This is a prospective, single center, randomized, open-label controlled Phase 1b/2a study designed to evaluate the safety and preliminary efficacy of MPCs combined with MasterGraft Granules when compared to use of autologous bone graft in the posterolateral fusion site in subjects requiring interbody fusion in combination with instrumented 1 or 2 level PLF procedure. All subjects in this study will undergo a 1 or 2-level (2 or 3 vertebrae) interbody fusion without the use of the investigational product.