Biologics in Spine Fusion

Area of Science:

• Orthopedics
• Biomaterials Science
• Regenerative Medicine

Background:

• Spine fusion success is challenged by patient comorbidities (e.g., smoking, diabetes) and the risks associated with autologous iliac crest bone graft harvesting.
• Pseudarthrosis, or failed fusion, leads to significant pain, instability, and the need for revision surgery, highlighting the need for effective fusion augmentation strategies.

Purpose of the Study:

• To review and discuss the various biologic materials available for augmenting spine fusion.
• To explore the advantages and limitations of different bone graft substitutes and their application in spinal fusion procedures.

Main Methods:

• Literature review of current biologic materials used in spine fusion.
• Analysis of the efficacy, risks, and applications of bone graft substitutes, including allografts, demineralized bone matrix, synthetic materials, and cellular therapies.
• Discussion of factors influencing biologic selection in spine surgery.

Main Results:

• Autologous iliac crest bone graft remains a standard but has associated morbidities.
• Alternative biologics include allografts (decellularized, demineralized bone matrix), synthetic materials (bioactive glass), and mesenchymal stem cells (autologous and allograft).
• Bone morphogenetic proteins are effective but carry significant risks and are not universally applicable.

Conclusions:

• A wide array of biologics are utilized to enhance spine fusion, with selection influenced by spinal region, surgeon preference, training, formulary, and cost.
• The development of alternative biologics aims to overcome the limitations of autologous bone grafting and improve fusion rates.
• Careful consideration of patient factors and biologic properties is crucial for optimizing spine fusion outcomes.