Active compression apparatus, methods of assembly and methods of use

Abstract Described herein is an active compression bone screw apparatus for generating active compression of bone segments. The apparatus comprises a distal bone engagement portion, a proximal bone engagement portion, and a helical strut configured to promote axial elongation and radial rotation of the apparatus during rotation of said apparatus into said bone segments, said helical strut interposed between the proximal bone engagement portion and the distal bone engagement portion and formed by a perforation through a sidewall of the apparatus. A plurality of radial deformation limiting features are formed along a length of the helical strut, each radial deformation limiting feature formed by an asymmetrically shaped receiving portion and a corresponding asymmetrically shaped protruding portion defined by opposing sides of the helical strut. A first linear side of the receiving portion and a corresponding first linear side of the protruding portion and a second linear side of the receiving portion and a corresponding second linear side of the protruding portion, opposite of the first linear sides of the receiving and protruding portions, are sloped in a same direction relative to a longitudinal central axis of the apparatus and non-parallel to one another.