Methods and systems for installing an implant in an intramedullary canal are discussed. In an example, an intramedullary sounder tool has a sounder head including a plurality of teeth extending proximally from a distal tip towards a shank extending from the sounder head, each tooth comprising a distal cutting edge, a middle scraping edge, and a proximal cutting edge. The sounder head can be advanced into the intramedullary canal until the scraping edge engages cortical bone. If the scraping edge does not engage cortical bone, sounder tools having successively larger diameters can be advanced into the intramedullary canal until a scraping edge does engage the cortical wall, thereby avoiding cutting and damaging of the cortical bone. At such point, the width of the intramedullary canal and the implant used therein can be determined using markings on the shank that indicate the diameter of the sounder head.