Osteonecrosis of the knee (also known as avascular necrosis) is a painful condition that occurs when blood flow to part of the femur (femur) or leg bone (tibia) is cut off.. Because bone cells need constant blood flow to stay healthy, osteonecrosis can eventually lead to premature destruction of the knee joint.. Medication to relieve pain or limit use of the affected knee.. However, advanced osteonecrosis is almost It always requires surgery to prevent further bone damage and improve joint function.... Anatomy of the knee **Knee** is the largest and strongest joint in your body... it is made up of the lower end of the femur (femur), the upper end of the lower leg (tibia) and the kneecap (patella).. a smooth, slippery substance that protects the bones and allows them to move easily against each other... (the femur)... osteonecrosis occurs when the blood supply to part of the bone is cut off.... without adequate nutrition, the affected part of the bone dies and gradually It breaks down....and the articular cartilage that covers the bone also breaks down, leading to debilitating arthritis....Osteonecrosis of the knee can affect anyone, but women are more than 60 times more likely to develop it....It's not always clear what causes reduced blood flow, but doctors have identified a number of risk factors that increase the likelihood of developing osteonecrosis: An injury to the knee, such as a stress fracture or dislocation, combined with some type of trauma to the knee, can damage blood vessels and reduce blood flow to the damaged bone....- **Oral corticosteroid medications**: Many diseases such as asthma and rheumatoid arthritis are treated with oral steroid medications... Although it is not clear exactly why these medications can lead to osteonecrosis, research shows that there is an association between this disease and long-term use of corticosteroids. Steroids are related.... Steroid-induced osteonecrosis often involves multiple joints in the body.... - **Medical Diseases**: Osteonecrosis of the knee is used in patients with medical conditions such as obesity, sickle cell disease.. HIV treatment... it reduces blood flow to the bone.... Regardless of the cause, if osteonecrosis is not diagnosed and treated early, it can develop into severe arthritis.... Symptoms of Osteonecrosis of the Knee Osteonecrosis progresses in stages. The first symptom is usually pain inside the knee. This pain may come on suddenly and be caused by a specific activity or minor injury. - Sensitivity to touch around the knee - Limitation in joint range of motion The progression of the disease may last from a few months to more than a year.. ### Physical examination Your doctor will talk with you about your general health and medical history and ask you to describe your symptoms.... Then he will perform a thorough examination of your knee and look for the following: - Swelling, heat or redness of the joint - sensitivity - Passive (assisted) and active (self-directed) range of motion. - Joint instability - Pain when putting weight on the knee - Any signs of damage to the muscles, tendons and ligaments around the knee Imaging tests help your doctor confirm the diagnosis... ### Osteonecrosis of the Knee Imaging Tests - **X-ray**: X-rays provide images of dense structures such as bone.... The doctor may prescribe X-rays to check for bone changes that occur in the later stages of osteonecrosis.... In the early stages of the disease, X-rays usually look normal... - **MRI scan**: Early bone changes that may not be visible on MRI can be detected on MRI.. Bone disease ....MRI scan may also show early osteonecrosis that has not yet caused symptoms, for example osteonecrosis that may develop in the opposite knee joint... - **Bone scan**: In some cases, the doctor may prescribe a bone scan... Treatment of osteonecrosis of the knee Osteonecrosis treatment depends on several factors, including: - Disease stage - Amount of damaged bone - The main cause of the disease ### Non-surgical treatment In the early stages of osteonecrosis, the treatment is non-surgical. If the affected area of ​​the knee is small, non-surgical treatment may be sufficient. Non-surgical treatment may include: - **Medications**: Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen, can help reduce pain and swelling in the knee.. Your doctor may also prescribe bisphosphonates for treatment, especially if diagnosed at a young age. "Offloading" can help reduce pressure on the joint surface by transferring weight from the affected area of the knee.. Recommendation - **Change in activity**: Your doctor may recommend avoiding activities that cause painful symptoms.... ### Surgical treatment If a large portion of the bone surface is affected or if your pain does not improve with non-surgical treatment, your doctor may recommend surgery... Several different methods are used to treat osteonecrosis of the knee: - **Debridement and microfracture arthroscopy**: In debridement (cleaning), the doctor uses a small camera and miniature surgical instruments to remove loose pieces of bone or damaged cartilage from inside the joint space....For small lesions, the surgeon may make several holes or microfractures in the underlying bone** and stimulate restorative blood flow...* This procedure involves drilling a large hole or several small holes in the bone to reduce pressure on the bone surface and create channels It is for new blood vessels to feed the damaged areas of the knee.. When osteonecrosis of the knee is detected in the early stages, nuclear decompression is often successful in preventing bone breakdown and joint inflammation.. This tissue may be taken from a donor (allograft) or from another bone in your body (autograft).... There are several artificial bone grafts available today. It is staged....First your doctor will do an arthroscopic procedure to remove a small number of cartilage producing cells from your cartilage cells (into chondrocytes)..where they are cultured for up to 6 weeks to get more cells.. Second, your doctor will do another procedure to implant cartilage cells in the cartilage area of ​​the knee.. and replace the damaged cartilage with healthy cartilage - **Osteotomy** of the knee: In an osteotomy, the lower leg (tibia) or thigh bone is cut.. He removes part of the bone or inserts a wedge of bone graft or artificial bone to transfer weight from the damaged area. Slow... - **Total Knee Replacement or Partial Knee Replacement**: If the disease has progressed to such an extent that the bone has already collapsed, surgery may be needed to replace the damaged parts of your knee.... In a knee replacement, the doctor removes the damaged bone and cartilage and then places new metal or plastic surfaces to restore the function of the knee bone.. For most patients, treatment of osteonecrosis is successful in relieving pain and improving function. Treatment varies. Your doctor will discuss with you the expected results of treatment for your particular condition.