The etiology of CMP is poorly understood,
although most authorities believe that the causes of chondromalacia are injury,
generalized constitutional disturbance and patellofemoral contact[14], or a result of trauma to the chondrocytes in the articular cartilage (leading to proteolytic enzymatic digestion of the superficial matrix). Some authorities believe that chondromalacia is caused by instability or maltracking of the patella that softens the articular cartilage. [15](1B) Chondromalacia patella is usually described as an overload injury (overuse, misuse), caused by malalignment of the femur to the patella and the tibia. [16](5F)
Sometimes, a muscular imbalance between the VL en VM lies underneath. Weakness of the VM causes the patella to be pulled too far laterally. The patella will grind onto the condylus lateralis, which causes the degenerative disease.[17]
Degenerative changes of the articular cartilage can be caused by [18](5F):
Trauma: instability caused by a previous trauma or misuse during recovery
Repetitive micro trauma and inflammatory conditions
Postural distortion: causes malposition or dislocation of the patella in the trochlear groove
Some authors will use the term “patellar pain syndrome” instead of “chondromalacia” in order to describe “anterior knee pain”. [19](5E)