Knee bursitis occurs when there is irritation or inflammation in one of the knee bursa.
Bursa are small fluid filled sacs that reduce the friction between two surfaces. They are found all over the body, and sit between bones and muscles, a bit like ball bearings.
They allow the muscles to move freely as they contract and relax without being subjected to too much strain or friction.
Bursitis of the knee results in pain and swelling, most commonly just below, behind or on the side of the knee.
Here, we will look at the common causes, symptoms and different types of knee bursitis, the best treatment options as well as how to prevent the condition from coming back.
There are a number of things that can lead to knee bursitis:
If the bursa is repeatedly placed under a lot of pressure, it responds by producing extra fluid as a protective mechanism to protect the knee from injury. This is common in people who spend a lot of time kneeling or squatting and can lead to bursitis of the knee.
Another situation where the bursa is placed under repeated pressure is when there is muscle tightness. If a muscle is tight, it pushes down on the bursa underneath, squashing it, which can lead to knee bursitis.
Activities that involve lots of jumping and kicking can lead to knee bursitis. This is because the repetitive friction on the bursa results in inflammation.
A sudden blow to the knee, such as a sporting tackle or a car accident, can place sufficient force through the bursa that it becomes inflamed.
If there is already swelling in the knee from wear and tear e.g. arthritis, or from inflammation e.g. gout, then this excess fluid can seep into the bursa, causing it to swell. In fact arthritis is the most common cause of bursitis behind the knee.
The most common symptoms of bursitis of the knee are pain and swelling. This tends to come on gradually over time. Symptoms often come and go and aren't always consistent which can make it hard to diagnose.
If however the bursitis of the knee was caused by an injury, symptoms will usually develop very rapidly.
Sometimes you can feel a squashy lump where the bursa has swollen, similar to a squashy orange. This is most common behind the knee, known as a Bakers Cyst.
There are approximately eleven bursa located around the knee and bursitis can develop at any one of the bursa knee locations.
The most common types of knee bursitis are:
The prepatellar bursa is found directly in front of the knee cap, just underneath the skin.
Irritation here is known as Prepatellar Bursitis, or more commonly Housemaids Knee, causing pain and swelling at the front of the knee.
It is a common problem for people who spend long periods kneeling e.g. carpet layers/roofers because of the continuous pressure going through the prepatellar bursa .
You can find out more about the common causes, symptoms and treatment options in the Housemaids Knee section.
Pes Anserine bursitis occurs on the inner side of the knee. The pes anserine bursa sits between the medial collateral ligament and the conjoined medial knee tendons of the gracilis, sartorius and semitendinosus muscles.
Pes Anserine bursitis of the knee usually develops from overuse and most commonly affects runners. You can find out more about the common causes, symptoms and best treatment options in the Pes Anserine Bursitis section.
Bursitis behind the knee is known as a Bakers Cyst or popliteal cyst which causes swelling and pain behind the knee. It is a common problem associated with knee injuries and arthritis.
The semimembranosus bursa sits between one of the hamstring tendons (semimembranosus) and the gastrocnemius calf muscle at the back of the knee.
You can find out all about the common causes, symptoms, diagnosis and treatment options in the Bakers Cyst Knee section.
Infrapatellar bursitis occurs just below the kneecap and is often referred to as Clergyman's knee.
There are two types of infrapatellar bursitis. The superficial infrapatellar bursa sits between the skin and the patellar tendon, and the deep infrapatellar bursa sits further in behind patellar tendon cushioning it from the shin bone behind.
Inflammation of either is referred to as infrapatellar bursitis.
Iliotibial bursitis occurs on the outer side of the knee. The iliotibial bursa sits between the iliotibial band and the outer shin bone, just below the knee. Inflammation of the iliotibial buras is often misdiagnosed as iliotibial band syndrome.
The two most common types of bursitis of the knee are Housemaids Knee and a Bakers Cyst. You can find out more about these conditions, including simple knee bursitis treatment techniques by choosing from the links.
With any problem, prevention is better than cure. The best things you can do to avoid knee bursitis are to:
1) Ensure there is no muscle imbalance in the leg (weakness or tightness)
2) Wear Gel knee pads if kneeling for prolonged periods
Knee stretches ensure the muscles aren’t putting the bursa under any extra strain, and strengthening exercises ensure the forces go through joint correctly without putting extra pressure on the bursa. There are easy to follow exercises that can help you avoid bursitis of the knee, just click on the links above.
Gel Knee Pads reduce the forces going through the joint when kneeling and eliminate friction on the bursa.
If knee bursitis isn't sounding quite like your problem, visit the knee pain diagnosis section for helping working out what is wrong and the best way to treat your pain and stop it coming back.
Page Last Updated: 14/9/18
Next Review Due: 14/9/20