Patellofemoral Syndrome - A Common Source of Anterior Knee Pain

A common source of pain in the knee is the knee cap, otherwise known as the patella.  The patella is the moveable round bone on the front of the knee that acts as a fulcrum to allow the large thigh muscles to power the knee joint.  The under surface of the patella is normally covered with a thick, smooth material known as articular cartilage.  This cartilage allows the patella to glide in a special groove of the thigh bone (femur).

Problems develop when the patella begins to wear out and the smooth cartilage begins to soften and breakdown.  This softening, know as chondromalacia, may be the result of genetic predisposition or from traumatic overuse.  Problems can also arise from excessive tightness of the muscles that control the motion of the patella.  Small fissures form in the cartilage.  Over time, these fissures become larger cracks and the cartilage tissue can be completely worn away.  

Often people will experience a noisy or 'creaky' sensation within the knee when the uneven surfaces of the patella and the femoral groove rub against one another.  Typical complaints include pain when walking down stairs or with any excessive bending.  Keeping the knee bent for long periods of time such as on long drives or sitting through a movie can also result in varying degrees of stiffness, soreness, and pain.  The knee may feel as though it gives out on occasion, but this is thought to be a reflex response to the pain and not an indication of knee instability.  Gentle motion can help the knee by circulating synovial fluid, which provides nutrition for the cartilage.

The diagnosis begins with a complete hisotry followed by an examination of the knee.  Clinically, chondromalacia can be mistaken for other knee problems because the symptoms are often vague.  X-rays are obtained on the initial consultation to determine the extent of wear under the knee cap and to confirm proper positioning of the patella within the femoral groove. Often an MRI scan is ordered to help rule out other conditions such as torn cartilage or ligament damage.

The initial treatment for patellofemoral sydrome begins by decreasing inflammation in the knee.  Rest and anti-inflammatory medication, such as ibuprofen, can help decrease the pain and swelling.  Oral nutritional supplements, like glucosamine, have also been reported to help decrease the amount of pain and stiffness in many individuals.  Physical therapy can help in the early stages by decreasing pain and inflammation.  As symptoms become controlled, your physical therapist can provide several treatment choices to correct problems with flexibility, strngth, alignment, and muscle balance.

If symptoms fail to improve despite these tradition methods of treatment, surgical intervention may be indicated.  Arthroscopic surgery of the knee is a minimally invasive procedure that allows for a complete assessment of the entire joint.  The surface of the patella and femoral groove can be visualized to determine the extent of wear and damage.  Loose areas of cartilage are removed leaving only stable fragments in place.  This procedure is called an arthroscopic chondroplasty.

In addition, arthroscopic surgery assesses whether the patella is properly tracking within the femoral groove.  In the presence of any mal-tracking disorder, an arthroscopic lateral release or realignment procedure can be done to relieve some of the pressure on the patella and help restore the biomechanics of the knee joint.



Luis M. Espinoza MD Dr. Espinoza served as the AAA Team Doctor for the the New Orleans Zephyrs/BabyCakes since joining the Orthopedic Center for Sports Medicine in 2003. He is double board certified in General Orthopedic Surgery and Sports Medicine.

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