title: Evaluation of cyanoacrylate augmentation of transpedicular screw pullout strength.
abstract: OBJECTIVE
  Pedicle screw fixation of osteoporotic bone in the elderly is a challenge. Various augmentation methods have been studied by many authors. Although polymethylmethacrylate (PMMA) augmentation is believed to be a standard method, its usage is fraught with complications. Butyl-2-cyanoacrylate is an alternative to PMMA as it is bioresorbable, biocompatible, inexpensive, and noninfective. The objective of the current study was to determine the pullout strength of the pedicle screws when butyl-2-cyanoacrylate is used for augmentation.
  
  
  METHODS
  Fresh calf lumbar vertebrae were obtained from male calves weighing 100-120 kg and implanted with pedicle screws. The screws were placed in native, unaugmented bone (group 1), butyl-2-cyanoacrylate-augmented bone (group 2), and PMMA-augmented bone (group 3). Axial pullout tests were done by an Instron 4411 universal testing machine. Statistical analysis was performed using the SPSS 9.0 for Windows program. Paired samples t test was used, and P < 0.05 was considered significant.
  
  
  RESULTS
  The mean bone mineral density of the vertebrae was 1.6 +/- 0.1 g/cm2. The mean pullout strengths were 1.55 +/- 0.23 kN for group 1, 1.62 +/- 0.42 kN for group 2, and 2.55 +/- 0.22 kN for group 3. There was no statistically significant difference between groups 1 and 2. PMMA augmentation increased the pullout strength significantly when compared with butyl-2-cyanoacrylate augmentation and native bone (P = 0.002 and P = 0.001, respectively).
  
  
  CONCLUSIONS
  The results of this study show that butyl-2-cyanoacrylate has no contribution to the augmentation of pedicle screw fixation in a calf model when compared with native bone or PMMA augmentation. Further studies are required to evaluate the effectiveness of butyl-2-cyanoacrylate in osteoporotic specimens and under cyclic loading in calf vertebra and animal and cadaver models before dispensing with its utility as an augmentation method in the clinical setting.
authors.affiliation: Department of Orthopedics and Traumatology, Faculty of Medicine, University of Mersin, Mersin, Turkey. amilcan@mersin.edu.tr
authors.forename: Abtullah
authors.initials: A
authors.lastname: Milcan
authors.forename: Irfan
authors.initials: I
authors.lastname: Ayan
authors.forename: Adalet
authors.initials: A
authors.lastname: Zeren
authors.forename: Tamer
authors.initials: T
authors.lastname: Sinmazcelik
authors.forename: Ali
authors.initials: A
authors.lastname: Yilmaz
authors.forename: Muzaffer
authors.initials: M
authors.lastname: Zeren
authors.forename: Fehmi
authors.initials: F
authors.lastname: Kuyurtar
mesh_terms: D000268:Adhesiveness; D000818:Animals; D001843:Bone Cements / Q000627:therapeutic use; D001863:Bone Screws; D002417:Cattle; D002484:Cementation / Q000379:methods*; D004659:Enbucrilate / Q000627:therapeutic use*; D019544:Equipment Failure Analysis; D066298:In Vitro Techniques; D008159:Lumbar Vertebrae / Q000187:drug effects / Q000503:physiopathology* / Q000601:surgery*; D008297:Male; D013718:Tensile Strength
chemical_list: D001843:Bone Cements; D004659:Enbucrilate