CAPLESS MULTIAXIAL SCREW AND SPINAL FIXATION ASSEMBLY AND METHOD
A bone fixation assembly and capless multi-axial screw system and method are shown. The assembly comprises a receiver having a rotary lock which in one embodiment includes a plurality of channels which urge and lock the elongated member to the screw using a bayonet type connection.
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This application is a continuation-in-part of application Ser. No. 11/193,523, filed Jul. 29, 2005, which is incorporated herein by reference and made a part hereof.
BACKGROUND OF THE INVENTIONThis invention relates to a capless multiaxial screw and spinal fixation assembly and method, particularly useful for fixing and/or aligning vertebrae of the spine. The invention permits multiple angular orientations of an elongated member or rod with respect to a screw that is screwed into a vertebra.
Various methods of spinal immobilization have been known and used in the past. The preferred treatment for spinal stabilization is immobilization of the joint by surgical fusion or anthrodesis. This method has been known since development in 1911 by Hibbs and Albe. However, in many cases, in particular cases involving fusion across the lumbosacral articulation and where there are many levels involved, pseudorarthrosis is a problem. It was discovered that immediate immobilization was necessary in order to allow a bony union to form. Post operative external immobilization, such as the use of splints and casts, was a favored method of treatment, however, as surgical techniques have become more sophisticated, various methods of internal and external fixation have been developed.
Internal fixation refers to therapeutic methods of stabilization which are wholly internal to the patient and include commonly known devices such as bone plates and pins. External fixation, in contrast, involves at least some portion of stabilization device which is external to the patient's body. Internal fixation is now the favored method of immobilization because the patient is allowed greater freedom with the elimination of the external portion of the device and the possibility of infection, such as a pin tract infection is reduced.
There have been numerous systems and methods developed in the past for correcting and stabilizing and aligning the spine for facilitating, for example, fusion at various levels or areas of the spine, such as those devices are shown in U.S. Pat. Nos. 4,085,744; 4,269,178; 4,805,602; 5,466,237; 5,474,555; 5,891,145; and 6,869,433 B2. Bone screws with a polyaxial head are commonly used in spine surgery today. They are used chiefly in the lumbar spine and screwed into bone (pedicle) posteriorly. The head of the screw is attached to the shaft of the screw by means of a ball and socket. The top of the screw is machined into a ball, and the head contains a socket into which the ball fits. The screw head further contains a receiver for receiving a separate rod. The rod is fastened to the screw head receiver via a threaded cap. The rod is then fastened to screws placed in adjacent vertebrae thus providing stabilization. The polyaxial head allows the rod to be placed in a variety of angles with respect to the screw allowing conformance to local anatomy.
When the threaded cap is tightened upon the rod, a frictional pressure is transmitted from the threaded cap to the rod thence to the top of the ball, thus locking the ball-in-socket and preventing motion after tightening has occurred. This concept is demonstrated in U.S. Pat. Nos. 5,466,237 and 5,474,555, which illustrate this type of screw.
U.S. Pat. No. 5,466,237 to Bird et al. discloses a bone screw having a spherical projection on the top of the bone screw. An externally threaded receiver member supports the bone screw and spinal rod on top of the spherical projection. An outer nut is tightened onto the receiver member to press the spinal rod against the spherical projection to accommodate various angular orientations of the bone screw relative to the rod.
In another approach shown in U.S. Pat. No. 4,946,458 to Harms, a spherical headed bone screw supported within separate halves of a receiving member. The bottom of the halves are held together by a retaining ring. The top of the receiver halves are compressed about the bone screw by nuts threaded onto a threaded spinal rod.
In still another approach taken by Harms et al. in U.S. Pat. No. 5,207,678, a receiver member is flexibly connected about a partially spherical head of a bone screw. Conical nuts on opposite sides of the receiver member threaded onto a threaded rod passing through the receiver. As the conical nuts are threaded toward each other, the receiver member flexibly compresses around the head of the bone screw to clamp the bone screw in its variable angular position. One detriment of the systems in the two Harms et al. patents is that the spinal rod must be threaded in order to accept the compression nuts.
U.S. Pat. No. 6,869,433 discloses the use of a pedicle screw assembly that comprises a screw having a head with a convex portion and a receiver that receives the head. The receiver also receives an elongated member, such as a spinal fixation rod. The receiver has a concave portion which has a radius of curvature which is less than the radius of curvature of the convex portion of the head whereby to create an interference fit between the convex portion of the head and the concave portion of the receiver. The device also includes an internal nut and external nut that compresses the rod against a pressure disc which in turn compresses the head convex portion of the screw into the receiver concave portion and locks the angular position of the receiver with respect to the screw.
One of the problems with the prior art devices is the number of parts and components, especially those components that utilize a threaded cap screw to secure the rod to the anchoring screw, whether internal or external, to fix the rod relative to the screw. Problems with the threaded fastener, that is, threaded cap or set screw, are numerous and include risk of cap loosening, loss of cap intra-operatively, cross threading, thread failure, failure of the cap in driving instrument and limitations upon torque application.
What is needed, therefore, is a system and method that provide a lock or connection between the rod and screw without the use of external nuts, screws, caps or threads of the type shown in the prior art.
SUMMARY OF THE INVENTIONThe present invention improves the spinal fixation and the locking between an elongated member or rod and a screw.
One object of the invention is to provide a system and method that reduces or eliminates the need for external or internal caps or screws to lock the relative position of a rod to a screw.
Another object of the invention is to provide a simple bayonet-type connection that eliminates the fixation systems of the past and/or simplifies the spinal fixation procedure.
In one aspect, this invention discloses a capless multiaxial screw system comprising a receiver comprising a receiver end comprising a receiver bore for receiving a threaded portion of a screw having a screw head; and a sleeve having a sleeve end for situating against at least a portion of the screw head after the threaded portion is received in the receiver bore, the sleeve having a sleeve bore associated with the sleeve end; the receiver having a channel for receiving an elongated member; the sleeve being adapted to permit the elongated member to engage the at least of portion of the screw head when the elongated member is received in the channel and the receiver is rotated to a locked position.
In another aspect, this invention discloses a spinal fixation assembly comprising a receiver having a receiver bore for receiving a screw having a screw head and a receiver channel in communication with the receiver bore for receiving an elongated member; and a stabilizer dimensioned to be received in the receiver bore, the stabilizer having a stabilizer channel associated with a first end of the stabilizer for receiving the elongated member and a stabilizer bore through a second end of the stabilizer, the second end being adapted to permit direct contact between at least a portion of the screw head and the elongated member; the receiver being capable of rotating relative to the elongated member after the elongated member is received in the receiver channel to force the elongated member into contact with the at least a portion of the screw head.
In yet another aspect, this invention relates to a receiver for use with a polyaxial screw comprising a body having a bore; and a channel for receiving an elongated member and for compressing it into engagement with a screw head of the polyaxial screw when the receiver is rotated.
In still another aspect, this invention relates to a spinal fixation assembly comprising a receiver having a bore for receiving a screw having a screw head; and an intermediate member dimensioned to be received in the bore and having a first end and a second end; the receiver comprising an integral rotary lock for forcing and locking an elongated member directly against the screw head when the receiver is rotated.
In another aspect, this invention discloses a spinal fixation assembly comprising a receiver having an opening for receiving a screw having a screw head; and an intermediate member dimensioned to be received in the opening and having an intermediate member receiving channel for receiving an elongated member and a screw head receiving opening adapted to receive at least a portion of the screw head; the receiver comprising a receiver channel for receiving the elongated member, the receiver channel forcing the elongated member into contact with the screw head when the receiver is rotated from an unlocked position to a locked position.
In another aspect, this invention relates to a capless multiaxial screw system comprising a screw having a threaded portion and a screw head; a receiver having a receiver bore for receiving the threaded portion and a receiving channel for receiving an elongated member, the receiver further comprising a locking channel in communication with the receiving channel; an intermediate member adapted to be situated in the receiver bore, the intermediate member comprising an intermediate member bore for receiving at least a portion of the screw head; and the intermediate member bore being adapted to permit the at least a portion of the screw head to extend into the locking channel so that the elongated member may engage and compress against the at least a portion of the screw head when the elongated member is received in the receiving channel and the receiver is rotated.
In still another aspect, this invention discloses a capless multiaxial screw fixation assembly comprising a screw having a threaded portion and a screw head; a receiver having a bore for receiving the threaded portion and a receiving channel for receiving an elongated member, the receiving channel further comprising a locking channel in communication with the receiving channel; and a guide for situating in the bore, the guide comprising a second receiving channel associated with a first end of the guide and a seat area associated with a second end of the guide; the guide being adapted to permit at least a portion of the screw head to extend into the second receiving channel so that the elongated member may engage the screw head to lock the elongated member to the screw when the elongated member is received in the first and second receiving channels and the receiver is rotated from an unlocked position to a locked position.
In yet another aspect, this invention relates to a spinal fixation assembly comprising a receiver having a receiver bore for receiving a screw having a screw head, the receiver further comprising a locking channel and a receiving channel in communication with the locking channel; and an intermediate member dimensioned to be received in the receiver bore, the intermediate member comprising a body having a first end having an intermediate member channel and a second end having an intermediate member opening; the intermediate member opening being adapted to permit at least a portion of the screw head to engage an elongated member after the elongated member is received in the receiving, locking and intermediate member channels and the receiver is moved to a locked position.
These and other objects and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to
As illustrated in
The system 10 comprises a retainer or receiver 20 having a generally cylindrical receiver wall 20c (
As shown in
Note that the receiver 20 comprises a receiving channel or slot 26 (
In one embodiment, the lock 28 cooperates and is in communication with the receiving channel 26 to provide a continuous channel 30 for receiving the elongated member or rod 24. The lock 28 cooperates with the receiving channel 26 and urges rod 24 toward the screw head 12b and vertebra, such as one of the vertebra 14-18 in
Note that the lock 28 comprises the first channel 32 and a second channel 34 (
As illustrated in
The channels 32 and 34 generally lay in planes P1 and P2 that are at the angles C (
As illustrated in
The system 10 may further comprise a compression member 40 (
The compression member 40 comprises a length D6 (
During operation, the compression member 40 is urged downward (as shown in
Note that the compression member 40 (
Referring back to
As shown in
An operation or method regarding this illustration will now be described. As illustrated in
The channel 26 of receiver 20 and channel 42 of compression member 40 are provided or arranged in a common plane P3, as shown in
Note that the rod 24 is supported by and between the arcuate or rounded wall portions 50 and 52, which causes the rod 24 to be situated above the bottom surface 40c of the channel 42 of compression member 40, as illustrated in
The camming or bayonet type action of the rotary lock 28 on receiver 20 forces the rod 24 in an axial direction parallel with axis A of receiver 20 when the receiver 20 is turned or rotated with a tool, such as a screwdriver (not shown), placed in channel 26, as illustrated in
It should be appreciated that when the rod 24 is in the locked position shown in
Thus, as illustrated in
If the compression member 40 is being used, compression member 40 is located in each bore 22 of each receiver 20 and generally aligns the channels 42 and 26, as illustrated in
At this point in the procedure, the surgeon aligns the rod 24 in the receiver 20 to the desired position relative to the spine, vertebrae and other receivers 20 that are being used. He positions the rod 24 and polyaxial or angular position of each receiver(s) 20 relative thereto. It should be understood that the screws and position of the vertebrae, such as vertebrae 14-18, relative to each other may also be adjusted. Once the bones 14-18 are adjusted and angular or polyaxial position of each receiver 20 is adjusted, the surgeon locks each receiver 20 to rod 24 by rotating or turning the receiver 20 with a tool, such as a screwdriver (not shown), placed in slot 26. This causes the receivers 20 to become fixed or locked onto their respective screws 12 and the spinal bones 14-18 (
It should be understood that before the rod 24 is placed in the receiving channel 26 and the receiver 20 is rotated, the surgeon may tighten one or more screws 12 to a tighter or fixed seated position by situating the tool, such as a hex wrench (not shown), through the aperture 43 (
As mentioned, the surgeon rotates the receiver 20 about its axis, as illustrated in
Thus, when it is desired to lock the receiver 20 and the screw 12 to the rod 24, the surgeon rotates the receiver 20 in the clockwise direction, as illustrated in
Thus, it should be understood that when receiver 20 is rotated, the walls 20e and 20h provide the camming force necessary to cam and urge the rod 24 against the receiver 40. This, in turn, causes the surface or wall 40b of receiver 40 to compress and lock against the end portion 12b2 (
As illustrated in
It should be appreciated from the foregoing that the receiving channel 26 is in communication with the channels 32 and 34 of lock 28 and that the lock 28 cooperates with the rod 24 to not only lock the rod 24 to the screw 12, but also to fix a position of the vertebrae 14, 16 and 18.
When it is desired to unlock the rod 24 from the screw 12, the surgeon simply rotates the receiver 20 in a counterclockwise direction in the illustration and reverses the procedure.
Referring now to
Note in the embodiment in
It should be appreciated that the intermediate area 60b in the channels 32′ and 34′ enable an intermediate step between initial rod 24′ insertion and final rod 24′ locking. In other words, this is a rod 24′ capturing step during which the rod 24′ is loosely captured in the receiver 20′, but it is not rigidly locked into place against screw 12′ yet. This allows the surgeon greater ease and flexibility when he adjusts the screws 12′ position with respect to the rod 24′ while the rod 24′ is in place. For example, the surgeon may move the screws 12′ closer together (compression) or In the illustration being described, the intermediate capturing step is accomplished by rotating the receiver 20′ partially, such as approximately 30 degrees in the illustration as shown in
The introduction area comprises an associated dimension D13 (
In the illustration shown in
The channels 32′ and 34′ are configured such that they comprise or define the introduction area 60a for receiving the rod 24′ in the receiver 20′, as illustrated in
During a surgical procedure, the surgeon may make the desired adjustments of the rod 24′ relative to the screws 12′ and vertebrae 14′-18′ while the rod 24′ is loosely captured in the intermediate area 60b. The surgeon then uses the tool, such as a screwdriver (not shown), to rotate the receiver 20′ to the locked position shown in
Advantageously, this system and method facilitates providing a locking receiver 20 that reduces or eliminates the need for threading, internally or externally.
Advantageously, the immediate areas 60b of channels 32′ and 34′ of the second embodiment are dimensioned and configured to facilitate locking the rod 24′ onto the screws 12′ while permitting ease of adjustment between the receiver 20′ and the rod 24′ when the rod 24′ and receiver 20′ are situated in the intermediate area 60b′, as illustrated in
In the embodiments being described, the rod 24, screw 12, receiver 20 and compression member 40 are all made of titanium alloy. Other materials may be used such as metals, metal alloys, carbon fibers, composites, plastics or hybrid materials.
For example, the screw 12 may have a length D11 (
Referring now to
In the embodiment being described, an assembly or system 100″ is shown. As illustrated in
In the embodiment illustrated in
Referring now to
The guide 104″ comprises or defines a bore 110″ (
It should be understood that in this illustrative embodiment, the guide or sleeve 104″ does not function as a compression member like the compression member 40 and 40′ described earlier herein. Thus, one feature of this embodiment is that the rod 24″ engages and compresses directly against at least a portion of the head 102a″ after the receiver 20″ is rotated to the locked position as described herein.
The sleeve or guide 104″ comprises a first wall portion 112″ and a generally opposed second wall portion 114″ that are curved about an axis B (
The guide or sleeve 104″ comprises the bore 110″ having an inner diameter D16 (
Notice that the first wall portion 112″ comprises a first end 112d″ having a chamfer surface and the second wall portion 114″ comprises a second end 114d″ having a chamfer surface as shown. The chamfer ends 112d″ and 114d″ facilitate guiding the rod 24″ into the receiving area 22″ and channel 121″ as described herein.
A second end 104b″ (
The first wall portion 112″ and generally opposed second wall portion 114″ have outer surfaces 112d″ and 114d″ that lie in a cylindrical or circumferential plane that is generally cylindrical and adapted and dimensioned to be slidably and rotatably received in the bore 22″ defined by the wall 22c″ of the receiver 20″, as illustrated in
Notice that edges 112a″, 112b″ and 114a″, 114b″ of the wall portions 112″ and 114″, respectively, and surfaces 117a″ (
As illustrated in
Notice in
The overall shape or configuration of an outer surface 102a1″ (
In the illustration being described, the engaging surface or portion 120″ has a surface 120a″ that is curved in the illustration being described. The walls 130″, 132″, 134″, and 136″ each have surfaces or portions 150″, 152″, 154″ and 156″, respectively, that are also curved in the illustration being described.
It should be understood that the head 102a″ may comprise any suitable configuration or surface shape as may be necessary to permit the at least a portion 120″ of the head 102a″ to engage or be engaged by the rod 24″. Although not shown, if the rod 24″ had a non-curved surface, then it may be desirable to provide a head (not shown) having a shape that is adapted to directly complement and engage the non-curved surface. For example, if the rod 24″ were hexagonal, octagonal, square or rectangular in cross section, then the head 102a″ may have a mating or engaging portion to facilitate directly engaging the rod 24″ when the receiver 20″ is moved or rotated to the locked position. Moreover, a radius of curvature of each of the surfaces 120a″, 150″, 152″, 154″ and 156″ may be generally constant, may vary over its surface, or may be non-constant if desired. Also, the curvatures or shapes of the surfaces may be larger or smaller if desired, and they may be different among them.
The surface 105″ may be straight or it may comprise a curvature, arcuate or spherical shape in order to adapt to and complement the curvature or shape of the head 102a″ and/or surfaces 150″, 152″, 154″ or 156″ as shown.
As illustrated in
As mentioned earlier, the arcuate or curved wall portions 112c″ and 114c″ cooperate with the joining portions 117″ and 119″ to define the aperture or bore 110″. As mentioned earlier herein, note that the dimension D16 generally corresponds to or is generally the same as the dimension D18 (
The dimensions D16 (
Unlike prior embodiments described herein, notice that no compression member 40 is necessary in this embodiment, and although not shown, the guide or sleeve 104″ is also optional in this embodiment. In the illustration being described, the guide or sleeve 104″ comes into direct contact with the head 102a″ of the screw 102″ when the receiver 20″ is rotated to the locked position, but the sleeve 104″ itself does not compress against the head 102a″ to lock the rod 24″ to the head 102a″ as does the compression member 40″ in the embodiments illustrated in
It should be understood that the embodiment being described relative to
As with the prior embodiment and as illustrated in
Note that the guide sleeve 104″ is located in the bore 22″ of the receiver 20″ and provides a guide for the rod 24″ to become aligned and positioned in receiver 20″, as illustrated in FIGS. 37, 43-46, 49-51 and 55-57. The walls 112″ and 114″ of the guide or sleeve 104″ perform lateral stabilization and alignment of the rod 24″. It should be understood that when the assembly 100″ is in the unlocked position (as illustrated, for example, in
As mentioned earlier herein, the receiver 20″ may have generally straight channels 32″ and 34″ of the type illustrated in
After the screw(s) 102″ are screwed into the bone a desired distance and the guide or sleeve 104″ is inserted into the receiver 20″, the surgeon aligns the rod 102″ in the receiver 20″ to the desired position relative to the spine, vertebrae or bone and also relative to one or more other receivers 20″, if any, that are being used during the procedure. It should be understood that the screws 102″ and the position of the vertebrae 14″-18″, relative to each other may be adjusted by the surgeon. Once the bones 14″-18″ are adjusted and the angular or polyaxial position of the receiver 20″ is adjusted, the rod 102″ is adjusted within the receiver 20″ and in the guide sleeve 104″. The surgeon or technician may then lock the receiver 20″ to the rod 24″ by rotating or turning the receiver 20″ with the tool, such as a flat-head screw driver (not shown), placed in the slot 26″. This causes the rod 24″ to directly engage at least a portion of the screw head 102a″, such as surfaces or portions 120a″, 150″, 152″, 154″ or 156″, thereby causing the rod 24″ to become locked or fixed onto the screw 102″. This causes the receiver 20″ to become affixed to its respective bone, such as spinal bones 14-18 (
As illustrated in
If the receiver 20″ comprises the channels 32″ and 34″ having the configurations of the type illustrated in
As with the embodiment described earlier herein, relative to
Notice in
It should be understood, however, that as with prior embodiments, the receiver 20″ may be situated such that its axis RA is not coaxial with the screw axis SA (
Advantageously, the screw head 102a″ is configured and adapted to have a desired shape, such as a curved, arcuate or spherical shape or other desired shape, so that the receiver 20″ can be positioned in a desired polyaxial position, even if its axis RA (
It should be appreciated that the recesses 122″, 124″, 126″ and 128″ (
Advantageously, this system and method provides apparatus, method and means for providing a capless and polyaxial positionable and moveable receiver 20″ which reduces or eliminates the need for a compression member, such as the compression member 40″ of the type described earlier herein relative to the embodiments shown in
Advantageously, this system and method provide a capless multiaxial screw which eliminates the need for caps or screws or threads of the type used in the prior art. This system and method combine a very simplified yet effective means for locking an elongated member or rod to a screw and bones, such as spinal bones or other human bones, in the manner described and shown herein.
While the apparatus, system and method herein described, and the form of apparatus for carrying this method into effect, constitute several illustrative embodiments of this invention, it is to be understood that the invention is not limited to this precise method and form of apparatus, and that changes may be made in either without departing from the scope of the inventions, which is defined in the appended claims.
Claims
1. A capless multiaxial screw system comprising:
- a receiver comprising a receiver end comprising a receiver bore for receiving a threaded portion of a screw having a screw head; and
- a sleeve having a sleeve end for situating against at least a portion of said screw head after said threaded portion is received in said receiver bore, said sleeve having a sleeve bore associated with said sleeve end;
- said receiver having a channel for receiving an elongated member;
- said sleeve being adapted to permit said elongated member to engage said at least of portion of said screw head when said elongated member is received in said channel and said receiver is rotated to a locked position.
2. The capless multiaxial screw system as recited in claim 1 wherein said sleeve end comprises an outer end surface that is tapered or concave, said outer end surface engaging said at least a portion of said screw head.
3. The capless multiaxial screw system as recited in claim 1 wherein said sleeve end comprises an inner end surface, said at least a portion of said screw head extending through said sleeve bore beyond said inner end surface when said receiver is in said locked position.
4. The capless multiaxial screw system as recited in claim 1 wherein said receiver comprises a plurality of channels for receiving said elongated member.
5. The capless multiaxial screw system as recited in claim 4 wherein each of said plurality of channels defines an intermediate area for capturing said elongated member to facilitate adjusting a position of said elongated member before it is locked in said receiver.
6. The capless multiaxial screw system as recited in claim 5 wherein said plurality of channels are defined by a first surface and a second surface, each of said plurality of channels having an intermediate step for defining said intermediate area.
7. The capless multiaxial screw system as recited in claim 6 wherein at least one of said first or second surfaces is not planar.
8. The capless multiaxial screw system as recited in claim 1 wherein said channel is a helical channel defined by at least one surface of said receiver.
9. The capless multiaxial screw system as recited in claim 1 wherein said sleeve end comprises a generally concave or semispherical seat, at least a second portion of said screw head having a curvature that generally complements said generally concave or semispherical seat.
10. The capless multiaxial screw system as recited in claim 1 wherein said channel comprises a receiving area that is generally parallel to an axis of said receiver and comprises a locking area that spirals about said axis of said receiver when moving in an axial direction.
11. The capless multiaxial screw system as recited in claim 10 wherein said locking area extends in a direction that is generally not parallel to said axis of said receiver.
12. The capless multiaxial screw system as recited in claim 1 wherein said receiver comprises at least one camming surface that cooperates with an opposing surface for defining said channel, said at least one camming surface facilitates compressing said elongated member directly against said at least a portion of said screw head.
13. The capless multiaxial screw system as recited in claim 1 wherein said receiver comprises a plurality of camming surfaces that cooperate with a plurality of opposing surfaces, respectively, to define said channel, said plurality of camming surfaces for camming against said elongated member and forcing it into compression against said at least a portion of said screw head.
14. The capless multiaxial screw system as recited in claim 13 wherein said locking channel comprises a first locking channel area and a second locking channel area, said receiver comprises a first camming surface generally opposed to a first opposing surface to define said first locking channel area and a second camming surface generally opposed to a second opposing surface to define said second locking channel area, said first and second camming surfaces camming against said elongated member to cause said elongated member to apply a compressive force against said screw head when said receiver is rotated.
15. The capless multiaxial screw system as recited in claim 1 wherein said channel comprises a lock member associated therewith for facilitating retaining said receiver in a locked position.
16. The capless multiaxial screw system as recited in claim 15 wherein said lock member cooperates with an end wall of said channel to define a locking area at which said receiving member is locked when it is in said locked position.
17. The capless multiaxial screw system as recited in claim 1 wherein said channel lies in a first plane that is generally planar and said receiver further comprising a locking channel that lies in a second plane that is non-planar.
18. The capless multiaxial screw system as recited in claim 1 wherein said receiver comprises a locking channel that spirals about an axis of said retainer.
19. The capless multiaxial screw system as recited in claim 1 wherein said receiver comprises a seat, said screw head having a screw head end that is generally spherical or semispherical and said seat is adapted to receive and complement said screw head end.
20. The capless multiaxial screw system as recited in claim 1 wherein said screw head comprises a plurality of recessed areas in at least a portion of said screw head adapted to receive a tool for driving said screw.
21. The capless multiaxial screw system as recited in claim 1 wherein said screw head comprises a simple recessed area adapted to receive a tool for driving said screw.
22. The capless multiaxial screw system as recited in claim 1 wherein said at least a portion of said screw head comprises an outer surface that is arcuate, curved, semispherical or spherical.
23. The capless multiaxial screw system as recited in claim 22 wherein said outer surface is spherical.
24. The capless multiaxial screw system as recited in claim 1 wherein said sleeve end is adapted to permit direct engagement or compression of said elongated member against said at least a portion of said screw head.
25. The capless multiaxial screw system as recited in claim 1 wherein said screw head is adapted to permit point contact and compression of said elongated member against said at least a portion of said screw head when a screw axis of said screw is not coaxial with a receiver axis of said receiver.
26. The capless multiaxial screw system as recited in claim 3 wherein said sleeve bore is adapted to permit said at least a portion of said screw head to extend into said sleeve bore a predetermined distance such that it extends into said channel.
27. The capless multiaxial screw system as recited in claim 1 wherein said sleeve comprises two generally opposing walls that stabilize and align said elongated member in said receiver.
28. The capless multiaxial screw system as recited in claim 27 wherein said at least a portion of said screw head comprises an outer surface that is arcuate, curved, semispherical or spherical in cross section.
29. A bone fixation assembly comprising:
- a receiver having a receiver bore for receiving a screw having a screw head and a receiver channel in communication with said receiver bore for receiving an elongated member; and
- a stabilizer adapted to be received in said receiver bore, said stabilizer having a stabilizer channel and a stabilizer bore through said stabilizer, said stabilizer adapted to permit direct contact between at least a portion of said screw head and said elongated member;
- said receiver being capable of rotating relative to said elongated member after said elongated member is received in said receiver channel to force said elongated member into contact with said at least a portion of said screw head.
30. The bone fixation assembly as recited in claim 29 wherein said receiver comprises at least one engaging surface for engaging said elongated member and for locking said elongated member to said at least a portion of said screw head when said receiver is rotated to a locked position.
31. The bone fixation assembly as recited in claim 29 wherein said receiver is generally cylindrical and said receiver bore extends along an axis of said receiver, said receiver comprising a first locking aperture in communication with said receiver bore and a second locking aperture in communication with said receiver bore; said first and second locking apertures cooperating to define a locking channel.
32. The bone fixation assembly as recited in claim 31 wherein said locking channel is defined by a first channel in a wall of said receiver and a second channel in said wall of said receiver, said first and second channels being generally opposed.
33. The bone fixation assembly as recited in claim 32 wherein said first channel and said second channel extend away from said receiver channel about a receiver axis of said receiver such that rotation of the receiver will cause said elongated member to move to a locked position whereupon it engages said at least a portion of said screw head.
34. The bone fixation assembly as recited in claim 32 wherein said first channel and said second channel spiral in a common direction about a receiver axis of said receiver.
35. The bone fixation assembly as recited in claim 29 wherein said receiver comprises a wall that lies in a generally circular or arcuate plane about a receiver axis of said receiver and said receiver channel being by said wall.
36. The bone fixation assembly as recited in claim 29 wherein said screw head comprises a plurality of recessed areas.
37. The capless multiaxial screw system as recited in claim 29 wherein said screw head comprises a single recessed area adapted to receive a tool for driving the screw.
38. The bone fixation assembly as recited in claim 29 wherein an outer surface of said at least a portion of said screw head is arcuate, curved, spherical or semispherical in cross section.
39. The bone fixation assembly as recited in claim 29 wherein an outer surface of said at least a portion of said screw head is arcuate or spherical at said at least a portion of said screw head.
40. The bone fixation assembly as recited in claim 39 wherein said screw has a truncated area for permitting maximal polyaxial movement of said receiver relative to said screw head.
41. The bone fixation assembly as recited in claim 29 wherein said stabilizer bore of said stabilizer is adapted to permit point contact of said elongated member against said at least a portion of said screw head.
42. The bone fixation assembly as recited in claim 39 wherein said stabilizer bore of said stabilizer is adapted to permit point contact of said elongated member against said at least a portion of said screw head.
43. The bone fixation assembly as recited in claim 29 wherein said screw head and said stabilizer bore are adapted to permit point contact of said elongated member against said at least a portion of said screw head and when a screw axis of said screw is not coaxial with a receiver axis of said receiver.
44. The bone fixation assembly as recited in claim 29 wherein said stabilizer bore is adapted to permit said at least a portion of said screw head to extend into said receiver bore a predetermined distance.
45. The bone fixation assembly as recited in claim 29 wherein said stabilizer comprises an inner end surface, said at least a portion of said screw head extends beyond said inner end surface and into said stabilizer bore when said elongated member is in a locked position in said receiver.
46. The bone fixation assembly as recited in claim 29 wherein said stabilizer comprises a first wall and a generally opposed second wall for defining a stabilizer receiving area or channel for receiving said elongated rod.
47. The bone fixation assembly as recited in claim 46 wherein said stabilizer bore is in communication with said stabilizer receiving area, said stabilizer bore being adapted to permit said at least a portion of said screw head to be received in said stabilizing bore so that said elongated member directly engages or is engaged by said at least a portion of said screw head when said receiver is rotated to a locked position.
48. The bone fixation assembly as recited in claim 47 wherein said stabilizer comprises a generally cylindrical wall that defines said stabilizer bore.
49. The bone fixation assembly as recited in claim 48 wherein said generally cylindrical wall comprises an inner diameter that generally corresponds to a distance between said first and second walls.
50. An intermediate member for use with a polyaxial screw having a head that is generally spherical comprising:
- a body having a bore; and
- a channel for receiving an elongated member;
- said bone being adapted to permit at least a portion of a screw head of the polyaxial screw to enter into said bore.
51. The intermediate member as recited in claim 50 wherein a width of said channel is at least as large as a radius of said bore.
52. The intermediate member as recited in claim 50 wherein said intermediate member comprises an end having a frusto-conical, or spherical or semispherical surface for engaging said screw head.
53. The intermediate member as recited in claim 50 wherein said intermediate member comprises an end having an opening adapted to permit said elongated member to engage or be engaged by at least one portion of said screw head.
54. A bone fixation assembly comprising:
- a receiver having a bore for receiving a screw having a screw head; and
- an intermediate member dimensioned to be received in said bore and having a first end and a second end;
- said receiver comprising an integral rotary lock for forcing and locking an elongated member directly against said screw head when said receiver is rotated.
55. The bone fixation assembly as recited in claim 54 wherein said integral rotary lock comprises a continuous channel for receiving said elongated member and for urging said elongated member toward said screw head when said receiver is rotated.
56. The bone fixation assembly as recited in claim 54 wherein said integral rotary lock comprises a first channel that extends about a receiver axis in a first direction and a second channel that extends about said receiver axis in a second direction and a receiver channel coupling said first and second channels.
57. The bone fixation assembly as recited in claim 56 wherein said first and second directions extend away from said receiver channel about a receiver axis of said receiver such that rotation of said receiver will move said elongated member from an unlocked position to a locked position.
58. The bone fixation assembly as recited in claim 56 wherein said receiver channel lies in a plane that generally extends along an axis of said receiver.
59. The bone fixation assembly as recited in claim 56 wherein said first and second channels spiral about said receiver axis.
60. The bone fixation assembly as recited in claim 56 wherein said first and second channels lie in imaginary planes that intersect an axis of said receiver at acute angles.
61. The bone fixation assembly as recited in claim 56 wherein said receiver channel lies in a receiver plane, said first channel lies in a first plane and said second channel lies in a second plane, each of said first and second planes intersecting said receiver plane at an acute angle that extends toward a bone when said screw is screwed into the bone.
62. The bone fixation assembly as recited in claim 54 wherein said receiver comprises a removable intermediate member for stabilizing said elongated member.
63. The bone fixation assembly as recited in claim 62 wherein said removable intermediate member comprises an end having an opening, said screw head and said opening being adapted to enable said elongated member to contact at least one portion of said screw head.
64. The bone fixation assembly as recited in claim 54 wherein said screw head is generally spherical.
65. The bone fixation assembly as recited in claim 62 wherein said screw head is generally spherical.
66. A bone fixation assembly comprising:
- a receiver having an opening for receiving a screw having a screw head; and
- an intermediate member dimensioned to be received in said opening and having an intermediate member receiving channel for receiving an elongated member and a screw head receiving opening adapted to receive at least a portion of said screw head;
- said receiver comprising a receiver channel for receiving said elongated member, said receiver channel compressing said elongated member against said screw head when said receiver is rotated from an unlocked position to a locked position.
67. The spiral fixation assembly as recited in claim 66 wherein said receiver channel comprises a locking channel that spirals about an axis of said receiver.
68. The spiral fixation assembly as recited in claim 67 wherein said locking channel provides a bayonet connection between said elongated member and said screw.
69. The bone fixation assembly as recited in claim 66 wherein said receiving channel comprises at least a portion that lies in a first plane and said intermediate member receiving channel comprises at least a portion that lies in a second plane, said second plane and said first plane being generally parallel when said elongated member is in said unlocked position and generally perpendicular when said elongated member is in said locked position.
70. The bone fixation assembly as recited in claim 66 wherein when said receiver is rotated from said unlocked position to said locked position, said elongated member directly engages said at least a portion of said screw head and becomes situated closer to said screw compared to when said elongated member is in said unlocked position.
71. The bone fixation assembly as recited in claim 70 wherein said receiver channel is in communication with a locking channel so that when said receiver is in said unlocked position, said receiving channel becomes generally aligned with said intermediate member receiving channel in said intermediate member.
72. The bone fixation assembly as recited in claim 66 wherein said receiver channel is generally perpendicular to an elongated member axis of said elongated member when said receiving member is in said locked position.
73. The bone fixation assembly as recited in claim 66 wherein said receiver channel comprises a locking channel that spirals from a first end of said receiver toward a second end of said receiver.
74. The bone fixation assembly as recited in claim 73 wherein said locking channel defines a helix.
75. The bone fixation assembly as recited in claim 66 wherein said receiver channel extends from an end of said receiver in a direction that is generally parallel to an axis of said receiver and further comprises a locking channel that extends at least partially about said axis of said receiver.
76. The bone fixation assembly as recited in claim 66 wherein said intermediate member receiving channel becomes generally aligned with said receiver channel when said elongated member is received in said receiver and said receiver channel and said intermediate member receiving channel become non-aligned when said receiver is rotated to said locked position.
77. The bone fixation assembly as recited in claim 66 wherein said receiver channel comprises a locking channel, said receiver comprising at least one camming surface that cooperates with an opposing surface that cooperates to define said receiver channel, said at least one camming surface camming against said elongated member to move said elongated member against said screw head when said receiver is rotated.
78. The bone fixation assembly as recited in claim 66 wherein said receiver comprises a plurality of camming surfaces that cooperate with a plurality of opposing surfaces, respectively, to define a locking channel, said plurality of camming surfaces camming against said elongated member to cause said elongated member to apply a compressive force against said screw head when said receiver is rotated.
79. The bone fixation assembly as recited in claim 66 wherein said receiver comprises a locking channel comprising a first locking channel area and a second locking channel area
- said receiver comprises a first camming surface generally opposed to a first opposing surface to define said first locking channel area and a second camming surface generally opposed to a second opposing surface to define said second locking channel area, said first and second camming surfaces camming against said elongated member to force said elongated member to apply a compressive force against said screw head when said receiver is rotated.
80. The bone fixation assembly as recited in claim 79 wherein said receiver comprises a detent or protrusion or a plurality of detents or protrusions in communication with said locking channel.
81. The bone fixation assembly as recited in claim 79 wherein said receiver comprises a surface that defines an end wall of said locking channel to define a locking area at which said elongated member is locked when it is in said locked position.
82. The bone fixation assembly as recited in claim 66 wherein said receiver comprises a locking channel, said receiver channel lies in a first plane that is generally planar and said locking channel lies in a second plane that is non-planar.
83. The bone fixation assembly as recited in claim 82 wherein said second plane spirals about an axis of said receiver.
84. The bone fixation assembly as recited in claim 82 wherein said locking channel extends in a direction that is non-axial relative to an axis of said receiver.
85. The bone fixation assembly as recited in claim 66 wherein said screw head is generally arcuate, spherical, semispherical or curved and said intermediate member comprises an end having an outer end surface that is generally complementary in shape and adapted to receive said screw head.
86. The bone fixation assembly as recited in claim 66 wherein said screw head comprises a plurality of recessed areas surrounding said at least a portion of said screw head.
87. The bone fixation assembly as recited in claim 66 wherein said at least a portion of said screw head is spherical in cross section.
88. The bone fixation assembly as recited in claim 66 wherein said at least a portion of said screw head is spherical in cross section at an area where said elongated member directly engages said screw head.
89. The bone fixation assembly as recited in claim 66 wherein said outer surface of said screw head is adapted to permit point contact of said elongated member directly against said at least a portion of said screw head.
90. The bone fixation assembly as recited in claim 66 wherein said screw head is adapted to permit point contact of said elongated portion against said at least a portion of said screw head when a screw axis of said screw is not coaxial with a receiver axis of said receiver.
91. The bone fixation assembly as recited in claim 66 wherein said intermediate member comprising an end having an opening adjusted to permit an engaging portion of said screw head to extend into said receiver opening a predetermined distance.
92. The bone fixation assembly as recited in claim 66 wherein said intermediate member comprises a bottom surface, said at least a portion of said screw extending beyond said bottom surface and into said receiver channel when said elongated member is in said locked position.
93. The bone fixation assembly as recited in claim 66 wherein said intermediate member comprises an end having an outer end surface that is frusto-conical.
94. The bone fixation assembly as recited in claim 66 wherein said screw head comprises an outer surface and at least one tool aperture or area for receiving a tool.
95. A capless multiaxial screw system comprising:
- a screw having a threaded portion and a screw head;
- a receiver having a receiver bore for receiving said threaded portion and a receiving channel for receiving an elongated member, said receiver further comprising a locking channel in communication with said receiving channel;
- an intermediate member adapted to be situated in said receiver bore, said intermediate member comprising an intermediate member bore for receiving at least a portion of said screw head; and
- said intermediate member bore and said screw head being adapted to permit said at least a portion of said screw head to extend into said locking channel so that said elongated member may engage and compress against said at least a portion of said screw head when said elongated member is received in said receiving channel and said receiver is rotated.
96. The capless multiaxial screw system as recited in claim 95 wherein said locking channel comprises a plurality of channels, each of said plurality of channels defining an intermediate area for capturing said elongated member to facilitate adjusting a position of said elongated member before it is locked in said receiver.
97. The capless multiaxial screw system as recited in claim 96 wherein each of said plurality of channels are defined by a first surface and a second surface, each of said plurality of channels having an intermediate step on at least one of said first surface or said second surface for defining said intermediate area.
98. The capless multiaxial screw system as recited in claim 97 wherein at least one of said first and second surfaces is not planar.
99. The capless multiaxial screw system as recited in claim 95 wherein said locking channel is a helical channel defined by at least one surface in a body of said receiver.
100. The capless multiaxial screw system as recited in claim 95 wherein said intermediate member comprises an end having a first side comprising a generally concave seat, at least a second portion of said screw head having a curvature that generally complements said generally concave seat.
101. The capless multiaxial screw system as recited in claim 95 wherein said receiving channel is generally parallel along an axis of said receiver and said locking channel spirals about said axis of said receiver when moving in an axial direction.
102. The capless multiaxial screw system as recited in claim 95 wherein said receiving channel extends from an end of said receiver in a direction that is generally parallel to said axis of said receiver and said locking channel extends in a direction that is generally not parallel to said axis of said receiver.
103. The capless multiaxial screw system as recited in claim 95 wherein said receiver comprises at least one camming surface that cooperates with an opposing surface to define said locking channel, said at least one camming surface forcing said elongated member against said at least a portion of said screw head.
104. The capless multiaxial screw system as recited in claim 95 wherein said receiver comprises a plurality of camming surfaces that cooperate with a plurality of opposing surfaces, respectively, to define said locking channel, said plurality of camming surfaces camming against said elongated member to lock said receiver to said at least a portion of said screw head.
105. The capless multiaxial screw system as recited in claim 95 wherein said locking channel comprises a first locking channel area and a second locking channel area, said receiver comprises a first camming surface generally opposed to a first opposing surface to define said first locking channel area and a second camming surface generally opposed to a second opposing surface to define said second locking channel area, said first and second camming surfaces camming against said elongated member to force said elongated member against said at least a portion of said screw head when said receiver is rotated.
106. The capless multiaxial screw system as recited in claim 95 wherein said receiving channel lies in a first plane that is generally planar and said locking channel lies in a second plane that is non-planar.
107. The capless multiaxial screw system as recited in claim 106 wherein said second plane spirals about an axis of said receiver.
108. The capless multiaxial screw system as recited in claim 95 wherein said locking channel spirals about an axis of said receiver.
109. The capless multiaxial screw system as recited in claim 95 wherein said receiver comprises a seat defining a seat area said screw head being generally spherical, said seat being adapted to receive and complement said screw head.
110. The capless multiaxial screw system as recited in claim 95 wherein said screw head comprises a plurality of recessed areas for receiving a tool used to turn said screw.
111. The capless multiaxial screw system as recited in claim 95 wherein said at least a portion of said screw head is spherical or semispherical.
112. The capless multiaxial screw system as recited in claim 95 wherein said at least a portion of said screw head is arcuate or spherical in cross section.
113. The capless multiaxial screw system as recited in claim 95 wherein said intermediate member comprises a seat defining a seat area adapted to permit point contact between said elongated member and said at least a portion of said screw head.
114. The capless multiaxial screw system as recited in claim 95 wherein said screw head and said screw head receiving opening are adapted to permit point contact of said elongated member against said at least a portion of said screw head when a screw axis of said screw is not coaxial with a receiver axis of said receiver.
115. The capless multiaxial screw system as recited in claim 95 wherein said intermediate member comprises an end, said intermediate member bore being adapted to permit said at least a portion of said screw head to extend into said locking channel a predetermined distance.
116. The capless multiaxial screw system as recited in claim 95 wherein said intermediate member comprises a first wall and a generally opposed second wall for defining an intermediate member receiving area for receiving said elongated member.
117. The capless multiaxial screw system as recited in claim 95 wherein said intermediate member bore is in communication with said intermediate member receiving area, said intermediate member bore being dimensioned to permit said at least a portion of said screw head to be received in both said receiver bore and said intermediate member bore so that when said receiver is rotated, said elongated member engages and locks against said at least a portion of said screw head.
118. The capless multiaxial screw system as recited in claim 95 wherein said intermediate member is generally cylindrical and defined by a generally cylindrical wall, an inner diameter of said generally cylindrical wall being greater than a diameter of said elongated member.
119. A capless multiaxial screw fixation assembly comprising:
- a screw having a threaded portion and a screw head;
- a receiver having an aperture for receiving said threaded portion and a receiving channel for receiving an elongated member, said receiving channel further comprising a locking channel in communication with said receiving channel; and
- a guide for situating in said bore, said guide comprising: a second receiving channel associated with a first end of said guide and a seat area associated with a second end of said guide;
- said guide being adapted to permit at least a portion of said screw head to extend into said receiving channel and said second receiving channel so that said elongated member may engage said screw head to lock or compress said elongated member to said screw when said elongated member is received in said first and second receiving channels and said receiver is rotated from an unlocked position to a locked position.
120. A bone fixation assembly comprising:
- a receiver having a receiver bore for receiving a screw having a screw head, said receiver further comprising a locking channel and a receiving channel in communication with said locking channel; and
- an intermediate member dimensioned to be received in said receiver bore, said intermediate member comprising a body having a first end having an intermediate member channel and a second end having an intermediate member opening;
- said intermediate member opening being adapted to permit at least a portion of said screw head to engage an elongated member after said elongated member is received in said receiving channel, said locking channel and said intermediate member channel and said receiver is moved to a locked position.
121. The bone fixation assembly as recited in claim 120 wherein said intermediate member comprises a pair of generally opposed walls that cooperate with said second end to define stabilize and align the elongated member in said receiver channel.
122. The bone fixation assembly as recited in claim 121 wherein said intermediate member bore is generally cylindrical and comprises a diameter substantially the same as a distance between said pair of generally opposed walls.
123. A method for stabilizing one or more bones, said method comprising the steps of:
- placing an elongated member into a receiving channel of said receiver and channel of said intermediate member; and
- rotating said receiver to cause said elongated member to directly engage at least a portion of said screw head.
Type: Application
Filed: Dec 14, 2006
Publication Date: May 31, 2007
Applicant: X-SPINE SYSTEMS, INC. (Centerville, OH)
Inventor: David Kirschman (Centerville, OH)
Application Number: 11/610,698
International Classification: A61F 2/30 (20060101);