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Osteoarthritis (OA) is a common form of arthritis that can develop over time and can affect many people. Osteoarthritis of the knee is a debilitating condition that affects the synovial membrane, the bones and the cartilage of the knee. Any damage to the cartilage from an external injury or the effects of rheumatoid arthritis could potentially lead to OA.

Osteoarthritis causes

Due to any number of causes and risk factors in our daily lives, research suggests that we can all be susceptible to this debilitating condition. There are a number of risk factors and causes of osteoarthritis of the knee that could increase the likelihood of you developing this condition. To help you understand more about OA of the knee, we have outlined some of the main causes:

Pre-existing conditions

Aside from current or historical injuries, certain pre-existing conditions can increase the likelihood of this condition appearing. These include rheumatoid arthritis (RA), gout, and type 2 diabetes. The link between type 2 diabetes and OA is mainly due to weight gain, so following a healthy diet and reducing weight can contribute to an overall relief from the symptoms in this case.

Previous injury to the knee

Once you have sustained an injury, regardless of which joint or muscle was affected, you are left with an inherent weakness in the injured area. This historic injury increases your chances of subsequent injury in the same area in the future. When we consider injuries to the knee, even a sports injury that occurred years before and from which you later recovered could increase your risk of developing osteoarthritis in later years.

Certain injuries to the knee are considered particularly damaging; for example, it is believed that those who have suffered ligament injury, specifically anterior cruciate ligament (ACL) injuries, are far more likely to experience OA due to the nature of the injury. Ligaments are tough bands of tissue that connect bones within the body and stabilise the joints. The ACL is one of four ligaments within the knee joint and is located at the front, with its main being to prevent your knee from moving forward beyond your tibia (shinbone). It is the ACL that enables you to walk, run and jump. Without this ligament, your stability can be compromised.

Damage to the ACL will vary depending on the injury; however, in grade 3 ruptures and tears, surgery is often required to either repair or replace the ligament. This will be followed by a period of intensive physiotherapy to rebuild the mobility and strength in the knee. Following this type of injury, you can expect to be in recovery for many months while your body heals.

Due to the potential risk of developing further problems in the knee joint, effective rehabilitation after an accident or operation involving the knee is critical, along with an emphasis on rebuilding the strength in the affected joints and muscles. Following a recovery protocol after an injury will go a long way towards minimising your risk of further injury to your knee or having future OA problems.

Cause Of Osteoarthritis - What Causes Osteoarthritis - OA Knee Pain Previous knee injuries can also increase the chance of osteoarthritis

Genetic factors / family history

Genetics plays a huge part in many debilitating health conditions, with osteoarthritis of the knee no different. Scientists are yet to identify a specific gene as being one of the root causes of OA knee, but it is commonly accepted that there could be a number of genetic factors that may be the source of the issue.

One such factor is the genetic link in our DNA that runs in our families and is passed down to our children, leading to similar conditions in the next generation. Other research has shown that there is an inflammatory response within the body that involves cytokines present in the fatty deposits in the body, which can contribute to the body's response to the inflammation of the osteoarthritis.


Sport has always been associated with injuries to the body in one form or another. Some sports have a higher risk of musculoskeletal injuries than others, especially high-impact or contact sports such as running, football or tennis. This is because the more force that is applied through the joint, the greater the strain; in turn, this can increase the risk of cartilage degradation and damage. To reduce the risk of developing osteoarthritis in the future, it is vital to pay close attention to any sporting injuries that occur and to take the appropriate remedial action.

It seems that osteoarthritis causes people to take less exercise, as they are concerned about experiencing sudden knee pain; however, exercise is vital in the management of this condition. Researchers have found that certain types of exercise are not only beneficial but can also aid recovery and build muscle strength.

To build muscle strength, you might like to consider taking a short walk or going swimming, which is especially recommended due to the water's warmth and buoyancy. Tai chi or yoga, with their gentle controlled stretches, have been a popular form of gentle muscle-strengthening exercise for centuries.

Causes Of Osteoarthritis - OA Causes - OA Knee Pain Swimming is recommended due to the water's warmth and buoyancy


It seems that women are more at risk of developing osteoarthritis than men due to a number of factors. One major factor is the female hormone oestrogen. This hormone has a number of roles within a female body and one of its little-known roles is the protection of the cartilage in the joints to allow more movement and flexibility.

This is particularly evident in younger women, whose bodies are designed to adapt for childbirth. Women also tend to have wider hips than men, which places a different directional load on their knees and can lead to additional strain on the joint.

When oestrogen levels naturally decline following the menopause, the protection that this hormone provided also drops. This leaves older women more susceptible to osteoarthritis in their joints.

Many women struggle with weight gain, especially after a pregnancy, which contributes to further strain on their knees. Some women also experience difficulties losing weight after they have gone through the menopause.


Unfortunately, our risk of developing osteoarthritis increases as we get older. Professionals often refer to this cause of osteoarthritis as 'wear and tear'. For some, arthritis is an unfortunate but natural part of the ageing process. Our knees are particularly susceptible to injury, as they are in constant use and weight-bearing. After a lifetime of activity, the cartilage can begin to degrade in places, leading to other painful conditions within the knee joint such as bone spurs.

In later years, without regular exercise, the leg muscles may also weaken, which will put additional strain on the knee joints. This highlights the importance of taking a proactive approach to our health by maintaining good muscle strength to help reduce such risks as we age.

Causes Of Osteoarthritis - OA Causes - OA Knee Pain Age is a contributing factor to the onset of osteoarthritis


Weight plays a large part in the management of osteoarthritis of the knee. We all know that the knee is a hard-working part of the body and is affected by the entire weight of the body; therefore, it is logical that the heavier you are, the more force is transmitted through your body to your knees, ankles and feet.

To address any concerns you may have about your weight and symptoms of osteoarthritis, you can refer to the NHS guidelines on maintaining a healthy weight and lifestyle. Such intervention could not only reduce the strain on your knees but also improve your health in other areas of your body.

What causes osteoarthritis to flare up?

Perhaps you have been diagnosed with osteoarthritis of the knee and have been managing the condition but have found that some days are worse than others? Several triggers could contribute to a flare-up, one of which is a repetitive strain injury (RSI). This is when you overuse a part of your body, such as your fingers, knees or elbows, which can lead to an RSI. This is particularly found in sports such as cycling or running, but even some forms of house or office work can lead to an RSI.

Another cause of a flare-up is an increase in your weight. Perhaps you have not kept an eye on your ideal weight and your body has let you know by sending a few pain signals from those weight-bearing knees?

Temperature changes can also be a factor in an osteoarthritis flare-up. You may have heard of people who say they can predict a change in the weather just by the feelings in their body, such as aching knees? This may not be too far from the truth.

Finally, certain foods could cause a flare-up. It is not surprising to learn that the most common offenders are white sugar, white rice, potatoes, sweets, gluten and alcohol. These foods are often recommended to be consumed in moderation, especially if you are following a healthy eating plan, but this is down to individual preference and taste.

Take the time to listen to your body. Through trial and error, you will arrive at a healthy eating and exercise plan that will suit you - and more importantly, it won’t cause a flare-up of your OA symptoms.

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