title: Bone morphogenetic protein-7 (osteogenic protein-1) promotes tendon graft integration in anterior cruciate ligament reconstruction in sheep.
abstract: BACKGROUND
  Bone morphogenetic proteins induce new bone both in patients with bone defects and at extraskeletal sites in animals. After anterior cruciate ligament rupture, tendon graft fixation into a bone tunnel is a widely used method for anterior cruciate ligament reconstruction.
  
  
  OBJECTIVE
  Bone morphogenetic protein-7 applied to the bone-tendon interface enables better integration of a free tendon graft into the surrounding bone.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  The anterior cruciate ligament was reconstructed using a free tendon graft in the right rear knees of 30 one-year-old male sheep. Recombinant human bone morphogenetic protein-7 (25 microg) was applied randomly to the bone-tendon interface in 15 animals, and a vehicle was applied in 15 control animals. At 3 weeks, 10 animals from each group were sacrificed, and the remaining sheep were sacrificed at 6 weeks after surgery. Subsequently, histologic analysis and mechanical testing were performed. In another group of 20 sheep, the same procedure was used and mechanical testing was performed after 3 weeks.
  
  
  RESULTS
  More new bone was formed at the bone-tendon interface in the knees treated with bone morphogenetic protein-7 as compared histologically with similar areas in control animals, creating areas of dense trabecular network with significantly greater invasion of the tendon fibrous tissue into the bone marrow space. Mechanical testing showed greater strain resistance to force (368 N) in the knees treated with bone morphogenetic protein-7 than in control specimens (214 N). There was no difference between mechanical testing of samples from 3 and 6 weeks after surgery.
  
  
  CONCLUSIONS
  Bone morphogenetic protein-7 promotes complete tendon graft integration into the newly formed surrounding trabecular bone in the reconstruction of the anterior cruciate ligament.
  
  
  CONCLUSIONS
  Bone morphogenetic protein-7 in tendon graft integration might be successfully used in reconstructive surgery of ligaments.
authors.affiliation: Orthopaedic Hospital, Lovran, Croatia.
authors.forename: Radovan
authors.initials: R
authors.lastname: Mihelic
authors.forename: Marko
authors.initials: M
authors.lastname: Pecina
authors.forename: Mislav
authors.initials: M
authors.lastname: Jelic
authors.forename: Sanja
authors.initials: S
authors.lastname: Zoricic
authors.forename: Vesna
authors.initials: V
authors.lastname: Kusec
authors.forename: Petra
authors.initials: P
authors.lastname: Simic
authors.forename: Dragica
authors.initials: D
authors.lastname: Bobinac
authors.forename: Boris
authors.initials: B
authors.lastname: Lah
authors.forename: Dalen
authors.initials: D
authors.lastname: Legovic
authors.forename: Slobodan
authors.initials: S
authors.lastname: Vukicevic
mesh_terms: D030201:Activin Receptors, Type I; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000254:growth & development / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001846:Bone Development; D008297:Male; D019637:Orthopedic Procedures / Q000379:methods* / Q000662:veterinary; D011506:Proteins / Q000494:pharmacology*; D011897:Random Allocation; D019651:Plastic Surgery Procedures; D012756:Sheep; D013710:Tendons / Q000637:transplantation*
chemical_list: D011506:Proteins; D030201:Activin Receptors, Type I