Systems and methods for estimating anatomic alignment between two or more bones are described herein. An example method can include registering an anatomic reference frame. Additionally, the method can include establishing a respective rotational relationship between each of one or more bones and an orientation sensor attached to each of the one or more bones. The method can also include receiving, from each of the orientation sensors, orientation information, and then calculating an orientation of a bone relative to the anatomic reference frame. The method can further include calculating, using the respective orientations of the bones relative to the anatomic reference frame, an anatomic alignment parameter between first and second bones.
