Knee pain is common in runners. If your pain is on the inside of your knee, you might have a condition called pes anserine bursitis or lower hamstring tendonitis. What does this mean and how do you manage it?

What is pes anserine bursitis? 

Pes Anserine means ‘goose’s foot’. It is the place where the three tendons on the inside of your knee attach to the lower leg. This three tendon attachment looks like a ‘goose’s foot’. These three tendons are the sartorius, gracilis, and semitendinosus. Bursitis is just another term for paratendonitis. Therefore, we should treat this condition as tendon swelling rather than a true inflammation.

picture of pes anserine bursitis

How does lower hamstring tendonitis present? 

Generally, pain is usually felt at the inside bottom part of the knee, just below the inside (medial) part of the joint. Sometimes, the pain moves up toward the lower inside hamstring muscles. Usually, pain warms up with activity but is often worse after activity. Occasionally, people report localised swelling at the inside of the knee.

When assessing your knee, it is important to rule out other causes of pain on the inside of your knee. Other causes of knee pain on the inside include stress fracture, torn meniscus, kneecap arthritis, fat pad impingement, and pain referred from the hip or spine. Remember, not all pain on the inside of your knee is pes bursitis.

Sometimes, pain can be due to another tendon on the inside of your knee called the semimembranosus tendon.

Often, we suggest investigations to confirm changes of pes anserine bursitis and exclude other causes. Generally, MRI is the investigation we choose for sorting out a cause.

Pes Anserine bursitis vs MCL strain

Both conditions cause pain at the inside of the knee. However, in general, there are significant differences between these two conditions. Firstly, pes bursitis usually occurs gradually due to overload whereas MCL strain occurs after a twisting injury. Secondly, the pain of pes bursitis is generally at the lower inside of the knee compared to MCL where the pain is higher near the top of the kneecap. Generally, most experienced doctors can tell the difference between these two conditions.

Pes anserine bursitis causes

This condition is usually caused by a repetitive overload of the tendons. This overload leads to swelling and pain. Often, patients report a change in usual intensity or frequency of running or sport. Sometimes a fall onto the inside of the knee causes swelling and pain in the pes bursa.

How to fix lower hamstring tendonitis

glute bridges

Generally, physiotherapy is the mainstay of treatment. Typically, exercise therapy will consist of flexibility, strength, and balance. Stretches to increase flexibility include hamstring, hip, and thigh exercises. Strengthening often focuses on the knee and hip. Balance exercises on a wobble board or uneven surfaces may help. Finally, correcting lifting and squatting patterns are also important.

Activity modification is also an important component of improving symptoms. As symptoms improve, you can gradually resume more exercises such as running or team sport.

Finally, anti-inflammatory treatments such as ibuprofen and ice can settle the inflammation.

Is a Pes Anserine bursitis injection useful? 

Yes, if you have tried simple treatments with no effect then an injection is useful. Injection should be done with ultrasound-guidance to improve accuracy and reduce side effects. A cortisone injection will improve pain and allow you to push on with treatment and your sport. Further details on the pros and cons of cortisone injections can be found in this recent blog.

How long does pes anserine bursitis take to heal? 

Generally, like most tendon problems, pes bursitis can be slow and take up to 3-6 months to completely recover. However, in some cases, early recovery of less than 6 weeks is possible.

Hamstring tendonitis after TKR

Lower hamstring tendonitis is seen after a total knee replacement (TKR). Generally, it is difficult to know whether pain after a TKR is due to a problem with the implant or another issue such as infection or tendon swelling. Overall, we suggest you see your surgeon first before considering a tendon cause of pain after a TKR.

Other commonly asked questions on pes bursitis:

Will a kneecap brace help pes anserine bursitis? 

Overall, we suggest that you should try a kneecap brace for this condition. We think a brace provides support to the kneecap, which in turn can improve pain from pes bursitis.

Is swimming good for pes anserine bursitis? 

Any aerobic activity that improves the conditioning of the muscles of the pelvis and lower limb will help pes bursitis. However, we suggest you avoid breaststroke as this stroke puts more load on the pes bursal tendons.

Final word from Sportdoctorlondon about lower hamstring tendonitis 

Pes anserine bursitis causes pain on the inside of your knee. It is important to rule out other causes such as a meniscal tear or a stress fracture. You should always start with simple treatments followed by an ultrasound-guided cortisone injection if no improvement. Remember, if you’re thinking about an injection, you should always do your homework first. We suggest you find a doctor experienced in ultrasound and injections.

Other related knee conditions:

Dr. Masci is a specialist sport doctor in London. 

He specialises in muscle, tendon and joint injuries.

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