Patellar tendinitis is an injury to the tendon connecting your kneecap (patella) to your shinbone. The patellar tendon works with the muscles at the front of your thigh to extend your knee so you can kick, run and jump.
Patellar tendinitis, also known as jumper's knee, is most common in athletes whose sports involve frequent jumping — such as basketball and volleyball. However, even people who don't participate in jumping sports can get patellar tendinitis.
For most people, treatment of patellar tendinitis begins with physical therapy to stretch and strengthen the muscles around the knee.
Pain is the first symptom of patellar tendinitis, usually between your kneecap and where the tendon attaches to your shinbone (tibia).
The pain in your knee may:
- At first be present only as you begin physical activity or just after an intense workout
- Worsen until it interferes with playing your sport
- Eventually interfere with daily movements such as climbing stairs or rising from a chair
When to see a doctor
For knee pain, try self-care measures first, such as icing the area and temporarily reducing or avoiding activities that trigger your symptoms.
Call your doctor if your pain:
- Continues or worsens
- Interferes with your ability to perform routine daily activities
- Is associated with swelling or redness about the joint
Patellar tendinitis is a common overuse injury, caused by repeated stress on your patellar tendon. The stress results in tiny tears in the tendon, which your body attempts to repair. But as the tears in the tendon multiply, they cause pain from inflammation and weakening of the tendon. When this tendon damage persists for more than a few weeks, it's called tendinopathy.
A combination of factors may contribute to the development of patellar tendinitis, including:
- Physical activity. Running and jumping are most commonly associated with patellar tendinitis. Sudden increases in how hard or how often you engage in the activity also add stress on the tendon, as can changing your running shoes.
- Tight leg muscles. Tight thigh muscles (quadriceps) and hamstrings, which run up the back of your thighs, can increase strain on your patellar tendon.
- Muscular imbalance. If some muscles in your legs are much stronger than others, the stronger muscles could pull harder on your patellar tendon. This uneven pull could cause tendinitis.
If you try to work through your pain, ignoring your body's warning signs, you could cause increasingly larger tears in the patellar tendon. Knee pain and reduced function can persist if you don't tend to the problem, and you may progress to the more serious patellar tendinopathy.
Tests and diagnosis
During the exam, your doctor may apply pressure to parts of your knee to determine where you hurt. Usually, pain from patellar tendinitis is on the front part of your knee, just below your kneecap.
Your doctor may suggest one or more of the following imaging tests:
- X-rays. X-rays help to exclude other bone problems that can cause knee pain.
- Ultrasound. This test uses sound waves to create an image of your knee, revealing tears in your patellar tendon.
- Magnetic resonance imaging (MRI). MRI uses a magnetic field and radio waves to create detailed images that can reveal subtle changes in the patellar tendon.
Treatments and drugs
Doctors typically begin with less invasive treatments before considering other options, such as surgery.
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.
A variety of physical therapy techniques can help reduce the symptoms associated with patellar tendinitis, including:
- Stretching exercises. Regular, steady stretching exercises can reduce muscle spasm and help lengthen the muscle-tendon unit. Don't bounce during your stretch.
- Strengthening exercises. Weak thigh muscles contribute to the strain on your patellar tendon. Exercises that involve lowering your leg very slowly after extending it are particularly helpful.
- Patellar tendon strap. A strap that applies pressure to your patellar tendon can help to distribute force away from the tendon and direct it through the strap instead. This may help relieve pain.
- Iontophoresis. This therapy involves spreading a corticosteroid medicine on your skin and then using a device that delivers a low electrical charge to push the medication through your skin.
Surgical and other procedures
If conservative treatments don't help, your doctor may suggest other therapies, such as:
- 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. In rare cases, if other treatments fail, your doctor might suggest surgical repair of the patellar tendon. Some procedures can be done through small incisions around your knee.
Lifestyle and home remedies
If your knee hurts, consider the following:
- Pain relievers. Over-the-counter medications such as ibuprofen and naproxen sodium may provide short-term pain relief.
- Avoid activity that causes pain. You may need to practice your sport less often or temporarily switch to a lower impact sport. Working through pain can further damage your patellar tendon.
- Ice. Apply ice after activity that causes pain. Place ice in a plastic bag and wrap the bag in a towel. Or try an ice massage. Freeze water in a plastic foam cup and hold the cup as you apply the ice directly to your skin.
To reduce your risk of developing patellar tendinitis, take these steps:
- Don't play through pain. As soon as you notice exercise-related knee pain, ice the area and rest. Until your knee is pain-free, avoid activities that put stress on your patellar tendon.
- Strengthen your muscles. Strong thigh muscles are better able to handle the stresses that can cause patellar tendinitis. Eccentric exercises, which involve lowering your leg very slowly after extending your knee, are particularly helpful.
- Improve your technique. To be sure you're using your body correctly, consider taking lessons or getting professional instructions when starting a new sport or using exercise equipment.