Non-invasive system and method for tracking bones

A system for determining a position and an orientation of a bone of an anatomical feature, the bone underlying an outer-skin surface of the anatomical feature, the system comprising:

• a wearable holder for enclosing at least part of the outer-skin surface of the anatomical feature, wherein the wearable holder is a boot for enclosing the outer-skin surface of a foot and the outer-skin surface of a lower leg, the anatomical feature and the bone being positioned in fixed relation with respect to the holder when the wearable holder is mounted about the anatomical feature;
• a plurality of holder imaging devices including a first holder imaging device fixedly mounted to the wearable holder at a first position and at least a second holder imaging device fixedly mounted to the wearable holder at a second position spaced apart from the first position, the first holder imaging device configured to obtain an image of a first landmark of the bone at a time interval and the at least second holder imaging device configured to obtain an image of a second landmark of the bone different from the first landmark at the same time interval;
• a bone imaging device separate from the plurality of holder imaging devices and configured to obtain a pre-operative image of the bone in its entirety including at least two landmarks of the bone and other surfaces of the bone, the position and the orientation of the at least two landmarks and the other surfaces of the bone in the pre-operative image being known in a reference coordinate system;
• and
• a processing unit configured to compare the images of the first and second landmarks at said time interval to the at least two landmarks in the pre-operative image, and to match the images of the first and second landmarks to the at least two landmarks in the pre-operative image in order to determine the position and the orientation of any portion of a remainder of the bone in the reference coordinate system at said time interval.