Acceleration of second and fourth metatarsal fracture healing with recombinant human bone morphogenetic protein-2/calcium phosphate cement in horses.
OBJECTIVE
To compare the efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2)/calcium phosphate (CP) to autogenous cancellous bone graft (CBG) and to no treatment on bone healing, in surgically induced osteotomies and ostectomies of the accessory metatarsal bones in an equine model.


METHODS
Experimental.


METHODS
Adult horses (n=9).


METHODS
Segmental ostectomies of the second metatarsal bone (MT2) and osteotomies of the fourth metatarsal bone (MT4) were performed bilaterally in 9 horses. There were a total of 35 defects (1 MT4 was previously fractured) created and supplemented randomly either with no treatment (untreated control), rhBMP-2/CP cement, or matrix (CPC or CPM), or CBG. Radiography was performed every 2 weeks until study endpoint at 12 weeks. After euthanasia, bone healing was evaluated using radiography, mechanical testing, and histology. Data were analyzed with ANOVA followed by the Duncan's Multiple Range Test or nonparametric analyses.


RESULTS
At 12 weeks, radiographic scores for union were significantly greater for the rhBMP-2 (P<.0001) and CBG (P=.004) groups compared with the untreated control group, for both MT2 ostectomies and MT4 osteotomies. The rhBMP-2 treated MT2 had greater maximum torque to failure in torsion than CBG and control limbs at 12 weeks (P=.011). Histologic analysis demonstrated increased bone formation and more mature bone at the ostectomy site for MT2 in the rhBMP-2 and CBG groups compared with the untreated control group.


CONCLUSIONS
Injection of rhBMP-2/CP into surgically induced ostectomies and osteotomies of the accessory metatarsal bones might accelerate early bone healing in the horse.


CONCLUSIONS
RhBMP-2/CP may be as effective if not superior to CBG as an adjuvant treatment to accelerate healing of bone defects.
Perrier
Melanie
M
Comparative Orthopaedic Research Laboratory, Department of Surgical Sciences and Medical Sciences, School of Veterinary Medicine and the Division of Sports Medicine, University of Wisconsin-Madison, Madison, WI, USA.
Lu
Yan
Y
Nemke
Brett
B
Kobayashi
Hirohito
H
Peterson
Anna
A
Markel
Mark
M
D000818:Animals; D001696:Biomechanical Phenomena; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000627:therapeutic use*; D002130:Calcium Phosphates; D005260:Female; D017102:Fracture Healing / Q000187:drug effects* / Q000502:physiology; D006736:Horses / Q000293:injuries* / Q000601:surgery; D008297:Male; D008682:Metatarsal Bones / Q000293:injuries* / Q000601:surgery*; D010027:Osteotomy / Q000662:veterinary; D011994:Recombinant Proteins / Q000627:therapeutic use*; D016212:Transforming Growth Factor beta / Q000627:therapeutic use*; D016896:Treatment Outcome
D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D002130:Calcium Phosphates; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2