I have watched and peripherally participated in the development of navigated knee replacement over the last 5 years. After a CT analysis of a number of my cases I became aware of the deficiencies of my instrumented approach. What I desired was a method that would allow avoidance of rodding the femur. And a way of more accurately reproducing posterior slope. I am currently using the Articular Surface Mounted system by Stryker with the Triathlon knee system. I am presenting this as a technique that we are currently evaluating.