Injury of the Month: Patella Tendinitis

Mike Dee, P.T., C.Ped.
Posted November 1st, 1999

Who gets it?
Runners, skiers, skaters, hikers, and any athlete who has to bend their knee repeatedly to play their sport can develop patella tendinitis.  It is more prevalent in adolescent girls involved in running, gymnastics and figure skating.  Long-distance runners are more prone to it than short-distance runners, and telemark skiers are more likely to get it than alpine or cross-country skiers.
Faulty patella mechanics is the overall cause of patella tendinitis.  The normal patella sits in a groove in the distal end of the femur.  The tendon leaves the bottom of the patella and angles slightly away from the midline of the body as it attaches to the top of the tibia.  If the patella does not sit in the groove properly, or if the angle of the tendon is too sharp, the tendon can become irritated with repeated forceful loading during a sport.  Sometimes the tendon is too long, when compared to the patella, and this also leads to tendinitis.  The long tendon is referred to as Patella Alta.
The adolescent girl, because of her changing boney alignment, often becomes “knock-kneed.”  This causes the tendon to angle out sharply.  It is this angle that causes non-uniform loading on the tendon which in turn leads to tissue breakdown and inflammation.  The long-distance runner may have subtle mechanical abnormalities, such as leg length difference or Patella Alta that irritate the tendon solely because of the repetitive nature of running.  A tennis player may have the same biomechanics yet not develop these symptoms.
Telemark skiing loads the patella tendon with great force and at very unusual angles, and is an obvious cause of patella tendinitis.  This usually happens to the novice telemarker as their technique is still developing.  The same is true for novice alpine and cross-country skiers, but it does not occur as frequently or intensely.
Pain below the kneecap and on the tendon which is always worse with exertion is the distinguishing characteristic of patella tendinitis.  The pain can linger after sports, but is usually painless at rest.  Standing up or sitting down are unpleasant reminders that there is something wrong.  If there is a lot of pain at rest and extreme tenderness to touch, you may have an inflamed bursa (bursitis) of the knee.  Pain felt under the kneecap may be an irritation of the patella’s cartilage and not tendinitis.
Treatment and
Preventing patella tendinitis may require the trained eye of a professional who treats athletes for their injuries.  A thorough exam of the biomechanics of the lower extremities should be done.  This exam evaluates posture, functional movements, joint motion, strength, and flexibility.  Recommendations can include specific exercises for the torso, hip, knee, foot, and ankle, proper footwear, and devices such as a knee strap or orthotics.  Runners should avoid running on the edge of the road since the road’s camber causes the uphill leg to function as a longer leg.  This often results in a knock-kneed stance.  A general rule for good prevention are good stretching and strengthening exercises.
Treating patella tendinitis requires active rest, which allows the athlete to remain active while avoiding any irritation to the inflamed tissue.  Runners should ride their bikes—make sure the saddle is not too low.  Other athletes should also try cycling, or decrease the intensity of their sport and focus on pain-free strengthening and stretching.  Ice, oral anti-inflammatories, and a kneesleeve or CHO-PAT knee strap should help.  Return to your sport once you can tolerate more aggressive strengthening.  If symptoms persist, seek medical advice and make sure you get a detailed exam of your training habits as well as your lower extremity biomechanics.  A thorough rehabilitation program properly administered is a sure cure for most cases of patella tendinitis.Patella Tendinitis is an inflammation of the knee’s patella tendon.  Tendons typically connect muscle to bone, however, in the case of the patella “tendon,” it connects bone to bone, which is what ligaments do.  Somewhere along the history of medical jargon, in the case of the patella tendon, the terms were interchanged and remain that way today.
The patella tendon originates on the bottom of the patella (knee cap) and attaches at the top of the tibia.  It acts like the rope of a pulley as it controls the tibia during knee motion.  Abnormal wear and tear irritates the tendon, resulting in inflammation.