The effect of platelet-rich plasma and bone marrow on murine posterolateral lumbar spine arthrodesis with bone morphogenetic protein.
BACKGROUND
Recombinant human bone morphogenetic protein-2 (rhBMP-2) has had limited success in stimulating osteogenesis at the site of posterolateral lumbar spine arthrodesis when used at the currently approved human dose for anterior lumbar interbody arthrodesis. The objective of the present study was to investigate the effect of co-administration of fresh harvested autologous bone marrow aspirate and platelet-rich plasma on rhBMP-2-mediated in vivo murine posterolateral lumbar spine arthrodesis.


METHODS
Forty adult male mice underwent posterolateral intertransverse process arthrodesis from L4 to L6. In three experimental groups, a collagen sponge was placed on each side, overlaying the decorticated transverse processes. Each collagen sponge was presoaked for fifteen minutes with 31 microg of rhBMP-2 in a 100-microL solution containing either saline solution (n = 10), platelet-rich plasma (n = 10), or donor bone-marrow cells (n = 10). Control mice underwent decortication alone (n = 10). The lumbar spine was harvested four weeks after surgery, and spinal fusion was evaluated on the basis of radiographs, computed tomography, and histological analysis.


RESULTS
Control mice showed no evidence of spinal fusion. The rate of fusion was radiographically and histologically similar in all three experimental groups. The area, volume, and density of the fusion mass were significantly greater (p < 0.05) for the group treated with rhBMP-2 and bone marrow as compared with the group treated with rhBMP-2 alone. The group treated with rhBMP-2 and platelet-rich plasma had intermediate fusion area and density. Histologically, the spines treated with rhBMP-2 alone consistently showed the presence of cortical bone between the two transverse processes but fewer trabeculae within the fusion mass; bone marrow co-augmentation resulted in more trabeculae within the fusion mass and a thicker cortical perimeter.


CONCLUSIONS
The present study quantitatively confirmed a synergistic effect of bone marrow cells when added to rhBMP-2 in an in vivo mouse posterolateral lumbar spine fusion model. The volume, area, and density of the fusion mass were significantly increased by augmentation with bone marrow cells.
Rao
Raj D
RD
Department of Orthopaedic Surgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
Gourab
Krishnaj
K
Bagaria
Vaibhav B
VB
Shidham
Vinod B
VB
Metkar
Umesh
U
Cooley
Brian C
BC
D000818:Animals; D001792:Blood Platelets / Q000502:physiology*; D016026:Bone Marrow Transplantation; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D008159:Lumbar Vertebrae / Q000473:pathology / Q000601:surgery*; D008297:Male; D051379:Mice; D010949:Plasma; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D013123:Spinal Fusion / Q000379:methods*; D016212:Transforming Growth Factor beta / Q000008:administration & dosage / Q000494:pharmacology*
D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2