Device for rotational stabilization of bone segments

A device for rotational stabilization of bone segments comprising:

• a bone lag screw having a bone-engagement end, a distal end, and a keyed cross-sectional profile, the bone-engagement end configured for engaging a first bone segment;
• a bone plate having a flat portion for engaging a second bone segment and a barrel portion having an internal bore for slidably receiving the lag screw;
• and
• a substantially cylindrical locking collar having a proximal end, a distal end, a hollowed cylindrical interior, a keyed internal profile and a plurality of deformable tabs at the distal end;
• wherein the keyed internal profile mates with the keyed cross-sectional profile of the lag screw to rotationally couple the locking collar and the lag screw when the lag screw is inserted through the locking collar, and the locking collar is configured and dimensioned for (1) free rotation, in a first position, within the internal bore of the bone plate barrel portion and (2) frictionally engaging, in a second position, the internal bore of the bone plate barrel portion to resist or prevent rotation of the collar relative to the bone plate, and thereby resist or prevent rotation of the lag screw relative to the bone plate.

A method for rotationally stabilizing bone segments utilizing a bone lag screw, a bone plate and a locking collar comprising:

• inserting a locking collar into a barrel portion of the bone plate;
• inserting a lag screw through the locking collar and barrel portion;
• rotationally coupling the locking collar and the lag screw;
• attaching the bone-engagement end of the lag screw to a first bone segment;
• and
• impacting the locking collar to frictionally engage a deformable distal end of the locking collar with the internal bore to resist or prevent further rotation of the collar relative to the bone plate, and thereby prevent further rotation of the lag screw relative to the bone plate.