lnfluence of cerclages on primary stability of tumor megaprostheses subjected to distal femur defects
Jahnke A 1, Jakubowitz E 2, Ishaque BA 3, Rickert M 3, Bischel O. 4
Injury. 2016 Feb;47(2):453-9. doi: 10.1016/j.injury.2015.10.031.
Epub 2015 Oct 23. PMID: 26620116
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Paul-Meimberg-Strasse 3, Giessen 35392, Germany.
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Paul-Meimberg-Strasse 3, Giessen 35392, Germany; Laboratory for Biomechanics and Biomaterials (LBB), Department of Orthopaedic Surgery, Hannover Medical School, Anna-von-Borries-Strasse 1-7, Hannover 30628, Germany.
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Paul-Meimberg-Strasse 3, Giessen 35392, Germany; Department of Orthopaedics and Orthopaedic Surgery, University Hospital Giessen and Marburg (UKGM), Klinikstrasse 33, Giessen 35392, Germany.
- Laboratory of Biomechanics, Justus-Liebig-University Giessen, Paul-Meimberg-Strasse 3, Giessen 35392, Germany; Department of Orthopaedics and Traumatology, BG Trauma Centre Ludwigshafen, Ludwig-Guttmann-Strasse. 13, Ludwigshafen 67071, Germany. Electronic address: oliver.bischel@gmx.de.
BACKROUND:
Purpose of this experimental study was to investigate the influence of cerclages on the primary stability of the MUTARS system using distally fractured synthetic femora.
METHODS:
4 MUTARS prostheses were implanted in synthetic femora respectively. Groups consisted of 4 intact bones, 4 fractured with cerclages and 4 fractured bones without cerclages. Spatial micromovements were measured with a high-precision rotational setup.
FINDINGS:
The order from the weakest to the strongest torque transmission of the intact bones was rm1-rm4-rm2-rm3 (p=0.011) and of the fractured bones with cerclages rm4-rm1-rm3-rm2 (p=0.013). The MUTARS stems broke out of the fractured femoral shaft by removing cerclages (p<0.001) and by the influence of bone defect A (p<0.001). Overall micromovements of the intact bones were lower than those of the fractured bones without cerclages (p<0.001) and overall micromovements of the fractured bones with cerclages were lower than those of bones without cerclages (p<0.001).
INTERPRETATION:
Due to high press-fit at the proximal and distal isthmus region fissural fractures of the femur may occur. This should always be taken into account. It is advisable to secure them and provide a prophylaxis for these fissural fractures by means of cerclages.
KEYWORDS:
Cerclage; Distal femur; Femur defects; Megaprostheses; Primary stability; Tumor
PMID: 26620116
DOI: 10.1016/j.injury.2015.10.031