Spinal fixation device

Abstract

A spinal fixation device is provided. The spinal fixation device includes a body portion including a stud portion defining a first annular groove. An outer housing is positionable on the stud portion of the body portion. An inner housing defines a second annular groove and is positionable between the outer housing and the stud portion. A ring member is positionable within each of the first and second annular grooves of the respective stud portion and inner housing to lock the inner housing to the body portion and to fixedly couple the outer housing to the stud portion.

What is claimed is: 
     
         1 . A spinal fixation device, comprising:
 a body portion including a stud portion defining a first annular groove;   an outer housing positionable on the stud portion;   an inner housing defining a second annular groove, the inner housing positionable between the outer housing and the stud portion; and   a ring member positionable within each of the first and second annular grooves of the respective stud portion and inner housing to lock the inner housing to the stud portion and to fixedly couple the outer housing to the stud portion.   
     
     
         2 . The spinal fixation device according to  claim 1 , wherein the stud portion includes a cylindrical configuration. 
     
     
         3 . The spinal fixation device according to  claim 2 , wherein the inner housing includes a bore having a cylindrical configuration which is configured to at least partially cover the stud portion when the inner housing is positioned through a bore of the outer housing. 
     
     
         4 . The spinal fixation device according to  claim 3 , wherein the stud portion defines at least one opening that is alignable with an opening defined in the inner housing and an opening defined through the outer housing when the inner housing is positioned through the outer housing and on the stud portion. 
     
     
         5 . The spinal fixation device according to  claim 4 , wherein a pin is receivable within the openings of the stud portion, the inner housing and the outer housing to prevent rotation of the inner housing with respect to the outer housing and body portion and align the inner housing with the outer housing for maintaining a fixed relationship between the inner housing and the outer housing. 
     
     
         6 . The spinal fixation device according to  claim 3 , wherein the bore and the opening defined through the outer housing are oriented perpendicular with respect to one another. 
     
     
         7 . The spinal fixation device according to  claim 1 , wherein the inner housing includes two upright arms that are spaced-apart from one another to define a generally U-shaped slot configured to receive a spinal rod. 
     
     
         8 . The spinal fixation device according to  claim 7 , wherein the two upright arms of the inner housing are flexible and configured to releasably connect the spinal rod within the slot. 
     
     
         9 . The spinal fixation device according to  claim 8 , wherein the inner and outer housing assume a first, unlocked position in which the upright arms are permitted to flex to receive a spinal rod, and a second, locked position in which the inner and outer housings are taper locked so that the upright arms grip the rod to secure the rod to the spinal fixation device. 
     
     
         10 . The spinal fixation device according to  claim 9 , wherein top surfaces of the inner and outer housings are substantially co-planar. 
     
     
         11 . The spinal fixation device according to  claim 1 , wherein the body portion includes a bottom portion having a hook configuration that is configured to engage a lamina of a vertebra of a patient. 
     
     
         12 . The spinal fixation device according to  claim 1 , wherein the body portion includes a bottom portion having an elongated configuration that is configured to connect to at least one other spinal fixation device. 
     
     
         13 . The spinal fixation device according to  claim 1 , wherein the ring member is flexible. 
     
     
         14 . The spinal fixation device according to  claim 13 , wherein the ring member includes a C-shaped configuration, which allows the ring member to flex, thereby allowing the ring member to expand for attachment to the stud portion. 
     
     
         15 . The spinal fixation device according to  claim 1 , wherein the ring member has an inner diameter that is slightly less than an outer diameter of the first annular groove of the stud portion. 
     
     
         16 . The spinal fixation device according to  claim 15 , wherein the ring member has an outer diameter that is slightly greater than an inner diameter of an interior of the inner housing such that the ring member is receivable within both the first annular groove of the stud portion and the second annular groove of the inner housing to lock the inner housing to the body portion. 
     
     
         17 . A method for assembling a spinal fixation device, comprising:
 positioning an outer housing on a stud portion of a body portion of the spinal fixation device, the stud portion defining a first annular groove;   positioning a ring member within the first annular groove defined on the stud portion; and   positioning an inner housing on the stud portion to engage the ring member with a second annular groove defined on the inner housing to lock the inner housing to the stud portion and to fixedly couple the outer housing to the stud portion.   
     
     
         18 . The method according to  claim 17 , wherein positioning the inner housing on the stud portion to engage the ring member with the second annular groove further includes moving a distal end of the inner housing distally past the first annular groove until the ring member is received within the second annular groove. 
     
     
         19 . A method for connecting a spinal rod to a spine of a patient, comprising:
 providing a first spinal fixation device, comprising:
 a body portion including a stud portion defining a first annular groove; 
 an outer housing positionable on the stud portion of the body portion; 
 an inner housing defining a second annular groove, the inner housing positionable between the outer housing and the stud portion; and 
 a ring member positionable within each of the first and second annular grooves of the respective stud portion and inner housing to lock the inner housing to the body portion and to fixedly couple the outer housing to the stud portion; 
   positioning a spinal rod within a slot of the inner housing;   moving the outer housing proximally relative to the inner housing to secure the spinal rod to the first spinal fixation device; and   engaging a bottom portion of the body portion with a lamina of a vertebra of the patient to secure the spinal rod to the spine of the patient.   
     
     
         20 . The method according to  claim 19 , wherein engaging the bottom portion of the body portion with the lamina of the vertebra of the patient further includes engaging a hook configuration of the bottom portion of the body portion with the lamina of the vertebra of a patient. 
     
     
         21 . The method according to  claim 19 , including connecting at least a second spinal fixation device to the spinal rod. 
     
     
         22 . The method according to  claim 21 , including connecting an elongated configuration of a bottom portion of a body portion of the at least second spinal fixation device to at least a third spinal fixation device.