Lumbar interbody fusion: recent advances in surgical techniques and bone healing strategies.

Abstract

Lumbar interbody fusion (LIF) is a treatment option for low back pain secondary to lumbar instability and/or deformity. This review highlights recent studies of surgical techniques and bone healing strategies for LIF. Relevant articles were identified by searching the PubMed database from January 1948 to April 2020, with a focus on the last 5years, using the following keywords: LIF approach, LIF cage, stem cells for LIF, biomaterials for LIF, and osteobiologics for LIF. LIF procedures were traditionally performed through either a posterior approach (PLIF), or an anterior approach. Later, the transforaminal LIF approach gained popularity over the PLIF as it entailed less nerve retraction. To minimize paraspinal muscle dissections, alternative approaches including lateral LIF, oblique LIF, and minimally invasive approaches have been developed and utilized. These modifications have improved the surgical outcomes of LIF. However, the most recent rates of non-union after LIF procedures still ranged from 7 to 20% with an even higher incidence in patients with osteoporosis. This review summarizes the advantages and disadvantages of each surgical approach and current efforts to enhance LIF by improving fusion cage material properties and developing novel osteobiologic products that contain nanomaterials for controlled release of effective osteogenic proteins and mesenchymal stem cells. There have been significant advances in surgical technologies for LIF over the past decades. Post-operative non-union remains a major challenge, which could be addressed by development of more effective surgical techniques, fusion cages, and bone healing products through joint efforts from spine surgeons, bone biologists, and material engineers.