Occipital fixation assembly, system and method for attaching the same

Abstract

An occipital fixation assembly is provided. The occipital fixation assembly includes a first mounting plate configured for placement within a sinus cavity adjacent a rear portion of a skull of a patient. A threaded post extends from the first mounting plate. A coupling member includes an aperture configured to receive the threaded post therethrough. The coupling member includes an offset extension configured to support a surgical rod thereon. A fixation nut configured to threadably engage the threaded post of the first mounting plate is rotatable about the threaded post and translatable therealong. The fixation nut is rotatable with respect to the first mounting plate and the coupling member such that rotation of the fixation nut in a predetermined direction brings the first mounting plate and the coupling member toward one another and into secured engagement with the skull of a patient.

1 . An occipital fixation assembly, comprising:
 a first mounting plate configured for placement within a sinus cavity adjacent a rear portion of a skull of a patient, the first mounting plate having a threaded post extending therefrom;   a coupling member including an aperture configured to receive the threaded post therethrough, the coupling member including an offset extension disposed in parallel orientation with respect to the threaded post and configured to support a surgical rod thereon; and   a fixation nut configured to threadably engage the threaded post of the first mounting plate, the fixation nut rotatable about the threaded post and translatable therealong, the fixation nut rotatable with respect to the first mounting plate and the coupling member such that rotation of the fixation nut in a predetermined direction brings the first mounting plate and the coupling member toward one another and into secured engagement with the skull of a patient.   
     
     
         2 . An occipital fixation assembly according to  claim 1 , wherein at least one barb is operably disposed on a top surface of the first mounting plate and at least one barb is operably disposed on a bottom surface of the coupling member. 
     
     
         3 . An occipital fixation assembly according to  claim 2 , wherein the at least one barb operably disposed on the top surface of the first mounting plate and the at least one barb operably disposed on the bottom surface of the coupling member each configured to anchor into an inside of the skull and outside of the skull, respectively, to minimize respective rotation of the first mounting plate and coupling member when the fixation nut is rotated about the threaded post. 
     
     
         4 . An occipital fixation assembly according to  claim 1 , wherein a washer is disposed between the fixation nut and the aperture on the coupling member and serves as a lock washer. 
     
     
         5 . An occipital fixation assembly according to  claim 4 , wherein a bottom surface of the fixation nut is receivable through the washer and at least partially extends through the aperture of the coupling member, wherein the fixation nut is swaged to the coupling member making the coupling member and fixation nut an integral assembly. 
     
     
         6 . An occipital fixation assembly according to  claim 1 , wherein the offset extension includes a generally elongated slot having a threaded portion configured to receive a set-screw therein and a non-threaded portion configured to receive the surgical rod therein, the threaded and non-threaded portions of the offset extension arranged such that when the surgical rod is secured thereto, the surgical rod is oriented perpendicular to the set-screw. 
     
     
         7 . An occipital fixation assembly according to  claim 1 , wherein a second mounting plate is operably coupled to the first mounting plate and is rotatable about the threaded post. 
     
     
         8 . An occipital fixation assembly according to  claim 7 , wherein a bottom surface of the second mounting plate is notched and configured to receive at least a portion of the first mounting plate therein such that a top surface of the first mounting plate and a top surface of the second mounting plate are flush with each other and the first and second mounting plates are disposed traverse to each other when the first and second mounting plates are attached to a skull of a patient. 
     
     
         9 . An occipital fixation assembly according to  claim 8 , wherein the bottom surface of the second mounting plate includes a pair of indents configured to releasably receive a corresponding pair of barbs operably disposed on the top surface of the first mounting plate, the pair of indents configured to maintain the first mounting plate in a relatively fixed orientation with respect to the second mounting plate to facilitate positioning the first and second mounting plates inside a skull. 
     
     
         10 . An occipital fixation assembly according to  claim 1 , wherein the threaded post of the first mounting plate includes a threaded aperture and a non-threaded aperture that extends traverse to the threaded aperture, the threaded aperture configured to receive one end of a surgical device for turning the fixation nut about the threaded post, and the non-threaded aperture configured to receive one end of a surgical device for grasping the threaded post. 
     
     
         11 . An occipital fixation system, comprising:
 an occipital fixation assembly, including:
 a first mounting plate configured for placement within a sinus cavity adjacent a rear portion of a skull of a patient, the first mounting plate having a threaded post extending therefrom; 
 a coupling member including an aperture configured to receive the threaded post therethrough, the coupling member including an offset extension disposed in parallel orientation with respect to the threaded post and configured to support a surgical rod thereon; 
 a fixation nut configured to threadably engage the threaded post, the fixation nut rotatable about the threaded post and translatable therealong, the fixation nut rotatable with respect to the first mounting plate and the coupling member such that rotation of the fixation nut in a predetermined direction brings the first mounting plate and the coupling member toward one another and into secured engagement with the skull of a patient; 
   a forceps configured to grasp a portion of the threaded post to facilitate positioning the first mounting plate through an aperture that has been previously drilled in the sinus cavity; and   a wrench assembly configured to engage and, subsequently, rotate the fixation nut about the threaded post.   
     
     
         12 . An occipital fixation system according to  claim 11 , wherein at least one barb is operably disposed on a top surface of the first mounting plate and at least one barb is operably disposed on a bottom surface of the coupling member. 
     
     
         13 . An occipital fixation system according to  claim 12 , wherein the at least one barb operably disposed on the top surface of the first mounting plate and the at least one barb operably disposed on the bottom surface of the coupling member each configured to anchor into an inside of the skull and outside of the skull, respectively, to minimize respective rotation of the first mounting plate and coupling member when the fixation nut is rotated about the threaded post. 
     
     
         14 . An occipital fixation system according to  claim 11 , wherein a washer is disposed between the fixation nut and the aperture on the coupling member and serves as a lock washer, wherein a bottom surface of the fixation nut is receivable through the washer and at least partially extends through the aperture of the coupling member, wherein the fixation nut is swaged to the coupling member making the coupling member and fixation nut an integral assembly. 
     
     
         15 . An occipital fixation system according to  claim 11 , wherein the offset extension includes a generally elongated slot having a threaded portion configured to receive a set-screw therein and a non-threaded portion configured to receive the surgical rod therein, the threaded and non-threaded portions of the offset extension arranged such that when the surgical rod is secured thereto, the surgical rod is oriented perpendicular to the set-screw. 
     
     
         16 . An occipital fixation system according to  claim 11 , wherein a second mounting plate is operably coupled to the first mounting plate and is rotatable about the threaded post. 
     
     
         17 . An occipital fixation system according to  claim 16 , wherein in a bottom surface of the second mounting plate is notched and configured to receive at least a portion of the first mounting plate therein such that a top surface of the first mounting plate and a top surface of the second mounting plate are flush with each other and the first and second mounting plates are disposed traverse to each other when the first and second mounting plates are attached to a skull of a patient. 
     
     
         18 . An occipital fixation assembly according to  claim 17 , wherein the bottom surface of the second mounting plate includes a pair of indents configured to releasably receive a corresponding pair of barbs operably disposed on the top surface of the first mounting plate, the pair of indents configured to maintain the first mounting plate in a relatively fixed orientation with respect to the second mounting plate to facilitate positioning the first and second mounting plates inside a skull. 
     
     
         19 . An occipital fixation system according to  claim 11 , wherein the threaded post of the first mounting plate includes a threaded aperture and a non-threaded aperture that extends traverse to the threaded aperture, the threaded aperture configured to receive one end of a surgical device for turning the fixation nut about the threaded post and the non-threaded aperture configured to receive one end of a surgical device for grasping the threaded post. 
     
     
         20 . An occipital fixation system according to  claim 19 , wherein the forceps includes first and second shafts each having a jaw member extending from a distal end thereof and a handle disposed at a proximal end thereof for effecting movement of the jaw members relative to one another about a pivot, the jaw members movable from a first position wherein the jaw members are disposed in spaced relation relative to one another to a second position wherein the jaw members cooperate to grasp the threaded post. 
     
     
         21 . An occipital fixation system according to  claim 20 , wherein each of the jaw members are curved and includes an inner facing surface having a proximal end and a distal end that is offset from the proximal end such that in the closed configuration the distal ends of the inner facing surfaces remain spaced-apart from each other to facilitate grasping the threaded post therebetween, at least one of distal ends of the jaw members including a protrusion thereon that is configured to releasably engage the non-threaded aperture on the threaded post. 
     
     
         22 . An occipital fixation system according to  claim 20 , wherein the wrench assembly comprises:
 a coupling member configured to threadably engage the threaded aperture on the threaded post of the first mounting plate; and   a wrench head member selectively and coaxially engageable with the coupling member, the wrench head member configured to releasably engage the fixation nut and rotate the fixation nut about the threaded post of the first mounting plate,   wherein the proximal end of the coupling member is complementary shaped to receive an end of a turn-key for facilitating rotation of the threaded distal end into the threaded aperture of the threaded post of the first mounting plate.   
     
     
         23 . An occipital fixation system according to  claim 22 , wherein the coupling member includes a generally elongated shaft having a threaded distal end, and proximal end that is configured to rotate the threaded distal end into the threaded aperture of the threaded post of the first mounting plate for securement of the coupling member to the first mounting plate. 
     
     
         24 . An occipital fixation system according to  claim 23 , wherein a portion of the coupling member proximate to the threaded distal end has an outer diameter that is slightly smaller than an inner diameter of the fixation nut  8 , the portion of the coupling member proximate to the threaded distal end configured to facilitate positioning the fixation nut on the threaded post of the first mounting plate. 
     
     
         25 . A method for attaching an occipital fixation assembly for subsequent attachment of a surgical rod thereon, comprising:
 creating an aperture within a sinus cavity adjacent a rear portion of a skull of a patient;   positioning a first mounting plate of an occipital fixation assembly through the aperture created within the sinus cavity;   attaching a coupling member of the occipital fixation assembly to the threaded post of the first mounting plate;   positioning a fixation nut about the threaded post and, subsequently, rotating the fixation nut in a predetermined direction thereabout such that the first mounting plate and the coupling member move toward one another and into secured engagement with the skull of a patient; and   coupling a surgical rod to the coupling member.