Knee Arthritis: Causes and Treatment
by Dr. Nachiket Kulkarni
Osteoarthritis is the most common cause of arthritis in the world. It is a disease of joint involving all components of joints. Though traditionally thought to be a disease of age it can occur in young too. This makes it very important to be aware about it.
Osteoarthritis is of predominantly two types: Primary and secondary. Primary is considered to be present if there has been no injury or joint disease. It's still known that there are risk factors that contribute to occurrence of Primary Osteoarthritis. These are
1.AGE: The incidence of OA increases with age.
2.GENDER: Post menopausal women have a higher chance of developing OA.
3.HEREDITY: Some genetic abnormalities can make a person susceptible for OA. Some of them have been found in studies to be hereditary.
4.LIFESTYLE: it's been proposed that a lifestyle requiring excessive use of knees like sitting crossed leg might be a predisposing factor for development of OA.
5.OBESITY: This has been the most studied and widely accepted risk factors for OA.
The causes that have shown to contribute to secondary OA are prior joint injury or surgery, some congenital diseases of joints and different joint structures and some diseases of joints like rheumatoid arthritis, Gout etc.
It is pertinent to know about the difference in various terminologies used in conjunction with joint problems. Arthritis is an umbrella term to describe disease of joint due to any cause. Inflammatory arthritis is a sub group of arthritis characterised by joint pain, swelling and destruction with potential to affect other organ systems, classical example being Rheumatoid Arthritis. They require specific treatment. Osteoarthritis is an exclusive joint disease also known as degenerative arthritis, more common with age and characterised by joint destruction. All inflammatory arthritis can cause secondary osteoarthritis.
As our knowledge about the disease increases, may be more risk factors or causes would be added to the list.
Osteoarthritis is a disease with potential to affect each and every joint of our body. For the purpose of this article though we will restrict ourselves to involvement of knee. Knee is a very important joint of our body. Our ambulation is mainly dependent on this joint. Its obvious to know that great amount of restrictions can befall by affection of this joint.
The symptoms of knee OA are varied. Lets go through the list.
1.Pain: pain is the first symptom that announces the presence of this disease. It is also the commonest reason for doctor’s visit. Initially the pain is only on extremes of activity like climbing stairs, walking, lifting weights. Gradually progresses to be even on simplest of activities. Attending to this symptom is of paramount importance for a doctor. It should be also known that it is important to describe pain correctly. It gives an idea of the joint movement capability which is useful to design treatment.
2.Swelling: Swelling is a prominent feature in patients with inflammatory arthritis like rheumatoid arthritis but can be seen in patients with primary osteoarthritis.
3.Stiffness: In inflammatory arthritis stiffness of the joint is common accompaniment and can last for more than an hour. In cases of primary OA it can still be seen to last for not more than half hour.
4.Decreased mobility: As the disease progress, the range of motions are significantly affected.
5.Deformity: Normally the knees are aligned in a straight line. In OA the knee gets progressively deformed to further affect functionality. The deformity is dependent on the type of disease.
6.Joint instability: in advanced OA the degeneration of joint structures can make the joint unstable. This renders it susceptible to buckling or subluxation. This is a potential serious condition sometimes requiring urgent intervention.
The diagnosis of osteoarthritis is primarily based on clinical grounds. But apart from diagnosis it is important to identify the cause and gravity of condition. The tests are also important to rule out other causes of joint pains apart from OA.
The tests that help in these aims are:
1.Xrays: X ray of knees are the cheapest and most easiest of all tests hence widely used. They can also help to differentiate the cause of OA in some cases. The disadvantage is radiation exposure, inability to identify early cases and also abnormalities of non bony components of joints like ligaments and cartilage.
2.MRI Knee: This test has the best sensitivity and specificity to identify OA even in early stages. The patterns of Inflammatory and other causes can be easily identified. The disadvantage is high cost, availability and difficulty in doing it in patients with claustrophobia.
3.Joint Fluid Aspiration: Rarely required. Requires expertise to remove fluid from joint to be done in aseptic conditions. The fluid evaluation guides in ascertaining the cause. Not a specific test.
4.Special Tests: These can range from special blood tests to synovial biopsy. These are done by Rheumatologist to diagnose the cause of OA.
The aim of treatment in OA is to decrease pain to minimum and to ensure functionality of the affected joint. Treatment is multipronged. It needs to be discussed as per the cause too. For Primary OA there is no definite treatment protocol for cure but if correctly planned and implemented, could be easily managed. The main components of treatment modalities are
Nonpharmacotherapy: OA is a mechanical disease and hence benefits with mechanical measures. This has proved to be of benefit and helping in both pain relief and salvaging the join
1.Exercise: exercise for OA joints consist of a mixture of aerobic and weight training. This helps in improving the muscle strength thereby improving the joint mechanics. This decreases pain. Its important to note that the nature of exercise is tailor made and hence please plan your schedule only on guidance of your Rheumatologist.
2.Lifestyle Modification: Using correct knee postures, assistance devices such as Walking stick and Chair commode have a great role in decreasing the pain and destruction of joint. Use of knee braces have been supported in few studies.
3.Weight Loss: As discussed earlier obesity is a risk factor for OA. It has been seen in studies that reducing weight helps in decreasing pain of OA. It also improves joint mechanics there by preserving it for long. Hence this measure is probably most important and this won't be an overstatement.
Pharmacotherapy: Medicines have a limited but defined role in management of OA.
1.Pain relief: This is ensured by medicines which are Analgesics or Non Steroidal Antiinflammatory Drugs. Some drugs have shown to improve joint mechanics too. Its imperative though to take them under your Rheumatologists guidance for your safety.
2.Disease Modifying Drugs: It is proposed that some drugs (eg Glucosamine, Chondroitin, Hyaluronic Acid) have the capacity to work on the cartilage and reverse or slow down the degeneration. So far their role is still to be established in clinical trials.
3.Ayurveda: For ages it has been discussed that Ayurved holds the keys to management of OA. It was only recently that benefit has been demonstrated in scientifically executed clinical trials. The pathbreaking evidence on the same comes from a trial conducted by Dr Arvind Chopra and group and published in international journal of 'Rheumatology'. It has been recognised world over and Ayurved is seen with respect and as a treatment potential.
4.Intra-Articular Injections: Rarely intra-articular (inside joint) injections of steroids in knee are required to tackle the pain and swelling not amenable to routine treatment. It needs to be undertaken by a skilled doctor as a Rheumatologist. The procedure is a simple office procedure. The doctor ensures asepsis during the procedure. It is important though that post injection rest needs to be given for 2-3 days and overuse of joint needs to be avoided.
Surgery: Surgery is the only option if the other treatment modality fail and disease has progressed significantly to affect mobility. The technology for these surgeries has significantly advanced lately. They are associated with minimal pain and ensure early functionality.
The different types of surgery are:
1.Arthroscopy: It involves insertion of a small telescope in the joint to visualise the damage and in some cases correct it. Useful in ligament and meniscal injuries.
2.Osteotomy: this involves reshaping the bones at areas of localised abnormalities.
3.Joint replacement surgeries: It involves replacing the deceased joint with a new prosthetic joint.
Inflammatory Arthritis: As discussed earlier these group of diseases require specific treatment. All measures as discussed above have to be instituted in these cases too but treatment is not restricted there itself. The primary cause of joint destruction isimmune dysregulation. Hence specific treatment of the disorder needs to be ongoing to prevent or slow down the joint damage. For example in Rheumatoid Arthritis Specific Disease Modifying Anti Rheumatic Drugs are the cornerstone of treatment. They have a potential to slow down and probably slow down the joint destruction. In Gout it requires handling of the elevated uric acid levels with Anti Uric Acid drugs. Hence identification of cause of OA is extremely important to plan correct treatment.
OA is both a difficult and easy disease to manage. Difficult if not understood and easy if followed with a defined plan. Please do discuss with your Rheumatologist.