Bone coupling device and method

A bone coupling device configured for joining a first bone piece to a second bone piece, the device comprising:

• a first component comprising an inner surface bounding a first cavity and a first stem portion having external threads for insertion into the first bone piece;
• a second component comprising a second stem portion having external threads for insertion into the second bone piece and an axially extending connector extending from the second stem portion and configured to be inserted into the first cavity;
• said connector having an outer surface, said outer surface and said inner surface complementarily shaped to inhibit rotation relative to each other when said connector is received in said cavity to engage said first component and said second component;
• each of said outer surface and said inner surface comprises a plurality of longitudinally extending substantially flat surfaces spaced circumferentially from each other about an axis of said first component and said second component, such that contact between said outer surface and said inner surface inhibits rotation of said first component and said second component relative to each other
• wherein inner flat surfaces of said plurality of longitudinally extending substantially flat surfaces forming said inner surface extend longitudinally along an entire length of said first cavity configured to receive said connector;
• wherein two outer flat surfaces of said plurality of longitudinally extending substantially flat surfaces forming said outer surface bound an axially aligned slot extending through said outer surface and along a longitudinal portion of said two outer flat surfaces to allow elastic deformation of said connector;
• wherein said outer surface comprises at least one locking projection having a larger radial dimension relative to a remainder of said outer surface, said at least one locking projection extending outwardly from at least one of said substantially flat surfaces of said outer surface, said at least one locking projection comprising an inclined surface configured to allow at least one of said inner flat surfaces of said first component to move along said inclined surface to said larger radial dimension of said at least one locking projection in response to an axial force engaging said first component and said second component to elastically deform said connector and provide a friction fit between said cavity of said first component and said connector of said second component to inhibit a separation of said connector from said cavity;
• wherein said connector comprises a first end opposite said second stem portion toward said first component and a second end closest to said second stem portion, wherein said at least one locking projection is spaced longitudinally from said first end of said connector by a flat surface portion of said at least one of said substantially flat surfaces of said outer surface and said at least one locking projection is spaced longitudinally from said second end by a second flat surface portion of said at least one of said substantially flat surfaces of said outer surface.