The present disclosure relates to polyaxial bone screws and methods that enable the positioning of the polyaxial bone screws to be reliably determined using a surgical navigation system including a navigation probe. In an embodiment, a polyaxial bone screw comprises a threaded shaft inserted in bone and a head connected to the shaft, the head being rotatable relative to the shaft about a centre of rotation of the head of the bone screw. The position of a navigation probe is monitored using a navigation device. A first mating surface of the head of the bone screw is engaged with a second mating surface of the navigation probe； and the location of the centre of rotation of the head of the bone screw is determined based on the monitored position of the navigation probe when the first mating surface and the second mating surface are engaged.
