The joint is mechanically a very demanding environment. For a tissue-engineered cartilage implant to survive those conditions, it needs to have sufficient material properties to withstand or respond to normal joint loading. This does not necessarily mean that the engineered tissue is an exact copy of the natural tissue; the tissue may further develop and adapt properties post-implantation. The questions arise, what exactly are these ‘sufficient material properties’, and how much do we need to improve our current tissue-engineered cartilage.