Figure 5.

Composition, shaping, and retention of OC implants. A) Biomaterials for subchondral bone and cartilage regeneration, including extracellular matrix (ECM); hyaluronic acid (HA), chondroitin sulfate (CS), other proteoglycans (PGs) and glycosaminoglycans (GAGs), calcium phosphates (CaP), polyethylene glycol (PEG). Percentages represent the number of studies including each polymer in the biomaterial, either alone or in combination with others. B) Implant shaping methods. C) Retention means used to maintain the implant in the defect. Here, easy‐to‐handle materials that can fill the defect but that are not injectable through a needle or syringe are considered malleable.