Spin precession along circular orbits in the Kerr spacetime: the   Frenet-Serret description
  The circular motion of spinning massive test particles in the equatorial plane of a rotating black hole is investigated in the case in which the components of the spin tensor are allowed to vary along the orbit. 
Donato Bini, Fernando de Felice, Andrea Geralico, Robert T. Jantzen
gr-qc