I was due to have a knee replacement 2 years ago, and because of this supplement, no longer need the replacement. The xrays and ultrasound images, show that the bone has indeed remineralised.
Yes, silica is essential for bone and cartilage. For bone silica helps to for the collagen matrix that gives bone the majority of its strength, and gives bone flexibility to reduce the risk of fractures. For cartilage, silica links glucosamine molecules together to form the structural protein chondroitin.