| CPC A61B 17/7034 (2013.01) [A61B 17/8635 (2013.01); A61B 17/8685 (2013.01)] | 9 Claims |
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1. A modular spinal fixation screw comprising:
a bone screw having a first end and a second end with a threaded shank therebetween, said first end for penetrating securement to bone, said second end forming a spherical head portion;
a connector consisting of a collet operatively associated with a clamp, said collet having a lower end spaced apart from an upper end with a cylindrical shaped side wall therebetween, said upper end forming a header which protrudes outwardly from said side wall with a tapered section extending from said side wall to said upper end, a u-shaped receptacle extending beneath said upper end constructed and arranged to receive a rod member, said collet lower end having an inner side wall forming a receptacle surface sized for coupling to said head portion of said bone screw, said receptacle surface having at least one T-shaped living hinge formed therein from a first relief cut extending from said collet lower end to a perpendicular positioned relief cut juxtapositioned to said lower receptacle surface, said collet including a split line extending between said receptacle surface and said lower end; said relief cuts placed between said living hinge and said split line, said collet including first and second vertically disposed pin slots extending along a length of said side wall;
said clamp having an elongated body with an interior wall and an exterior wall, said interior wall including at least one annular bulge constructed and arranged to change the diameter of said collet sidewall when said clamp is drawn over said collet, a rod slot constructed to accept a rod member, said clamp including a first and second pin holes extending between said interior wall and said exterior wall; and
first and second pins, said first pin coupled to said first pin hole and extending into said first pin slot, said second pin coupled to said second pin hole and extending into said second pin slot wherein said pins regulate linear movement of said collet;
wherein said collet is linearly traversable between a first position and a second position by application of a linear force applied along a longitudinal axis of said clamp, whereby traversal of said collet from said first position to said second position causes said collet to cooperate with said at least one annular bulge to apply concurrent compressive forces to simultaneously immobilize movement between said connector and said rod member and immobilize movement between said connector and said bone screw.
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