What is Patellofemoral dysfunction?
Patellofemoral dysfunction refers to pain that originates in the patellofemoral joint (between the knee cap and the thigh bone). It is common and is also referred to as “Anterior Knee Pain”. It may occur spontaneously although is not infrequently seen after a traumatic injury to the knee. The characteristic pain persists after the initial symptoms of the injury resolve. It may also occur after knee surgery. Although it may occur at any age, teenage females are the most commonly affected.
What causes patellofemoral dysfunction?
There are a number of factors that contribute to patellofemoral dysfunction. The pain comes from the knee cap moving abnormally in the groove on the thigh bone. This causes increased forces on the joint and results in pain. Factors that contribute include weakness of the thigh muscles, tightness of the muscles on the outer aspect or back of the thigh, and flat feet.
What are the symptoms?
The main symptom is pain which usually starts gradually and progressively worsens over time, often without any history of injury. Pain is localised under or around the knee cap, or the inside aspect of the knee. It is worse when walking downstairs, with prolonged sitting or when first getting up from a chair. Clicking or grinding of the knee cap is often present. Both knees may be affected. In its extreme form, patellofemoral dysfunction can lead to a dislocation of the knee cap.
How is patellofemoral dysfunction diagnosed?
Patellofemoral dysfunction is usually diagnosed on clinical examination. If the condition is prolonged or unusual, an MRI scan may be required to assess the knee joint.
Can patellofemoral dysfunction be treated without surgery?
Yes. Patellofemoral dysfunction is best treated non-surgically. Physiotherapy is the mainstay of treatment. The aim of physiotherapy is to assist in strengthening the thigh muscles, stretching the tight soft tissues and correcting other factors above and below the knee that contribute to the condition. The knee may be taped into the correct position to assist the knee cap to move more efficiently in the groove on the thigh bone. Although this physiotherapy program is very effective, it needs to be followed diligently for full recovery which may take more than 6 weeks.
Other non surgical treatments include ice packs and anti inflammatory medications to treat the symptoms of swelling and inflammation. The goal of treatment is a return to a desired level of activity without pain. Most patients need to refrain from activities that exacerbate the knee pain until strength and flexibility have improved. As symptoms resolve, return to normal sports is encouraged.
What operation may be beneficial?
In rare cases conservative treatment will not be sufficient to alleviate symptoms and surgical options may be considered. In cases where the knee cap continues to dislocate, an operation to release a tendon on the outside of the knee may be combined with other procedures to improve knee stability.