title: Reduction of cement leakage by sequential PMMA application in a vertebroplasty model.
abstract: Leakage is the most common complication of percutaneous cement augmentation of the spine. The viscosity of the polymethylmethacrylate (PMMA) cement is strongly correlated with the likelihood of cement leakage. We hypothesized that cement leakage can be reduced by sequential cement injection in a vertebroplasty model.
  
  
  
  A standardized vertebral body substitute model, consisting of aluminum oxide foams coated by acrylic cement with a preformed leakage path, simulating a ventral vein, was developed. Three injection techniques of 6 ml PMMA were assessed: injection in one single step (all-in-one), injection of 1 ml at the first and 5 ml at the second step with 1 min latency in-between (two-step), and sequential injection of 0.5 ml with 1-min latency between the sequences (sequential). Standard PMMA vertebroplasty cement was used; each injection type was tested on ten vertebral body substitute models with two possible leakage paths per model. Leakage was assessed by radiographs using a zonal graduation: intraspongious = no leakage and extracortical = leakage.
  
  
  
  The leakage rate was significantly lower in the "sequential" technique (2/20 leakages) followed by "two-step" (15/20) and "all-in-one" (20/20) techniques (p < 0.001). The RR for a cement leakage was 10.0 times higher in the "all-in-one" compared to the "sequential" group (95 % confidence intervals 2.7-37.2; p < 0.001).
  
  
  
  The sequential cement injection is a simple approach to minimize the risk for leakage. Taking advantage of the temperature gradient between body and room temperature, it is possible to increase the cement viscosity inside the vertebra while keeping it low in the syringe. Using sequential injection of small cement volumes, further leakage paths are blocked before further injection of the low-viscosity cement.
authors.affiliation: Department of Orthopedic Surgery and Traumatology, Inselspital Bern, Bern University Hospital, 3010, Bern, Switzerland. svenhoppe@gmail.com.
authors.forename: Sven
authors.initials: S
authors.lastname: Hoppe
authors.affiliation: Department of Orthopedic Surgery and Traumatology, Inselspital Bern, Bern University Hospital, 3010, Bern, Switzerland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Wangler
authors.affiliation: Institute for Evaluative Research in Medicine, University of Bern, Bern, Switzerland.
authors.forename: Emin
authors.initials: E
authors.lastname: Aghayev
authors.affiliation: Institute for Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Gantenbein
authors.affiliation: Ansbach University of Applied Science, Ansbach, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Boger
authors.affiliation: Department of Orthopedic Surgery and Traumatology, Inselspital Bern, Bern University Hospital, 3010, Bern, Switzerland.
authors.forename: Lorin M
authors.initials: LM
authors.lastname: Benneker
mesh_terms: D001843:Bone Cements / Q000009:adverse effects*; D006801:Humans; D008954:Models, Biological; D019904:Polymethyl Methacrylate / Q000627:therapeutic use*; D011183:Postoperative Complications / Q000517:prevention & control*; D016103:Spinal Fractures / Q000601:surgery*; D054854:Vertebroplasty / Q000009:adverse effects / Q000379:methods
chemical_list: D001843:Bone Cements; D019904:Polymethyl Methacrylate
keywords: Cement extravasation; Cement viscosity; Extraosseous leakage; Safety; Vertebroplasty; Vertebroplasty model
references.citation: Eur Spine J. 2009 Sep;18(9):1272-8
references.pmid: 19479285
references.citation: AJNR Am J Neuroradiol. 1997 Nov-Dec;18(10 ):1897-904
references.pmid: 9403451
references.citation: Eur Spine J. 2004 Oct;13(6):496-501
references.pmid: 15083353
references.citation: J Neurosurg. 2002 Jan;96(1 Suppl):56-61
references.pmid: 11795714
references.citation: AJNR Am J Neuroradiol. 2010 Mar;31(3):504-8
references.pmid: 20044508
references.citation: Eur Spine J. 2010 Nov;19(11):1913-20
references.pmid: 20725752
references.citation: Spine J. 2011 Sep;11(9):839-48
references.pmid: 21889417
references.citation: Eur Spine J. 2013 Oct;22(10):2241-8
references.pmid: 23775292
references.citation: Spine (Phila Pa 1976). 2008 Nov 1;33(23):E906-10
references.pmid: 18978585
references.citation: Eur Spine J. 2012 Sep;21(9):1826-43
references.pmid: 22543412
references.citation: Acta Radiol. 2007 Oct;48(8):854-9
references.pmid: 17924216
references.citation: Spine (Phila Pa 1976). 2010 Feb 1;35(3):353-60
references.pmid: 20075781
references.citation: AJR Am J Roentgenol. 2005 Apr;184(4):1364-5
references.pmid: 15788629
references.citation: Biomaterials. 2003 Jul;24(16):2721-30
references.pmid: 12711518
references.citation: Spine (Phila Pa 1976). 2006 Aug 1;31(17):1983-2001
references.pmid: 16924218
references.citation: Spine (Phila Pa 1976). 2014 Feb 27;:null
references.pmid: 24583722
references.citation: AJR Am J Roentgenol. 2004 Oct;183(4):1097-102
references.pmid: 15385313
references.citation: Lancet. 2010 Sep 25;376(9746):1085-92
references.pmid: 20701962
references.citation: Spine (Phila Pa 1976). 2006 Oct 15;31(22):2562-8
references.pmid: 17047545