Chondromalacia patellae
Chondromalacia patellae (CMP; from Greek μαλακία (malakia) 'softening', χόνδρος (chondros) 'cartilage' and Latin patella 'kneecap') is an inflammation of the underside of the kneecap and softening of the cartilage. The cartilage under the kneecap is a natural shock absorber, and overuse, injury, and many other factors can cause increased deterioration and breakdown of the cartilage.