title: Efficacy of silicate-substituted calcium phosphate ceramic in posterolateral instrumented lumbar fusion.
abstract: METHODS
  Retrospective review of a consecutive, nonrandomized series operated on by 2 surgeons.
  
  
  OBJECTIVE
  To evaluate the clinical and radiographic effectiveness of a silicated hydroxyapatite ceramic as a bone graft substitute in a series of patients undergoing posterolateral instrumented lumbar fusion.
  
  
  BACKGROUND
  Newer-generation synthetic ceramics have been refined to maximize their host-graft interaction and stimulation of new tissue formation, including silicate-substitution.
  
  
  METHODS
  An independent radiologist interpreted the computed tomography images at 6, 12, and 24 months after surgery. Forty-two patients with 1- or 2-level lumbar degenerative disorders underwent posterior laminectomy (when indicated) and posterolateral fusion with instrumentation. Surgical levels included 15 patients who underwent 2-level and 27 single-level fusion procedures (57 levels operated on in total).
  
  
  RESULTS
  The average back pain scores improved from 5.6 ± 2.5 preoperative to 2.1 ± 2.5 at follow-up (P < 0.05). Similar results were seen with leg pain improvement from 5.8 ± 2.5 to 1.4 ± 1.9 (P < 0.05). At 6 months, 35% of levels revealed fusion, which increased to 76.2% and 76.5% at 12 and 24 months, respectively. No evidence of ectopic bone formation or osteolysis was noted.
  
  
  CONCLUSIONS
  In this study, a silicated calcium phosphate-based ceramic has been shown to be effective as a graft substitute and eliminate the need for autogenous iliac crest bone graft. The results confirm radiographic healing in posterolateral instrumented lumbar fusion at 24-months follow-up. The clinical outcomes also substantiate significant pain improvement consistent with published data in the literature compared with other bone graft alternatives.
authors.affiliation: Boston Spine Group, Newton, MA, USA. ljenis@partners.org
authors.forename: Louis G
authors.initials: LG
authors.lastname: Jenis
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Banco
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002130:Calcium Phosphates / Q000627:therapeutic use*; D002516:Ceramics / Q000627:therapeutic use*; D017886:Durapatite / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010012:Osteogenesis; D010014:Osteolysis; D010146:Pain / Q000453:epidemiology; D011446:Prospective Studies; D011859:Radiography; D012189:Retrospective Studies; D017640:Silicates / Q000627:therapeutic use*; D013123:Spinal Fusion / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D002130:Calcium Phosphates; D017640:Silicates; D017886:Durapatite; C020243:calcium phosphate