Although less common than patellar tendonitis, quadriceps tendonitis is an important cause of quad pain above kneecap. So, how do we diagnose quadriceps tendon pain, and what can we do about it?

What is the quadriceps tendon? 

knee joint

The quadriceps tendon attaches the large quadriceps muscle to the top of the kneecap (or patella). This large tendon transfers forces from the lower leg and foot to the trunk, like the patellar tendon. 

Causes of quadriceps tendonitis 

Like the Achilles and patellar tendons, the large quadriceps tendon undergoes swelling and collagen breakdown when subjected to an excessive load. Usually, we see quadriceps tendon pain in popular jumping sports such as CrossFit, rugby, and volleyball. Generally, there is a history of a sudden increase in training frequency or intensity, which can lead to quad tendon swelling and breakdown. Additionally, we observe this condition in older, active individuals with calcification of the quadriceps tendon. We know that calcification can cause pain and irritation in the quadriceps tendon.

In some cases of quadriceps tendinopathy, the tendon swelling is caused by a suprapatellar plica. This plica can block the movement of knee fluid, resulting in pressure in the upper part of the knee. This pressure can lead to swelling of the quadriceps tendon and tendonitis. In an observational study co-authored by Dr Masci, seven active athletes with intractable quadriceps tendonitis underwent arthroscopic surgery. All seven cases had a large suprapatellar plica, which separated the suprapatellar pouch from the rest of the knee joint. We suspect that a sizable suprapatellar plica, which separates the top from the bottom, leads to a buildup of pressure in the knee joint. We hypothesise that higher pressure in the knee joint leads to altered forces on the quadriceps tendon, increasing the risk of tendonitis. 

Diagnosis of quad tendonitis

Generally, common symptoms of quadriceps tendon pain include:

  • Quad pain above the kneecap that is worse during and after activity.
  • Often, there is no swelling, locking, or giving away of the knee.
  • It is often tender to touch the quadriceps tendon.

Your doctor will perform a clinical examination to rule out other causes of pain above the kneecap or at the front of the knee, such as kneecap arthritis, fat pad impingement, torn meniscus, pes bursitis,  housemaid’s knee, and patellar tendonitis.

Often, we use imaging to diagnose quad tendonitis and rule out other causes. Usually, ultrasound and MRI scans can detect changes in swelling and collagen breakdown of the tendon. Ultrasound has advantages over MRI scans, including the ability to see calcification more clearly and at a lower cost.

Treatment 

patellar tendonitis

Overall, we use simple treatments first for this condition. Some treatments include activity modification (reducing jumping training), soft tissue massage to the leg, anti-inflammatory tablets such as ibuprofen, and strengthening exercises.

Quadriceps tendonitis exercises

Generally, strengthening exercises that target the quadriceps muscle can help alleviate knee pain above the knee. A physical therapist should supervise these exercises. Exercises for quadriceps tendonitis include weighted squats, lunges, hack squats, leg press and leg extensions. Generally, we recommend single-leg exercises over double-leg exercises.

If simple treatments fail, we often use other therapies to help. These different treatments include GTN patches, shockwave therapy, or tendon injections.

Shockwave and needle tenotomy injections are particularly effective if calcification occurs in the quadriceps tendon. 

Ultimately, surgery should be reserved for cases that have failed all other treatments. Open tendon surgery to remove degenerative tendons is often unsuccessful. Other options include knee arthroscopy to excise a suprapatellar plica. A recent observational study found that seven athletes with intractable quadriceps tendonitis had a large suprapatellar plica. Removal of the plica resulted in significantly improved symptoms and a full return to sports. We recommend considering arthroscopy for intractable quadriceps tendonitis that has not responded to other treatments.  

More on injections for quadriceps tendonitis 

Injections for quadriceps tendons are invasive treatments and introduce an element of risk and unpredictability. While injections can help with complex cases of quad pain above the knee, they should only be performed after you have tried non-invasive treatments, such as exercise and shockwave therapy.

There are a few options for injection therapy.

Cortisone injections are sometimes harmful and should be avoided. Needle tenotomy is thought to stimulate inflammation and encourage healing. Finally, some doctors use platelet-rich plasma to promote healing. However, while there is some evidence to support PRP treatment for tennis elbow, there is limited evidence to support its use for quad pain above the kneecap.

Generally, we recommend a needle tenotomy for quadriceps tendon calcification to break down the calcification. Sometimes, we use a small dose of cortisone to help dissolve the calcification after needle breakdown.

Ususally, we recommend using ultrasound to improve accuracy and ensure the injection hits the right spot.

How Do We Manage Quadriceps Tendon Tears? 

Quadiceps tendon tears usually occur after acute trauma such as a fall or explosive movement. Generally, the treatment for a complete tear is acute tendon repair. However, partial tears are usually treated with rehab supplemented by PRP injections if needed. 

Final word from Sportdoctorlondon about Quadriceps Tendonitis

Quadriceps tendonitis is a less common cause of pain at the front of the knee. Often, there is focal quad pain above the knee. Nevertheless, the treatment of this condition follows the general principles of tendon treatment. We suggest GTN patches or shockwave therapy, followed by injections in complex cases. Surgery is only a last resort.

Related conditions:

Dr Masci is a specialist sports doctor in London. 

He specialises in muscle, tendon and joint injuries.