Patent ID: 8535354
Filing Date: 2013-09-17
Classification: A61B

Abstract:
1. A bone plate locking system comprising: a threaded screw body having a proximal end and a distal end, the proximal end comprising a head, the head comprising an upper portion, a groove adjacent the upper portion defining an at least partially circular surface, a lower portion adjacent the groove, a notch in at least a portion of the groove and a notch in at least a portion of the upper portion, a center-axis of the threaded screw body passing through both the proximal end and distal end of the threaded screw body, a center-axis of the groove of the head substantially parallel to the center-axis of the threaded screw body, wherein the center-axis of the groove of the head is off-axis to the center-axis of the threaded screw body, and wherein the lower portion of the head is centered on the center-axis of the threaded screw body; a locking ring configured to at least partially reside within the groove of the head, the locking ring comprising an outer curved surface, an inner curved surface, an anterior surface, a posterior surface, a first protrusion on at least a portion of the anterior surface of the locking ring that is configured to reside within the notch in the upper portion of the head and a second protrusion on at least a portion of the inner curved surface; and a plate comprising an anterior surface, a posterior surface and at least one through-hole through the anterior surface and the posterior surface, the through-hole comprising an upper portion, a groove adjacent the upper portion and a lower portion adjacent the groove, the head of the screw body being receivable in the through-hole; wherein the locking ring is adapted to be rotatably positioned around the groove of the head such that in an unlocked position the locking ring is outside the groove of the through-hole, the first protrusion is at one end of the notch in the upper portion of the head and the second protrusion of the locking ring is within the notch in the groove of the head, and in a locked position the locking ring is at least partially within the groove of the through-hole, the first protrusion is at another end of the notch in the upper portion of the head and the second protrusion of the locking ring is outside the notch in the groove of the head.