title: The Influences of Different Ratios of Biphasic Calcium Phosphate and Collagen Augmentation on Posterior Lumbar Spinal Fusion in Rat Model.
abstract: OBJECTIVE
  To determine the influence of different ratios of hydroxyapatite (HA)/beta tricalcium phosphate (β-TCP) and collagen augmentation for posterior lumbar fusion in a rat model.
  
  
  METHODS
  We generated a posterior lumbar fusion model in 50 rats and divided it into five groups of equal number as follows; 1) autologous bone graft as group A, 2) 70% HA+30% β-TCP as group B, 3) 70% HA+30% β-TCP+collagen as group C, 4) 30% HA+70% β-TCP as group D, and 5) 30% HA+70% β-TCP+collagen as group E. Rats were euthanized at 12 weeks after surgery and fusion was assessed by manual palpation, quantitative analysis using microCT and histology.
  
  
  RESULTS
  The score of manual palpation was significantly higher in group C than group E (3.1±1.1 vs. 1.8±0.8, p=0.033). However, in terms of microCT analysis, group D showed significantly higher scores than group B (5.5±0.8 vs. 3.1±1.1, p=0.021). According to quantitative volumetric analysis, 30% HA+70% β-TCP groups (group D and E) showed significantly reduced fusion mass at 12 weeks after surgery (123±14.2, 117±46.3 vs. 151±27.3, p=0.008, 0.003, respectively). Collagen augmentation groups revealed superior results in terms of both microCT score and histologic grade.
  
  
  CONCLUSIONS
  A 7:3 HA/β-TCP ratio with collagen augmentation rather than a 3:7 HA/β-TCP ratio could be a more favorable graft substitute for lumbar spinal fusion. There was positive role of collagen as an adjunct for spinal bone fusion process.
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kyung Hyun
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jeong Yoon
authors.initials: JY
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyo Suk
authors.initials: HS
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Keun Su
authors.initials: KS
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Dong Kyu
authors.initials: DK
authors.lastname: Chin
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yong Eun
authors.initials: YE
authors.lastname: Cho
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea. kuhsu@yuhs.ac.
authors.forename: Sung Uk
authors.initials: SU
authors.lastname: Kuh
mesh_terms: D000818:Animals; D016025:Bone Transplantation; D003094:Collagen / Q000008:administration & dosage*; D006882:Hydroxyapatites / Q000008:administration & dosage*; D010173:Palpation; D019736:Prostheses and Implants; D051381:Rats; D013123:Spinal Fusion / Q000379:methods*; D014182:Transplantation, Autologous; D055114:X-Ray Microtomography
chemical_list: D006882:Hydroxyapatites; C074950:hydroxyapatite-beta tricalcium phosphate; D003094:Collagen
keywords: Biphasic calcium phosphate; collagen; fusion; hydroxyapatite; rat; β-TCP