Rod to rod connector

Abstract

The invention is a rod to rod connector that can be used to interconnect two generally parallel spinal rods of a spinal rod and anchor system. The connector comprises a transverse rod and two pairs of clamping bodies, one for each spinal rod. Each pair connects one of the longitudinal spinal rods to the transverse rod in infinitely adjustable angular relationship. One of the two clamping bodies of each pair comprises a C-shaped channel for accepting the spinal rod. The channel is in communication with a slot that defines a hinge. A threaded screw hole passes transversely through the slot and permits a screw to squeeze the hinge, thereby causing the C-shaped channel to close around and clamp the rod. The second clamping body is similar to the first except that there is no slot or hinge and the screw hole preferably is not threaded, but includes a countersink for seating a chamfered screw head. Also, an angular portion of the screw hole intersects the C-shaped channel. The two clamping bodies are aligned with each other so that their screw holes are coaxial so that a single screw can pass through both holes thereby clamping both rods in the C-shaped channels and fixing the angle between the two clamping bodies and, hence, the two rods. The first clamp clamps the spinal rod by squeezing the hinge to cause the C-shaped channel to squeeze around the rod. The second clamp clamps the transverse rod by virtue of the bottom of the screw head bearing down on the transverse rod over the portion of the screw hole that intersects the C-shaped channel.