What is Rotator Chondromalacia? Chondromalacia patellae is a condition where the cartilage at the back of the kneecap (or patella) deteriorates, becoming rough and uneven. This can cause pain and discomfort in the knee joint, especially when performing movements that put pressure on the kneecap, such as climbing stairs or squatting. It is very common to hear a creaking or crackling sound as a result of this wear.