| 主权项 |
1. A bone screw system comprising:
an elongate fixation element adapted to engage a bone and having a head portion and a threaded shank portion; a receiving element defining an internal bore sized to receive the shank portion of the fixation element and a seat adapted to support the head portion of the fixation element, the receiving element comprising a pair of opposed legs separated by a rod receiving channel sized for complimentary engagement with a stabilizer rod, wherein the pair of opposed legs defines a compression element receiving chamber, each opposed leg having a wall of a thickness with internal threads extending inwardly from each wall; a pair of leg extensions, one leg extension coupled to each opposed leg; a compression element configured to engage a portion of the receiving element and be complimentarily received in the compression element receiving chamber, the compression element configured to compress the stabilizer rod into the receiving element to fix the position of the stabilizer rod with respect to the receiving element, the compression element has external threads complimentary to the internal threads of the opposed legs; a breakaway groove positioned externally between each leg and leg extension, the breakaway groove extending inwardly at least partially through the wall of each leg or leg extension, the breakaway groove extends through the wall between each leg and leg extension to create an aperture, wherein the aperture is positioned leaving the wall having a pair of leg attachments between each leg or leg extension, one leg attachment on each side of the aperture, each leg extension being an arcuate shape; and wherein the leg or leg extension has a second cut at a leading end of the breakaway groove, the second cut being an undercut to create an enlarged opening and another second cut is positioned at the trailing end of the breakaway groove to create an enlarged opening, the second cuts forming a point of fracture break initiation due to the arcuate shape of the legs. |
