Patellofemoral Instability

The patella is the thick bone known as the kneecap, and patellofemoral instability means that the patella moves out of position, most commonly causing the sufferer to feel that the knee is either very loose or that the kneecap itself is 'sliding away.' It is a common injury among physical athletes and people who do a lot of exercise.

Symptoms of Patellofemoral Instability

A strange feeling that the kneecap is loosened and may be moving uncomfortably in the wrong direction, often associated with the sensation that it is 'sliding away.' This primary symptom is regularly accompanied by sharp pain in the anterior (front) of the knee and inflammation (possibly reddening) in the area. If the patella becomes dislocated then this is called subluxation and is also linked to patellofemoral instability, as is full dislocation of the bone which can present over time if the injury is left untreated or you continue with your normal physical activities.

Causes of Patellofemoral Instability

Causes of patellofemoral instability are multiple and complex, but there are a few that involve faulty mechanisms in and around the knee. Patella alta means that the patella is too high up in the knee joint, and this often contributes to the condition. Other mechanism is that the tibial tuberosity, which is the projection you can feel below and just to the outside of the knee on both legs, can be positioned extending too far towards the lateral part of the tibia bone. In other cases the injury can be provoked due to loosened or inordinately flexible ligaments surrounding the knee, allowing excessive and detrimental movement in the patella. A primary knee dislocation can also cause the injury.

Medical Treatment for Patellofemoral Instability

As soon as you have identified this problem, stop any strenuous leg training and consult your doctor. They will be able to assess the severity of the condition and recommend suitable treatment as a result. Often it will be sufficient to rest the affected knee while wearing a knee extension brace or similar construct to immobilise the knee during recovery. Specific methods of taping the patella are often advised; these help to assist in maintaining patella alignment. If the cause or one of the causes is identified as loose ligaments then it will be beneficial, after the doctor gives their approval, for you to commence strengthening of the quadriceps (particularly the vastus medialis obliquus) using appropriate stretches and strengthening techniques. A physical therapist may be on hand to help you with specifics, and this can be a gradual process to avoid further injury.

Occasionally it might be necessary to fix the patella's alignment using surgery. The doctor will be able to talk you through the process and the prognosis for recovery.