Comparison of two doses of recombinant human bone morphogenetic protein in absorbable collagen sponges for bone healing in dogs.
OBJECTIVE
To determine the effects of 2 doses of recombinant human bone morphogenetic protein-2 in an absorbable collagen sponge (rhBMP-2/ACS) on bone healing in dogs.


METHODS
27 adult dogs.


METHODS
Dogs underwent a mid-diaphyseal (1-mm) tibial osteotomy (stabilized with external skeletal fixation) and received an ACS containing 0.28 mg (0.2 mg/mL) or 0.56 mg (0.4 mg/mL) of rhBMP-2 or no treatment (control dogs). All dogs were examined daily; bone healing was assessed via radiography and subjective lameness evaluation every 2 weeks. After euthanasia at 8 weeks, tibiae were evaluated biomechanically and histologically.


RESULTS
Control dogs required antimicrobial treatment for pin-site-related complications more frequently than did rhBMP-2/ACS-treated dogs. At 4 and 6 weeks, weight bearing was greater in dogs treated with rhBMP-2/ACS (0.2 mg/mL) than in control dogs, albeit not significantly. Compared with control treatment, both doses of rhBMP-2/ACS accelerated osteotomy healing at 4, 6, and 8 weeks, and the 0.2 mg/mL dose enhanced healing at 2 weeks; healing at 6 weeks was greater for the lower-dose treatment than for the higher-dose treatment. Histologically, healing at 8 weeks was significantly improved for both rhBMP-2/ACS treatments, compared with control treatment. Among groups, biomechanical variables did not differ, although less osteotomy-site failures occurred in rhBMP-2/ACS-treated groups.


CONCLUSIONS
In dogs that underwent tibial osteotomy, rhBMP-2/ACS (0.2 mg/mL) appeared to accelerate bone healing and reduce lameness (compared with control treatment) and apparently augmented bone healing more than rhBMP-2/ACS (0.4 mg/mL). Compared with control dogs, rhBMP-2/ACS-treated dogs required antimicrobial treatments less frequently.
Comparative Orthopaedic Research Laboratory, Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706-1100, USA.
Chad W
CW
Schmiedt
Yan
Y
Lu
Kathleen
K
Heaney
Peter
P
Muir
Deborah M
DM
Amodie
Mark D
MD
Markel
D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage* / Q000494:pharmacology* / Q000627:therapeutic use; D003094:Collagen; D004305:Dose-Response Relationship, Drug; D017102:Fracture Healing / Q000187:drug effects*; D050723:Fractures, Bone / Q000188:drug therapy*; D006801:Humans; D011994:Recombinant Proteins; D015503:Surgical Sponges
D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins; D003094:Collagen