A method of generating a 3-D patient-specific bone model, the method comprising: (a) acquiring a plurality of raw radiofrequency (“RF”) signals from an A-mode ultrasound scan of a patient's bone at a plurality of locations using an ultrasound probe that comprises a transducer array； (b) tracking the acquiring of the plurality of raw RF signals in 3-D space and generating corresponding tracking data； (c) transforming each of the plurality of raw RF signals into an envelope comprising a plurality of peaks by applying an envelope detection algorithm to each of the plurality of raw RF signals, each peak corresponding with a tissue interface echo； (d) identifying a bone echo from the tissue interface echoes of each of the plurality of raw RF signals to comprise a plurality of bone echoes by selecting the last peak having a normalized envelope amplitude above a preset threshold, wherein the envelope amplitude is normalized with respect to a maximum peak existing in the envelope； (e) determining a 2-D bone contour from the plurality of bone echoes corresponding to each location of the ultrasound probe to comprise 2-D bone contours； (f) transforming the 2-D bone contours into an integrated 3-D point cloud using the tracking data； and, (g) deforming a non-patient specific 3-D bone model corresponding to the patient's bone in correspondence with the integrated 3-D point cloud to generate a 3-D patient-specific bone model.
