1. A probe for guiding placement of an identifier relative to an orthopaedic implant, comprising: an elongated element that includes an anti-rotation feature, the anti-rotation feature comprising a non-circular cross-sectional geometry of at least a portion of the elongated element, wherein the elongated element is configured to engage a stop at any of a plurality of points along a length of the elongated element, wherein the elongated element comprises a plurality of detents, wherein at least a portion of the elongated element has a longitudinal axis that has a natural curvature, and wherein the elongated element is configured to limit rotation of the elongated element relative to the stop when the elongated element is received through a slot in the stop; and a magnetic sensor coupled to the elongated element.