title: OP-1 for cervical spine fusion: bridging bone in only 1 of 4 rheumatoid patients but prednisolone did not inhibit bone induction in rats.
abstract: We used OP-1 (also called BMP-7) on a collagen type-1 carrier in atlanto-axial posterior fusions to promote bony healing after wire fixation. 4 patients who had instability between the atlas and axis due to rheumatoid disease received the implants. The patients were examined with conventional radiography postoperatively at 2, 6 and 10 months. In 3 patients, no new bone formation was detectable. In 1 patient, new bone bridged the fusion site at 6 months. 3 patients were on chronic steroid treatment, including the patient in whom bone formation was detected. To determine whether steroid treatment could be responsible for the low rate of bone induction, 24 rats each received OP-1 implants in an abdominal muscle pouch. They were divided into 3 groups receiving saline, 0.1 or 1.0 mg/kg BW of prednisolone daily until they were killed 3 weeks postoperatively. Specimens were decalcified for histology and the amount of calcium in the decalcifying solution was measured. All groups showed ossicles induced by OP-1, and no effect of prednisolone was detected. Thus the failures in the patients may have causes other than prednisolone treatment.
authors.affiliation: Department of Orthopedics, Lund University Hospital, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Jeppsson
authors.forename: H
authors.initials: H
authors.lastname: Säveland
authors.forename: U
authors.initials: U
authors.lastname: Rydholm
authors.forename: P
authors.initials: P
authors.lastname: Aspenberg
mesh_terms: D000818:Animals; D001172:Arthritis, Rheumatoid / Q000188:drug therapy / Q000601:surgery*; D001368:Axis, Cervical Vertebra / Q000601:surgery; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins / Q000008:administration & dosage*; D001864:Bone Wires; D001270:Cervical Atlas / Q000601:surgery; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D016348:Osseointegration / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects; D011239:Prednisolone / Q000494:pharmacology* / Q000627:therapeutic use; D019736:Prostheses and Implants; D051381:Rats; D017207:Rats, Sprague-Dawley; D013123:Spinal Fusion / Q000379:methods*; D016212:Transforming Growth Factor beta
chemical_list: C525819:BMP7 protein, human; C525821:Bmp7 protein, rat; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; D005938:Glucocorticoids; D016212:Transforming Growth Factor beta; D011239:Prednisolone