In todays blog we are going to discuss Baker’s cysts, what they are, why they happen and what we can do to help treat it. Baker’s Cysts, or popliteal cysts as they are also known, are a fluid filled sack that can arise in the area directly behind the knee (popliteal fossa).
The knee is a large and complex joint where three bones meet – your thigh bone (femur), shin bone (tibia) and kneecap (patella).
Surrounding the joint is a tough capsule filled with lubricating fluid called synovial fluid. This fluid allows your knee to move freely. Small fluid-filled sacs, known as bursa, cushion the joint and help reduce the friction between tissues caused by movement.
A Baker’s cyst occurs when there is too much synovial fluid being produced in the knee joint which in turn increases the pressure in the area causing it to bulge backwards forming a lump or cyst in the back of the knee.
The simple answer to what causes a Baker’s cysts is inflammation and swelling from inside the knee joint. However, this swelling can be caused by a range structures in the knee.
Injury to the knee is one of the most common causes, this can include: direct trauma to the bone or muscle surrounding the knee itself or an injury to the muscles, ligaments or cartilage inside the knee which in turn cause excessive swelling.
Arthritis is another common cause of Baker’s cysts particularly in rheumatoid and osteoarthritis which result in increased intra-articular (joint) swelling.
Infection to the area whether after the knee has been subjected to contamination or from secondary infections near the joint can also cause swelling in the area. There are also some Baker’s cysts which occur for an unknown reason, but generally indicate irritation to structures in the knee joint.
There are often little to no signs and symptoms of a Baker’s cyst and it is common to not even know you have one, however if there are symptoms they can include:
· A lump or swelling behind the knee, this can be visibly obvious.
· Pain in the knee joint or at the back of the knee
· stiffness or tightness at the back of the knee
Although the symptoms are mild, and some swelling is common in most areas of the body there are some complications to these cysts that can be a cause for concern. It’s also important to remember that the presence of a Baker’s cyst generally indicates that something in the knee is being irritated, often this is the meniscus or cartilage of the knee.
The cyst can continue to grow causing an increase in painful symptoms, it may also extend inferiorly into the calf muscle or it can rupture causing fluid to leak into the calf region leading to increased pain and bruising extending to the ankle.
When this occurs, it can be difficult to distinguish the symptoms between a ruptured Baker’s cyst and other serious conditions such as blood clots in the lower limb. As such, if you do have any swelling or pain in your calf, it is safest to contact a medical professional to determine what it is causing the pain.
Conservative treatment for this condition is the first course of action, as is identifying the underlying structure that is giving rise to the cyst. Your physio, chiro or massage therapist will start by treating this underlying cause to remove the irritation and stem the excess production of synovial fluid.
This course of action will include rest, ice and avoiding any aggravating activities. Therapy will also involve exercises and stretches to maintain the mobility and function of the knee as allowed. If the cyst is persisting steroid injections may be needed to reduce pain and inflammation to the area and if that isn’t successful surgery may be needed for complete removal of it and potentially the underlying structure. In most patients it does not progress this far and responds well to conservative management.
Due to their size and function, knee joints are susceptible to injury during every day and sporting activities. Preventing knee injuries from occurring in the first place can drastically reduce the risk of a Baker's cyst developing. Things you can do to prevent knee injuries include:
1. Ensuring you engage in a good warm up and cool down before and after exercising or playing sports.
2. Always ensure you have good, supportive, footwear
3. Maintain good flexibility and strength through the knee’s
As mentioned above Bakers cysts aren’t, generally, a debilitating condition (unless they rupture) however they do indicate damage or irritation to an underlying structure that needs to be addressed. There are more serious conditions that have similar signs and symptoms, so if you do have any persistent pain through the back of the knee or calf, be sure to contact your health care professional for an accurate diagnosis and treatment plan.
So that’s an overview of how Baker’s cysts arise. If you have any questions or comments please e-mail us at firstname.lastname@example.org and we will be happy to answer them for you.
If you suffer with pain through the back of the knee, feel free to call us on (08) 9486 8653 and our therapists will be happy to chat with you about the best management plan.