3 The procedure
3.1 Microstructural scaffold insertion without autologous cell implantation for repairing symptomatic chondral knee defects is done with the patient under general or local anaesthesia, using an open or arthroscopic approach. The damaged articular cartilage is removed and standard bone marrow stimulating procedures, such as microfracturing or Pridie drilling, are done. The microstructural scaffold is cut to fit the size of the defect and then fixed in place over the damaged area using, for example, fibrin glue, resorbable suture thread or absorbable tacks. The position of the implanted scaffold is checked by bending and extending the knee and the wound is sutured. The aim of this procedure is that the graft or patch 'captures' the bone marrow cells and stem cells released by the microfracturing, and acts as a scaffold on which new articular cartilage can grow.