BACKGROUND:: Rapid, reliable fusion is the goal in anterior cervical discectomy and fusion (ACDF). Iliac crest autograft has a high rate of donor site morbidity. Alternatives, such as bone graft substitutes, lack osteo-inductivity, and recombinant bone morphogenetic proteins risk life-threatening complications. Both allogeneic mesenchymal precursor cells (MPCs) and amnion derived epithelial cells (AECs) have osteogenic potential. OBJECTIVE:: To compare, for the first time, the capacity of MPCs and AECs to promote osteogenesis in an ovine model. METHODS:: Five groups of 2 year old ewes were subjected to C3/4 ACDF using a Fidji interbody cage packed with: A: Iliac crest autograft (AG) alone (n=6); B: Hydroxyapatite-tricalcium phosphate Mastergraft Granules (HA/TCP) alone (n=6); C: HA/TCP containing 5 million MPCs (n=6); D: HA/TCP containing 5 million AECs (n=5); E: age-matched non-operative controls (n=6). At 3 months, animals were sacrificed and quantitative multi-slice CT, functional radiography, biomechanics, histology, and histomorphometry were performed. RESULTS:: No procedural or cell related adverse events were observed. There was significantly more fusion in the MPC group (C) than in groups A, B, or D. CT scan at 3 months revealed 5/6 (83 ) MPC-treated animals had continuous bony bridging compared with 0/5 AEC and only 1/6 AG and 2/6 HA/TCP treated animals (p= 0.01). CONCLUSION:: Implantation of allogeneic MPCs in combination with HA/TCP within an interbody spacer facilitates interbody fusion following discectomy. The earlier, more robust fusion observed with MPCs, relative to autograft and HA/TCP bone substitute, indicates that this approach may offer a therapeutic benefit.
Goldschlager, T., Ghosh, P., Zannettino, A., Williamson, M. M., Rosenfeld, J. V., Itescu, S., & Jenkin, G. (2011). A comparison of mesenchymal precursor cells and amnion epithelial cells for enhancing cervical interbody fusion in an ovine model. Neurosurgery, 68(4), 1025 - 1034. https://doi.org/10.1227/NEU.0b013e31820d5375