title: Effect of fabrication pressure on the fatigue performance of Cemex XL acrylic bone cement.
abstract: During a cemented arthroplasty, the prepared polymerizing dough of acrylic bone cement is subjected to pressurization in a number of ways; first, during delivery into the freshly prepared bone bed, second, during packing in that bed (either digitally or with the aid of a mechanical device), and, third, during the insertion of the prosthesis. Only a few studies have reported on the influence of the level of pressurization experienced during these events (which, depending on the cementing technique used, has been put at between 8 and 273 kPa) on various properties of the cement. That was the focus of the present study, in which the fully reversed tension-compression (+/-15 MPa; 5 Hz) fatigue lives (expressed as number of cycles to fracture, N(f)) of rectangular cross-sectioned "dog-bone" specimens (Type V, per ASTM D 638) fabricated from Cemex XL cement, at pressure applied continuously to the cement dough during curing in the specimen mold, p=75,150, and 300 kPa, were determined. The N(f) results were analyzed using the linearized transformation of the three-parameter Weibull relationship to obtain estimates of the Weibull mean, N(WM), which was taken to be the index of fatigue performance of the specimen set. Over the range of p studied, N(WM) increased as p increased (for example, from 329,118 cycles when p was 75 kPa to 388,496 cycles when p was 300 kPa); however, the increase was not significant over any pair of p increment steps (Mann-Whitney U-test; alpha<0.05).
authors.affiliation: Department of Mechanical Engineering, The University of Memphis, 316 Engineering Science Building, Memphis, TN 38152-3180, USA. glewis@memphis.edu
authors.forename: Gladius
authors.initials: G
authors.lastname: Lewis
authors.forename: S I
authors.initials: SI
authors.lastname: Janna
mesh_terms: D019245:Compressive Strength; D008422:Materials Testing / Q000379:methods*; D019904:Polymethyl Methacrylate / Q000138:chemical synthesis / Q000737:chemistry*; D011312:Pressure; D013718:Tensile Strength
chemical_list: D019904:Polymethyl Methacrylate