Patellofemoral Pain Syndrome Explained

Anatomy of the knee Patellofemoral Pain Syndrome is a common cause of pain around the knee cap, that is sometimes referred to as ‘Anterior Knee Pain'. When the knee bends or straightens, the knee cap glides in a special groove on the thigh bone called the ‘Patellofemoral groove', controlled by the quadriceps (thigh) muscles. However, for several reasons it may stray from this path (usually towards the outside of the knee). This is called Patellofemoral Maltracking and produces abnormal stresses on the under-surface of the patella that can cause knee cap pain.

The knee joint is made up of three bones:

  • the Femur (thigh bone),
  • Tibia (shin bone)
  • and Patella (kneecap).

The Patella is wrapped inside a Quadriceps tendon that connects the thigh muscles (Quadriceps) to the shin. When the knee bends, or straightens, the knee cap normally glides in a special groove on the thigh bone called the Patellofemoral groove.

With Patellofemoral maltracking, abnormal stresses are put on the under-surface of the knee cap that can cause pain. This is similar to having the front tyre of a car slightly out of alignment, leading to abnormal wear. If allowed to progress, these stresses can cause damage to the articular cartilage on the knee cap (a condition called Chondromalacia Patella) and femur.

Patellofemoral maltracking is one of the most common causes of knee pain and can be caused by numerous factors:

  • Tightness in certain structures. (e.g. calf and hamstring muscles).
  • Weakness or incoordination in muscles that should help maintain normal patella tracking.
  • Altered hip, knee or foot posture.
  • Anatomic variations such as a shallow Patellofemoral groove.

Patellofemoral Pain Syndrome Signs & Symptoms

The most common symptom of Patellofemoral maltracking is pain at the front of the knee that can occur while ascending or, more often, descending stairs and whilst running. Pain can also result from prolonged sitting and some people may experience instability (this can involve a sensation of insecurity or actual giving way of the knee) or locking of the knee.

Patellofemoral Pain Syndrome Treatment

The causes of Patellofemoral maltracking will be specific for each person and so it is important that a treatment plan is formulated to meet the patient's individual needs. Physiotherapy often plays a vital role in the treatment of Patellofemoral maltracking. The first priority is to attempt to settle the pain, usually through ice therapy or analgesics prescribed by a GP.

Ice Packs can be applied for periods of twenty minutes every couple of hours (never apply ice directly to the skin as it can cause an ice burn). The ice packs relieve pain and reduce inflammation within the tissue. The Aircast Knee Cryo/Cuff is the most effective method of providing ice therapy and can be used for the home treatment of knee injuries and knee pain. It can provide continuous ice cold water and compression for 6 hours and significantly reduce knee pain and knee swelling.

Once the initial pain has settled, treatment is likely to include stretches for the Calf muscles, Quadriceps, Hamstrings, Hip flexors, Hip rotators and Ilio Tibial band.

A Guide to Stretching

Of even greater importance are exercises to both strengthen and improve the coordination of the Vastus Medialis Oblique (VMO) muscle. The VMO forms part of the Quadriceps muscle group and is located just above the knee cap, on the inner aspect of the thigh. It is believed to help maintain the knee cap in its correct position in the Patellofemoral groove. Methods of improving VMO function with a physiotherapist may involve EMG biofeedback machines or taping of the patella.

Strengthening of the Quadriceps muscle group as a whole is also thought to be beneficial, but it is important to note that traditional knee extension exercises may actually exacerbate the problem through over-stressing the Patellofemoral joint. Closed-chain exercises (where the sole of the foot is in contact with a flat surface) such as the squat and leg-press are more appropriate but should only be performed in a safe, pain-free range of motion and under the supervision of a Chartered physiotherapist.

During the enforced rest from running activities many people find that they are able to do pool running and exercises in water using a Buoyancy Aid as a means of maintaining fitness, but it is important that these exercises are pain free.

Patellofemoral Pain Syndrome Prevention

There are a number of causes of Patellofemoral maltracking, which are different in each individual. A specific assessment and treatment programme should be formulated by a physiotherapist in order to address individual issues. In terms of preventing symptoms, many people find that a Knee Brace can be effective in preventing Patellofemoral Pain Syndrome.

Knee Injuries