CA2444586C - Spinal implant system - Google Patents
Spinal implant system Download PDFInfo
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- CA2444586C CA2444586C CA002444586A CA2444586A CA2444586C CA 2444586 C CA2444586 C CA 2444586C CA 002444586 A CA002444586 A CA 002444586A CA 2444586 A CA2444586 A CA 2444586A CA 2444586 C CA2444586 C CA 2444586C
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- sleeve
- rod
- attachment device
- open back
- spinal
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Abstract
A spinal implant system including components designed to be affixed to the spinal column. The system includes spinal rods, attachment devices, and interpositional sleeves for securing the attachment devices to the rods. The attachment devices may be various types of spinal hooks, screws, couplers, rod connectors, clamps, or other such devices.
Description
SP(NAL IMPLANT SYSTEM
This is a divisional of application 2,095,599 filed May 5, 1993.
BACK~I~OUN~ OF THE iNVENT10N
The.preSent invention relates to a°spinal implant system, and is suitable for use in treatments for.correcting various spinal deformities. In particular, this invention relates to a spinal system of the type. that includes an interposit~ional sleeve for securing various types of attachment devices to a spinal r°od.
_~
The use of an interpositional sleeve ~o secure a spinal attachment device to a rod is taught in the prior art, such as in.U.S.
Patents 5,112,332 and 5;116,334 to Cozad et al. The present invention is a modification and improvement of these Cozad'et al. patents, and as such tl;ese two U.S. Patents, 5,112,332 and 5,116,334, are w background infQrmat~on. Both of these Cozad et at. patents, as r~eif as the present invention, are assigned to Zimmer, Inc. These two Cozad et al. patents are both divisional of U.S. Patent 5,074,864 to Cozad et al.
These Cozad et al. patents disclose a spinal implant system which includes a tapered split sleeve having a separate, discrete lock member or lock nut securable over the sleeve. The lock member interacts with the open back attachment device by acting on an exterior surface of the attachment device to secure an interference frictional interconnection between the tapered sleeve and the attachment device to secure the device to the rod.
The following other spinal systems are known which disclose the use of an interpositional sleeve:
U.S. Patent 5,010,879 to Moriya et al. discloses a spinal system having a wedge-like slit sleeve having a cylindrical body with a flange 7a on one end and a tapered portion 8a on the other end. The wedge-like member is forcibly inserted at the tapered end thereof between a spinal hook and a rod.
U.S. Patents 4,815,453 and 4,641,636 to Cotrel disclose a spinal system which includes a sleeve 30 having,a conical part 31. A pressure screw 25 is provided to selectively fix the anchoring members in position on the spinal rod or pin, which hay a roughened surface.
U.S. Patent 4,404,96 to Racal et al. discloses a spinal system having a split or cut sleeve 3 with skew recesses 4 made along the cut.
The inner surfaces of recesses 4 constitute bearing surfaces for a pin 2 which protrudes from the apinal rod 1. A conical end of the sleeve fits into a corresponding recess in the hook.
U.S. Patent 4,259,178 to Keene discloses an open back spival hook having a sleeve. which is slidable along the spinal rod and into the hook. A lock nut may then be used to secure the position of the s 1 eeve.
SUMMARY OF THE INVENTION
A principal object of this invention is to provide a spinal implant system with a secure attachment mechanism that is easy to use, but effective.
One aspect of the invention provides a spinal implant system including a spinal rod, an attachment device, and an interpositional sleeve for securing the attachment device to the rod, wherein the sleeve has a length and includes a longitudinal bore therethrough and an open back extending the length of the sleeve and connecting with the bore, and wherein the open back of the sleeve has a width sufficient to enable the sleeve to snap fit lateral 1y onto the rod and lateral 1y retain the sleeve on the rod.
This is a divisional of application 2,095,599 filed May 5, 1993.
BACK~I~OUN~ OF THE iNVENT10N
The.preSent invention relates to a°spinal implant system, and is suitable for use in treatments for.correcting various spinal deformities. In particular, this invention relates to a spinal system of the type. that includes an interposit~ional sleeve for securing various types of attachment devices to a spinal r°od.
_~
The use of an interpositional sleeve ~o secure a spinal attachment device to a rod is taught in the prior art, such as in.U.S.
Patents 5,112,332 and 5;116,334 to Cozad et al. The present invention is a modification and improvement of these Cozad'et al. patents, and as such tl;ese two U.S. Patents, 5,112,332 and 5,116,334, are w background infQrmat~on. Both of these Cozad et at. patents, as r~eif as the present invention, are assigned to Zimmer, Inc. These two Cozad et al. patents are both divisional of U.S. Patent 5,074,864 to Cozad et al.
These Cozad et al. patents disclose a spinal implant system which includes a tapered split sleeve having a separate, discrete lock member or lock nut securable over the sleeve. The lock member interacts with the open back attachment device by acting on an exterior surface of the attachment device to secure an interference frictional interconnection between the tapered sleeve and the attachment device to secure the device to the rod.
The following other spinal systems are known which disclose the use of an interpositional sleeve:
U.S. Patent 5,010,879 to Moriya et al. discloses a spinal system having a wedge-like slit sleeve having a cylindrical body with a flange 7a on one end and a tapered portion 8a on the other end. The wedge-like member is forcibly inserted at the tapered end thereof between a spinal hook and a rod.
U.S. Patents 4,815,453 and 4,641,636 to Cotrel disclose a spinal system which includes a sleeve 30 having,a conical part 31. A pressure screw 25 is provided to selectively fix the anchoring members in position on the spinal rod or pin, which hay a roughened surface.
U.S. Patent 4,404,96 to Racal et al. discloses a spinal system having a split or cut sleeve 3 with skew recesses 4 made along the cut.
The inner surfaces of recesses 4 constitute bearing surfaces for a pin 2 which protrudes from the apinal rod 1. A conical end of the sleeve fits into a corresponding recess in the hook.
U.S. Patent 4,259,178 to Keene discloses an open back spival hook having a sleeve. which is slidable along the spinal rod and into the hook. A lock nut may then be used to secure the position of the s 1 eeve.
SUMMARY OF THE INVENTION
A principal object of this invention is to provide a spinal implant system with a secure attachment mechanism that is easy to use, but effective.
One aspect of the invention provides a spinal implant system including a spinal rod, an attachment device, and an interpositional sleeve for securing the attachment device to the rod, wherein the sleeve has a length and includes a longitudinal bore therethrough and an open back extending the length of the sleeve and connecting with the bore, and wherein the open back of the sleeve has a width sufficient to enable the sleeve to snap fit lateral 1y onto the rod and lateral 1y retain the sleeve on the rod.
Another aspect provides a spinal implant system including a spinal rod, an attachment device, and an interpositional sleeve for securing the attachment device to the rod, wherein the attachment device incl4,~des a first means for partially seating the sleeve between the rod and 'the attachment device and a second means for fully seating the sleeve between the rod and the attachment device.
A still further aspect provides a spinal implant system including a spinal rod, an attachment device, and an interpositional sleeve for securing the attachment device to the rod, wherein the sleeve includes a retainment tab means extending therefrom for providing alignment and anti rotation of the sleeve in the attachment device.
The spinal implant system described hereafter includes components designed to be affixed to the spinal column. The system includes spinal rods, attachment devices, and interpositional sleeves for securing the attachment devices to the rods. The attachment devices may be various types of spinal hooks, screws, couplers, rod connectors, clamps or other such devices. The attachment device provides two discrete positions far positioning the sleeve, a first partially seated position and a second fully seated position. The sleeve can advantageously be snap fit onto the rod in the desired location. In addition, the sleeve has a first taper and a second reverse taper with the narraw ends of each taper converging to form a reduced portion. The reduced portion may further include a recessed transition zone. The spinal implant system provides a stable and secure way to fix the position of a spinal attachment device onto a spinal rod.
A still further aspect provides a spinal implant system including a spinal rod, an attachment device, and an interpositional sleeve for securing the attachment device to the rod, wherein the sleeve includes a retainment tab means extending therefrom for providing alignment and anti rotation of the sleeve in the attachment device.
The spinal implant system described hereafter includes components designed to be affixed to the spinal column. The system includes spinal rods, attachment devices, and interpositional sleeves for securing the attachment devices to the rods. The attachment devices may be various types of spinal hooks, screws, couplers, rod connectors, clamps or other such devices. The attachment device provides two discrete positions far positioning the sleeve, a first partially seated position and a second fully seated position. The sleeve can advantageously be snap fit onto the rod in the desired location. In addition, the sleeve has a first taper and a second reverse taper with the narraw ends of each taper converging to form a reduced portion. The reduced portion may further include a recessed transition zone. The spinal implant system provides a stable and secure way to fix the position of a spinal attachment device onto a spinal rod.
BRIEF DESCRIPTION OF THE DRAWINGS
These features and objects of the invention, as well as others, will become apparent to those skilled in the art by referring to the accompanying drawings:
Fig. 1 is a perspective view of a rod, an attachment device, and an interpositional sleeve according to the present spinal implant system invention, and , shown prior to insertion of the sleeve in the attachment device;
Fig. 2 is a perspective view of the~components of Fig. 1 with the sleeve shown in the first partially seated position in the attachment device;
Fig. 3 is a perspective view of the components of Fig. l~i~ith the sleeve shown in the second fully seated position in the attachment device;
Fig. 4 is a perspective view of the sleeve of Fig. 1;
Fig. 5 is a perspective view of the sleeve of Fig. a shown from the opposite end;
Fig.~6 is a bottom view of the sleeve of Fig. 4;
Fig. 7 is a top view of the sleeve of ~'ig. ~;
Fig. 8 is a perspective view of the attachment device of Fig. 1;
Fig. 9 is a top view of the attachment device of Fig. 8;
Fig. I0 is a cross-sectional view taken along lines 10-10 of Fi,g.9;
Fig. 11 is a cross-sectional view taken along lines 11-11 of Fig.
8; and Fig. 12 is an end view of the attachment device of Fig. 8 as viewed from lines i2-12 of Fig. 8.
_5_ DETAILED DESCRIPTION OF THE INVENTION
Figs. 1-I2 illustrate a particularly advantageous embodiment of a spinal implant system according to the present invention. The spinal implant system includes a spinal rod 1, an attachment device 40, and an interpositional sleeve 10 for securing .the device 40 to rod 1. The attachment device 40 may be .one of various types of spinal hooks, screws, couplers, rod connectors, clamps, or other such devices. The present invention is illustrated with the attachment device as a spinal hook with extending hook portion 49; however,. it is understood that any suitable attachment device may be utilized in accordance with the present invention.
It is understood in keeping with spinal suwgery techniques that a plurality of spinal rods can be used, each with 4 plurality of spinal attachment devices affixed thereto. The attachment devices may either be used to affix the rods to the spinal column or to affix the position of two rods with respect to each other.
The attachment device 40 includes a first position for partially seating the sleeve 10 between the rod 1 and the attachment device 40, as shown in Fig. 2, and a second position for fully seating the sleeve 10, as shown in Fig. ~:
Fig. 1 shows the sleeve 10 prior to insertion in device 40. The sleeve 10 is positioned on the rod 1, while the attachment device 40 is held in position by a suitable hook holder' instrument (not shown).
Such hook holder instruments are kn~wn in the art and grip the attachment device 4U via recessed gripping holes 48. Then a suitable pusher or cruncher type instrument (not shown) ca,n be used to insert the sleeve 10 into attachment device 40 by applying pressure on one side of sleeve 10 and on the opposite side of attachment device 40 to bring the sleeve to the partially seated position of Fig. 2. This partially seated position attaches the sleeve 10 to.device 40 about rod 1, and yet allows the sleeve 10/device 40 assembly to still slide along rod 1 to allow adjustment of their position along rod i. Then a further suitable cincher-type instrument (not shown) is used to apply pressure to the one side of sleeve 10 and the opposite side of device 40 to bring these camponents together into the fully seated position of Fig. 3. This fully seated position locks or secures the attachment device 40 onto rod 1. Final locking of the attachment device 40 and the sleeve 10 to the rod 1, and thus final component fixation is obtained by the interference fit of the sleeve 10 between both the attachment device 10 and rod 1 at this fully seated position. It is noted that when the sleeve 10 is fully seated in the attachment device 40, the length of the sleeve (LS) is preferably fully contained within i5 the length of the attachment device (LA).
The elongated spinal rod 1 may be any switable length or any suitable diameter (D). The cylindrical rod 1 has a smooth outer surface. The sleeve 10 has a longitudinal cylindrical bore 16 therethrough for fitting about rod 1. The surface of the bore 16 is also smooth.
The sleeve 10 includes a first portion 15 and a second porti~n 25. The second portion is relatively shorter than the first portion.
The first portion I5 includes a first outer taper 11 with a wide end 13 tapering to a narrow end 12. The second portion 25 includes a second outer reverse taper 21 with a narrow end 22 tapering to a wide~end 23.
The narrow end 12 of first taper 11 converges with the narrow end 22 of second taper 21 forming a reduced or narrowed portion~ A recessed transition zone or groove 29 ,may be provided between the first and second tapers 11 and 21. The recessed transition zone 29 of sleeve 10 aligns with the edge 44 of counterbore 45.of device 40 when the sleeve is fully seated therein. Thusn neither taper 1l or 21 of sleeve 10 is providing a line contact. The reverse taper 21 helps provide a 5 locking position when the sleeve IO is .pushed to its fully seated position with the second portion 25 of sleeve 10 located in counterbore 45 of attachment device 40. This dual taper design provides an audible and force-feel feedback to the surgeon to communicate a positive lock of the sleeve 10 in the fully seated position in device 40. The 10 reverse taper 21 of tt,e sleeve 10 also allows the sleeve to be unlocked from the attachment aevice 40 with a suitable instrument {not shown) should ,rec~oval of the sleeve 10 be necessary.W'he reverse taper 21 allows sleeve 10 to slide over the edge 44 of counterbore 45 in l attachment device 40 facilitating such removal (as opposed to a sharp edge such as a 90 degree flange which would catch on edge 44 t~ resist removal). The counterbore 45 provides a retaining wall 55 to help lock dual taper sleeve 10 into its fully seated position.
The attachment device 40 includes an inner taper 51 having a wide end 53 tapering to a narrow end 54. A chamfer 52 extends from the wide end 53 of inner taper 5-1. The :counterbore 45 is positioned at the narrow end 54 of taper 51 forming retaining wall 55 therebetween. When the sleeve l0 is positioned and fully seated between rod 1 and device 40, the first outer taper 11 mates with the inner taper ~1 of device 40. The second portion 25 of .sleeve 10 mates with counterbore 45 to secure device 40 to rod 1.
The sleeve 10 has an open back 17 extending the length (LS) of the sleeve 10. The open back 17 interconnects ~~ith bore 16. The attachment device 40 has an~open back 57 extending the length (LA) of the attachment device 40. The open back of device 40 interconnects with inner taper 51 and counterbore 45. The open back 57 of device 40 allows rod :1 to easi 1y drop into positions The open back 17 of the sleeve 10 has a width (WS), while the, open back of the attachment device has a width (WA). The counterbore 45 includes a~semicircular bottom wall 46 which extends into oppositely located straight side walls 47. The counterbore 45 between side walls 47 has a width (WC).
The width (WC) of counterbore 45 is larger than the width (WA) of attachment device 40.
The second portion 25 of sleeve l0 includes a tapered rounded bottom surface 24 forming the second outer reverse taper 2i and two relief cuts 28 on. opposite sides of second portion 25 fflrming-two legs 26 extending from bottom surface 24. The depth of the relief cuts 28 can vary. These relief cuts 28 help give clearance to allow sleeve 10 to enter the taper 51 of attachment device 40. A retainment tab 27 extends from each leg 26. The retainment tabs 27 allow the sleeve 10 to maintain proper alignment within the attachment device. These retainment tabs help prevent rotation of sleeve 10 within attachment device 40, thus acting as antirotation tabs. The tabs 27 help engage the sleeve in the attachment device 40 in both the partially seated and fully seated positions. The retainment tabs 27 extend above the two longitudinal spaced upper edges 31 on either side of open back 17 of sleeve 10. A chamfer 18 extends from each upper edge 31 of sleeve 10 to a .longitudinal lower edge 32. It is the distance between spaced lower edges 32 which creates the width (WS) of the open back 17 of sleeve 10. The distance between the upper edges 31 would be wider than width (WS) as the chamfer 18 extends outwardly from lower edges 32 to upper edges 31. The included angle between the two angled chamfered surfaces is about 60 degrees. The width (WS) of .sleeve 10 is sufficient to enable the sleeve 10 to snap fit laterally onto rod 1 and laterally retain sleeve l0 on rod 1. The rod :t has a diameter (D).
The width (WS) of the open back 17 of sleeve 10 is slightly s~aaller than the °diameter (D) of rod 1, but is large enough to snap fit laterally onto rod 1. The sleeve 10 can be snapped back off the rod, if needed. The ability to snap fit the sleeve 10 onto rod 1 al°lows the sleeve 10 to be easily positioned at the desired location on rod 1.
Whi 1e tire sleeve 10 can sti 11 be slid onto the rod 1 from an end of the rod, the ability to snap the sleeve onto the rod laterally at any desired location along the rod 1 provides more versatility than designs in which the'sleeve 10 has to be slid from an end of the rod 1.
The retainment tabs 27 each include an abutting tab face 37 to abut against retaining wall 55 of counterbore 45: This abutting relationship helps secure the sleeve 10 in,the counterbore 45 of attachment device 40, and thus secure the sleeve 10 and attachment device to rod 1 in.its fully seated positian. When the sleeve 10 is fully sea~:ed in the attachment device 40, the bore 16 of sleeve 10 is frictionally retained on cylindrical rod 1, while the taper 51 of attachment device 40 is frictionally secured on F=irst sleeve taper 11 with the second portion 25 of sleeve 10 secured and retained via the second reverse taper 21 and retainment tabs 27 in counterbore 45. The open back 17 of sleeve 10 enables the sleeve 10 to be compressed between the rod 1 and device 40 to create a secure friction fit therebetween. Thus, ~~etention of the attachment device 40 and sleeve 10 to the rod 1 is accomplished by the locking of tapers 1l and 51 and the mechanical resistance of the second portion 25 or locking hub in the counterbore 45.
The upper longitudinal spaced edges 51 of device 40 created by the open back 57 include two oppositely located recessed cuts 58.
These recessed cuts provide a locating position for accepting retainment tabs 27 therein to provide the partially seated position of Fig. 2. '~hus9 the open back 57 of device 40 enables sleeve 10 to be maintained in a partially seated position via the interconnection of recessed cuts 58 and tabs 27. The retainment tabs 27 each include a tapered leading edge 35. This tapered leading edge 35 helps allow the retainment tab to slide out of recessed 'cuts 58 in order to move the sleeve from the partially seated position to the fully seated position.
The sleeve 10 further includes a through slot 19 which is a relatively thinner opening than the open back I7 of sl2e~re 10. The through slot 19 extends longitudinally into :>leeve 10 from the wide end I3 of the first portion I5 of sleeve 10. fhe through slot 19 I5 terminates part way into the sleeve 10 ~in order to maintain the structural integrity of sleeve 10. The through slot I9 connects continuously with a partial slot 20 which extends the remainder of the length of the sleeve. The partial slot extends only partially into the thickness of sleeve 10 leaving a thin connecting portion 6 to maintain the structural integrity of sleeve 10. The slots I9 and 20 help give additional flexibility to sleeve 10 to aid in snap fitting the sleeve 10 to rod 1. The through slot I9 and partial slot 20 also provide additional compressibility to the sleeve to allow the sleeve 10 to be tightly compressed and secured bet~veen the rod l and device 40. The slotted sleeve 10 thu provides a press-fit interface to secure an attachment device 40 to a rod 1 with the sleeve press-fit therebetween.
The rod, sleeve, and attachment device components of the spinal implant system of the present invention may be made of any suitable surgical grade material. One such suitable material is a high-grade stainless'steel, such as 22-i3-5 stainless steel.
It is noted that the first taper 11 on tP~e sleeve 10 and the mating inner taper 51 on attachment device ~0 may each suitably about a 6 degree~included taper, providing the.necessary force for locking therebetween. The second reverse taper 21 on sleeve 10 may be about a degree,taper. However, these suggested tapers are not intended to be limiting. The diameter of. bore 16 of sleeve 10 is suitably and matingly sized to tie compressed about a rod 1 having diameter (D).
10 Accordingly, the di.mer'sio.ns and sizes of the various components in this inventive system may be any suitable dimensions and sizes whicfi enable the components to have the desired~strength as needed, and, the desired function as described herein.
While this invention has been described in terms of a particularly advantageous embodiment, those skilled in the art can appreciate that modifications can be made without departing from the spirit and scope of this invention.
These features and objects of the invention, as well as others, will become apparent to those skilled in the art by referring to the accompanying drawings:
Fig. 1 is a perspective view of a rod, an attachment device, and an interpositional sleeve according to the present spinal implant system invention, and , shown prior to insertion of the sleeve in the attachment device;
Fig. 2 is a perspective view of the~components of Fig. 1 with the sleeve shown in the first partially seated position in the attachment device;
Fig. 3 is a perspective view of the components of Fig. l~i~ith the sleeve shown in the second fully seated position in the attachment device;
Fig. 4 is a perspective view of the sleeve of Fig. 1;
Fig. 5 is a perspective view of the sleeve of Fig. a shown from the opposite end;
Fig.~6 is a bottom view of the sleeve of Fig. 4;
Fig. 7 is a top view of the sleeve of ~'ig. ~;
Fig. 8 is a perspective view of the attachment device of Fig. 1;
Fig. 9 is a top view of the attachment device of Fig. 8;
Fig. I0 is a cross-sectional view taken along lines 10-10 of Fi,g.9;
Fig. 11 is a cross-sectional view taken along lines 11-11 of Fig.
8; and Fig. 12 is an end view of the attachment device of Fig. 8 as viewed from lines i2-12 of Fig. 8.
_5_ DETAILED DESCRIPTION OF THE INVENTION
Figs. 1-I2 illustrate a particularly advantageous embodiment of a spinal implant system according to the present invention. The spinal implant system includes a spinal rod 1, an attachment device 40, and an interpositional sleeve 10 for securing .the device 40 to rod 1. The attachment device 40 may be .one of various types of spinal hooks, screws, couplers, rod connectors, clamps, or other such devices. The present invention is illustrated with the attachment device as a spinal hook with extending hook portion 49; however,. it is understood that any suitable attachment device may be utilized in accordance with the present invention.
It is understood in keeping with spinal suwgery techniques that a plurality of spinal rods can be used, each with 4 plurality of spinal attachment devices affixed thereto. The attachment devices may either be used to affix the rods to the spinal column or to affix the position of two rods with respect to each other.
The attachment device 40 includes a first position for partially seating the sleeve 10 between the rod 1 and the attachment device 40, as shown in Fig. 2, and a second position for fully seating the sleeve 10, as shown in Fig. ~:
Fig. 1 shows the sleeve 10 prior to insertion in device 40. The sleeve 10 is positioned on the rod 1, while the attachment device 40 is held in position by a suitable hook holder' instrument (not shown).
Such hook holder instruments are kn~wn in the art and grip the attachment device 4U via recessed gripping holes 48. Then a suitable pusher or cruncher type instrument (not shown) ca,n be used to insert the sleeve 10 into attachment device 40 by applying pressure on one side of sleeve 10 and on the opposite side of attachment device 40 to bring the sleeve to the partially seated position of Fig. 2. This partially seated position attaches the sleeve 10 to.device 40 about rod 1, and yet allows the sleeve 10/device 40 assembly to still slide along rod 1 to allow adjustment of their position along rod i. Then a further suitable cincher-type instrument (not shown) is used to apply pressure to the one side of sleeve 10 and the opposite side of device 40 to bring these camponents together into the fully seated position of Fig. 3. This fully seated position locks or secures the attachment device 40 onto rod 1. Final locking of the attachment device 40 and the sleeve 10 to the rod 1, and thus final component fixation is obtained by the interference fit of the sleeve 10 between both the attachment device 10 and rod 1 at this fully seated position. It is noted that when the sleeve 10 is fully seated in the attachment device 40, the length of the sleeve (LS) is preferably fully contained within i5 the length of the attachment device (LA).
The elongated spinal rod 1 may be any switable length or any suitable diameter (D). The cylindrical rod 1 has a smooth outer surface. The sleeve 10 has a longitudinal cylindrical bore 16 therethrough for fitting about rod 1. The surface of the bore 16 is also smooth.
The sleeve 10 includes a first portion 15 and a second porti~n 25. The second portion is relatively shorter than the first portion.
The first portion I5 includes a first outer taper 11 with a wide end 13 tapering to a narrow end 12. The second portion 25 includes a second outer reverse taper 21 with a narrow end 22 tapering to a wide~end 23.
The narrow end 12 of first taper 11 converges with the narrow end 22 of second taper 21 forming a reduced or narrowed portion~ A recessed transition zone or groove 29 ,may be provided between the first and second tapers 11 and 21. The recessed transition zone 29 of sleeve 10 aligns with the edge 44 of counterbore 45.of device 40 when the sleeve is fully seated therein. Thusn neither taper 1l or 21 of sleeve 10 is providing a line contact. The reverse taper 21 helps provide a 5 locking position when the sleeve IO is .pushed to its fully seated position with the second portion 25 of sleeve 10 located in counterbore 45 of attachment device 40. This dual taper design provides an audible and force-feel feedback to the surgeon to communicate a positive lock of the sleeve 10 in the fully seated position in device 40. The 10 reverse taper 21 of tt,e sleeve 10 also allows the sleeve to be unlocked from the attachment aevice 40 with a suitable instrument {not shown) should ,rec~oval of the sleeve 10 be necessary.W'he reverse taper 21 allows sleeve 10 to slide over the edge 44 of counterbore 45 in l attachment device 40 facilitating such removal (as opposed to a sharp edge such as a 90 degree flange which would catch on edge 44 t~ resist removal). The counterbore 45 provides a retaining wall 55 to help lock dual taper sleeve 10 into its fully seated position.
The attachment device 40 includes an inner taper 51 having a wide end 53 tapering to a narrow end 54. A chamfer 52 extends from the wide end 53 of inner taper 5-1. The :counterbore 45 is positioned at the narrow end 54 of taper 51 forming retaining wall 55 therebetween. When the sleeve l0 is positioned and fully seated between rod 1 and device 40, the first outer taper 11 mates with the inner taper ~1 of device 40. The second portion 25 of .sleeve 10 mates with counterbore 45 to secure device 40 to rod 1.
The sleeve 10 has an open back 17 extending the length (LS) of the sleeve 10. The open back 17 interconnects ~~ith bore 16. The attachment device 40 has an~open back 57 extending the length (LA) of the attachment device 40. The open back of device 40 interconnects with inner taper 51 and counterbore 45. The open back 57 of device 40 allows rod :1 to easi 1y drop into positions The open back 17 of the sleeve 10 has a width (WS), while the, open back of the attachment device has a width (WA). The counterbore 45 includes a~semicircular bottom wall 46 which extends into oppositely located straight side walls 47. The counterbore 45 between side walls 47 has a width (WC).
The width (WC) of counterbore 45 is larger than the width (WA) of attachment device 40.
The second portion 25 of sleeve l0 includes a tapered rounded bottom surface 24 forming the second outer reverse taper 2i and two relief cuts 28 on. opposite sides of second portion 25 fflrming-two legs 26 extending from bottom surface 24. The depth of the relief cuts 28 can vary. These relief cuts 28 help give clearance to allow sleeve 10 to enter the taper 51 of attachment device 40. A retainment tab 27 extends from each leg 26. The retainment tabs 27 allow the sleeve 10 to maintain proper alignment within the attachment device. These retainment tabs help prevent rotation of sleeve 10 within attachment device 40, thus acting as antirotation tabs. The tabs 27 help engage the sleeve in the attachment device 40 in both the partially seated and fully seated positions. The retainment tabs 27 extend above the two longitudinal spaced upper edges 31 on either side of open back 17 of sleeve 10. A chamfer 18 extends from each upper edge 31 of sleeve 10 to a .longitudinal lower edge 32. It is the distance between spaced lower edges 32 which creates the width (WS) of the open back 17 of sleeve 10. The distance between the upper edges 31 would be wider than width (WS) as the chamfer 18 extends outwardly from lower edges 32 to upper edges 31. The included angle between the two angled chamfered surfaces is about 60 degrees. The width (WS) of .sleeve 10 is sufficient to enable the sleeve 10 to snap fit laterally onto rod 1 and laterally retain sleeve l0 on rod 1. The rod :t has a diameter (D).
The width (WS) of the open back 17 of sleeve 10 is slightly s~aaller than the °diameter (D) of rod 1, but is large enough to snap fit laterally onto rod 1. The sleeve 10 can be snapped back off the rod, if needed. The ability to snap fit the sleeve 10 onto rod 1 al°lows the sleeve 10 to be easily positioned at the desired location on rod 1.
Whi 1e tire sleeve 10 can sti 11 be slid onto the rod 1 from an end of the rod, the ability to snap the sleeve onto the rod laterally at any desired location along the rod 1 provides more versatility than designs in which the'sleeve 10 has to be slid from an end of the rod 1.
The retainment tabs 27 each include an abutting tab face 37 to abut against retaining wall 55 of counterbore 45: This abutting relationship helps secure the sleeve 10 in,the counterbore 45 of attachment device 40, and thus secure the sleeve 10 and attachment device to rod 1 in.its fully seated positian. When the sleeve 10 is fully sea~:ed in the attachment device 40, the bore 16 of sleeve 10 is frictionally retained on cylindrical rod 1, while the taper 51 of attachment device 40 is frictionally secured on F=irst sleeve taper 11 with the second portion 25 of sleeve 10 secured and retained via the second reverse taper 21 and retainment tabs 27 in counterbore 45. The open back 17 of sleeve 10 enables the sleeve 10 to be compressed between the rod 1 and device 40 to create a secure friction fit therebetween. Thus, ~~etention of the attachment device 40 and sleeve 10 to the rod 1 is accomplished by the locking of tapers 1l and 51 and the mechanical resistance of the second portion 25 or locking hub in the counterbore 45.
The upper longitudinal spaced edges 51 of device 40 created by the open back 57 include two oppositely located recessed cuts 58.
These recessed cuts provide a locating position for accepting retainment tabs 27 therein to provide the partially seated position of Fig. 2. '~hus9 the open back 57 of device 40 enables sleeve 10 to be maintained in a partially seated position via the interconnection of recessed cuts 58 and tabs 27. The retainment tabs 27 each include a tapered leading edge 35. This tapered leading edge 35 helps allow the retainment tab to slide out of recessed 'cuts 58 in order to move the sleeve from the partially seated position to the fully seated position.
The sleeve 10 further includes a through slot 19 which is a relatively thinner opening than the open back I7 of sl2e~re 10. The through slot 19 extends longitudinally into :>leeve 10 from the wide end I3 of the first portion I5 of sleeve 10. fhe through slot 19 I5 terminates part way into the sleeve 10 ~in order to maintain the structural integrity of sleeve 10. The through slot I9 connects continuously with a partial slot 20 which extends the remainder of the length of the sleeve. The partial slot extends only partially into the thickness of sleeve 10 leaving a thin connecting portion 6 to maintain the structural integrity of sleeve 10. The slots I9 and 20 help give additional flexibility to sleeve 10 to aid in snap fitting the sleeve 10 to rod 1. The through slot I9 and partial slot 20 also provide additional compressibility to the sleeve to allow the sleeve 10 to be tightly compressed and secured bet~veen the rod l and device 40. The slotted sleeve 10 thu provides a press-fit interface to secure an attachment device 40 to a rod 1 with the sleeve press-fit therebetween.
The rod, sleeve, and attachment device components of the spinal implant system of the present invention may be made of any suitable surgical grade material. One such suitable material is a high-grade stainless'steel, such as 22-i3-5 stainless steel.
It is noted that the first taper 11 on tP~e sleeve 10 and the mating inner taper 51 on attachment device ~0 may each suitably about a 6 degree~included taper, providing the.necessary force for locking therebetween. The second reverse taper 21 on sleeve 10 may be about a degree,taper. However, these suggested tapers are not intended to be limiting. The diameter of. bore 16 of sleeve 10 is suitably and matingly sized to tie compressed about a rod 1 having diameter (D).
10 Accordingly, the di.mer'sio.ns and sizes of the various components in this inventive system may be any suitable dimensions and sizes whicfi enable the components to have the desired~strength as needed, and, the desired function as described herein.
While this invention has been described in terms of a particularly advantageous embodiment, those skilled in the art can appreciate that modifications can be made without departing from the spirit and scope of this invention.
Claims (34)
1. A spinal implant system including a spinal rod, an attachment device, and an interpositional sleeve for securing the attachment device to the rod, wherein the sleeve has a length and includes a longitudinal bore therethrough and an open back extending the length of the sleeve and connecting with the bore, and wherein the open back of the sleeve has a width sufficient to enable the sleeve to snap fit laterally onto the rod and laterally retain the sleeve on the rod.
2. The system of Claim 1 wherein the rod has a diameter and the width of the open back of the sleeve is slightly smaller than the diameter of the rod, but is large enough to snap fit laterally onto the rod.
3. A spinal implant system including a spinal rod, an attachment device, and an interpositional sleeve for securing the attachment device to the rod, wherein the attachment device includes a first means for partially seating the sleeve between the rod and the attachment device wherein the sleeve is attached to the attachment device while permitting relative movement between the interpositional sleeve and the spinal rod and a second means for fully seating the sleeve between the rod and the attachment device wherein the sleeve is attached to the attachment device and prevents relative movement between the sleeve and the spinal rod.
4. The system of Claim 3 wherein the attachment device includes an open back providing two upper longitudinal spaced device edges and, the attachment device has a first end and a second end, and wherein the first means is provided in between the first and second ends, and the second means is provided adjacent one of either the first or second ends.
5. The system of claim 4 wherein the first means comprises two oppositely located recessed cuts and the second means comprises a counterbore.
6. The system of Claim 5 wherein the sleeve includes a retainment tab means for locating in either the first or second means.
7. The system of Claim 6 wherein the sleeve includes an open back providing two longitudinal spaced sleeve edges and wherein the sleeve further includes a retainment tab on each of the spaced sleeve edges for locating in either the first or second means.
8. A spinal implant system including a spinal rod, an attachment device, and an interpositional sleeve for securing the attachment device to the rod, wherein the sleeve includes a retainment tab means extending therefrom for providing alignment and antirotation of the sleeve in the attachment device.
9. A spinal implant system including a spinal rod, an attachment device, and an interpositional sleeve for securing the attachment device to the rod, wherein the sleeve has a length and includes a longitudinal bore therethrough for fitting about the rod and wherein the sleeve includes a first portion and a second portion, and wherein the first portion includes a first outer taper with a first wide end tapering to a first narrow end and the second portion includes a second outer reverse taper with a second narrow end tapering to a second wide end wherein the first narrow end of the first taper converges with the second narrow end of the second taper.
10. The system of claim 9 wherein the first taper and second taper converge at a recessed transition zone between the first and second tapers.
11. The system of claim 9 wherein the attachment device includes an inner taper having a third wide end tapering to a third narrow end and a counterbore positioned at the third narrow end of the inner taper forming a retaining wall therebetween, such that when the sleeve is positioned and fully seated between the rod and the attachment device, the first outer taper mates with the inner taper of the attachment device and the second portion of the sleeve mates with the counterbore to secure the attachment device to the rod.
12. The system of claim 11 wherein the sleeve has an open back extending the length of the sleeve, and wherein the attachment device has a length and an open back extending the length of the attachment device.
13. The system of claim 12 wherein the counterbore of the attachment device includes a semicircular bottom wall which extends into oppositely located substantially straight widewalls.
14. The system of claim 13 wherein the second portion of the sleeve comprises a tapered rounded bottom surface forming the second outer reverse taper and two relief cuts on oppositely located sides of the second portion forming two legs extending from the bottom surface.
15. The system of claim 14 wherein the sleeve further includes two retainment tabs, one extending from each of the legs.
16. The system of claim 15 wherein the open back of the sleeve creates two longitudinal spaced upper edges, and wherein the retainment tabs extend above the longitudinal upper edges.
17. The system of claim 16 wherein the open back of the sleeve creates two longitudinal spaced lower edges, one lower edge below each upper edge with a chamfer extending from each lower edge to a corresponding upper edge, and wherein the distance between the spaced lower edges creates a width therebetween, and wherein the width is sufficient to enable the sleeve to snap fit laterally onto the rod and laterally retain the sleeve on the rod.
18. The system of claim 17 wherein the rod has a diameter and the width of the open back of the sleeve is slightly smaller than the diameter of the rod, but is large enough to snap fit laterally onto the rod.
19. The system of claim 15 wherein the retainment tabs of the sleeve each include an abutting tab face to abut against the retaining wall of the counterbore of the attachment device to secure the sleeve in the attachment device and the sleeve and attachment device to the rod.
20. The system of claim 15 wherein the open back of the attachment device creates two upper longitudinal spaced edges and wherein a means for partially seating the sleeve in the attachment device is provided along the upper longitudinal edges of the attachment device.
21. The system of claim 20 wherein the means for partially seating the sleeve includes two oppositely located recessed cuts for accepting the retainment tabs therein.
22. The system of claim 21 wherein the retainment tabs each include a tapered leading edge.
23. The system of claim 12 wherein the sleeve further includes a through slot means therein which is a relatively thinner opening than the open back of the sleeve, and wherein the through slot means extends longitudinally into the sleeve from the first wide end of the first portion of the sleeve and terminates part way into the sleeve to maintain the structural integrity of the sleeve.
24. The system of claim 23 wherein the through slot means connects continuously with a partial slot means which extends the remainder of the length of the sleeve, and wherein the partial slot means extends only partially into the thickness of the sleeve leaving a thin connecting portion to maintain the structural integrity of the sleeve.
25. The system of claim 11 wherein the third wide end of the inner taper of the attachment device includes a chamfer extending outwardly therefrom.
26. The system of claim 9 wherein the attachment device has a length and wherein the length of the sleeve is fully contained within the length of the attachment device when the sleeve is fully seated with the attachment device.
27. The system of claim 9 wherein the sleeve includes an open back providing two longitudinal spaced sleeve edges, and wherein the sleeve further includes a retainment tab means on each of the spaced sleeve edges for providing alignment and antirotation of the sleeve in the attachment device.
28. A spinal implant system including a spinal rod, an attachment device, and an interpositional sleeve for positioning between the rod and the attachment device for securing the attachment device to the rod, wherein the sleeve has a length and includes a longitudinal bore therethrough and an open back extending the length of the sleeve and connecting with the bore, and wherein the open back of the sleeve has a width sufficient to enable the sleeve to snap fit laterally onto the rod and laterally retain the sleeve on the rod, and wherein the rod has a diameter and the width of the open back of the sleeve is slightly smaller than the diameter of the rod, but is large enough to snap fit laterally onto the rod by passing the rod laterally through the open back of the sleeve.
29. A spinal implant system including a spinal rod, an attachment device, and an interpositional sleeve for securing the attachment device to the rod, Wherein the attachment device includes a first means for partially seating the sleeve between the rod and the attachment device and a second means for fully seating the sleeve between the rod and the attachment device, and wherein the attachment device includes an open back providing two upper longitudinal spaced device edges and, the attachment device has a first end and a second end, and wherein the first means for partially seating the sleeve is provided in between the first and second ends of the device, and the second means for fully seating the sleeve is provided adjacent one of either the first or second ends of the device, and wherein the second means is longitudinally spaced from the first means on the attachment device.
30. The system of claim 29 wherein the first means comprises two oppositely located recessed cuts along the spaced device edges and the second means comprises a counterbore.
31. The system of claim 30 wherein the sleeve includes a retainment tab means for locating in either the first or second means.
32. The system of claim 30 wherein the sleeve includes an open back providing two longitudinal spaced sleeve edges and wherein the sleeve further includes a retainment tab on each of the spaced sleeve edges for locating in either the first or second means.
33. A spinal implant system including a spinal rod, an attachment device, and an interpositional sleeve for securing the attachment device to the rod, wherein the attachment device includes an inner taper and a counterbore at one end of the inner taper, and wherein the sleeve includes a retainment tab means extending therefrom for mating with the counterbore for providing alignment and antirotation of the sleeve in the attachment device.
34. A method of utilizing a spinal implant system including the steps of:
a) providing a spinal rod, an attachment device, and an interpositional sleeve, wherein the sleeve has a length and includes a longitudinal bore therethrough and an open back extending the length of the sleeve and connecting with the bore, and wherein the open back of the sleeve has a width sufficient to enable the sleeve to snap fit laterally onto the rod and laterally retain the sleeve on the rod, and wherein the rod has a diameter and the width of the open back of the sleeve is slightly smaller than the diameter of the rod, but is large enough to snap fit laterally onto the rod, such that the method further includes;
b) snap fitting the sleeve laterally onto the rod by passing the rod laterally through the open back of the sleeve; and c) then positioning the sleeve between the rod and the attachment device for securing the attachment device to the rod.
a) providing a spinal rod, an attachment device, and an interpositional sleeve, wherein the sleeve has a length and includes a longitudinal bore therethrough and an open back extending the length of the sleeve and connecting with the bore, and wherein the open back of the sleeve has a width sufficient to enable the sleeve to snap fit laterally onto the rod and laterally retain the sleeve on the rod, and wherein the rod has a diameter and the width of the open back of the sleeve is slightly smaller than the diameter of the rod, but is large enough to snap fit laterally onto the rod, such that the method further includes;
b) snap fitting the sleeve laterally onto the rod by passing the rod laterally through the open back of the sleeve; and c) then positioning the sleeve between the rod and the attachment device for securing the attachment device to the rod.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/906,901 | 1992-06-30 | ||
| US07/906,901 US5281222A (en) | 1992-06-30 | 1992-06-30 | Spinal implant system |
| CA002095599A CA2095599C (en) | 1992-06-30 | 1993-05-05 | Spinal implant system |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002095599A Division CA2095599C (en) | 1992-06-30 | 1993-05-05 | Spinal implant system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2444586A1 CA2444586A1 (en) | 1993-12-31 |
| CA2444586C true CA2444586C (en) | 2005-07-19 |
Family
ID=30001246
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002444586A Expired - Fee Related CA2444586C (en) | 1992-06-30 | 1993-05-05 | Spinal implant system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2444586C (en) |
-
1993
- 1993-05-05 CA CA002444586A patent/CA2444586C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2444586A1 (en) | 1993-12-31 |
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| EEER | Examination request | ||
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