Recombinant human bone morphogenetic protein 2 enhances bone healing in an experimental model of fractures at risk of non-union.
BACKGROUND
Identification of patients at risk of developing non-union and institution of procedures preventing non-union could be attractive in routine fracture management. We investigated whether recombinant human bone morphogenetic protein (rhBMP-2) delivered in a hyaluronic acid carrier could prevent non-union development in an experimental non-union model, which simulates the clinical situation of open mid-tibial fractures.


METHODS
Sixteen rabbits underwent a standard non-union operation comprising mid-tibial osteotomy, excision of periosteum and endosteum, and plate fixation. Before closure of the wound eight rabbits received interfragmentary deposition of 200 microg rhBMP-2 delivered in a hyaluronan gel carrier, and eight rabbits received gel carrier alone.


RESULTS
After 7 weeks, torsional failure moment of the osteotomy and energy absorbed at failure, macroscopic and radiographic appearance, callus area, and interfragmentary bone volume fraction confirmed that rhBMP-2 delivery significantly improved bone healing. Blood flow at the osteotomy site, measured using radiolabelled microspheres, was not higher in the united osteotomies than in non-united osteotomies.


CONCLUSIONS
rhBMP-2 delivered in a hyaluronic acid carrier-induced formation of competent bone in an experimental model of compromised healing. We, therefore, propose interfragmentary deposition of rhBMP-2 delivered in a hyaluronic acid carrier to patients encountering fractures at risk of non-union or delayed union.
Eckardt
Henrik
H
Department of Orthopedics, Aalborg Hospital, 9000 Aalborg, Denmark. henrikeckardt@mail.dk
Christensen
Knud S
KS
Lind
Martin
M
Hansen
Ebbe S
ES
Hall
David W R
DW
Hvid
Ivan
I
D000818:Animals; D001783:Blood Flow Velocity; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage*; D004195:Disease Models, Animal; D004337:Drug Carriers; D017102:Fracture Healing / Q000187:drug effects*; D005599:Fractures, Ununited / Q000188:drug therapy / Q000517:prevention & control; D006820:Hyaluronic Acid; D008863:Microspheres; D010027:Osteotomy; D011817:Rabbits; D011897:Random Allocation; D011994:Recombinant Proteins / Q000008:administration & dosage; D013314:Stress, Mechanical; D013978:Tibial Fractures / Q000188:drug therapy*; D016212:Transforming Growth Factor beta / Q000008:administration & dosage*
C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D004337:Drug Carriers; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; D006820:Hyaluronic Acid