4.1 These test methods can be used to determine the effects of head and cone materials, design variables, manufacturing, and other conditions on the static and cyclic load-carrying ability of modular femoral heads mounted on the cones of femoral stem prostheses.

4.2 These test methods may use actual femoral prostheses or neck-cone models of simplified geometry with the same geometrical and material characteristics as in the implants. In either case, the matching metallic cone region of the test specimen selected shall be of the same material, tolerances, and finishing as the final femoral stem prosthesis.

4.3 The static test data may yield valuable information about the relative strengths and merits of different head and cone designs for particular applications. Due to the high forces anticipated for this type of destructive test (>40 kN), the boundary conditions and load levels far exceed possible in vivo loading parameters and therefore may not necessarily be applicable as a quantitative indicator of expected in vivo device performance.

4.4 In the fatigue test methods, it is recognized that actual loading in vivo is quite varied, and that no one set of experimental conditions can encompass all possible variations. Thus, the test methods included here represent a simplified model for the purposes of comparisons between designs and materials. These test methods are intended to be performed in air.

4.5 The test data may yield valuable information about the relative strengths of different head and cone designs.