The invention is based on the use of polyisobutylmethacrylate instead of PMMA as an adhesive or spinal fill material for treating diseases of the spine. Polyisobutylmethacrylate has several advantages over PMMA, mainly less heat is developed during the in situ polymerization process. When using any spinal adhesive of fill material that is light activated, a tube can be used to transmit activating light to the light-activated adhesive or spinal polymerizable fill material at the surgical site. In addition, a mesh bag comprising optical fibers or similar light transmitting material can be employed to receive the injected light-activated fill, with the mesh bag, irradiated externally, for directing the light via the bag to the polymerizable fill.