Bone Grafting Options for Single-Level TLIF: So Many Options, What Is the Evidence?

Background: This review seeks to investigate the clinically relevant bone graft materials in single-level transforaminal lumbar interbody fusion (TLIF) procedures as defined by (1) primary outcomes (ie, fusion rates and complication rates) and (2) patient-reported outcomes (ie, visual analog scale [VAS] and Oswestry disability index [ODI]). Because of the advantages in stimulating bone growth, autologous bone grafts such as the iliac crest bone graft (ICBG) have been the gold standard. Numerous alternatives to ICBG have been introduced. Understanding the risks and benefits of bone graft options is vital to optimizing patient care.

Methods: A PubMed search was performed for all clinical studies published between January 2008 and March 2023 that referenced the single-level TLIF procedure as well as one of the following grafts: autograft, allograft, bone morphogenetic protein (BMP), demineralized bone matrix, or mesenchymal stem cells (MSCs). Case studies and reports were excluded.

Results: Twenty-eight studies met the inclusion criteria. Studies from the PubMed search demonstrated similarly high fusion rates across nearly all graft materials, the lone exception being MSCs, which showed lower fusion rates. ICBG grafts experienced higher rates of postoperative graft site pain. The BMP graft material had high rates of radiculitis, heterogeneous ossification, and vertebral osteolysis. Patients saw an overall improvement in VAS and ODI scores with all graft materials.

Conclusion: Local autografts and ICBG have been the most studied. Fusion rates during single-level TLIF were similar across all graft materials except MSCs. Patient-reported pain levels improved after TLIF surgery regardless of the type of grafts used. While BMP implants have shown promising benefits, they have introduced a new array of complications not normally seen in ICBG implants. The study is limited by the lack of evidence of certain graft materials as well as nonuniformity in metrics evaluating the efficacy of graft materials.