title: Rh-BMP-2 in distraction osteogenesis: dose effect and premature consolidation.
abstract: We asked whether locally applied recombinant-bone morphogenic protein-2 (rh-BMP-2) with a type I collagen carrier could enhance the consolidation phase in distraction osteogenesis and whether a dose effect could be reported. We performed unilateral transverse osteotomy of the tibia in 15 immature male rabbits. In Group I (five rabbits), 750 microg of rh-BMP-2 on the type I collagen sponge (Inductos, Medtronic) was locally applied on the day of osteotomy; the Group II animals (five rabbits) received 375 microg of the drug and the Group III (control group, five rabbits) had no local application. After 7 days, 3 weeks of distraction was begun at a rate of 0.5 mm/12 h. Starting week 2 of distraction, we assessed radiographic, ultrasonographic, and densitometric parameters once per week. Animals were sacrificed after a 3-week consolidation period. Radiographic evaluation revealed increased regenerate ossification in the rh-BMP-2 groups compared with the control group. The bone mineral content was significantly higher in the rh-BMP-2 treated groups at each time point. A dose effect is shown as densitometric parameters were significantly higher between Groups I and II. 3/5 of the Group I treated animals developed a premature bony union in the regenerate resulting in premature fusion and incomplete distraction.
authors.affiliation: Department of Orthopaedic Surgery, Hôpital Cochin, 27, rue du Faubourg Saint-Jacques, 75014 Paris, France. fred.sailhan@wanadoo.fr
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sailhan
authors.forename: Baptiste
authors.initials: B
authors.lastname: Gleyzolle
authors.forename: Roger
authors.initials: R
authors.lastname: Parot
authors.forename: Henri
authors.initials: H
authors.lastname: Guerini
authors.forename: Eric
authors.initials: E
authors.lastname: Viguier
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004305:Dose-Response Relationship, Drug; D008297:Male; D019857:Osteogenesis, Distraction / Q000379:methods*; D010027:Osteotomy; D011817:Rabbits; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000493:pharmacokinetics; D013977:Tibia / Q000187:drug effects / Q000378:metabolism* / Q000601:surgery
chemical_list: D055396:Bone Morphogenetic Protein 2; D011994:Recombinant Proteins