title: A clinical comparative study on low versus medium viscosity polymethylmetacrylate bone cement in percutaneous vertebroplasty: viscosity associated with cement leakage.
abstract: METHODS
  Comparative, prospective follow-up study.
  
  
  OBJECTIVE
  Comparison of outcome between patients treated with Percutaneous VertebroPlasty (PVP) using low and medium viscosity PolyMethylMetAcrylate (PMMA) bone cement.
  
  
  BACKGROUND
  Viscosity is the characterizing parameter of PMMA bone cement, currently the standard augmentation material in PVP, and influences interdigitation, cement distribution inside the vertebral body, injected volume and extravasation, thereby affecting the clinical outcome of PVP. Currently, low, medium, and high viscosity PMMA bone cements are used interchangeably. However, effect of viscosity on clinical outcome in patients with Osteoporotic Vertebral Compression Fractures (OVCFs) has not yet been explicit subject of investigation.
  
  
  METHODS
  Follow-up was conducted using a 0 to 10 Pain Intensity Numerical Rating Scale (PI-NRS) and the Short Form 36 (SF-36) Quality of Life questionnaire before PVP and at 7 days (PI-NRS only), 1, 3, and 12 months after PVP. Injected cement volume, degree of interdigitation, and cement leakage were analyzed on direct postoperative computed tomography scanning. At 6 and 52 weeks and at suspicion, patients were analyzed for new fractures.
  
  
  RESULTS
  A total of 30 consecutive patients received PVP using low viscosity PMMA bone cement (OsteoPal-V) for 62 OVCFs, followed by 34 patients who received PVP using medium viscosity PMMA bone cement (Disc-O-Tech) for 67 OVCFs. Results regarding PI-NRS and SF-36 were comparable between both groups. Postoperative comparison of injected cement volume, degree of interdigitation, proportion of bipedicular procedures, incidence of new vertebral fractures and complications revealed no differences between both groups. Viscosity was identified as a risk factor for the occurrence of cement leakage (yes/no, OR: 2.925, 95% confidence interval: [1.072-7.984], P = 0.036).
  
  
  CONCLUSIONS
  No major differences in clinical outcome after PVP in OVCFs using low and medium viscosity PMMA bone cement were found. Viscosity of PMMA bone cement was identified as an independent predictor of cement leakage.
authors.affiliation: Department of Orthopedic Surgery, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Nieuwenhuijse
authors.forename: Sander P J
authors.initials: SP
authors.lastname: Muijs
authors.forename: Arian R
authors.initials: AR
authors.lastname: van Erkel
authors.forename: Sander P D
authors.initials: SP
authors.lastname: Dijkstra
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001843:Bone Cements; D005260:Female; D005500:Follow-Up Studies; D050815:Fractures, Compression / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019904:Polymethyl Methacrylate; D011446:Prospective Studies; D011788:Quality of Life; D012044:Regression Analysis; D012307:Risk Factors; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D017211:Treatment Failure; D016896:Treatment Outcome; D054854:Vertebroplasty / Q000379:methods*; D014783:Viscosity
chemical_list: D001843:Bone Cements; D019904:Polymethyl Methacrylate