Arthritis or osteoarthritis is a condition where the articular cartilage of a joint is damaged and is progressively lost.
The knee joint is commonly affected by arthritis. Because it is a significant weight-bearing joint with a pivotal role in may activities, it can have a considerable impact on a person’s life. Arthritis is a progressive disease. However, it comes on over years and decades. When the cartilage is completely lost, the person may reach the stage of having “bone on bone”.
Many conditions lead to cartilage damage and osteoarthritis. However, most cases are idiopathic, which means that there is no specific cause. There is probably a genetic component to this idiopathic variety and that joints other than the knee are commonly involved (hips and hand). Knee injuries can damage the cartilage. Injuries include fractures that extend into the joint and fractures of the leg bones that heal in a “crooked” position. Ligament and meniscal tears can also predispose to arthritis. There are also a group of diseases that cause inflammation of a joint such as Rheumatoid Arthritis that can lead to cartilage damage. Arthritis is commoner as a person ages, but it is not an inevitable consequence of ageing.
Symptoms of knee arthritis
The predominant symptom of arthritis is pain. However, a person can have significant arthritis but only mild symptoms. Often the pain from osteoarthritis is intermittent. Factors such as increased activity (e.g. going for a much longer walk than usual) or a minor injury may trigger an acute exacerbation. Typically these flares tend to resolve with time and appropriate nonsurgical treatment. As the arthritis progresses, the pain tends to worsen both in intensity and duration. In the later stages of the disease, the pain can be disabling. Arthritic pain tends to “mechanical,” i.e. it is worse physical activities such as walking or work. Rest usually helps settle the pain.
Arthritis can cause other symptoms in the knee. These include swelling, deformity, “mechanical” symptoms such as catching, loss of movement, including the inability to straighten the leg entirely and limp.
Knee arthritis diagnosis
The diagnosis of osteoarthritis of the knee can be made based on the person’s age, symptoms and the findings when a doctor examines your knee. However, imaging of the knee is required to confirm the diagnosis. Although the severity of the symptoms is vital in assessing the stage of the arthritis, imaging plays an important role too. X-Rays, especially weight-bearing X-Rays, show characteristic changes. The most significant changes are a reduced gap between the two bones (indicative of the extent of cartilage damage) and the presence of bone spurs (osteophytes) that project out from the bones. An MRI is not required to confirm the presence of arthritis but will demonstrate characteristic features.
It is essential to know that as yet the cartilage damage cannot be repaired. The cartilage loss is progressive but occurs over the years to decades. As mentioned above, and it needs to be stressed enough, the pain from the arthritis is intermittent.
The initial treatment of arthritis is non-surgical.
Low impact exercise
It is vital to reduce activity initially until the pain resolves. Physical activity reduction may mean stopping running or other high impact activities. However, in the long term, walking, cycling, swimming and other water-based exercise is appropriate. If you continue to walk, avoid walking on hard surfaces such as concrete and wear walking shoes with good shock-absorbing qualities.
If you are overweight, losing weight will reduce the load and stress on the knee. Weight loss can have a significant beneficial effect on the arthritis as well as improving your overall health.
Loss of muscle mass starts in our thirties and worsens as we age. Arthritis will compound the problem. An appropriate exercise program, facilitated by a physiotherapist or an exercise physiologist, will strengthen your leg and improve its function. At a minimum should include the quadriceps, gluteal and “core” muscle groups.
If the arthritis predominantly affects one side of the joint an unloader brace can reduce the stress going through that side of the knee.
Medications may be required to help with the arthritic pain. Paracetamol is the recommended first-line analgesic. Paracetamol is useful for an acute flare of pain, or more regularly, as the arthritis worsens. Nonsteroidal anti-inflammatory drugs (NSAIDs) can be helpful for short term use. Because of potential side effects, use caution for people with heart, kidney and gastrointestinal conditions. Therefore please discuss with your family doctor before using. COX-2 inhibitors such as Celebrex can be tried and are often better tolerated.
More potent analgesics such as opioid-containing drugs should be used cautiously and only for a short duration. Surprisingly they are often not that helpful for the pain of arthritis.
Cortisone injections into the knee can be helpful for some people, mainly if there is an inflammatory component to the arthritis. The duration of benefit of a cortisone injection is variable. They also tend to be less effective with repeated injections.
There are also many treatments purported to help or “cure” arthritis, but there is little evidence for their use. Glucosamine and chondroitin are two of the building blocks of cartilage. Although widely used, their benefit remains unproven. There is no scientific substantiation for many other heavily advertised supplements. Stem cell therapy is a costly and heavily promoted procedure with little evidence of its clinical benefit.
For many years arthroscopic “cleaning up” the joint was an accepted treatment tool for people with arthritis. However, there is convincing evidence from many good quality research studies showing that arthroscopy has a minimal role in the management of osteoarthritis.
Knee replacement (or knee arthroplasty) has become the treatment of choice for people with end-stage knee arthritis. It is a significant procedure. It involves removing the worn-out articular cartilage and then resurfacing the knee with metal and plastic components. Most people stay in the hospital for three to four days after the operation. Rehabilitation to get the knee moving and to build up strength is critical to a good outcome. A rehab program should continue for a minimum of three months to gain the most value after a knee replacement. The vast majority of people obtain good pain relief and improved function.
Another option is a partial knee replacement. This procedure is not ideal for all patients. However, if a person is suitable for a “partial”, then the results are excellent in terms of pain relief and return to activities.
Osteoarthritis commonly affects just one side of the knee, typically the inside (medial) compartment. Medial arthritis causes a characteristic bowing of the leg that increases the load passing through the diseased part of the knee. An osteotomy of the tibia will straighten the leg. The straightening improves the pain and the biomechanics of the knee. A tibial osteotomy involves cutting the bone, correcting the deformity, fixing the bone with a plate and then bone graft. This operation is suitable for younger (less than 60) and more active individuals. It can delay the need for a knee replacement by many years.
Arthritis affecting the outside (lateral) compartment causes a “knock knee” deformity. This deformity can be treated with an osteotomy of the femur to restore the normal alignment of the knee.
Dr Brown has particular expertise dealing with knee arthritis and will be able to recommend the best course of treatment to reduce pain and increase movement.