A bone resection system for a prosthetic implant having an anterior and posterior outer surface attached to bone has a cutting guide having slotted guide surfaces thereon mountable on the prosthetic implant. The guide surfaces are alignable with the implant outer anterior and posterior surfaces. A saw comprising a housing having spaced apart first and second sides joined by first and second edge surfaces and having a proximal end and a distal end can be inserted into the slotted guide surfaces. A cutting head drive system on the housing drives a cutting head having teeth extending outwardly of the distal end of the housing. A cam element is mounted on the saw housing intermediate the proximal and the distal ends. The cam element has a distal end with a guide arm extending therefrom engagable, during insertion, with the guide surface on the cutting guide. The cam element having a stop surface for engaging a stop surface on the cutting guide to limit blade travel.
