Osteoarthritis is the most common form of arthritis affecting the knee joint. In a healthy knee, the joint is lined with cartilage, acting as a cushion and a smooth surface for easy, frictionless movement. Osteoarthritis results in cartilage destruction and alters the bony surfaces and ligaments of the knee, making movement difficult and painful.
The most common symptom of osteoarthritis is knee is pain. The exact nature of pain will vary from person to person. Initially it can be pain that is felt only when doing more strenuous exercise or after prolonged periods on your feet, although when more severe the pain can be present for most of the day and even cause disruption to sleep. In addition to pain, some patients will experience stiffness, swelling and the feeling of the knee ‘giving way.’
The exact cause of osteoarthritis is not always known. It is usually a long-term problem causing progressive wear and tear of the joint, Osteoarthritis is more common in older patients. Most often, there are a mixture of factors which contribute to an individual’s risk of developing osteoarthritis of the knee. Although there is no single gene that causes osteoarthritis, we know that it can run in families. Patients who have abnormal alignment of their legs can be predisposed to arthritis. Importantly, osteoarthritis may develop after trauma to the knee or lower limb.
Often, the diagnosis of osteoarthritis can be confirmed following a medical consultation and examination and dedicated x-rays of your knees. Sometimes you might be offered an MRI scan, which can help determine whether damage to other areas of the knee (e,g, the ligaments or menisci) are contributing to your pain.
Unfortunately, progressive damage to the cartilage and tissues of the knee is irreversible, so there is no ‘cure’ for osteoarthritis. Because of this, the treatment of osteoarthritis generally revolves around managing symptoms in the initial stages, and progressing to more definitive treatments when indicated.
Most often, osteoarthritis of the knee is initially managed non-operatively, with a combination of exercise therapy and medication. Low-impact activities such as swimming, cycling, pilates and yoga can be extremely effective in reducing the stress on the arthritic joint and strengthening the muscles of the leg. A dedicated physiotherapy program is often recommended for patients with osteoarthritis. Commonly prescribed medications such as paracetamol and anti-inflammatories (if indicated) may also assist in alleviating symptoms.
In some cases, I may recommend steroid injections to the knee with a local anaesthetic to help to reduce knee pain. It is important to maintain a healthy body weight since we know that excessive weight contributes to the stress placed on an arthritic knee.
In more advanced cases, I may recommend that you consider surgery to treat your knee osteoarthritis. Surgical procedures include joint replacement, joint realignment, and joint debridement.
Joint replacement – Knee Replacement (Total Knee Arthroplasty)
This is the most common surgical treatment for osteoarthritis of the knee and is now the most common joint replacement performed in Australia. When performing a total knee replacement, the knee joint is exposed and the diseased portions of bone and cartilage are surgically removed. A new prosthesis is then inserted into the knee. This is made of metal, with a polyethylene (plastic) liner between the femoral and tibial components which facilitates safe and pain-free movement. The patella may or may not be replaced in this surgery, depending on your individual circumstances.
Unicompartmental Knee Replacement
In some cases, knee osteoarthritis will be confined to one area of the knee. This is less common, but in selected cases, I may recommend replacing only one half of the knee, known as a unicompartmental knee replacement. In theory, this can provide a more ‘normal’ feeling knee, although it is much less commonly used than total knee replacement.
This is often done in younger patients who have developed osteoarthritis to one side of their knee in an effort to improve the alignment of the knee and therefore unload the diseased portions of the joint. This is done via an osteotomy, whereby the bones are altered in their position and then held with a plate and screws to improve the alignment of the knee. This type of surgery is often recommended for younger patients as it may avoid the need for a knee replacement, or at least delay it for some years.
Joint Debridement (Arthroscopy)
Arthroscopy purely for osteoarthritis is generally not recommended, as the disease process is too far gone to be able to give people reliable and long-term improvement in pain. Occasionally, patients may be getting symptoms from other areas in their knee, in which case key hole surgery (arthroscopy) can be useful.
For more information please read the Australian Knee Society’s official Position Statement on Arthroscopy for Osteoarthritis
If you suffer from osteoarthritis of the knee, please make an appointment to discuss your treatment options.