A comparison of mesenchymal precursor cells and amnion epithelial cells for enhancing cervical interbody fusion in an ovine model.
BACKGROUND
Rapid, reliable fusion is the goal in anterior cervical diskectomy and fusion. Iliac crest autograft has a high rate of donor-site morbidity. Alternatives such as bone graft substitutes lack osteoinductivity, 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 anterior cervical diskectomy and fusion with a Fidji interbody cage packed with iliac crest autograft alone (group A; n = 6), hydroxyapatite-tricalcium phosphate Mastergraft granules (HA/TCP) alone (group B; n = 6), HA/TCP containing 5 million MPCs (group C; n = 6), or HA/TCP containing 5 million AECs (group D; n = 5); group E was made up of age-matched nonoperative controls (n = 6). At 3 months, animals were euthanized and quantitative multislice computed tomography, functional radiography, biomechanics, histology, and histomorphometry were performed.


RESULTS
No procedure- or cell-related adverse events were observed. There was significantly more fusion in the MPC group (C) than in group A, B, or D. Computed tomography scan at 3 months revealed that 5 of 6 MPC-treated animals (83%) had continuous bony bridging compared with 0 of 5 AEC-treated and only 1 of 6 autograft- and 2 of 6 HA/TCP-treated animals (P = .01).


CONCLUSIONS
Implantation of allogeneic MPCs in combination with HA/TCP within an interbody spacer facilitates interbody fusion after diskectomy. 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.
Monash Immunology and Stem Cell Laboratories, Melbourne, Victoria, Australia. tony.goldschlager@med.monash.edu.au
Tony
T
Goldschlager
Peter
P
Ghosh
Andrew
A
Zannettino
Mark
M
Williamson
Jeffrey Victor
JV
Rosenfeld
Silviu
S
Itescu
Graham
G
Jenkin
D000650:Amnion / Q000166:cytology / Q000637:transplantation*; D000818:Animals; D002574:Cervical Vertebrae / Q000166:cytology / Q000000981:diagnostic imaging / Q000601:surgery*; D004847:Epithelial Cells / Q000166:cytology / Q000637:transplantation*; D005260:Female; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000166:cytology; D023421:Models, Animal; D010012:Osteogenesis / Q000502:physiology; D011859:Radiography; D011897:Random Allocation; D034561:Sheep, Domestic; D013123:Spinal Fusion / Q000379:methods*