Expedited Fracture Repair: A Novel Approach

Delivering a growth factor in a dissolvable carrier at the site of a bony fracture results in accelerated healing when compared to untreated horses, and it is as effective as treating horses with a bone graft post-fracture, researchers recently reported.

Fractures are an important problem in athletic horses. According to a group of researchers from the University of Wisconsin-Madison, fractures account for more than two-thirds of fatal musculoskeletal injuries in Thoroughbred racehorses and are associated with huge economic losses due to prolonged recovery periods. As such, novel techniques for fracture repair resulting in accelerated healing are of particular interest.

The growth factor in this study, recombinant human bone morphogenetic protein-2 (rhBMP-2), is known to initiate bone formation. When combined with a dissolvable carrier such as calcium phosphate, rhBMP-2 can be delivered directly to the fracture site and will maintain sufficiently high concentrations for a long enough period to signal the migration and multiplication of bone-forming cells at that site.

To study the effect of rhBMP-2 on bone healing, researchers created a fracture in either the second or fourth metatarsal bones. The bones were treated with injection of rhBMP-2, an autogenous bone graft from the horse's own tibia, or were left untreated.

Twelve weeks after the repair, rate of healing was found to be superior in the rhBMP-2 group compared to the non-treated control group and the repair was equally or more successful than in the group of horses who received a bone graft. Success was determined via radiography (X rays), mechanical testing, and histology (microscopic analysis).

Additional research using rhBMP-2 on speed and strength of bone healing in other bones commonly fractured in athletic horses is needed.

The study, "Acceleration of second and fourth metatarsal fracture healing with recombinant human bone morphogenetic protein-2/calcium phosphate cement in horses," was published in the October 2008 edition of the journal Veterinary Surgery.

About the Author

Stacey Oke, DVM, MSc

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from TheHorse.com. Learn More