Osteoarthritis (OA) is the most common joint disease in Australia and affects approximately 1 in 8 Australians. Life does not stop with a diagnosis of OA – you can continue to live an active life and there is a lot you can do to manage symptoms and keep moving well.
OA is a collection of changes to a joint including damage to cartilage and underlying bone, joint inflammation and deterioration of ligaments and tendons. The process of OA can cause pain, swelling and restricted movement. This can happen at any joint with the hips, knees, neck, lower back, fingers and big toe are commonly affected areas.
In this blog we are going to discuss what happens to an arthritic joint, how we can reduce the risk of OA and how to manage OA and maintain your quality of life if you already have symptoms.
Osteoarthritis – what is happening?
OA impacts many structures within the joint so let’s cover some anatomy. Joints are surrounded by a joint capsule which holds bones together while allowing movement and joint fluid providing lubrication. A healthy joint allows for smooth movement largely due to cartilage. Cartilage has two main roles – providing a smooth surface for movement and distributing force to underlying bone.
We have a constant turnover of cartilage through life. Our body constantly breaks down old cartilage and creates new. OA occurs when the process of cartilage break down is greater than the new cartilage produced. There are 3 phases in the development of OA within a joint:
- Cartilage injury: This can be contributed to by many factors such as age, genetics, history of injury and weight.
- Early OA: Cartilage cells release chemical mediators causing an inflammatory response. Joint structure begins to change and there is secondary inflammation of joint fluid and the bone underlying cartilage (sub-chondral bone).
- Late OA: Ongoing inflammation and repeat injury cause a loss of cartilage and changes to underlying bone.
The most common symptoms of OA include pain, swelling, stiffness (particularly after periods of inactivity), muscle weakness and joint instability. It is important to keep in mind that symptoms vary greatly from person to person. Many people with OA changes on X-ray may experience only mild symptoms or no symptoms at all.
Risk Factors for Osteoarthritis
Any circumstance where there is normal load placed on an abnormal joint, or abnormal load placed on a normal joint the chances for OA will increase. Some risks cannot be avoided however below are some key areas that we can change to reduce the risk of OA.
Body Weight
No doubt about this one. Being overweight/obese increases the force going through a joint. For every step the amount of force travelling through your knee is equal to 2-3x body weight – so for each additional kg of weight there is an extra 2-3kg going through the knee. In addition to the physical load, higher amounts of fat tissue change the chemical environment by increasing inflammation at the joint and throughout the entire body. This inflammation derived from fat is also associated with rheumatoid arthritis and diabetes.
Injury
Injury to the joint will affect movement and a history of injury and re-injury increases the risk of OA. After injury joint structure is changed and can result to an uneven distribution of force – areas of high force can cause a loss of cartilage and damage to sub chondral bone. Knee injuries such as cruciate ligament ruptures, meniscal and cartilage tears and fractures have been shown to increase risks of OA almost 6 times in young adults. Injuries happen and we see it everyday at the clinic – with any injury it is important to undergo rehab to prevent re-injury and mitigate health risks such as OA.
Weakness
Muscles control movement by absorbing energy and force. If our muscles are weak they cannot control movement and protect our joints. In other words, if load cannot be transmitted through muscle due to weakness, it will be transmitted through cartilage and bone. Strength training will help give your muscles the capacity to protect joints.
Overuse (Occupation/Sport)
Some occupations involving heavy lifting and lots of repetitive movements such as squatting, gripping, twisting and kneeling. This might be unavoidable depending on your job but change what you can – make use of tools and equipment and pay attention to manual handling to reduce risks.
High intensity or impact sports have also been identified as a risk particularly if the athlete is deconditioned. If you are not trained for the requirements of the sport, you are more likely to fatigue with poor motor control and muscle weakness causing increased load through the joint – there is also a greater risk of acute injury.
Some risks cannot be avoided – age and genetics certainly play a role in the development and progression of OA. Age has been identified as a risk factor because as we get older, we typically lose strength and muscle control therefore joints get less protection. While we cannot train your chronological age, we can certainly train muscle!
Management (what can I do)
Currently there is no cure for OA – be very wary of anyone claiming to cure or reverse OA! Despite this there are many ways to effectively control symptoms and maintain quality of life. The foundations for managing OA are education, exercise and weight management.
Exercise is proven to reduce pain levels, reliance on pain medication and is shown to delay or prevent the need for surgery. Your Physiotherapist will work with you to come up with an exercise program appropriate for your condition and ability. Essential components of your exercise program will be:
- Strength training to build muscle surrounding joints to offer protection and relieve pain
- Cardiorespiratory exercise to assist weight management (as well as heart, sleep, cognitive, stress benefits, anti-inflammatory effect)
Weight loss has been shown to ease pain and inflammation and slow the degeneration of cartilage. Losing weight is tough but if you are overweight there is no better thing you can do for OA and risks to your general health such as diabetes, heart disease and cancer.
There are many myths surrounding OA – the more that you can learn regarding the effects of the disease the better. Understanding the science of pain and what can be done with conservative management (without surgery) contributes to better outcomes for people living with OA.
There are instances where conservative measures are not successful. In this instance medications can be prescribed by your GP for pain management and joint replacement surgery can be considered if symptoms cannot be managed adequately with other measures.
If you have a diagnosis of OA or if you would like some guidance on how to reduce the risk speak to your Physiotherapist. We will happily discuss imaging results with you, explain the symptoms of OA and come up with a management plan tailored to you.