Partial thickness defects or Mild Cartilage Injuries – macroscopically or examined by the unaided eye, they can be identified by softness and afterward by fibrillation of the cartilage, i.e., by the formation of some fibrous scar tissues. These scarred areas are thick with no access to bone marrow stem cells, which leads to a low ability to spontaneous or natural repair. Those defects evolve with time, being associated with swelling and mechanical symptoms caused by detachment of cartilage flaps that happens when cartilage separates from the bone and moves like a door with a hinge at one end