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

Gianluca Giavaresi, Milena Fini, Roberto Giardino, Francesca Salamanna, Maria Sartori, Veronica Borsari, Silvia Spriano, Chiara M. Bellini, Marco Brayda-Bruno

Research output: Contribution to journalArticle


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.

Original languageEnglish
Pages (from-to)1289-1296
Number of pages8
JournalEuropean Spine Journal
Issue number8
Publication statusPublished - Aug 2011



  • Osseointegration
  • Osteoporosis
  • Pedicle screws
  • Surface treatment

ASJC Scopus subject areas

  • Surgery
  • Orthopedics and Sports Medicine

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