This document discusses various techniques for lumbar interbody fusion. It begins by providing background on spinal fusion and its goals of eliminating segmental motion and symptoms through bone bridging. It then reviews the history and indications for fusion, including degenerative conditions. The document focuses on the techniques of interbody fusion, including anterior approaches like anterior lumbar interbody fusion (ALIF) and lateral approaches. It discusses the advantages of ALIF like restoring lordosis and large graft surface area. It also covers posterior lumbar interbody fusion (PLIF) and complications of different approaches.