Biomechanical Evaluation of a New Bone Cement for Use in Vertebroplasty

Spine (Phila Pa 1976). 2000 May 1;25(9):1061-4. doi: 10.1097/00007632-200005010-00004.

Abstract

Study design: Comparative ex vivobiomechanical study.

Objectives: To determine the strength and stiffness of osteoporotic vertebral bodies subjected to compression fractures and subsequently stabilized via bipedicular injection of one of two bone cements: one is a commercially available polymethylmethacrylate (Simplex P) and one is a proprietary glass-ceramic-reinforced BisGMA/BisEMA/TEGDMA matrix composite that is being developed for use in vertebroplasty (Orthocomp).

Summary of background data: Osteoporotic compression fractures present diagnostic and therapeutic challenges for the clinician. Vertebroplasty, a new technique for treating such fractures, stabilizes vertebral bodies by injection of cement. Little is known, however, about the biomechanics of this treatment.

Methods: Five vertebral bodies (L1-L5) from each of four fresh spines were harvested from female cadavers (age, 80 +/- 5 years), screened for bone density using DEXA (t = -3.4 to -6.4), disarticulated, and compressed in a materials testing machine to determine initial strength and stiffness. The fractures then were repaired using a transpedicular injection of either Orthocomp or Simplex P and recrushed.

Results: For both cement treatments, vertebral body strength after injection of cement was significantly greater than initial strength values. Vertebral bodies augmented with Orthocomp recovered their initial stiffness; however, vertebral bodies augmented with Simplex P were significantly less stiff than they were in their initial condition.

Conclusions: Augmentation with Orthocomp results in similar or greater mechanical properties compared with Simplex P, but these biomechanical results have yet to be substantiated in clinical studies.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Analysis of Variance
  • Biocompatible Materials / therapeutic use*
  • Biomechanical Phenomena
  • Bone Cements / therapeutic use*
  • Female
  • Humans
  • Lumbar Vertebrae / injuries
  • Lumbar Vertebrae / surgery
  • Methylmethacrylate / therapeutic use*
  • Osteoporosis / surgery*
  • Spinal Fractures / surgery*

Substances

  • Biocompatible Materials
  • Bone Cements
  • Methylmethacrylate