Knee pain after a run or a lot of walking? Perhaps while sitting for long? You could have PFS.

[Mark Reyneker]

 

Patello - femoral Syndrome (PFS) by Johan Steenkamp of the Family Podiatry Centre

This is the umbrella-term used to describe pain in the region of the patella. There are multiple synonyms; chondromalacia patella, patellar mal-alignment, PatelloFemoral disorder and runner’s knee. The main hallmark feature is that of pain experienced behind the patella. Degeneration of the articular surface of the patella is often the cause of the pain.

 

Signs and symptoms:

 

• Pain behind the knee cap, especially so when walking or running downhill or when descending stairs.
• A deep, generalized, dull, aching type pain within the vicinity of the anterior knee.
• Pain when squatting.
• Pain after being seated for some time.
• A grating or creaking sensation – known as crepitus - when bending the knee.

 

Fig. 1. Illustration of degeneration of the articular cartilage behind the patella.

 

 

What causes Patella Femoral Syndrome ?

Most often it is brought about by overuse of the knee during sports and activities that cause repetitive stresses to the knee. These include running, walking, jumping and even cycling. Other times, it is just part of a degenerative process. 

Contributing factors can be divided into intrinsic and extrinsic factors. 

 

Extrinsic factors include:

 

• Speed of gait/activity.
• Body mass/weight. The more weight, the higher the forces acting on the knees.
• Surfaces. Hard surfaces such as tar or concrete cause higher impact to the knees than softer surfaces such as grass.
• Footwear – selecting the correct footwear for your foot type reduces impact on the knees
• High volume training.
• Downhill running

 

Intrinsic factors include:

 

• Patella position.
• Patella tracking, thus the way that the patella articular surface slides over the femoral condyle during activity.
• Femoral internal rotation.
• Knee valgus (Knock-knees).
• Tibial rotation.
• Foot subtalar joint over-pronation.
• Muscle flexibility.

Together, these intrinsic and extrinsic factors may cause an excessive load on the patella and so cause injury/patellafemoral syndrome pain.

 

Diagnosis:

 

A clinical diagnosis can be derived based on a thorough biomechanical  examination conducted by a registered podiatrist. X-ray may be required in some cases to confirm the diagnosis and to rule out other differential diagnosis.

 

Treatment:

 

Treatment for this follows a conservative approach and surgery is rarely required.

The conservative management focuses on stabilizing and realigning the patella by way of custom orthotics and specialized taping and bracing techniques. Physiotherapy and muscle strengthening is considered part of the standard treatment of PFS. Therapeutic modalities such as Extracorporeal Shock Wave Therapy (ESWT) and ultrasound reduce pain and aid healing and are of tremendous benefit. 

Our findings at the Family Podiatry Centre have shown that the most successful treatment still remains to be an accurately prescribed pair of custom made orthotics by a registered podiatrist. The orthotics are able to change the mal-tracking of the patella by controlling the rotation of the leg. Symptoms are relieved by the 5th week. This is in line with recent studies conducted on PFS.

 

References:

1. Hilton BM. Foot problems in older people. Philadelphia: Churchill Livinstone; 2008.
2. Lorimer D, French G, O’Donnell M, Burrow JG, Wall B. Neale’s disorders of the foot. 7^th Ed. Philadelphia: Churchill Livingstone; 2006
3. Merriman LM, Turner W. Assessment of the lower limb. 2^nd Ed. Philadelphia: Churchill Livingstone; 2007. 
4. Brukner P, Khan K. Clinical sports medicine. 3^rd Ed. Australia: Mc Graw Hill; 2007.