Chondromalacia patella was an old synonym for pain in the front of the knee. Technically, chondromalacia patella means a softening of the cartilage of the knee-cap. To recapitulate the anatomy of the knee, the knee is formed by the union of three bones, the thigh bone (femur), the leg bone (tibia) and the knee cap (patella). The knee- cap sits in a pulley like groove in the lower end of the thigh bone (trochlear groove). The under surface of this and the surface of the thigh bone are lined by articular cartilage. Preservation of this cartilage is responsible for the smooth gliding of the knee -cap during bending and straightening of the knee. Presently anterior knee pain is a better word for this condition. The cartilage lining instead of being smooth is roughened or can be eroded upto bone.

Symptoms

Pain in the front of the knee, which is worse on sitting for prolonged periods, descending or ascending stairs and rising from a squatting position. Crunching or grating in the knee. The pain can radiate to the back of the knee. Repeated swelling with out any significant injury may pose a diagnostic challenge to the clinician. There is no pain at rest.

Risks-

Certain sports like athletics especially running, sailing, fencing, soccer, and football. Trauma. .Anatomical factor include a high kneecap, which makes it easily dislocatable, a low knee cap which increases the stresses to which it is subjected and muscle weakness. Increased inward twisting of the thigh bone (ante version) and outward twisting of the leg bone (external tibial torsion) alter the line of pull of the quadriceps tendon and subject the knee cap to stresses. Increased Q angle. This is the angle between the line of pull of the thigh muscle tendon and the ligament patella. The normal angle is 12-18