In order to treat chondromalacia patellae (runner's knee), mesenchymal stem cells (MSCs) from the patient are injected into the knee. Usually, these cells come from bone marrow or fat. They can change into cartilage-like tissue, lower inflammation, and ease the pain that comes from the kneecap cartilage breaking down and softening. This regenerative method aims to fix damaged cartilage and make the joint work better. It is a less invasive option to surgery, especially for mild to early cases.