Patent ID: 7815648

Claim:
A method of conducting measurements on a spine of a patient through the use of a measurement tool comprising a registration interface, a contact feature, and a displacement structure that couples the contact feature to the registration interface, the method comprising: attaching a frame directly to a first bone portion such that the frame abuts the first bone portion; coupling the registration interface to the first bone portion, wherein the registration interface comprises a bore having a noncircular shape, wherein the first bone portion is part of the spine, wherein coupling the registration interface to the first bone portion comprises inserting a post of the frame into the bore to couple the registration interface to the first bone portion, wherein coupling the registration interface to the first bone portion comprises limiting relative translation between the registration interface and the first bone portion along three nonparallel directions; restricting relative rotation between the registration interface and the first bone portion in response to coupling of the registration interface to the first bone portion; moving the displacement structure to position the contact feature in contact with a bony landmark, wherein the bony landmark is part of the spine; and acquiring data from the displacement structure to indicate a displacement of the bony landmark with respect to the registration interface in at least two dimensions.