Introduction: Advances in the field of stem cell technology have stimulated the development and increased use of allogenic bone grafts containing live mesenchymal stem cells (MSCs), also known as cellular bone matrices (CBMs). It is estimated that CBMs comprise greater than 17% of all bone grafts and bone graft substitutes used.
Methods: A series of Ovid Medline and Pubmed-National Library of Medicine/National Institutes of Health (www.ncbi.nlm.nih.gov) searches were performed. Only articles in English journals or published with English language translations were included. Level of evidence of the selected articles was assessed. Specific technical information on each CBM was obtained by direct communication from the companies marketing the individual products.
Results: Five different CBMs are currently available for use in spinal fusion surgery. There is a wide variation between the products with regards to the average donor age at harvest, total cellular concentration, percentage of MSCs, shelf life and cell viability after defrosting. Three retrospective studies evaluating CBMs and fusion have shown fusion rates ranging from 90.2% to 92.3% and multiple industry sponsored trials are underway. No independent studies exist to evaluate spinal fusion rates with the use of CBMs. All the commercially available CBMs claim to meet the FDA criteria under Section 361, 21 CFR Part 1271 and are not undergoing FDA pre-market review. The CBMs claim to provide viable MSCs and are offered at a premium cost. Numerous challenges exist in regards to MSCs survival, function, osteoblastic potential and cytokine production once implanted into the intended host.
Conclusions: CBMs may be a promising bone augmentation technology in spinal fusion surgery. While CBMs appear to be safe, their efficacy in spinal fusion surgery remains highly inconclusive. Large, non-industry sponsored, studies evaluating the efficacy of CBMs are required. Without results from such studies, surgeons must be made aware of the potential pitfalls of CBMs in spinal fusion surgery.
Patient Care: It will establish awareness regarding the lack of evidence for the use of CBMs.
Learning Objectives: By the conclusion of this session, participants should be able to: 1)Describe the use of CBMs in spinal fusion surgery, 2) become familiar with the different available CBMs, 3) become familiar with pitfalls of CBMs