Patellofemoral Pain Syndrome
Patellofemoral Pain Syndrome (PFPS) also known as runners knee, chondromalacia patellae, anterior knee pain and patellofemoral joint syndrome is a generic term used to describe pain at the front of the knee and around the knee cap.
Symptoms include an aching pain in the knee joint, particularly at the front of the knee around and under the patella. There is often tenderness along the inside border of the kneecap and swelling will sometimes occur after exercise. Patellofemoral pain is often worse when walking up and down hills or sitting for long periods of time.
Other signs a sports medical practitioner may pick up include a click or cracking sound when bending the knee, wasting of the quadriceps muscles if the injury is an old one and tight muscles around the knee joint.
Read more on symptoms and diagnosis.
What is patellofemoral pain?
Patellofemoral pain syndrome occurs when the patella (kneecap) rubs on the femur bone underneath. It is often thought that incorrect tracking or rubbing of the patella over the femur bone is a significant factor and results in damage or irritation of the articular cartilage underneath the patella.
Patellofemoral pain is common in people who do a lot of sport and in particular adolescent girls. It can have a number of causes but damage to the cartilage itself cannot directly cause pain because there are no blood vessels or nerves involved. However it can lead onto other problems which in turn result in pain. These include synovitis (inflammation of the synovial membrane or joint lining), erosion of the cartilage and bone under the patella, soft tissues injury or irritation for example to the lateral retinaculum and the infra patella fat pad.
The initial cause of patellofemoral pain syndrome is likely to be overuse. This may be from external factors for example a sudden increase in training, or performing high intensity jumping and knee bending, or it can be from internal factors such as poor patella tracking. Identifying the cause is and important part of treatment.
Read more on causes and prevention.
Treatment and rehabilitation is based around reducing pain, identifying the causes and strengthening or re-training muscles which may have contributed to the injury. Apply PRICE principles of protection, rest, ice, compression and elevation after activity to help reduce pain and swelling. Rest completely from aggravating activities until there is no pain.
Wearing a patella tracking knee brace or support may help. These usually have a hole in the middle for the kneecap and straps which are pulled across the knee applying support to the patella. A patella taping technique is excellent for helping to control the position of the patella and relive symptoms.
A professional practitioner can confirm the diagnosis and rule out other conditions which may have similar symptoms such as a synovial plica. A doctor may prescribe anti-inflammatory medication such as ibuprofen which should not be taken if you have asthma.
Sports massage can help loosen tight structures and muscles which may be contributing. Gait analysis can also be done to determine if the athlete overpronates and orthotic inserts can correct poor foot biomechanics. In chronic cases a surgeon may operate to release the tight lateral structures of the knee although there is little evidence as to the success of surgery.
Read more on treatment and rehabilitation.
Depending on what is causing the patella pain exercises to strengthen the muscles on the inside of the thigh are usually recommended. In particular heel drop exercises can strengthen the vastus medialis muscle on the inside of the thigh. This is an important muscle for controlling patella tracking and is often weak in athletes with patellofemoral pain. Thigh stretching exercises are also important as the muscles on the outside of the thigh (vastus lateralis muscle) is often tight.
Read more on exercises.