Abstract: Various embodiments of a variable diameter calcar planer for reaming a boney surface and associated methods of using the same are disclosed. An example device may include a cylindrical body defining a longitudinal axis extending from a proximal end to a distal end and a positioning ring disposed at the distal end. Various devices may include plurality of primary blades that are radially disposed on the positioning ring that are configured for reaming at the first diameter. Various devices may include a collar disposed around the cylindrical body and axially aligned with the longitudinal axis, for example. Some devices may further include a plurality of secondary blades, configured to expand a reaming area by moving the collar towards the distal end. In various embodiments, the collar facilitates reaming of a boney surface at various diameters by moving the blades laterally outward with respect to the longitudinal axis.