people who are overweight.

Symptoms and Diagnosis

According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), osteoarthritis causes knee pain that gets worse with activity and is relieved by rest. Patients often experience stiffness in the joint if they have been sitting or reclining for a long period of time. Eventually the pain becomes worse and patients experience pain even while at rest. Osteoarthritis is typically diagnosed using a physical exam, x-rays and a detailed patient medical history. The x-ray can show a loss of space in the joint and damage to the bones (in severe cases).

First-Line Treatments

Knee pain caused by osteoarthritis is initially treated conservatively. explains that patients will be told to rest the affected knee(s) frequently and to apply an ice pack for 20 to 30 minutes a few times a day. The ice will help relieve the inflammation and some of the pain. Patients can also take non-steroidal anti-inflammatory medications (NSAIDs), which include aspirin and ibuprofen. Physical therapy will help strengthen the muscles around the knee and can improve the patient’s range of motion.


Osteoarthritis of the knee can also be treated using injections. Corticosteroids are potent inflammation-reducing drugs that can be injected directly into the knee joint. Local anesthetics can also be injected to help reduce the pain. Finally, a compound called hyaluronic acid can be injected into the affected joint to help replace some of the supportive fluid that is normally in the knee. These kinds of injections can relieve knee pain, but explains that they do not work for everyone.


For patients who do not respond to more conservative therapies, surgery can also be performed to relieve pain. The simplest technique is called arthroscopy, in which an orthopedic surgeon inserts a flexible camera into the knee via a small incision. The surgeon can then see how badly the knee is damaged and remove any injured tissue that is causing the pain and inflammation. Osteotomies are used when only one side of the knee is damaged and involve reshaping and aligning the leg bones to relieve the pain and swelling in the knee. In extreme cases, the knee joint can be replaced with a prosthetic knee.

About this Author

Adam Cloe has been published in various scientific journals. He is an M.D./Ph.D. student at the University of Chicago. He has a Bachelor of Arts in biochemistry from Boston University, where he won an award for excellence in undergraduate science writing.