title: The effect of recombinant human bone morphogenetic protein-2 in single-level posterior lumbar interbody arthrodesis.
abstract: BACKGROUND
  In this prospective, randomized controlled trial, our objective was to assess both the clinical and radiographic effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) in patients treated with an instrumented single-level posterior lumbar interbody arthrodesis with polyetheretherketone cages.
  
  
  METHODS
  Forty patients were randomized with a 1:1 ratio. Two patients who had a two-level arthrodesis (L4-L5 and L5-S1) were excluded. Patients completed the Oswestry Disability Index, the Short Form-36, and the visual analog scale preoperatively and postoperatively at three, six, twelve, and twenty-four months. Computed tomography scans with coronal and sagittal reconstructions were made at three, six, and twelve months postoperatively. Interbody arthrodesis was performed using polyetheretherketone cages, which were filled with 8 mg of rhBMP-2 in the study group and 2.5 mL of autologous bone in the control group.
  
  
  RESULTS
  Baseline demographic data showed no significant difference between groups, except for the body mass index, which was higher in the study group (p = 0.032). There were no significant differences in the clinical results (visual analog scale, Oswestry Disability Index, and Short Form-36) between the groups at each postoperative visit. At three months, end-plate resorption was noted around the cages filled with rhBMP-2 in all patients in the study group. No cage migration or subsidence was observed. Bridging trabecular bone scale scores and bone density measures were significantly lower in the study group. Osteolysis and ectopic bone formation occurred in seven of nineteen patients in the study group and did not occur in the control group. This did not result in radicular symptoms within the time span of this study. At one year, computed tomography scans showed osseous healing in all patients. There were no revision procedures.
  
  
  CONCLUSIONS
  This trial showed no clinical difference when rhBMP-2 was used in posterior lumbar interbody arthrodesis compared with autologous bone. On computed tomography scans, fusion was equally achieved, but trabecular bone formation occurred at a slower rate and interbody bone density was lower within the first year after surgery when rhBMP-2 was used. End-plate resorption, osteolysis, and ectopic bone formation were frequently noted in the rhBMP-2 group.
authors.affiliation: Departments of Orthopaedics and Traumatology, Monica Hospital, Florent Pauwelslei 1, 2100 Antwerp, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Michielsen
authors.forename: J
authors.initials: J
authors.lastname: Sys
authors.forename: A
authors.initials: A
authors.lastname: Rigaux
authors.forename: C
authors.initials: C
authors.lastname: Bertrand
mesh_terms: D000328:Adult; D000368:Aged; D001577:Benzophenones; D001672:Biocompatible Materials; D015519:Bone Density / Q000187:drug effects*; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage / Q000494:pharmacology*; D016723:Bone Remodeling / Q000187:drug effects*; D016025:Bone Transplantation; D005260:Female; D005500:Follow-Up Studies; D006305:Health Status Indicators; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000601:surgery; D007405:Intervertebral Disc Displacement / Q000601:surgery; D007659:Ketones; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000187:drug effects / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011092:Polyethylene Glycols; D011108:Polymers; D011446:Prospective Studies; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology; D013122:Spinal Diseases / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D013168:Spondylolisthesis / Q000601:surgery; D011795:Surveys and Questionnaires; D014057:Tomography, X-Ray Computed; D016212:Transforming Growth Factor beta / Q000008:administration & dosage / Q000494:pharmacology*; D016896:Treatment Outcome
chemical_list: D001577:Benzophenones; D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D007659:Ketones; D011108:Polymers; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; C063834:polyetheretherketone; D011092:Polyethylene Glycols