gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2022)

25. - 28.10.2022, Berlin

Investigation of screw osseointegration enhancement by extracellular vesicles (EV) and bone morphogenetic protein 2 (BMP-2) in a rat animal model – a novel study design

Meeting Abstract

  • presenting/speaker Christian Deininger - Universitätsklinik für Orthopädie und Traumatologie, Institut für Sehnen- und Knochenregeneration (SCI-TReCS), Salzburg, Austria
  • Florian Wichlas - Universitätsklinik für Orthopädie und Traumatologie, Salzburg, Austria
  • Thomas Freude - Universitätsklinik für Orthopädie und Traumatologie, Salzburg, Austria
  • Herbert Tempfer - Paracelsus Medizinische Privatuniversität, Institut für Sehnen- und Knochenregeneration (SCI-TReCS), Salzburg, Austria
  • Nadja Weißenbacher - Paracelsus Medizinische Privatuniversität, Institut für Sehnen- und Knochenregeneration (SCI-TReCS), Salzburg, Austria
  • Amelie Deluca - Paracelsus Medizinische Privatuniversität, Institut für Sehnen- und Knochenregeneration (SCI-TReCS), Salzburg, Austria
  • Andrea Wagner - Paracelsus Medizinische Privatuniversität, Institut für Sehnen- und Knochenregeneration (SCI-TReCS), Salzburg, Austria
  • Andreas Traweger - Paracelsus Medizinische Privatuniversität, Institut für Sehnen- und Knochenregeneration (SCI-TReCS), Salzburg, Austria

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2022). Berlin, 25.-28.10.2022. Düsseldorf: German Medical Science GMS Publishing House; 2022. DocAB56-219

doi: 10.3205/22dkou420, urn:nbn:de:0183-22dkou4201

Veröffentlicht: 25. Oktober 2022

© 2022 Deininger et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objectives: Particularly in osteoporotic bone, loosening of osteosynthesis material is a well-known problem in clinical practice. This leads to secondary fracture dislocation and non-healing. The aim of this study is to improve the stability of screws inserted into bone by adding Extracellular Vesicles (EVs) or Bone-Morphogenetic-Protein-2 (BMP-2) with alginate (Alg) as a carrier material.

Methods: Operations were performed on 30 rats (Sprague Dawley). These were divided into 3 groups of equal size: Alg only, Alg EV, and Alg BMP-2. To analyze the osseointegration, a novel surgical procedure and biomechanical protocol were established. Here, a diaphyseal fracture was created with a Gigli saw (0.66 mm) and angular stable 5-hole plate osteosynthesis was placed with four 1.5 mm screws. The 4.0mm long proximal and distal screws were placed monocortically in a 2.0mm hole that was too wide, so the screw had no contact area with the surrounding bone. The hole was filled with the substances mentioned above. The 2 screws next to the osteotomy were placed bicortically to stabilize the fracture. After the endpoint was reached 6 weeks postoperatively, µ-CT, and a biomechanics pull-out test and a stiffness analysis were performed.

Results and conclusion: The novel study design and the examinations were well feasible. The µ-CT scan shows significantly more Bone Volume/Tissue Volume in the BMP-2 treated group compared to the EV treated one (*p= 0.0203). The screw-bone contact area was also significantly increased in the BMP-2 treated group compared to the EV treated (**p= 0.0063) group, the contact area was significantly increased in the Alg only group compared to the Alg EV group (*p= 0.0438), too. The biomechanical pull-out test showed a significant increase of the maximal force of the BMP-2 treated group compared to the EV treated one (*p= 0.0240). The stiffness of the BMP-2 treated group was significantly higher compared to the Alg EV group (*p= 0.0414) and the Alg only group (*p= 0.0363).

Figure 1 [Fig. 1]

The results of the µ-CT scans and the biomechanics studies indicate that the use of BMP-2 can improve the osseointegration of osteosynthesis materials. The use of EVs seems to have a rather negative effect on osseointegration in this animal model.