SPINAL STABILIZATION SYSTEM UTILIZING SCREW AND EXTERNAL FACET AND/OR LAMINA FIXATION
A surgical implant for support of spinal vertebrae comprising a screw element having a threaded shank for screwing into a pedicle of a first vertebra and a fixation component that is moveably secured to the screw element. The fixation component has a first end for receiving the screw element and a fixation surface adapted to engage or attach to at least one of an external facet or laminar surface of a second vertebra. Various embodiments are provided for polyaxial movement of the fixation component relative to a polyaxial screw. Also, various apparatus and means for locking the screw element to the fixation component are provided.
1 . A surgical implant for support of spinal vertebrae, said surgical implant comprising:
a screw element having a threaded shank for screwing into a pedicle of a first vertebra;
a fixation component that is moveably secured to said screw element;
said fixation component having a first end for receiving said screw element and a fixation surface adapted to engage or attach to at least one of an external facet or laminar surface of a second vertebra.
2 . The surgical implant as recited in claim 1 wherein said screw element comprises a connection portion opposite an end of said threaded shank, said connection portion being adapted to removably receive said fixation component.
3 . The surgical implant as recited in claim 2 wherein said connection portion has a threaded portion that is coaxial with said threaded shank, said fixation component having an aperture for receiving said threaded portion, said threaded portion being adapted to receive a nut for fixing said fixation component to said screw element after said screw element is screwed into said first vertebra.
4 . The surgical implant as recited in claim 1 wherein said second vertebra is an immediately adjacent vertebra.
5 . The surgical implant as recited in claim 2 wherein said screw element comprises a connection portion adapted to receive a compression element, said first end of said fixation component having an fixation component wall that defines a fixation component receiving opening in said first end of said fixation component, said compression element being adapted to secure said fixation component to said screw element upon compression of said compression element after said compression element is mounted on said connection portion.
6 . The surgical implant as recited in claim 5 wherein said connection portion comprises an attachment shaft that is integral and contiguous with said threaded shank, said compression element comprising a bore for receiving said attachment shaft, said fixation component receiving opening in said first end of said fixation component being adapted to receive said compression element and upon compression thereof, said fixation component becomes affixed to said screw element.
7 . The surgical implant as recited in claim 6 wherein said fixation component comprises a threaded area associated with said first end defining a nut receiving area that cooperates with said fixation component receiving opening to define a compression element receiving area for receiving said compression element, said nut engaging said compression element to compress against said attachment shaft of said screw element when said nut is screwed onto said threaded area of said first end of said fixation component, thereby fixing said fixation component to said screw element.
8 . The surgical implant as recited in claim 1 wherein said screw element comprises a polyaxial portion for permitting said fixation component to move polyaxially on said screw element until said fixation component is fixed thereto.
9 . The surgical implant as recited in claim 8 wherein said polyaxial portion comprises a polyaxial mount located on said screw element, said polyaxial mount being adapted to polyaxially receive said first end of said fixation component.
10 . The surgical implant as recited in claim 9 wherein said polyaxial mount comprises a spherical head.
11 . The surgical implant as recited in claim 10 wherein said spherical head is defined by a compressive member removably received on said screw element,
12 . The surgical implant as recited in claim 1 wherein said fixation component comprises a linear or curvilinear body having said fixation surface.
13 . The surgical implant as recited in claim 12 wherein said fixation surface comprises a plurality of teeth for engaging said at least one of said external facet or said laminar surface of said second vertebra.
14 . The surgical implant as recited in claim 1 wherein said fixation surface comprises a curved, concave or multi-angular surface to match an anatomy of said at least one of said external facet or said laminar surface of said second vertebra.
15 . The surgical implant as recited in claim 1 wherein said screw element and said fixation component are adapted to permit at least one of polyaxial motion of said fixation component relative to said screw element or polyaxial motion of said screw element relative to said fixation component.
16 . The surgical implant as recited in claim 15 wherein said at least one of polyaxial motion of said fixation component relative to said screw element or said polyaxial motion of said screw element relative to said fixation component is achieved by adapting said screw element and said fixation component to define a ball and socket coupling.
17 . The surgical implant as recited in claim 16 wherein said ball is located on said screw element and said socket is located on said fixation component.
18 . The surgical implant as recited in claim 16 wherein said ball is located on said fixation component and said socket is located on said screw element.
19 . The spinal implant as recited in claim 1 wherein said spinal implant further comprises:
a retainer having a bore for receiving said screw element and at least a portion of said fixation component;
said retainer comprising a lock for locking said fixation component in said retainer and to said screw element.
20 . The spinal implant as recited in claim 19 wherein said lock comprises a cap for threadably mounting on said retainer.
21 . The spinal implant as recited in claim 19 wherein said retainer comprises a channel for receiving said at least a portion of said fixation component.
22 . The spinal implant as recited in claim 21 wherein said retainer comprises a pair of generally opposed and generally L-shaped channels that define said channel and that provide said lock by defining a bayonet connection for locking said at least a portion of said fixation component to said retainer upon rotation of said retainer relative to said screw element.
23 . The spinal implant as recited in claim 19 wherein said retainer defines a capless retainer for locking said at least a portion of a rod to said retainer and a head of said screw element together upon rotation of said retainer.
24 . The spinal implant as recited in claim 19 wherein the screw element is a polyaxial screw having a polyaxial head that is received in said retainer and that permits polyaxial movement of said fixation component relative to said polyaxial head.
25 . The spinal implant as recited in claim 21 wherein said fixation component comprises a cylindrical rod portion adapted to be received in said channel, wherein said cylindrical rod portion directly or indirectly engages or compresses against a head of a polyaxial screw in said retainer in order to lock said fixation component in said retainer and against said head.
26 . The spinal implant as recited in claim 1 wherein said screw element comprises a polyaxial screw having a polyaxial head, said fixation component comprising a socket for receiving said polyaxial head and at least one screw or cap for locking said fixation component to said polyaxial screw.
27 . The spinal implant as recited in claim 1 wherein said screw element comprises a head having a socket and said fixation component comprises a ball or spherical component for mounting in said socket,
said spinal implant further comprising a lock for locking said ball in said socket.
28 . The spinal implant as recited in claim 27 wherein said lock is at least one of a set screw, a cap or an interference or frictional fit between said ball and said socket.
29 . The spinal implant as recited in claim 26 wherein said lock is at least one of a set screw, a cap or an interference or frictional fit between said ball and said socket.
30 . The spinal implant as recited in claim 19 wherein said fixation component has a bone-engagement portion and a locking portion for locking onto said screw element, said bone-engagement portion having an engagement surface for engaging bone;
said bone-engagement portion being generally circular or elongated and generally conforming to a local anatomy.
31 . The spinal implant as recited in claim 1 wherein said spinal implant further comprises a lock for locking said fixation component to said screw element.
32 . The spinal implant as recited in claim 31 wherein said lock comprises at least one of a set screw, cap, nut or bolt.
33 . A fixation component that is moveably secured to a screw element; said fixation component comprising:
a first end secured to said screw element and a fixation surface adapted to engage or attach to at least one of an external facet or laminar surface of a second vertebra.
34 . The fixation component as recited in claim 33 wherein said fixation component further comprises an aperture for receiving a threaded portion of said screw element, said threaded portion being adapted to receive a nut for fixing said fixation component to said screw element after said screw element is screwed into said second vertebra.
35 . The fixation component as recited in claim 33 wherein said second vertebra is an immediately adjacent vertebra.
36 . The fixation component as recited in claim 35 wherein said first end of said fixation component having an fixation component wall that defines a generally spherical fixation component receiving opening for receiving a portion of said screw element and a generally spherical member associated therewith.
37 . The fixation component as recited in claim 36 wherein said generally spherical member is a compression element.
38 . The fixation component as recited in claim 37 wherein said fixation component comprises a set screw associated with said fixation component wall and adapted to engage and lock said fixation component to said generally spherical member.
39 . The fixation component as recited in claim 36 wherein said generally spherical member comprises a split ball.
40 . The fixation component as recited in claim 33 wherein said fixation component comprises a threaded area associated with said first end for receiving an open nut, said open nut having an inner wall that defines a nut receiving area that cooperates with said fixation component receiving opening to define a receiving area for receiving a portion of the screw element to facilitate locking said fixation component thereon.
41 . The fixation component as recited in claim 40 wherein said portion of said screw element comprises a polyaxial portion for permitting said fixation component to move polyaxially on said screw element until said fixation component is fixed thereto.
42 . The fixation component as recited in claim 41 wherein said polyaxial portion comprises a polyaxial mount located on said screw element, said polyaxial mount being adapted to polyaxially receive said first end of said fixation component.
43 . The fixation component as recited in claim 33 wherein said fixation component comprises a linear or curvilinear body having said fixation surface.
44 . The fixation component as recited in claim 43 wherein said fixation surface comprises a plurality of teeth for engaging said at least one of said external facet or said laminar surface of said second vertebra.
45 . The fixation component as recited in claim 33 wherein said fixation surface comprises a curved, concave or multi-angular surface to match the anatomy of said at least one of said external facet or said laminar surface of said second vertebra.
46 . The fixation component as recited in claim 33 wherein said fixation component is adapted to permit at least one of polyaxial motion of said fixation component relative to said screw element or polyaxial motion of said screw element relative to said fixation component.
47 . The fixation component as recited in claim 46 wherein said fixation component comprises a socket or ball and said screw element comprises a ball or socket, respectively, said ball being received in said socket to permit said at least one of polyaxial motion of said fixation component relative to said screw element or said polyaxial motion of said screw element relative to said fixation component.
48 . The fixation component as recited in claim 47 wherein said ball is located on or integral with said screw element and said fixation component comprises said socket.
49 . The fixation component as recited in claim 47 wherein said ball is located on or integral with said fixation component and said screw element comprises said socket.
50 . The fixation component as recited in 33 wherein said screw element comprises a polyaxial portion and a receiver having a channel, said fixation component having an elongated member adapted to be received in said channel.
51 . The fixation component as recited in claim 50 wherein said elongated member is a rod extending from said first end of said fixation component.
52 . The fixation component as recited in claim 50 wherein said channel defines a bayonet channel for capturing and locking said elongated member therein upon rotation of said receiver.
53 . The fixation component as recited in claim 50 wherein said receiver comprises a cap for mounting on said receiver in order to lock said elongated member in said receiver upon rotation of said receiver.
54 . The spinal implant as recited in claim 33 wherein said screw element comprises a polyaxial screw having a polyaxial head, said fixation component comprising a socket for receiving said polyaxial head and at least one screw or cap for locking said fixation component to said polyaxial screw.
55 . The spinal implant as recited in claim 35 wherein said screw element comprises a head having a socket and said fixation component comprises a ball or spherical component for mounting in said socket,
said spinal implant further comprising a lock for locking said ball in said socket.
56 . The spinal implant as recited in claim 55 wherein said lock is at least one of a set screw, a cap or an interference or frictional fit between said ball and said socket.
57 . The spinal implant as recited in claim 55 wherein said fixation component has a bone-engagement portion and a locking portion for locking onto said screw element, said bone-engagement portion having an engagement surface for engaging bone;
said bone-engagement portion being generally circular or elongated and generally conforming to a local anatomy.