- Patellofemoral pain syndrome (PFPS) is a broad term used to describe pain in the front of the knee and around the patella, or kneecap. It is sometimes called “runner’s knee” or “jumper’s knee” because it is common in people who participate in sports — especially females and young adults — but PFPS can occur in nonathletes, as well.
- The pain and stiffness caused by PFPS can make it difficult to climb stairs, kneel down, and perform other everyday activities.
- Patellofemoral pain syndrome occurs when nerves sense pain in the soft tissues and bone around the kneecap. These soft tissues include the tendons, the fat pad beneath the patella, and the synovial tissue that lines the knee joint.
- In some cases of patellofemoral pain, a condition called chondromalacia patella is present. Chondromalacia patella is the softening and breakdown of the articular cartilage on the underside of the kneecap. There are no nerves in articular cartilage — so damage to the cartilage itself cannot directly cause pain. It can, however, lead to inflammation of the synovium and pain in the underlying bone.
- The most common symptom of PFPS is a dull, aching pain in the front of the knee. This pain—which usually begins gradually and is frequently activity-related—may be present in one or both knees. Other common symptoms include:
- Pain during exercise and activities that repeatedly bend the knee, such as climbing stairs, running, jumping, or squatting
- Pain on the front of the knee after sitting for a long period of time with your knees bent, such as one does in a movie theater, in a car, or on an airplane
- Pain related to a change in activity level or intensity, playing surface, or equipment
- Popping or crackling sounds in your knee when climbing stairs or when standing up after prolonged sitting.
