Orthopedic Cement Technique

Polymethylmethacrylate (PMMA): bone cement Propertieis

• no adhesive properties.  Works as grout, not glue.
• does not chemically bond to bone or implants
• three times stronger in compression than tension.
• peak blood levels of monomer occur 3 minutes after the cement is placed.
• monomer is cleared by the lungs.
• hypotension associated with cement is more closely related to diminished blood volume than to circulating monomer levels.
• Higher porosity = decreased tensile and fatigue strength. Manually mixed = 27%. Vacuum mixed = 1%
• Antibiotics in cement does not appreciably affect compressive or tensile forces.  Fatigue strength may be reduced.

Third-generation cement technique:  porosity reduction techniques, centralization devices, and surface modifications to the femoral component.