Chondromalacia

What Is Chondromalacia?

Chondromalacia (also called chondromalacia patellae) refers to softening of the cartilage of the kneecap. The disorder occurs most often in young adults and may be caused by trauma, overuse, loss of proper alignment, or muscle weakness. Instead of gliding smoothly across the lower end of the thigh bone, the kneecap rubs against it, thereby roughening the cartilage underneath the kneecap. The damage may range from a slight abnormality of the surface of the cartilage to a surface that has been worn away completely to the bone. Traumatic chondromalacia occurs when a blow to the knee cap tears off either a small piece of articular cartilage or a large fragment containing a piece of bone (osteochondral fracture).

What Are the Symptoms of Chondromalacia?

The most common symptom of chondromalacia is a dull pain around or under the kneecap that starts to worsen when walking down stairs or hills. A person may also feel pain when climbing stairs or during other activities when the knee bears weight as it is straightened. The disorder is common in runners and is also seen in cyclists and athletes.

How Is It Diagnosed?

A patient's description of symptoms and a followup x ray usually help the doctor make a diagnosis. Although arthroscopy can confirm the diagnosis of chondromalacia, it is not performed unless the condition requires extensive treatment.

How Is Chondromalacia Treated?

Many doctors recommend that patients with chondromalacia perform low-impact exercises that strengthen muscles, particularly the inner part of the quadriceps, without injuring joints. Swimming, riding a stationary bicycle, and using a cross-country exercise machine are acceptable as long as the knee is not bent more than 90 degrees. Electrical stimulation may also be used to strengthen the muscles. If these treatments fail to improve the condition, the physician may perform arthroscopic surgery to smooth the surface of the articular cartilage and wash out” cartilage fragments that cause the joint to catch during bending and straightening. In more severe cases of chondromalacia, surgery may be necessary to correct the angle of the kneecap and relieve friction involving the cartilage or to reposition parts that are out of alignment.