In vivo preclinical evaluation of the influence of osteoporosis on the anchorage of different pedicle screw designs

Eur Spine J. 2011 Aug;20(8):1289-96. doi: 10.1007/s00586-011-1831-5. Epub 2011 May 5.

Abstract

We investigate the anchorage of pedicle screws with different surface treatments in osteoporotic bone. Eight ewes were divided into two groups of four animals each: four sheep underwent bilateral ovariectomy (OVX Group), whereas the operation was simulated in the remaining group (SHAM Group). Eighteen months after the first operation, the Dynesys(®) System was fitted to the sheep using pedicle screws with three different surface treatments: untreated, rough blasted (uncoated) and bioactive coated (bioactive). Uncoated screws showed a significantly higher bone ingrowth value compared with the untreated screws in the OVX group (9.3%, p < 0.005) and a significantly lower bone ingrowth value in the SHAM group (-11.0%, p < 0.05). Furthermore, the bioactive pedicle screws had a significant lower bone ingrowth value than the untreated screws in the SHAM group (-12.1%, p < 0.05). These results suggest that both tested surface treatments of pedicular screws may provide an advantage in terms of bone quality and osseointegration, when implanted in osteoporotic vertebrae.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Animals
  • Bone Screws / standards*
  • Disease Models, Animal
  • Equipment Design / methods
  • Female
  • Osseointegration / physiology*
  • Osteoporotic Fractures / diagnostic imaging
  • Osteoporotic Fractures / pathology*
  • Osteoporotic Fractures / surgery*
  • Radiography
  • Sheep, Domestic
  • Spinal Fractures / diagnostic imaging
  • Spinal Fractures / pathology*
  • Spinal Fractures / surgery*
  • Spinal Fusion / instrumentation*
  • Spinal Fusion / methods