title: Lumbar body fusion with a bioresorbable cage in a goat model is delayed by the use of a carboxymethylcellulose-stabilized collagenous rhOP-1 device.
abstract: The purpose of this study was to evaluate the efficacy of recombinant human osteogenic protein-1 (rhOP-1) with a carboxymethylcellulose-stabilized collagenous carrier as a bone graft substitute for instrumented lumbar spinal fusion in an established goat model. Twenty goats received a resorbable poly-L-lactic acid (PLLA) interbody cage packed with either rhOP-1 and its carrier or autologous bone graft. The carrier material was bovine collagen type-1 stabilized with carboxymethylcellulose. The fusion segments were retrieved at 3 or 6 months postimplantation and evaluated by radiographic and histologic analyses. The rhOP-1 graft substitute, used in combination with the resorbable PLLA cage, showed inferior results as compared to autologous bone graft in the goat lumbar fusion model. Whereas four out of five segments from the autograft group were fused after 6 months, none of the four segments receiving the rhOP-1 graft substitute were fused at this time point. Bone ingrowth into the cage was delayed or absent in the experimental group, whereas all autograft specimens showed advanced bone ingrowth (3 months) or fusion (6 months). We suggest that the fusion process was inhibited, because cells were unable to penetrate the rhOP-1 graft material. This led to delayed bone formation and in some cases inadequate tissue formation.
authors.affiliation: Department of Orthopaedic Surgery, Vrije Universiteit Medical Center, Amsterdam, The Netherlands.
authors.forename: Margriet G
authors.initials: MG
authors.lastname: Mullender
authors.forename: Matthijs R
authors.initials: MR
authors.lastname: Krijnen
authors.forename: Marco N
authors.initials: MN
authors.lastname: Helder
authors.forename: Theo H
authors.initials: TH
authors.lastname: Smit
authors.forename: Vincent
authors.initials: V
authors.lastname: Everts
authors.forename: Paul I J M
authors.initials: PI
authors.lastname: Wuisman
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins / Q000627:therapeutic use*; D002266:Carboxymethylcellulose Sodium; D003094:Collagen; D005260:Female; D006041:Goats; D006801:Humans; D016268:Internal Fixators; D019344:Lactic Acid; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D011091:Polyesters; D011108:Polymers; D011859:Radiography; D011994:Recombinant Proteins / Q000627:therapeutic use; D013123:Spinal Fusion / Q000379:methods*; D014783:Viscosity
chemical_list: C525819:BMP7 protein, human; D001672:Biocompatible Materials; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; D011091:Polyesters; D011108:Polymers; D011994:Recombinant Proteins; D019344:Lactic Acid; C033616:poly(lactide); D003094:Collagen; D002266:Carboxymethylcellulose Sodium