Bone-methyl methacrylate interfacial shear strength: an experimental study of dogs.

Bone-methyl methacrylate interfacial shear strength at failure in chronically implanted hip prostheses was studied. Gorman total hip prostheses fixed with methyl methacrylate bone cement were implanted in 6 large dogs. Interface shear strength studies were performed at 8, 16, and 24 weeks. Mechanical testing determined that the mean interfacial shear strength was 15.2 +/- 13.0 kg/cm2. Variability of the data was too great to allow conclusions to be drawn from statistical analysis, but trends in the data were observed. It was concluded that the interfacial bond had sufficient strength to withstand axial loads 3 to 6 times greater than those applied under normal physiologic conditions.