Dr Kevin McCarrollMedical Matters with Dr Kevin McCarroll
Aches and pains are common with advancing age and contribute to significant disability, pain, loss of function and quality of life. Osteoarthritis is the commonest cause of joint pain occurring in over 400,000 people in Ireland and affecting over 50% of those aged over 65. It predominantly affects the weight bearing joints of the back, hips, knees and ankles and also frequently involves the neck, shoulders, hands and feet.
For several decades, osteoarthritis was considered to be simply a ‘wear and tear’ disease due to excessive mechanical loading and/or injuries to our joints. However, it is now believed to have more complex multi-factorial causes which may explain why some people and not others develop it later in life. These include genetic as well as physical factors such as joint alignment, bone anatomy, physical activity and movements, muscle strength and lifestyle factors such as smoking,
Osteoarthritis is characterised by inflammation in and round the joints and damage to the cartilage that covers the bones that normally allows for easy movement without friction. In time, the joint space becomes narrowed and the articulating bones are damaged and eventually make direct contact with each other. Forced physical activity and increased loads and twisting forces on the joints will increase the risk of disease particularly in the hips and knees.
Poor posture can also contribute to osteoarthritis of the spine and shoulders. Repetitive micro-trauma related to occupational or lifestyle activities such as climbing, kneeling, lifting or typing can also cause permanent damage in the joints over time.
As we age, there is reduced capacity to regenerate this cartilage. Beyond this, evidence also supports a role for chronic inflammation in the joint mediated by factors such as smoking and obesity. There is also a significant genetic component with up to 80 genes implicated and with a well-established increased risk in those with a family history.
The symptoms due to osteoarthritis may be initially quite mild and indeed the diagnosis can be missed. Pain in the joints may be episodic and only occur after longer periods of weight bearing or use. However, as it progresses this becomes more frequent and in more advanced cases pain can be constant and occur at rest.
Stiffness
There can be joint stiffness (especially in the morning), reduced range of movement at the joints and swelling in the hands, knee and ankle. In the knees, there is frequently pain on walking upstairs or an incline.
In hip disease, pain can also be felt over the groin area and may radiate to the knee, but never into shin or foot which is nearly always due to nerve entrapment.
Diagnosis is based on history and/or clinical findings as well as plain x-ray of the joint. MRI is occasionally used to aid diagnosis as it is more sensitive and is particularly good at visualising soft tissues around the joint and ruling out other problems such disc disease in the spine, cartilage and muscle tears, and bursitis.
Exercise is an often ignored but important treatment option, and may be guided and tailored by physiotherapy.
It promotes correct movement and posture of our body and helps to maintain muscle strength which supports the joints.
Walking aids may help to relieve the pressure of affected joints as can splints and shoe insoles.
Shorter periods of weight bearing with rest intervals can be helpful. Weight loss where appropriate is hugely important and can significantly reduce the mechanical load on joints and improve pain and joint mobility.
Heat or cold packs provide some symptomatic relief. Topical anti-inflammatories are effective in reducing pain over more superficial joints such as the knee and hands, and have little or no side effects as they are only locally absorbed.
For mild pain, paracetamol may be helpful and despite a recent analysis of several studies this year showing a minimal affect it remains a safe and practical option.
Glucosamine sulphate and chondroitin sulphate (supplements that may help in cartilage regeneration) are available over the counter and may reduce pain but studies are conflicting and where shown, the benefit is small.
Whilst oral anti-inflammatories are very effective in controlling pain, side effects including peptic ulcer disease and worsening renal function mean that in general they should be avoided or only used in the short term or sparingly.
Opioid or morphine based painkillers are effective but they can cause drowsiness so it is important to start a low dose.
Low dose opioid patches which can be applied on the skin once a week are a good alternative to tablets as they provide continuous background pain relief and their dose can be adjusted easily.
For severe osteoarthritis of the knee, steroid injections into the joint can reduce pain but the effect is often only short-term. However, they can be repeated and may avoid the need to use increasing doses of other medications.
Finally, if osteoarthritis is severe and/or pain is difficult to control then a joint replacement or resurfacing will be required. Hip and knee replacements are commonest but other joints including the shoulder can be done.