By ROSIE TAYLOR FOR THE DAILY MAIL
Thousands of patients could avoid painful knee replacements after scientists developed a material to help cartilage regrow. 
The ‘bouncy bio-glass’ mimics the structure of cartilage and can be 3D-printed to fit precisely into damaged areas and stimulate new cell growth.
Cartilage – the flexible connective tissue found in joints and between vertebrae in the spine – is difficult to repair.
Using the new material, scientists can create a tiny biodegradable ‘scaffold’ and implant it into a damaged area to encourage existing cartilage cells to grow through microscopic pores in the bio-glass.
Over time, the scaffold degrades naturally and safely in the body, leaving fresh cartilage in its place. Bio-glass, which is based on silica, has been used since the Vietnam War to help regrow bones.