Microfracturing was the first surgical method to be used on cartilage injuries to stimulate healing by tissue regeneration. A pointed awl is used to make many small holes in the bone surface around the cartilage injury; this results in a small amount of blood escaping from the bone tissue.

After surgery, the joint must be kept free from stress for around six to eight weeks, but it can be moved to allow new cartilage tissue to grow above the microfractured bone tissue.

Unfortunately, the regenerated tissue consists of fribrocartilage rather than normal cartilage, and the results usually worsen after a few years. Another unfortunate side effect is that irregular healing after the “injury” to the bone seriously complicates any surgery required at a later date, such as cartilage transplantation.


BST-CarGel is a natural polymer consisting of chitosan obtained from marine crustaceans. This powdery material is mixed with some autologous blood from the patient in the operating room, forming a gel within a few minutes; the gel is introduced into the injured cartilage.

The operation takes place using arthroscopy alone or together with classic open surgery depending on the location of the injury. This innovative treatment option is a clear development and improvement on the previously used microfracture technique. More effective guidance helps the natural healing process while repairing cartilage healing.