A device for treating a spine includes a proximal component positioned partially or entirely within a first vertebra and a distal component positioned partially or entirely within a second vertebra and may also include an intermediate component. A method for treating a spine includes forming a curved channel that extends through a first vertebra from a pedicle to an endplate, and advancing the components through the curved channel, the orientation of the proximal component relative to the distal component changing by at least 40 degrees while the proximal component passes through the curved channel. In another aspect, a method for treating a spine includes forming a curved channel that has a pedicle region, a central region, and an endplate region, where the channel diameter for the central region is larger than the channel diameter for the pedicle region or the endplate region, and advancing an implant through the channel.