Procedures for enhancing and directing tissue repair and renewal processes, such as BONE REGENERATION; NERVE REGENERATION; etc. They involve surgically implanting growth conducive tracks or conduits (TISSUE SCAFFOLDING) at the damaged site to stimulate and control the location of cell repopulation. The tracks or conduits are made from synthetic and/or natural materials and may include support cells and induction factors for CELL GROWTH PROCESSES; or CELL MIGRATION.