Fig 1.

Key steps of arthroscopic treatment of cartilage lesions with microfracture and BST-CarGel. (A-C) The cartilage defect is debrided down to the subchondral bone, with removal of the calcified layer, and to a stable rim of healthy cartilage. (D) Microfractures are performed with an awl. (E) The defect is arranged in a horizontal position, and the liquid is drained. (F) The defect can be further dried with a swab. (G) The BST-CarGel is injected into the defect and (H) forms a stable clot in the defect after 15 minutes.