What is the patellar tendonitis?

Patellar tendonitis is an injury that affects the tendon connecting the patella (kneecap) to the tibia (shinbone). The patellar tendon helps muscles extend the lower leg so that the leg can be straightened and support the body’s weight with walking or jumping. It is most common in an athlete whose sport involves frequent jumping, such as basketball, soccer and volleyball. Because of this, patellar tendonitis is commonly known as jumper's knee, but in reality anybody can experience patellar tendonitis especially if the tendon is stressed through overuse, lack of conditioning and stretching, or because of obesity.
Patellar tendonitis is defined by inflammation in the patellar tendon, generally below the kneecap. The most common cause is overuse or repetitive injury, and it has been reported to occur in athletes of virtually every sport.  With repetitive jumping, microscopic tearing and injury of the tendon can occur, leading to inflammation and localized pain.

What are the symptoms of patellar tendonitis?

The diagnosis of patellar tendonitis is fairly straightforward. Pain can be reproduced by applying gentle pressure with the fingertips to the area of inflammation and injury. This is most common near where the patella (kneecap) meets the tendon, but can occur anywhere along the course of the tendon. Compared to the opposite, normal knee, the tendon will often appear swollen and often warm to the touch. Depending on the severity, the person may have significant pain with jumping or kneeling. Walking up and down stairs can also worsen the pain.

What are the causes of patellar tendonitis?

Factors that may increase the risk of this injury include:

• Overuse, particularly with recurrent jumping activities.
• Inadequate conditioning or stretching can increase strain on the patellar tendon and increase the risk of injury.
• Obesity – small increases in weight place dramatically increased stress on the kneecap and extensor mechanism. In fact, a gain of one pound can manifest as 8 to 10 more pounds of force on the knee with certain activities.
• Patella alta – a “higher than normal” kneecap position may increase the strain and risk of injury to the patellar tendon.

How is it treated?

Early stages may be treated conservatively using rest, ice, compression, and elevation (RICE).  A physical therapist may also recommend specific exercises and stretches to strengthen the muscles and tendons. Gentle stretching and strengthening exercises are encouraged. These exercises help to restore the normal length-tension relationship or the muscles and tendons.  It is very important for athletes to learn proper jumping and landing techniques, and to strengthen the muscles around the kneecap to reduce the forces on the tendon itself. Eccentric strengthening exercises can be effective in treating patellar tendonitis.  Taping or use of a patellar tendon “strap” brace has often provided significant relief although the success is quite variable.

It is critical that the patient avoid the activities that are causing pain. Typically, this means ceasing competition and a period of rest from running and jumping activities. This will decrease the strain and prevent recurrent injury to the tendon. 

If you have knee pain and it persists or worsens over time; of if the knee joint appears swollen or red, you should consult a health care professional. In chronic cases, effective treatment can help return a person to full mobility and functioning.  Trying to ignore or work through the pain can lead to further injury and increase the amount of time necessary for treatment and recovery.

Additional Resources
Patellar Tendonitis - Jumpers Knee, SportsMD.com
What is Patellar Tendonitis, About.com Orthopedics
Patellar Tendonitis, Institute for Sports Medicine