A method of generating a 3-D patient-specific musculoskeletal model, the method comprising: acquiring a plurality of radio frequency ("RF") signals (142) across a plurality of locations using an ultrasound probe (60) comprising a transducer array (68)； tracking the acquiring of the plurality of RF signals (142) in 3D space and generating tracking data； identifying a plurality of bone echoes (162a) in the plurality of RF signals (142)； determining 2-D bone contours (180) from the plurality of bone echoes (162a)； transforming the 2-D bone contours (180) into a 3-D point cloud (194) using the tracking data； and creating a 3-D patient-specific musculoskeletal model (260) by deforming a 3-D bone model into conformity with the 3-D point cloud (194), where deforming the 3-D bone model includes using an optimization algorithm to change shape descriptors that deform the 3-D model.
