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Patellofemoral Pain Syndrome

What is Patellofemoral Pain Syndrome

Knee pain is a very common problem in teenagers and young adults. Most knee problems in this age group are related to the facts that teens are growing rapidly and tend to be very physically active. In the “patello-femoral pain syndrome,” or PFPS, the kneecap (patella) rubs against the end of the thigh bone (femur) and causes pain. The patella is a bone that lives inside a tendon. That tendon connects the big thigh muscles to the top part of the lower leg. The patella works a little like a pulley, and lets the tendon slide easily over the knee joint. Sports, dancing, and other activities in which the teenager uses the thigh muscles a lot can put enough pressure on the patella to cause the pain.

Scientists aren’t sure exactly what causes the PFPS. It is possible that the rapid growth in adolescence and the changing angle of the hip, thigh, and knee cause the patella to rub against the femur. This theory would explain why PFPS is more common in teen girls than boys, because young women’s hips widen during puberty. It is also possible that the kinds of sports women engage in may be more likely to cause PFPS.

People with PFPS usually have pain along the lower edge of their patella and/or along the line of the knee joint itself. There is usually very little swelling or redness, which can make parents or coaches skeptical of the amount of pain present. The pain is often worse with activities like jumping, walking or running downhill, or going down stairs. The doctor may be able to find a small amount of fluid underneath the patella when s/he does the examination. People with PFPS may develop a limp, but the knee joint itself remains strong, and the knee does not usually “give out” suddenly.

What is the biggest concern?

PFPS is not a dangerous condition. The two biggest concerns are pain and the possibility that the teenager may injure a different body part while trying to protect the painful knee. Of course, it is also important to be sure that PFPS is the correct diagnosis, so that a more serious condition is not missed.

Patellofemoral Pain Syndrome treatment

More than 80% of people with PFPS do not need surgery for successful treatment. Doctors and athletic trainers have a variety of opinions about the best treatment. All agree that the first thing to do once the doctor has diagnosed PFPS is to rest the knee for 5 -7 days. This can be a challenge for a competitive young athlete. Often the best approach is to help the athlete remember that the team would be happier to have him or her back in tip-top shape so that s/he can help the team win. Coming back too soon may seem heroic to the player, but it can actually let the team down very badly if the athlete isn’t at his or her best.

Along with rest, an anti-inflammatory and anti-pain medication is important. Ibuprofen (Advil® or Motrin®) is still the most effective and safest of the drugs called “non-steroidal anti-inflammatory drugs,” or NSAIDs. Please remind your teen that these drugs are not just painkillers. They are very effective at reducing the swelling and inflammation of an athletic injury. This speeds healing and reduces pain at the same time. These medicines only work well if the athlete takes them regularly on a schedule. “As needed for pain” is the worst possible way to use these medicines. Please check with your doctor for the recommended dose. Most athletes over 100 pounds can take 600 – 800 mg of ibuprofen (3 -4 of the 200 mg over-the-counter pills) every 6 hours for at least 5 days without problems. High doses of ibuprofen can cause stomach pain. If this happens please try cutting back the dose, or using an antacid like Maalox or Mylanta along with the medication.

During the resting phase of treatment, your teen may need to use crutches. Please read our article on Fractures/Cast Care and Crutches. During this phase your teen should remain out of all athletic activity, including gym class.

After the rest phase, the pain should be markedly improved. This usually happens about a week after starting the rest phase. Your teen can then begin a controlled knee exercise program and modified activity. Some experts recommend knee taping in addition to or instead of the exercise program. Please discuss exercise vs. taping and activity limitations in this phase with your teen’s doctor and his or her coach or trainer.

If your physician or trainer recommends knee exercises, please have your teen do them for about the same amount of time every day as instructed. The idea is to increase the upper leg muscles’ strength to restore a balance. For the first week of this phase, please have your athlete sit on a chair or couch and simply extend each leg, one at a time, in sets of 12. Do three sets with each leg. It may help to hold the leg straight for a few seconds before relaxing. At this stage, do not add any weight to the legs. If your doctor has recommended continuing the medication, it is important to remember to do that as well. After a week of no-weight exercise, add one ankle weight of 2.5 pounds (about 1 kg) to each ankle. Continue the exercises as recommended. Your doctor and trainer will work with you to increase the weight as needed. Please remember that this is not a “bulking” exercise, so large amounts of weight are not the goal!

After several weeks of exercise, you and your athlete should discuss his or her progress with the doctor and coach/trainer. With good relief of pain and normal function, your teen should be able to return to normal activity within 4-6 weeks, depending on how severe the original pain was. After this, the coach/trainer may recommend continuing the regular knee exercises as part of an overall training program. This can help prevent a recurrence of the PFPS.

When should I be worried?

PFPS is not a dangerous condition. The main things to be worried about are ensuring that your teen takes his or her medication reliably and that s/he does the recommended exercise or taping. In some cases, more serious conditions can be present instead of or in addition to PFPS. Here are a few things to look out for:

  • Pain that gets worse despite rest and medication
  • Marked swelling of the knee, or any redness or spreading tenderness
  • A feeling of “crunching” or “crackling” with movement of the knee
  • Fever
  • Complete inability to walk
  • Swelling of the area below the knee
  • Pain or swelling in the groin

If any of these occur, please be sure to call your doctor’s office right away.

Other points of concern

Teens, and particularly athletes, often want to rush back into activity as soon as they can. It will be important for you and your teen to work out a sensible and realistic plan for getting back into the game or activity. Although it will feel like the end of his or her career, chances are your athlete or dancer will only need to be out for a few weeks. It may help to work with the coach, trainer, or instructor to find ways that your teen can still participate in ways that help the team or troupe, but don’t put the knee at risk. Please remind your teen that it is very easy to injure another body part by trying to be vigorously active with a known injury. The last thing that will help is an ankle sprain or wrist fracture as a result of working out hard with a minor knee condition.

Other Conditions that Might Be Present with Patellofemoral Pain Syndrome

The knee is a simple joint with a big responsibility for bearing most of the brunt of physical activity.  Some common causes of knee pain that can occur in children and teens include:

  • “Osgood-Schlatter Syndrome” – this is a painful swelling of the cartilage and bone just below the knee. Much of the treatment is similar except for the exercise regimen.
  • “Chondro-malacia Patellae” (konn-droe-mal-ae-she-uh Pah-tell-eye) is a softening and breakdown of cartilage on the back of the patella. This causes pain when it slides over the end of the thigh bone. This condition often causes crackling or a feeling of rubbing in the joint, and there is often swelling. An MRI scan makes the diagnosis.
  • Knee sprains or torn ligaments – these are injuries that usually have an easily identifiable cause. They are very painful right at the moment of an injury such as a blow to the knee from the side, or a twisting injury. The athlete or dancer usually feels a “pop” or “click” as the injury happens. These injuries often make it hard or impossible to bear weight on the leg, and they usually cause a good deal of swelling.
  • Dislocation of the patella means that the patella is actually pushed off to one side, and won’t slide in its normal groove. This is extremely painful and usually quite obvious when there’s a bulge in the skin at the knee.
  • Infections – skin and fat infections, called “cellulitis,” as well as bone infections can cause knee pain and swelling. There’s usually a lot of redness and heat at the joint, and the child or teen may run a fever. People with these infections feel generally ill. Bone and joint infections are quite serious, so if you become concerned about these, please call your doctor right away.