The Patellofemoral Foundation's Mission Statement

Striving to improve the quality of life
for individuals of all ages

affected by anterior knee pain.

Patellofemoral Syndrome

    What is it?

    Knee pain is one of the most common symptoms experienced by sports participants.  Studies have shown that patellofemoral pain syndrome comprises up to 50% of overuse injuries.  This syndrome is caused by irritation of the undersurface of the patella (kneecap) which, in its normal state, is smooth.  The irritation can lead to a roughening of the patella undersurface, a condition called chondromalacia.

    The patella is a moving part, gliding up and down in a groove in the femur (thigh bone).  The pain is caused by pressure between the patella and the groove in the femur.  As you bend your knee, you gradually increase the pressure and stress between the patella and the femur.  The irritation and roughening of the patella causes an inflammation which causes the pain.   Patellofemoral pain syndrome and chondromalacia are not arthritis.  Children and adolescents almost always grow out of this problem.

    Predisposing Factors

    • When the patella is not symmetrical in the femoral groove, there is an imbalance resulting in wear and tear.  An unsymmetrical kneecap is called "jockey cap" patella.  This condition can be identified on x-rays.

    • Overuse (especially downhill running)

    • Wide hips

    • Knock knees

    • Increased Q-Angle:  Constructed by drawing a line from the anterior iliac spine (a part of the pelvis) to the center of the patella, then to the center of the tibial tubercle (leg bone).  Greater than 21 degrees in females and 18 degrees in males is abnormal.

    • Tibial torsion (rotation of lower leg)

    • Flat (pronated) feet

    • Weak inner thigh muscles

    • Previous injury to the knee

    Treatment


    This is based on two principles: reducing the inflammation and improving the dynamics of the patella/femoral relationship.

    Rest

    When the knee is painful and swollen, you must rest it.  Let pain be your guide.  You are aggravating the condition if you continue activities while experiencing pain.  Mild discomfort or ache is not a problem but definite pain is cause for concern.


    Ice

    Apply an ice pack (frozen peas) to your knee for 15 minutes 2-3 times daily and after any sporting activities.  This reduces inflammation and pain.


    Medication

    Your doctor may rarely prescribe anti-inflammatory pills to reduce the inflammation.  This can be very important.


    Physiotherapy

    Various techniques can be used to reduce the inflammation.  Exercises can be used to stretch and strengthen the thigh muscles.   These muscles control the patella in the groove.  When thigh muscles are strong, the patella will move through the groove with less pressure.


    Surgery

    In some cases surgery may be indicated.   This is in the form of an arthroscopic examination (a look with a fiber optic light).  In some cases repositioning the patella is required.


    Adjustments


    The structure of your foot may also alter the patella/femoral relationship.  Some physicians may prescribe specific shoes or occasionally orthotics (shoe inserts) to help your problem.  New materials (Sorbothan, Spenco) have been designed to fit into your shoe to help absorb the impact as your foot hits the ground. 


    Sports

    There is very little pressure between the patella and the femur when the leg is straight or only slightly bent.  The best activities are ones that limit the knee to a range between 135 degrees (1/4 squat) and 180 degrees (straight).


    Good Sports

    These sports will be easiest on the knee:

    • Swimming (flutter kick, knees straight)
    • Slow jogging, walking
    • Skating
    • Cross-country skiing

    Questionable Sports

    These sports can be performed by some, but could cause problems to others:

    • Cycling (seat high and avoid hills)
    • Soccer
    • Baseball
    • Hockey
    • Skiing (downhill)
    • Tennis

    Bad Sports

    These sports are hard on the knees as they include deep knee bends.  These sports are most likely to aggravate your condition:

    • Volleyball
    • Basketball
    • Running (sprints, downhill)
    • Football
    • Racquetball
    • Squash

    Use your judgment.  When your knees hurt, avoid all but the good sports.  Total rest may be required.  When your knees get better after treatment, you should be able to enjoy all sports.

     

    This information is courtesy of Orthopedic Associates of Hartford.

     


    PATIENT Experiences

    Comments from an MD radiologist with patellofemoral pain
 


Patellofemoral Foundation,

P.O. Box 1761, Litchfield, CT 06579

(860) 549-8269