Multi-axial connection system
View Patent ↗A system and method for a multi-axial connection of an apparatus to bone. The system may include a fastener inserted into a body and a head of the fastener held within a chamber of the body through a combination of a retention ring, a pressure cap, a rod, and a compression element. The compression element applies force to the rod which, in turn, pushed on the pressure cap. The force on the pressure cap urges it against the head of the fastener and pushed it against the retention ring. The force on the retention ring causes it to expand to the walls of the chamber. Once the ring can no longer expand within the chamber, the head of the fastener is wedged between the retention ring and the pressure cap.
1. A fixation system, comprising:
a body, wherein the body has a first end and a second end;
a body rod receiving channel disposed adjacent the first end of the body and defined by a first wall and a second wall of the body;
a fastener head receiving chamber disposed adjacent the second end of the body, wherein the fastener head receiving chamber is tapered towards the second end of the body, and wherein the body rod receiving channel and the fastener head receiving chamber are operatively connected;
a pin mounting channel positioned in the body having a first diameter that is larger than a second diameter;
a pin fixably attached to the body via the pin mounting channel, wherein the pin includes a pin head that is larger than a pin shaft, the pin head is configured to not extend beyond the first diameter of the pin mounting channel;
a pressure cap slidably engaged with a body engagement element, wherein the pressure cap includes pin receiving slots that extend through an entire width of a wall of the pressure cap, and wherein the pin receiving slots are elongated so that the pressure cap slidably moves within the body's first and second ends; and
a compression element configured to cooperate with the body that urges a rod, when the rod is disposed within the body rod receiving channel, into contact with at least part of the pressure cap.
2. The fixation system of claim 1 , further comprising a fastener having a head at a first end, wherein the head of the fastener includes a drive element, wherein the pressure cap is configured to press the head of the fastener towards the tapered end of the fastener head receiving chamber.
3. The fixation system of claim 1 , further comprising a retention device disposed within the fastener head receiving chamber and configured to retain a fastener head within the fastener head receiving chamber.
4. The fixation system of claim 3 , wherein the retention device is a split ring.
5. The fixation system of claim 1 , further comprising a flange disposed over a body aperture at the second end of the body, wherein the flange has an elongated flange aperture.
6. The fixation system of claim 5 , wherein the flange is integral to the body.
7. The fixation system of claim 1 , wherein the pressure cap comprises:
a fastener head receiving face configured to contact a fastener head; and
a pressure cap rod receiving channel, wherein the pin receiving slots are configured to slideably engage with the pin.
8. The fixation system of claim 7 , wherein at least one of the pin receiving slots include a tab that is disposed within a tab channel of the body.
9. The fixation system of claim 1 , further comprising a rib configured to bridge a top portion of the first and second walls of the body rod receiving channel and thereby prevents a rod that is positioned in the body rod receiving channel to be moved passed the top portions of the first and second walls.
10. The fixation system of claim 9 , wherein the body comprises an aperture in one of the walls of the body rod receiving channel.
11. The fixation system of claim 1 , wherein the body rod receiving channel comprises an extension of a wall of the body rod receiving channel removeably connected to the body at the first end.
12. The fixation system of claim 1 , wherein the compression element is a set screw.