A femoral component instrument includes a rotatable locking mechanism such as a post and is capable of interchangeable use between posterior stabilizing (“PS”) and cruciate retaining (“CR”) femoral component types via the locking mechanism. The instrument further includes a modular pad so that a pad specific to the prosthesis type may be chosen. Each pad of a particular femoral component type is useable with a variety of sizes of that femoral component type. The locking mechanism of the instrument is alternatively useable with a variety of femoral component types. The locking end of the post keys to a pad aperture to rotatably align the post to an appropriate securement position. If a femoral component is not locked to the pad, the post of the instrument moves from an exposed position proximal to the proximal pad surface to a retracted position distal to the proximal pad surface, thereby permitting impaction.