Patellar tendonitis, also known as Jumpers Knee, is caused by damage to the patella tendon just below the kneecap.
Repetitive sporting activities such as kicking and jumping place a large amount of strain on the tendon resulting in microscopic tears, inflammation and the gradual onset and progression of pain. Effective treatment is vital to prevent patellar tendinitis from deteriorating until the tendon ruptures completely.
The patella tendon is the most common place to develop knee tendonitis. It can be found at the front of the knee just under the kneecap and it attaches the quad muscles to the top of the shin bone. The tendon is approximately 2cm wide, is extremely strong and its job is to work with the quadricep muscles to straighten the leg.
Here, we will look at the common causes, symptoms, stages and treatment options for Patellar Tendonitis.
Common Causes of Jumpers Knee
Patellar tendonitis develops when there is repeated excess force placed on the patella tendon, usually during sports. Kicking places a force approx 7x bodyweight on the tendon. The largest force placed on the tendon is during jumping and landing, approx 10x body weight. To be able to jump, the quads work with the calf muscles to propel the body off the ground and during landing, the quads work to stabilise the leg.
Patellar Tendonitis develops when there is excessive force on the tendon causing irritatio
If someone is doing lots of kicking or jumping, e.g. sports players, the strain on the patella tendon becomes too great and microscopic tears develop in the tendon. This may not cause pain initially, but as it progresses, the knee will get gradually more and more painful.
These microscopic tears make the tendon less strong and therefore prone to further damage. The tendon may even completely tear with severe patellar tendonitis.
Patellar Tendonitis Symptoms
Patellar tendinitis usually comes on gradually over time, rather than being caused by a specific incident. The most common symptoms are:
1) Pain just below the knee cap with activity e.g. jumping, running, squatting
2) Pain with any pressure through the tendon e.g. touch, kneeling
3) Aching and stiffness after activity
4) Stiffness in the morning
5) Thickening of the tendon
Jumpers Knee is often misdiagnosed as Runners Knee, Osgood Schlatters or Chondromalacia Patella, but the most defining characteristic of Patellar Tendonitis is tenderness when you press on the patella tendon, just below the kneecap.
Stages of Patella Tendonitis
Patella tendonitis can be classified into 4 stages:
Stage 1: Pain only after activity which doesn’t affect function
Stage 2: Pain with initial activity that disappears as you warm up, but returns after activity. Performance is not usually affected.
Stage 3: Prolonged pain during and after activity with increasing difficulty performing at a satisfactory level
Stage 4: Complete tear of the tendon requiring surgical repair
Inflammation or Degeneration?
It used to be thought that inflammation was the main cause of Jumpers Knee, hence the name patellar tendonitis (itis = inflammation). However, recent studies have shown that an inflammatory response is actually very rare. It is more common to have degeneration of the tendon, so it is now often referred to as Patellar Tendonosis (osis means degeneration). This explains why non-steroidal anti-inflammatories like ibuprofen usually have little effect on the symptoms of patella tendonitis and they can actually make things worse by slowing down healing.
The body heals Jumpers Knee by producing collagen that repairs the tissue damage, but it takes approx 3 months for the collagen to be laid down and mature to allow the tendon to return to full strength.
Treatment of Patella Tendonitis
There are a number of different treatment options for Patellar Tendonitis and people usually get the most benefit by using a combination of them:
Rest: Patellar tendonitis is one of those cases where the saying “no pain no gain” does NOT apply. It is really important to rest completely from any activity that causes pain to allow the tendon to heal. It may be up to 3 months before you can return to sports.
Immobilization. Your doctor may recommend you wear a knee immobilizer or brace. This will keep your knee straight to help it heal. You will most likely need crutches to help you avoid putting all of your weight on your leg. You can expect to be in a knee immobilizer or brace for 3 to 6 weeks.
Ice : Ice packs applied for 10-15 minutes every couple of hours, before and after activity can help to reduce pain. Visit the Ice Treatment section to find out how to safely and effectively use ice therapy and the ice wrap section for the best ways to apply ice.
Pain relievers such as ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve, others) may provide short-term relief from pain associated with patellar tendinitis.
Physical therapy. Specific exercises can restore strength and range of motion.
While you are wearing the brace, your doctor may recommend exercises to strengthen your quadriceps muscles. Straight-leg raises are often prescribed. As time goes on, your doctor or therapist will unlock your brace. This will allow you to move more freely with a greater range of motion. You will be prescribed more strengthening exercises as you heal.
Knee Straps: In the early stages of Jumpers Knee, knee straps can work really well to reduce the stress going through the patellar tendon and alleviate symptoms. They reduce the cross sectional area of the tendon and the pressure applied by the strap reduces the force going through the tendon. Visit the knee strap section to find out more about them, including recommendations based on users feedback.
exercise: Tightness in the hips, quads and hamstrings can contribute to Jumpers Knee so it is important to stretch these muscles out. Visit the knee stretches section for simple tests you can do to see if your muscles are tight and for different ways to stretch.
Eccentic Muscle Training: Studies have shown that eccentric muscle training (when the muscle lengthens as it works) is the most effective treatment for tendonopathies like Jumpers Knee. Click the link to find a detailed training programme.
Muscle strenghtening is an important part of the recovery process with Jumpers Knee
Muscle Strengthening: Weak glutes can affect the position of the knee and lead to increased force going through the patellar tendon. The simplest way to strengthen the glutes is through Clam and Bridging exercises – visit the knee strengthening section to find out more.
- Corticosteroid injection.An ultrasound-guided corticosteroid injection into the sheath around the patellar tendon may help relieve pain. But these types of drugs can also weaken tendons and make them more likely to rupture.
- Platelet-rich plasma injection.This type of injection has been tried in some people with chronic patellar tendon problems. Studies are ongoing. It is hoped the injections might promote new tissue formation and help heal tendon damage.
Surgery: If patellar tendonitis fails to resolve after 6-12 months of rehab, surgery is performed as a last resort. Surgery involves removing the degenerative tissue and looks to increase blood flow to the area to promote healing.
If the patellar tendon ruptures (tears completely), surgery is required to repair the tendon by sewing it back together. After surgery, careful rehabilitation is essential as the tendon will be weak and it usually takes 3-6 months of physical therapy to return to sports.