title: Effectiveness of Posterolateral Lumbar Fusion Varies with the Physical Properties of Demineralized Bone Matrix Strip.
abstract: METHODS
  A randomized, controlled animal study.
  
  
  OBJECTIVE
  To investigate the effectiveness of fusion and new bone formation induced by demineralized bone matrix (DBM) strips with jelly strengths.
  
  
  BACKGROUND
  The form of the DBM can make a difference to the outcome. The effect of different jelly strengths on the ability of DBM to form new bone is not known.
  
  
  METHODS
  Forty-eight rabbits were randomized into a control group and two experimental groups. In the control group (group 1), 1.4 g of autologous iliac crest bone was placed bilaterally. In the experimental groups, a high jelly strength DBM-hyaluronic acid (HA)-gelatin strip (group 2) and a low jelly strength DBM-HA-gelatin strip (group 3) were used. The fusion was assessed with manual manipulation and radiographs. The volume of the fusion mass was determined from computed tomographic images.
  
  
  RESULTS
  The fusion rates as determined by manual palpation were 37.5%, 93.8% and 50.0% in group 1, group 2, and group 3, respectively (p<0.05). By radiography, the fusion rate of High jelly strength DBM strip was statistically significantly greater than that of the other alternatives (p<0.05). The mean bone volume of the fusion mass as determined by computed tomography was 2,142.2±318.5 mm(3), 3,132.9±632.1 mm(3), and 2,741.5±380.4 mm(3) in group 1, group 2, and group 3, respectively (p<0.05).
  
  
  CONCLUSIONS
  These results indicate that differences in the structural and mechanical properties of gelatin that are associated with jelly strength influenced cellular responses such as cell viability and bony tissue ingrowth, facilitating greater bone fusion around high jelly strength implants.
authors.affiliation: Department of Orthopaedics, Kwangju Christian Hospital, Gwangju, Korea.
authors.forename: Yong-Soo
authors.initials: YS
authors.lastname: Choi
authors.affiliation: Department of Orthopaedics, Kwangju Christian Hospital, Gwangju, Korea.
authors.forename: Dae-Hee
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Department of Orthopaedics, Kwangju Christian Hospital, Gwangju, Korea.
authors.forename: Ji-Hun
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Orthopaedics, Oregon Health and Science University, Portland, OR, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Johnstone
authors.affiliation: Department of Orthopaedics, Oregon Health and Science University, Portland, OR, USA.
authors.forename: Jung-U
authors.initials: JU
authors.lastname: Yoo
keywords: Demineralized bone matrix; Spinal fusion