Anatomy of the pes anserine tendons and bursa

There are three pes anserine tendons located on the inside of the knee. A tendon attaches a muscle to the bone. The pes anserine tendons attach three muscles from the inside of the thigh onto a common insertion point on the inside of the tibia bone (just below the knee joint).

The image below helps to illustrate the anatomy. Sartorius (A), gracilis (B) and semitendinosus (C) are three large muscles located within the upper thigh. They are responsible for bringing your legs together (adduction) and bending your knee. These three muscles converge into one common tendon. This common tendon is called the pes anserine tendon (Latin for ‘goose foot’).

Surrounding the tendons on the attachment to the bone is a thin sac, known as the bursa. This bursa can also be involved in pain at this attachment point (more later).

How is the pes anserine injured?

The pes anserine tendon is a common site of overuse. Overuse can occur due to the constant transmission of compressive and tensile force on the tendon, during repetitive knee movement. For example, during prolonged walking, running or cycling.

To help reduce the risk of an overuse injury at this ‘anatomical hotspot,’ the body has a thin sac called the bursa. This bursa acts as a shock absorber, reducing friction and allowing smooth movement to occur between the structures.

If you do not overload these structures, they can withstand repetitive load and the tendon and bursa will not become inflamed. However, if this is not the case or you increase your training too quickly, i.e. you do too much too soon, then the tendons and the bursa can become inflamed and cause pain (see image below).

If the tendons become painful, this is known as a pes anserine tendinopathy, whereas an irritated bursa is called a pes anserine bursitis. They often occur together (however not always) and it is important to ascertain whether your issue is a tendon or bursa, as this can influence your treatment options.

diagram showing the pes anserine bursa healthy and when inflammed

The cause and symptoms of a tendon problem can vary compared with a bursa issue. However, there is often some overlap between the two. To differentiate these conditions, a diagnostic ultrasound scan or an MRI is required. At Complete, we always carry out a diagnostic ultrasound (at no extra charge) in your first session.

Pes anseurine bursitis:

The bursa can become irritated during the following activities;

  • Activities with repetitive knee flexion (bending) such as weight-lifting (particularly heavy squats), hiking, cycling and running.
  • Sports which involve repetitive lunging and jumping such as squash, tennis, volleyball and basketball
  • Sustained postures such as crossing your legs or prolonged standing.
  • Prolonged periods resting directly on the knee – such as kneeling, particularly on hard, uneven ground.

The bursa can become inflamed and irritated due to other underlying medical conditions such as:

  • Rheumatoid arthritis
  • Gout
  • Diabetes
  • Reactive arthritis

If your physiotherapist is suspicious, there may be an underlying diagnosis; they will be able to refer you to the appropriate specialist.

What are the symptoms of a pes anserine bursitis?

  • Achy pain located around the inside of the knee, particularly at night or at rest.
  • Sharp pain with repetitive bending and straightening of your knee such as during running, cycling or squatting
  • Pain with full knee flexion (bend) and straightening with an associated sensation of stiffness.
  • Pain and tenderness with direct pressure on the area

Pes anserine tendinopathy (sometimes known as tendinitis)

If the pes anserine tendon is subject to overuse it can become inflamed and painful. Tendon tissue has a relatively poor blood supply and therefore healing can be slow. Like most tendon issues, they often require several months to fully resolve.

diagram showing the 3 tendons that concern the pes anserine bursa, describing them as a 'goose foot' formation

What are the symptoms of Pes anseurine tendinopathy?

  • Sudden sharp pain directly over the tendon.
  • Pain with movement after a period of rest, such as waking first thing in the morning.
  • Pain starts without a specific event and is usually associated with an increase in activity such as running or jumping.
  • Pain during activities of daily living such as ascending and descending stairs and walking.
  • Pain with hamstring activities such as hamstring curls in the gym, bridging exercises and/or pulling your shoe off with your other foot
  • A sensation of stiffness which is associated with the inflamed tendon. This may reduce the range of movement at the joint.

The pes anserine tendons and the bursa are in the same anatomical location, and so the symptoms often present quite similarly.

How is pes anserine tendinopathy/bursitis diagnosed?

A clinical examination can determine that your pain is arising from either the bursa or tendon but cannot differentiate which one or whether both are the problem. In some cases, determining which specific structure is involved can be very important to ensure we select the most appropriate intervention for you.

On your first appointment at Complete, we will assess the painful area using a series of clinical tests to help formulate a diagnosis. These tests include knee range of movement and strength testing as well as more functional exercises such as squatting or the assessment of your running style (if you are a runner!). We may also review your choice of footwear. Footwear can be pivotal in lower limb injuries and may need to be considered during the assessment process.

As discussed, an accurate diagnosis of pes anserine pathology-based solely on clinical testing can be challenging. Research has shown the necessity of diagnostic imaging to accurately diagnose the presence of a pes anserine pathology and differentiate whether there is a bursitis or a tendinopathy (or both) (Rennie et al, 2004). At your first session, a diagnostic ultrasound scan is carried out to provide this diagnostic clarity.

Other conditions can also cause pain on the inside of the knee in the same location as the pes anserine tendon and bursa. These include:

Your clinician will consider these conditions during your initial assessment.

Diagnostic ultrasound imaging

Diagnostic ultrasound imaging has been shown to be an excellent modality commonly used to assess the pes anserine tendon and bursa (Sarifakioglu et al,2016). Research has proven it to be as effective as MRI for the assessment of tendon pathology. Diagnostic ultrasound is also highly sensitive and specific at identifying the amount of inflammation present in your condition. This can help with predicting how long your condition will take to resolve and whether or not an ultrasound-guided injection is required.

Complete has a team of highly experienced clinicians who are fully qualified physiotherapists and musculoskeletal sonographers.

If you would like more information or would like to book an appointment, please contact us on 0207 4823875  or email injections@complete-physio.co.uk.

How is pes anserine tendinopathy/bursitis treated?

The majority of people with pes anserine pain respond very well to physiotherapy.

It is important to modify (reduce) your load/activity levels, i.e. those activities that make your pain worse. This does not normally mean you have to totally stop all exercises, for example, if you get pain whilst running, we would suggest you significantly reduce your running load and/or introduce a more non-impact activity such as cycling or swimming.

Physiotherapy treatment focuses on:

  • Reducing pain and inflammation – this may include advice on ice, medication, exercise and/or injection therapy.
  • Increasing knee joint range of movement – if there is a restriction of the joint into full flexion or extension, this must be restored.
  • Hamstring and adductor stretching – if you have a restriction (a good start is to compare your muscle length to the other side)
  • Lower limb muscle strengthening – this is a key element of most rehabilitation programmes and may involve strengthening the core, gluteal, quadriceps, hamstring and calf muscles.
  • Increasing lower limb balance and stability
  • Correct movement patterns during functional movements such as squatting and lunging
  • Correcting abnormalities present during walking and running gait patterns

physio treating patient with pes anserine tendinopathy

What can you do if my pain does not settle with physiotherapy treatment alone?

If your pain does not settle with conservative management, there are still some effective treatment modalities available to you:

Extracorporeal shockwave therapy (ESWT)

Shockwave therapy is an evidence-based treatment modality used to treat tendon pathology, and there is emerging evidence that it can be an effective tool in treating pes anserine tendinopathy (Khosrawi et al, 2017). It is important to establish if your pain is related more to the tendon or a bursa before considering shockwave therapy. Shockwave is more effective for tendon issues rather than a bursa issue. We always carry out a diagnostic ultrasound scan prior to administering shockwave to ensure it is the right treatment option for you.

Shockwave creates a series of repetitive high-pressure waves that produce a small dose of controlled microtrauma to the tendon. These soundwaves stimulate the healing process and initiate tendon repair. Often patients get an immediate reduction in pain due to desensitisation of the local nerve fibres. It has shown positive effects with shockwave and requires between 3-5 treatment sessions.

Shockwave is not a stand-alone treatment programme but works alongside a comprehensive physiotherapy programme. If you would like more information or would like to book an appointment, please contact us on 0207 4823875 or email injections@complete-physio.co.uk.

Ultrasound-guided corticosteroid injection.

If your pain is not improving despite physiotherapy input, then an ultrasound-guided steroid injection may be an appropriate treatment option for you. A corticosteroid is a strong anti-inflammatory injectable medication used to reduce pain and inflammation associated with persistent pain. An injection will provide a ‘window of opportunity’ for you to engage in a comprehensive rehabilitation programme with a physiotherapist.

A diagnostic ultrasound scan is used to guide a small amount of corticosteroid medication and local anaesthetic directly to the pes anserine bursa and/or tendon. All clinicians at Complete are very experienced in providing ultrasound-guided injections for this condition.

Ultrasound-guided injections have been clinically proven to be highly accurate and more effective at reducing pain and inflammation than landmark guided injections, i.e. with no needle guidance. At Complete, we believe it is essential these injections are ‘guided’ to ensure only one injection is required and to reduce any side effects to the surrounding tissues.

An ultrasound-guided injection should be considered for the following patients:

1. Patients where a diagnostic ultrasound reveals a significantly inflamed pes anserine bursitis. If this is the case, they respond very favourably to an ultrasound-guided steroid injection alongside physiotherapy. If you have failed to improve with physiotherapy or you are getting throbbing pain at night, this may indicate you have an inflamed bursa.

2. Pain not improving or getting worse with comprehensive physiotherapy input and a reduction in training/exercise.

3. Pain waking you up at night.

4. Severe pain with low load activities such as walking (i.e. the pain is effecting simple everyday tasks)

5. Pain preventing you from completing a very important race/competition, e.g. a marathon, and you do not have time, or the pain is not improving with physiotherapy. An injection will only be considered if taking part will not cause you any long term issues. If you have pain that arises in the last few months of marathon training, it is essential that you get a clear diagnosis as soon as possible to prevent wasting precious training weeks.

At Complete we are able to offer a same day service on all ultrasound-guided injections. All our clinicians are independent prescribers and can prescribe the most effective medication. On your initial assessment, we will complete a full clinical assessment and a diagnostic ultrasound prior to carrying an ultrasound-guided injection. You do not need a referral from your GP to access our service.

If you would like more information or would like to book an appointment, please contact us on 0207 4823875 or email injections@complete-physio.co.uk.

Related conditions, blogs and patient’s stories from our specialists

Our highly experienced team of expert clinicians have written a selection of blogs on various treatment methods for Pes anserine bursitis, some stories from patients that came to us seeking relief from their knee pain, as well as explanations of other knee conditions that might be causing your pain. Please take a look at any of the following links and get in touch with us if you think you are suffering from any of these conditions and may require treatment.

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