Runner's Knee

Chondromalacia of the Patella

The knee joint is a combination of three bones - the femur (thigh), the tibia (lower leg), and the patella (kneecap). The most common knee problems in running occur at the patello-femoral articulation. This is the quadriceps muscle, kneecap, and patellar tendon. Chondromalacia essentially means softening of the cartilage of the kneecap. During running certain mechanical conditions may cause your kneecap to track improperly on the femur. Portions of the cartilage of the kneecap may have too much pressure on it. This may result in deterioration of the cartilage and thus result in pain.

Symptoms

Individuals with runner's knee often feel pain after sitting for long periods of time with the knee bent, especially when driving a car for long periods. Another complaint is walking up or down stairs.

Causes

There are a number of possible causes of chondromalacia. One of the most common is an imbalance in the muscles on the front of the thigh - the quadriceps (quads). One of the inside quad muscles becomes overpowered by the muscles on the outside. This allows the patella to track improperly on the femur. Another common cause is tightness of the muscles on the outside of the thigh and tightness of the hamstrings (the muscles on the back of the thigh). Tightness of these muscles reduces the ability of the knee to operate properly and causes compressive forces on the kneecap. A further structural problem occurs when the foot does not have an adequate arch. This causes a rotation of the tibia and femur. When the tibia and femur rotate, this again allows the patella to track improperly. Wearing high quality shoes and/or orthotics can be extremely helpful in controlling this problem.

Treatment

The best treatment is prevention. While ice and rest will help, the problem often returns if the muscles are not strengthened or stretched, or if the foot arch is not corrected. Early intervention in this problem can save a lot of pain and disability.