[Mechanical in vitro testing of fifteen commercial bone cements based on polymethylmethacrylate].
INTRODUCTION The long-term stability in cemented hip arthroplasty depends not only on the mechanical properties of the acrylic bone cements but also on an improvement of cementing techniques.


METHODS
The bending strengths of 15 commonly used bone cements (CMW 3 Gentamycin; CMW 3; Refobacin Palacos R; Palacos R; Palamed G; Palamed; Cerafixgenta; Cerafix; Duracem; Simplex Tobramycin; Simplex P; Versabond; Sulcem; Sulcem 3 Genta; Copal) have been mechanically tested in a standardised in vitro four-point bending test (ISO 5833). The fatigue fracture surfaces were morphologically analysed with light microscopy.


RESULTS
The highest values of bending strength were found in vacuum mixed specimens cured under pressure. The lowest values of strength were seen in with blood contaminated specimens. Fatigue cracks were often initiated from air bubbles or other inclusions such as antibiotics or blood in the bone cement.


CONCLUSIONS
The present in vitro study highlights the supposition that the quality of the cementing technique is of eminent importance in determining the long-term stability of cemented hip arthroplasties.
Gravius
S
S
Universitätsklinik für Orthopädie und Unfallchirurgie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn. sascha.gravius@web.de
Wirtz
D C
DC
Marx
R
R
Maus
U
U
Andereya
S
S
Müller-Rath
R
R
Mumme
T
T
D019644:Arthroplasty, Replacement, Hip; D001843:Bone Cements / Q000592:standards*; D046169:Dermoscopy; D004548:Elasticity; D019544:Equipment Failure Analysis; D006801:Humans; D066298:In Vitro Techniques; D019904:Polymethyl Methacrylate / Q000592:standards*; D011786:Quality Control; D013499:Surface Properties; D013718:Tensile Strength; D014618:Vacuum
D001843:Bone Cements; D019904:Polymethyl Methacrylate