There is a genuine dispute for trial as to whether the anatomical model is a useful article under the copyright law, since the question is not the tactile uses to which it might be put in an educational context, but rather whether its usefulness arises from the fact that it correctly depicts the human frame.
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.