Systems and methods for determining position and orientation of a bone of an anatomical feature are described. These include the use of a wearable holder configured to be mounted about an outer-skin surface of the anatomical feature, such that the anatomical feature and the bone are positioned in fixed relation with respect to the wearable holder when the wearable holder is mounted about the anatomical feature. Reference marker arrays are fixedly mounted to the wearable holder, each being positioned on the wearable holder to identify a landmark of the bone within the wearable holder when the wearable holder is mounted to the anatomical feature. The position and orientation of the reference markers are trackable to determine position and orientation of the wearable holder in a reference coordinate system, thereby enabling position and orientation of the landmarks on the bone to be determined.