The fast facts:
- One of the most common causes of frontal knee pain
- Women are more likely to develop pfps
- The pain is aggravated by bending the knee
- Extending the knee is often painless
- A patellar femoral pain syndrome is present in 15% of all people presenting to the general practitioner with knee problems
- Reduced strength in the hip can potentially cause patellar femoral pain syndrome
- Training in an open chain is recommended in patellar femoral pain syndrome(more later)
- Patella femoral complaints last an average of 12 months
- In general, the PFPS is common in adolescents and teenagers
Patella femoral pain syndrome
Patellar femoral pain syndrome is a collective term for various complaints at the front of the knee, around the patella, or kneecap. The pain is located at the front of the knee and is triggered by activities such as climbing stairs, cycling or sitting for long periods with a bent knee (driving a car or sitting at a desk). The complaints often arise gradually. Patellar femoral pain syndrome is more common in young women of puberty. The reason is still unclear but it probably has to do with hormonal changes in the body together with overloading of the knee. This means that the load on the knee has (temporarily) been greater than the load capacity. Some examples are the start of the season, untrained, but also for example by illness or simply a longer vacation. The result is sensitivity of the knee. Previous injuries to the knee also often play a role in the development of patellar femoral complaints. The symptoms are often intermittent. Pain-free periods alternate with provocation of symptoms. Often the complaints are on one side. In some cases, both sides. One side is often more painful than the other knee.
Anatomy and function of the knee joint
A joint is a place in the body where two parts of the bone meet. In the knee, this is the femur (upper leg) and the tibia (lower leg). The patella (knee cap) also forms a joint with the femur. Between these bone parts is cartilage which has a very smooth surface so that it can move smoothly. In order to steer the knee joint properly, there are different types of ligaments in and around the knee. On the inside and outside are the collateral ligaments. Between the femur and tibia is the inner and outer meniscus which acts as a shock absorber between these two bone parts. In the knee is the anterior and posterior cruciate ligament. The anterior cruciate ligament provides passive stability. Ligaments, bones, capsules and the position of joints provide passive stability you have no control over. Active stability is controlled by muscles and tendons. Here you do have control. The active and passive stability together determine how stable a joint is.
Diagnosis of patella femoral pain syndrome
The diagnosis is often made based on the information from the interview, current symptoms and additional physical examination. Imaging studies such as an X-ray or MRI are not necessary and do not add anything. Also, various risk factors that may maintain the symptoms are identified. Risk factors in patellar femoral pain syndrome are:
- Reduced strength of the hip muscles
- Abnormal position of the knee
- Reduced strength of the upper leg muscles
- Decreased general fitness
- Previous knee injury
We use various physical tests to assess the function or pain provocation of the patellar femoral joint:
Lateral and medial glide test: tij During this test, the physical therapist moves the kneecap from left to right. The patient has the knee in a stretched position on the bench. The degree of mobility of the kneecap is assessed.
Patella apprehension: the kneecap is pushed to the outside by the examiner. With patella femoral complaints this is often experienced as unpleasant. The person will want to stop this by tightening the muscles vigorously.
Patella tilt: dhe person lies in the supine position on the couch. The physical therapist tilts the kneecap inward. Thus, the kneecap comes upward on the outside and will provide compression to the inside of the knee. The structures that run on the outside of the knee are especially tested for stiffness.
Decline squat test: While the person is standing on an incline on two legs, a squat is performed. The test is positive when there is recognizable pain in the knee. The incline puts more pressure on the kneecap resulting in faster provocation of the area to be examined than when a squat is performed without an incline.
The treatment of patellar femoral pain syndrome
Successful rehabilitation consists of several phases and steps. Good strength, stability and control of the knee is necessary to safely return to your daily activities and sports. Exercise therapy is most effective in the treatment of patellar femoral complaints. There must be a proper balance between adequate rest, adjustments in daily activities and training. Often a structural improvement is noticeable within 12 weeks. In a few cases it will help to tape the kneecap. This is mainly a short-term effect. During the first phase of the treatment it is not recommended to continue playing sports. Some pain may even be felt during exercise but should subside at rest. An average pain score of 3 on a scale of 0-10 is acceptable. However, the pain should not increase from day to day. If you have more pain during the day as a result of the treatments, you should take a step back. In time, when the leg gets stronger, you can start doing your sport again. In the meantime there is more of a build up in strength and function of the muscles around the knee. The last phase focuses mainly on maximum strength, jumping power and explosiveness. This is all necessary to be able to change direction quickly within your sport. We also work towards a competition condition so that you can continue to perform under fatigue. The quality of movement must remain good under these conditions.