Patellofemoral Pain Syndrome
Patellofemoral Pain Syndrome (PFPS) is an umbrella term used to describe pain felt in the front of the knee. PFPS causes pain and stiffness around the knee that is felt especially when running, jumping and landing which can make it difficult to kneel down, climb stairs and perform other day to day activities. Whilst anyone can develop and suffer from PFPS, it is most common in people who participate in sport particularly females, young adults and elderly people.
PFPS can occur due to multiple causes due to the complexity of the joint and its structures. Essentially the knee joint consists of two major joints, the tibiofemoral joint and the patellofemoral joint.
Tibiofemoral Joint is where the femur (thigh bone) meets the tibia (shin bone)
Patellofemoral Joint is where the patella (kneecap), which is shaped like an upside-down triangle (called sesamoid bone), articulates with the femur which covers and protects the front (anterior articular surface) of the knee joint.
Structures of the Knee
The Patellofemoral Joint is supported by a number of soft tissue structures to make movement of the knee joint easier and efficient. These structures include ligaments, tendons, muscles, articular cartilage (which is a slippery substance that covers each end of the joint to allow bones to glide smoothly against each other to stop bone rubbing on bone). Another important element is the synovium or the synovial membrane which is a thin connective tissue that lines the inside of the joint capsule and it produces some fluid that lubricates the cartilage. In addition, just below the kneecap is fatty tissue called a fat pad which provides cushioning of the kneecap and it acts as a shock absorber.