Patellofemoral pain syndrome (PFPS) is a common cause of knee pain in athletes, particularly young women and those who are involved in running. The pain is felt around or behind the kneecap, and is often of gradual onset unless trauma is involved. There is increased pain with prolonged sitting (knee flexion), stair climbing, squatting, running, kneeling and jumping. Generally there is no swelling around the knee cap, nor is there any pain in the patella tendon or surrounding ligaments.
PFPS is usually a functional problem rather than a structural one. It has to be differentiated from another patella condition, chondromalacia, which is the wearing down of the cartilage under the knee cap, and may accompany PFPS. The causes are multifactorial and can be broken down into three categories:
Biomechanical, or patellar tracking problems, are caused by lower extremity malalignment, which pulls the patella out of its groove. Factors such as flat feet which cause the knee to internally rotate (knock knees) and wider Q angles of the hip, which are more common in women, contribute to PFPS. A “J” sign can be seen with lateral patellar tracking, as the knee is extended from 90 degrees of flexion to full extension.
Muscular imbalance is another factor, with weak quad muscles (particularly the medial quad) and a tight iliotibial band and hamstring, as well as weak hip extensors/abductors and tight hip flexors. Overuse or overload of the patella caused by repeated weight bearing impact, such as with running, is also a contributing factor in PFPS.
Conservative treatment is multipronged, based on the underlying reasons for the PFPS. Relative rest from aggravating activity (running) to another non impact activity (swimming, elliptical); icing after activity; cold laser therapy to reduce pain/inflammation and heal the tissue; taping or a knee brace with a U shaped insert to keep the patella in alignment; orthotics to help support the arch; and specific exercises to strengthen weak muscles (quads and gluts) and stretch tight muscles (TFL ,hams and psoas). Rarely surgery is indicated, but true chondromalacia may be amenable to arthroscopic surgery to smooth out the cartilage under the knee cap, and lateral retinaculum release if the problem is caused by excessive lateral pulling.
