Patellofemoral Syndrome
Patellofemoral pain syndrome (PFPS) is a common cause of pain in the front of the knee but may be felt anywhere in the knee joint. The front of the thigh consists of four muscles (quadriceps) which aid in the correct tracking/movement of the kneecap (patella). Problems can be caused by any imbalance or dysfunction of the stabilizing forces that keep the patella moving correctly over the knee joint. When muscle imbalances occur around the knee joint, the result is “maltracking” of the patella. This is where the pain stems from.
The onset of PFPS can be due to a combination of several factors such as overloading of the patellofemoral joint, anatomical/biomechanical abnormalities, muscular weakness and/or muscular dysfunction. PFPS usually has a gradual onset but can also present secondary to a traumatic injury or following knee surgery.
What causes PFPS?
The exact cause of PFPS is not clear, however it is thought to be related to abnormal forces on the patellofemoral joint that affect the way the kneecap glides through the groove of the femur (thigh bone). Your quadriceps muscles attach to the patella, if there is a muscle imbalance between the vastus lateralis, which pulls your patella up and outwards, and the vastus medialis, which pulls your kneecap up and in, then your patella won’t track centrally in the groove, it will be pulled laterally (outwards).
This condition is more common in athletes (such as runners or basketball players) and in people who have “knock-knees”. Over-pronation or rolling in of the feet can increase internal rotation of the leg which can also be a factor in the development of patellofemoral pain.
PFPS is more common during adolescence because the long bones are growing faster than the muscles, tendons and ligaments, putting abnormal stresses on the joints. Active children who do not stretch the appropriate muscles are predisposed to patella malalignment.
What does PFPS feel like?
Pain is often described as sharp or aching in the front of the knee, but may be felt vaguely throughout the whole knee in some cases. Pain is increased with loaded activities such as running, jumping, using stairs, squatting, or prolonged sitting. Swelling is present in some cases.
How can PFPS be prevented?
Many steps can be taken to prevent an incidence or recurrence of patellofemoral knee pain. These include:
- Wearing shoes appropriate to your activities and foot type
- Warming up thoroughly before physical activity
- Incorporating stretching for the quadriceps and hamstrings into your warm up and cool down routine
- Increasing training gradually
- Reducing any activity that has hurt your knees in the past
- Maintaining a healthy body weight to avoid overstressing your knees.
How is PFPS treated?
Tre treatment of PFPS depends on the severity of the symptoms. In many cases, PFPS will improve with some simple at home treatment:
Activity changes – stop doing the activities that make the knee hurt until pain has resolved. This may mean changing the training routine or switching to low-impact activities such as riding a stationary bike or swimming.
The RICE method – RICE stands for rest, ice, compression, and elevation.
- Rest – avoid putting weight on the painful knee
- Ice – use ice packs for 20 minutes at a time, several times a day. Remember not to apply the ice directly on the skin
- Compression – to prevent additional swelling, lightly wrap the knee in an elastic bandage. Make sure the bandage doesn’t cause additional pain
- Elevation – as often as possible, rest with your knee raised up higher than your heart.
Medication – non-steroidal anti-inflammatory drugs such as ibuprofen can help reduce swelling and relieve pain.
The management of a patient with patellofemoral pain syndrome requires a holistic approach. Podiatry looks to address the underlying cause for the pain and uses modalities such as manual therapy, taping, targeted exercise, orthotics, and advice around activity modification. Recovery may take 6-8 weeks depending on a variety of lifestyle factors and the underlying cause for your specific pain.
Physical therapy – specific exercises will help you improve range of motion, strength, and endurance. It is especially important to focus on strengthening and stretching your quadriceps since these muscles are the main stabilizers of the kneecap.
Orthotics – shoe inserts can help align and stabilize your foot and ankle, taking stress off your lower leg and helping to correct your biomechanics.
