Instrumentation for inserting and deploying an expandable interbody spinal fusion implant

ES 2 298 665 T3

DESCRIPTION

Instruments to insert and deploy an expandable interbody spinal fusion implant.

Background of the invention

Scope of the invention

The present invention refers to a system as described in the preamble of claim 1. Consequently, the present invention relates generally to instrumentation for the insertion of interbody spinal implants into an implantation space located in the spine, and more specifically to be used with expandable interbody spinal fusion implants (for at least partial placement between adjacent vertebral bodies, in the space previously occupied by the disc material) for the purpose of immobilization of vertebrae.

Description of Related Art

A system of the type initially mentioned is known from US-A-5,800,550. Expandable spinal fusion implants have the ability to raise their height, which is done after the implant is initially placed. This ability to raise its height can be used within the spinal column anteriorly, posteriorly, or in both positions, and in different measures, respectively, to raise the front, rear, or both of the implant to the same or different heights. More specifically, these implants have upper and lower surfaces of the upper and lower elements that, in a first position, or insertion position, are folded over one another and in a second position, or deployment position, are adapted to enter into contact with adjacent vertebral bodies.

Expandable fusion implants offer the advantage of allowing potentially large implants to be placed through smaller holes in the patient's body. Selective expansion in a single direction (for example, vertically only when the implant is correctly positioned) offers the advantage of increasing implant height and thus disc space separation, without requiring a concomitant increase in width of the implant. implant.

US-A-5,665,122 discloses a box-type spinal prosthesis composed of a box-shaped body in two halves, with upper and lower sections, and an expansion screw with proximal and distal end parts, with the proximal end being arranged of means to adopt dimensions and a shape that allow forcing the upper and lower sections of the box, opening it, as the screw is introduced longitudinally through the body of the box.

WO-00/35388 discloses a variable expansion device for stabilizing an upper vertebra and an adjacent lower vertebra, which is conical in shape and can be screwed longitudinally into the expandable insert in order to expand said expandable insert.

Expandable fusion implants are described in the related art. The first expandable spinal fusion implant (allowing bone growth between vertebral body and vertebral body through the implant) was invented by Michelson and is also disclosed in US Patent 5,776,199, filed June 28, 1988.

In the related art insertion spinal fusion implants provided with non-arcuate upper and lower surfaces suitable for placement in contact with adjacent vertebral bodies are described. An insertion spinal fusion implant was invented by Michelson and is disclosed in US Pat. No. 5,776,199.

In the related art insertion spinal fusion implants are described provided with arcuate portions facing the adjacent vertebral bodies and designed to join the vertebral bodies along the arcuate incisions they present, typically formed with a perforator. An insert spinal fusion implant was invented by Michelson and is disclosed in US Patent 5,593,409, filed February 17, 1995. Spinal fusion insertion implants have the advantage of easy placement in the implantation space and good holding or grip qualities.

Threaded spinal fusion implants that require rotation to be inserted into the implantation space of the spine are also known in the related art. The first artificial threaded spinal fusion implant was invented by Michelson and is disclosed in US Patent 5,015,247. Threaded spinal fusion implants offer the advantage of easy placement in the implantation space and excellent holding or grip qualities. Michelson discloses some examples of instrumentation and methods for inserting spinal implants in US5,484,437 and US-6,080,155.

Spinal insertion, lordotic, or tapered fusion implants are also known in the art. By way of example, Michelson invented implants of this type and disclosed them in US Patent 5,609,635, filed June 7, 1995. Threaded, lordotic, frusto-conical or tapered spinal fusion implants are also known in the art. By way of example, Michelson invented implants of this type and disclosed them in US Pat. No. 6,210,412. Also known in the art are lordotic, frusto-conical or tapered insertional spinal fusion implants. A way

For example ES 2 298 665 T3, Michelson invented implants of this type and disclosed them in US patent application serial number 08 / 484,928, filed June 7, 1995. Lordotic or conical spinal fusion implants have the advantage to restore or improve a spinal lordosis.

Expandable interbody spinal fusion implants can preferably be inserted from an anterior approach to the spine, a posterior approach to the transverse processes of the vertebrae, on both sides of the spinal midline in pairs, or from a lateral approach anterior to the spine. . These expandable implants are able to increase their anterior height (at their initial ends) or posterior (at their final ends) from a first folded state, passing to a second expanded state to increase spinal lordosis in that interspace, or they can also increase its anterior and posterior height simultaneously. During the placement of expandable interbody spinal fusion implants, it is desirable that the surgeon have sufficient skill to accurately control the implant using the appropriate instruments and methods in order to load the implant with sufficient bone growth enhancing material, insert the implant in the implantation space, unfold the implant to a final expanded position and reload the implant with bone growth material, if so desired.

There is a need for instruments that can be used with expandable interbody spinal fusion implants and provide all of the aforementioned functions, either individually or in combination.

Summary of the invention

In accordance with the objectives of the present invention, as broadly described herein in one embodiment, a system according to claim 1 is presented. Other embodiments of the invention are described in the dependent claims.

In accordance with the present invention, the implant holder remains attached to the spinal implant during expansion of the spinal implant from a collapsed position to the expanded position, within the implantation space prepared to house the spinal implant.

The implant support also contains at least two extensions that start from the distal end of the body. The extensions can have an inner surface and an outer surface, opposite the inner surface. The extensions may be suitable for one to displace the other by exerting an inward force applied to the outer surface, so that the extensions of the implant holder are allowed to pass through one end of the implant and the outer surface to engage. to the end of the implant as soon as the inward force is no longer exerted.

The drawings illustrating the invention, incorporated in and forming an integral part of this description, are offered by way of non-limiting example and illustrate various embodiments of the invention that will serve, together with the description, to explain the principles of the invention. . The scope of the invention is considered limited only by that of the claims and those skilled in the art will find other embodiments from what is described herein.

Brief description of the drawings

Shown in Figure 1 is a detailed perspective view of one embodiment of an expandable, non-arched, impact interbody spinal fusion lumbar implant that can be used with the instrumentation of the present invention;

Shown in Figure 1A is a perspective view of an alternative embodiment of a blocker in the form of an expansion device that can be used with the implant of Figure 1;

Shown in Figure 1B is a perspective view of another alternative embodiment of a blocker that can be used with the implant of Figure 1;

Shown in Figure 1C is a perspective view of another alternative embodiment of a blocker for use with the implant of Figure 1;

In Figure 2 a view of the initial end of the implant of Figure 1 is shown;

In figure 3 a top view of the implant of figure 1 is shown;

In figure 4 a view of the end end of the implant of figure 1 is shown;

In figure 5 a side view of the implant of figure 1 is shown;

Figure 6 shows a cross-sectional view along a mid-longitudinal axis of the implant of Figure 1;

In figure 7 a perspective view of the initial end of the implant of figure 1 is shown;

ES 2 298 665 T3

Figure 8 shows a front view of an embodiment of an expansion device of Figure 1;

Figure 9 shows a side elevation view of the expansion device of Figure 8;

Figure 10 shows a schematic representation of a geometric configuration of a cross section of an embodiment of an expansion device that can be used with the instrumentation of the present invention;

Figure 11 shows a top plan view of a non-arcuate and expandable impact interbody spinal fusion anterior lumbar implant, provided with two expansion devices shown by dashed lines, to be used with the instruments of the present invention from a anterior approach to the column;

Figure 12 shows a top plan view of the base element of another preferred embodiment of a non-arcuate and expandable anterior lumbar interbody spinal fusion implant provided with a set of expansion devices located on both sides of the median longitudinal axis. of the implant to be used with the instruments of the present invention, from an anterior approach to the spine;

Shown in Figure 13 is a side view of the end cap of the implant shown in partial cross-section, for use with the implant of Figure 12;

Figure 14 shows a top plan view of another preferred embodiment of a non-arched and expandable posterior lumbar interbody spinal fusion implant to be used preferably in pairs with the instruments of the present invention, from a posterior approach to the spine. ;

Shown in Figure 15 is a partial cross-sectional plan view of an embodiment of an implant support instrument of the present invention illustrated in a retracted position for inserting an implant, for example the implant of Figure 1;

Figure 16 shows a side elevation view in partial cross-section of the support instrumentation of Figure 15;

Figure 17 shows a top plan view of an embodiment of an instrument-expansion unit of the present invention for rotating the expansion device, similar to, for example, the expansion device of Figure 1;

Figure 18 shows a side elevation view of the instrument-expansion unit of Figure 17;

Figure 19 shows a top plan view of the implant of Figure 1 in partial cross section, in the unexpanded position, and a top plan view in partial cross section of the support instrument of Figure 15, in the retracted position, positioned to engage the implant;

Figure 20 shows a top plan view of a partial cross-section of the support instrument of Figure 15, in an extended position, with the lateral extension elements separated and hooked to the flanges by means of complementary grooves at the end end of the implant. Figure 1, shown in partial cross section;

Figure 21 shows a top plan view of the support instrument of Figure 15, in partial cross section, fixed by rotation in the extended position to maintain the lateral extension elements coupled to the end end of the implant of Figure 1, shown in partial cross section;

Figure 22 shows a detailed top plan view of an instrument-expansion unit of Figure 17, being inserted into the support instrument of Figure 15 and the implant of Figure 1, shown in partial cross section;

Figure 23 shows a top plan view of the instrument-expansion unit of Figure 17 locked in an extended position by a first and second spring locks of the support instrument of Figure 15, shown in partial cross-section, being each of these spring locks suitable for engaging the first and second fasteners on a shaft of the instrument-expansion unit, ready to insert an implant into an implantation space;

Figure 24 shows an enlarged top plan view of a fragment along line 24 of Figure 23, showing the relationship established between the first and second spring locks of the support instrument and the complementary fasteners first. and second of the instrument-expansion unit while the instrument-expansion unit is in the extended position;

Figure 25 shows a posterior perspective view of a lumbar segment of the spine, with the dural sac folded to the left, showing a prepared receptor implantation site and the supporting instrument.

ES 2 298 665 T3 of figure 15, with the instrument-expansion unit of figure 17 inserted therein and approaching the disc space between the adjacent vertebral bodies, having the implant of figure 1 attached;

Figure 26 shows a fragmentary side view of the implant of Figure 1 being inserted by the support instrument of Figure 15 through a shield, from a generally posterior approach to the spine, at an implantation point formed along the length of the disc space and in two adjacent vertebral bodies of the spine, shown in partial cross section;

Shown in Figure 27A is a fragmentary side view of the implant of Figure 1 being inserted by the support instrument of Figure 15, from a generally posterior approach to the spine, at an implantation site formed along a disc space and in two adjacent vertebral bodies of the spine, shown in partial cross section;

Figure 27B shows a fragmentary side view of the implant of Figure 1, inserted through the implant holder of Figure 15 at an implantation site formed along the disc space and in two adjacent vertebral bodies of the spine, shown in partial cross section;

Figure 28 shows a top plan view of a lower vertebral body and implant of Figure 1, in partial cross-section, inserted into an implantation site formed in a posterior position along a disc space and the instrument - expansion unit of figure 17 locking in the folded position by means of a second spring closure of the support instrument of figure 15, shown in partial cross section, hooked to the fastener of the instrument-expansion unit;

Figure 29 shows a top plan view of an enlarged fragment along line 29 of Figure 28, illustrating the relationship between the first and second spring locks of the support instrument and the complementary first and second fasteners. of the instrument-expansion unit when the instrument-expansion unit is in the retracted position;

Figure 30 shows a top plan view of a lower vertebral body and implant of Figure 1, shown in partial cross-section, implanted through the support instrument of Figure 15 shown in partial cross-section, at a point of implantation formed posteriorly through a disc space, and the instrument-expansion unit of Figure 17 moving the expansion device of Figure 1 to expand the implant;

Figure 31 shows a partial side view of the implant of Figure 1 and the supporting instrument of Figure 15 with the implant in the expanded position inserted into an implantation site formed along the disc space and in two vertebral bodies. adjacent columns, shown in partial cross section;

Figure 32 shows a side view of the implant of Figure 1 in partial cross section and the support instrument of Figure 15 with the instrument-expansion unit of Figure 17 coupled to the expansion device of Figure 1;

Figure 33 shows an initial end view, in partial cross section, of the implant of Figure 1, implanted between adjacent vertebral bodies, with the expansion device in the initial insertion position;

A partial cross-sectional view of the initial end of the implant of Figure 1 is shown in Figure 34, implanted between adjacent vertebral bodies, with the expansion device in the final deployed position;

Figure 35 shows a top plan view of the instrument-expansion unit of Figure 17 being removed from the implant of Figure 1, shown at an implantation point, and the support instrument of Figure 15;

Figure 36 shows a top plan view of the support instrument of Figure 15 and of the implant of Figure 1 shown at an implantation point, after having used the instrument-expansion unit of Figure 17 to fill the implant space that remains empty when removing the instrument-expansion unit with bone growth enhancing material;

Figure 37 shows a top plan view illustrating the operation of removing the support instrument of Figure 15 from the implant of Figure 1, shown in an implantation space; Y

Shown in Figure 38 is a top plan view of a lower vertebral body and two implants of Figure 1 implanted in a final position, at an implantation site formed posteriorly along the disc space;

Figure 39 shows a cross-sectional side view of the implantation site formed along the disc space and two adjacent vertebral bodies from an anterior approach to the spine, with the implant of Figure 11 installed at the implantation site and in the final deployed position, with the upper and lower surfaces oriented angularly relative to each other and the bone screws in place to anchor the implant;

ES 2 298 665 T3

Figure 40 shows a cross-sectional side view of the implantation site formed along the disc space and two adjacent vertebral bodies with the implant of Figure 11 positioned in the implantation space, in the final deployed position with the surfaces upper and lower oriented parallel to each other and bone screws positioned to anchor the implant;

Shown in Figure 41 is a detailed perspective view of one embodiment of an expandable arcuate interbody spinal fusion anterior lumbar implant for use with the instrumentation of the present invention;

Figure 42 shows a top plan view of the implant of Figure 41;

Shown in Figure 43 is an end end view of the implant of Figure 41;

Shown in Figure 44 is a side elevation view of the implant of Figure 41;

Shown in Figure 45 is a view of the initial end of the implant with the end cap of Figure 41 attached to it;

Shown in Figure 46 is a cross-sectional view along line 46-46 of Figure 42;

Shown in Figure 47 is a cross-sectional view along line 47-47 of Figure 45;

Shown in Figure 48 is a side elevation view of an end cap for use with the implant of Figure 41;

Figure 49 shows a perspective view of the implant of Figure 41 and an implant insertion device with a head configured to help engage the end end of the implant, said head being provided with two projections to engage two receiving holes. complementary at the end of the implant;

Figure 50 shows a side view of the implant of Figure 41 being inserted by the implant insertion device of Figure 49 from a generally anterior approach to the spine, at an implantation point formed throughout the height of a space disc and between two adjacent vertebral bodies of the spine, illustrated in partial cross section;

Shown in Figure 51 is a cross-sectional view of the implant of Figure 41 inserted into the implantation site of Figure 50;

Figure 52 shows a perspective view of the final end of the implant of Figure 41 with an expansion unit instrument positioned to engage the expansion device, said expansion unit-instrument having an end configured to help engage the expansion device. expansion;

Figure 53 shows a cross-sectional view of the implant of Figure 41 inserted from an anterior approach to the spine, at an implantation point of Figure 50 and expanded by the expansion unit instrument of Figure 52, to place the Adjacent vertebral bodies in lordosis;

Figure 54 shows an end end view of the anterior face of two adjacent vertebral bodies and two implants of Figure 41, implanted between them in a final position;

Figure 55 shows a perspective view of the initial end of an implant, an implant support with a head configured to help hook the final end of the implant, said head having two projections to hook into two complementary receiving holes of the end. end of the implant, the support of the implant being hollow and capable of admitting the passage of the expansion device through it, the expansion device being illustrated in a folded position inside the implant holder;

Figure 56 shows a perspective view of the final end of the implant, and a perspective view of the initial end of the implant holder and the expansion device of Figure 55, illustrating the expansion device in a folded position inside the implant support;

Figure 57 shows a perspective view of the final end of the implant, and a perspective view of the initial end of the insertion and expansion device of the implant of Figure 55, illustrating the expansion device in a partially extended position;

Figure 58 shows a side view of the implant of Figure 55 being inserted by the implant insertion device of Figure 55, from a generally posterior approach to the spine, at an implantation point formed over the entire height of a disc space and between two adjacent vertebral bodies of the spine, shown in partial cross section;

Shown in Figure 59 is a cross-sectional view of the implant of Figure 55, inserted into the implantation site of Figure 58;

ES 2 298 665 T3

Figure 60 shows a cross-sectional view of the implant of Figure 55 inserted from a posterior approach to the spine at the point of implantation of Figure 58 and expanded by the expansion unit instrument of Figure 55, illustrated in full position. extended to place adjacent vertebral bodies in lordosis;

Shown in Figure 61 is an end-end perspective view of another embodiment of an implant for use with the instrumentation and method of the present invention and the expansion device of Figure 55;

Figure 62 shows a side view of another embodiment of an implant that is inserted by the implant holder of Figure 49 from a generally anterior approach to the spine, at an implantation point formed along the entire length of the spine. height of a disc space and two adjacent vertebral bodies, illustrated in partial cross section;

Figure 63 shows a cross-sectional view of the implant of figure 62 expanded, from an anterior approach to the column, by an instrument-expansion unit provided with an extended shaft configured to engage more than one expansion device with the in order to place the adjacent vertebral bodies in lordosis;

Shown in Figure 64 is a cross-sectional side view of the implantation site formed along the space between two adjacent vertebral bodies and the implant of Figure 62 installed in the implantation space and anchored to the spine with bone screws;

Figure 65 shows an end end view of the anterior presentation of two adjacent vertebral bodies and the implant of Figure 62, implanted between them, in an expanded position, as well as another embodiment of an implant intended to be used as a juxtaposed pair;

Shown in Figure 66 is a top plan view of the implants of Figure 65 inserted at least partially into the lower vertebral body from an anterior forming implantation point along the disc space, with the vertebral body illustrated in cross-section. partial, the implants being provided with an expansion device at each of their initial and final ends;

Shown in Figure 67 is a perspective view of another embodiment of an implant insertion device of the present invention, with protrusions at the top and bottom and a pair of side extensions with flanges on them that help engage. the complementary receiving holes and slots, respectively, of the trailing end of a cylindrical implant generally suitable for insertion from a posterior approach; Y

Shown in Figure 68 is a detailed perspective view of another embodiment of a spinal fusion implant for use with the instrumentation of the present invention.

Detailed description of the drawings

Reference will now be made in detail to preferred embodiments (exemplary embodiments) of the invention, illustrated by way of example in the accompanying drawings.

The instrumentation of the present invention can be used from a posterior, anterior, lateral or posterolateral approach to the spine. The present invention, in a preferred embodiment, is an integral instrumental set suitable for application in a method consisting of inserting non-arched and expandable interbody spinal fusion implants, from a posterior approach to the transverse vertebral processes, to both sides of the spinal midline and preferably in pairs, in which the implants are able to increase their height in the anterior position (at their end ends), starting from an initial folded position, moving to a second expanded position to produce an interspace gap and / or increase spinal lordosis in said interspace. In other preferred embodiments, the instruments of the present invention are used to insert impact interbody spinal fusion implants, not arched and expandable from an anterior approach to the spine, said implants being suitable to be able to increase their anterior height and, if necessary necessary, its height both anterior and posterior, even preferring the anterior to the posterior (at its initial ends). With little modification, the methods and instrumentation shown can also be used to insert such implants in a lateral orientation.

Figures 1 to 14 show preferred embodiments of an expandable interbody spinal fusion implant such as those described by Michelson in the international patent application PCT / US01 / 03657, entitled "Expandable impact interbody spinal fusion implant" and instrumental to be used therewith in accordance with the present invention. To better understand the structure and interrelationship between the instruments and the methods associated with their use, the structure and associated characteristics corresponding to an embodiment of an implant suitable for insertion with these instruments and methods will first be described.

As shown in Figures 1-7, reference will be made generally to 100 to a preferred embodiment of a non-arcuate, expandable, impact interbody spinal fusion implant for use with instruments and implants. method of the present invention. The implant 100 is preferably provided with a start end 102, an end end 104, an upper element 106 and a lower element 108. The upper and lower elements

ES 2 298 665 T3

106, 108 are preferably non-arched and able to be inserted, at least partially, inside the upper and lower part of two adjacent vertebral bodies, respectively.

According to the meaning attributed to it here, "non-arched" is understood to be an upper or lower surface of the implant with the following characteristics: (1) it does not present curvature, as in a flat surface, (2) it presents a slight or smooth curvature between the initial end and the end end of the implant and / or (3) presents a slight or smooth curvature across the width of the implant. A slight or smooth curvature does not include the curvature associated with the upper and lower surfaces of implants that are inserted into disc spaces of circular cross-section formed along a spinal disc and into adjacent vertebral bodies. While the upper and lower surfaces of this preferred embodiment of an expandable non-arcuate implant could exhibit some curvature compared to circular cross-section implants, such curvature is minimal. In implants of circular cross-section, such as threaded implants, the curvature of the upper and lower surfaces that are in contact with the adjacent vertebral bodies has a radius that is half the width of the implant. If curvature occurs in the upper and lower surfaces of the non-arcuate implant described above, the circle of said curvature is much larger than the width of the implant; thus, it exhibits a slight curvature that could correspond to the anatomical curvature of a disc or the surface of the end vertebral plate. Conversely, the surface could have partially arched protrusions, but the implant itself would still be considered non-arched in general terms.

Each of the upper and lower elements 106, 108 preferably have at least one hole 110 that communicates with another to allow bone growth between an adjacent vertebral body and another adjacent vertebral body, through implant 100.

On an outer surface 112, of each of the opposed upper and lower members 106, 108 there is at least one bone engagement projection 114 suitable for linear insertion which, in a preferred embodiment, is a retainer. Optionally, bone engagement projection 114 may be a rough, ridged, grooved surface, or any other configuration suitable for the intended purposes of limiting expulsion of the implant from the disc space after it has been implanted.

The upper and lower elements 106,108 are mobile relative to each other and can adopt a first position that allows the height of the implant to be folded and a second position that allows its height to be increased. In the first position, the upper and lower elements 106, 108 can be parallel, but can also be arranged at an angle if desired. The upper and lower elements 106, 108 are preferably articulated at an articulation point close to the end end 104 of the implant 100. The upper and lower elements 106, 108 are articulated, so that one of the respective ends of the upper and lower elements 106, 108 remains hinged when the other of the respective ends of the upper and lower members 106, 108 is free and can be separated from the other.

As illustrated by way of example in Figure 1, the upper and lower elements 106, 108 preferably have a combined rotary joint or pivot point 116 between the upper and lower elements 106, 108. The combined rotary joint 116 is preferably proximal to one of the ends, the proximal or the distal, of the upper and lower elements 106, 108 at an end opposite the expansion mechanism or expansion device 120.

Each of the upper and lower elements 106, 108 of the implant of Figure 1 preferably has a channel 122, 124 within which the expansion device 120 can rotate. As best illustrated in Figures 1 and 7, the channel 122, 124 is configured in such a way as to allow expansion device 120 to rotate within and then move from one side of the channel 122, 124 to the other.

The implant 100 has a slot 126 suitable for hooking it to an implant support 500 (described later) and fixing it to it and, subsequently, if the surgeon so wishes, admitting a plug that can be closed by pressure into the implant. slot 126.

Figures 8-10 show various views of an expansion device for use with expandable spinal fusion implants suitable for use with the instrumentation of the present invention.

A specialized model of a blocker 128 is described in detail below in relation to the expansion device 120, such as that illustrated in Figures 1B and 1C, but it is not necessary for the blocker 128 to be in contact with the upper elements. and lower 106, 108 when implant 100 is initially inserted into the implantation space. The blocker 128 can be a block or any type of spacer that is inserted between the upper and lower articulated elements 106, 108 once the implant 100 has been placed in place to keep the upper and lower elements 106, 108 apart at a height. separation and with an optimal angle between both elements. That is, the implant can be expanded using the expansion unit 600 described in more detail below, and then the expanded parts are kept apart in the second position by a third body blocker positioned between them. Furthermore, the doctor will be able to choose from a range of blockers of different heights suitable for use on the same implant.

The blocker 128, which is preferably in the form of an expansion device 120, is located near at least one of the ends of the upper and lower elements 106, 108 of the implant and maintains at least a portion of the

ES 2 298 665 T3 upper and lower elements 106, 108 separated, so that the increased height of implant 100 is preserved and folding of implant 100 to its folded height is resisted. The expansion device 120 of the present embodiment increases the height of the implant as measured in a plane along the median longitudinal axis of the implant 100 and the upper and lower elements 106, 108 during positioning of the expansion device 120 and If necessary, you can selectively increase the height of just the implant.

The expansion device 120 in the present embodiment is capable of rotating in a single direction, approximately 90 degrees, in order to move from an initial I (first) insertion position, as more graphically illustrated in Figures 1 and 2. 7, to a final deployed (second) position F, as best illustrated in Figure 34, to increase the maximum height H of implant 100.

Expansion device 120 has an opening 130 capable of engaging expansion unit 600 used to rotate expansion device 120 in order to increase the height H of implant 100. Expansion unit 600 rotates preferably, and approximately, by an axis parallel to the longitudinal axis L of implant 100 to rotate expansion unit 120 and increase the height H of implant 100. Aperture 130 may also be used as a passageway to deliver fusion enhancing materials through expansion device 120 into implant 100.

By rotating the expansion device, the longest dimension of the expansion device is replaced by the shortest dimension of the expansion device, which consequently increases the maximum height of the implant when moving from the first to the second position.

As best illustrated in FIG. 10, the schematic representation of the geometric configuration of a cross section of the expansion device 120 in accordance with one embodiment of the present invention includes the following elements: a first dimension X corresponding to the height of the expansion device 120 when the implant 100 is initially inserted into the spine and the width of the expansion device 120 when the expansion device 120 is rotated to increase the height H of the implant 100; and a second dimension Y corresponding to the width of the expansion device 120, when the implant 100 is initially inserted in the column, and to the width of the expansion device 120, when the expansion device 120 is rotated to increase the height H of the implant 100. The second dimension Y is greater than the dimension X. Preferably, the expansion device 120 offers the surgeon several sensory advantages: tactile sensitivity of the expansion device 120 as it travels through the center and becomes locked in place; visibility of the handle of a tool to rotate the expansion device 120 so that the handle passes from a perpendicular to parallel position, and vice versa, or even to the disc space to be positioned; the ability to hear the sound of the expansion device 120 as it snaps into place.

As illustrated in Figures 1 and 7, in a preferred embodiment of the present invention for subsequent insertion, the expansion device 120 is positioned near the initial end 102 of the upper and lower members 106, 108. It is noted that, Depending on the desired results, the expansion device can also be located at the end end 104 of the upper and lower elements 106, 108 or elsewhere within the implant. Furthermore, various expansion devices can be used in contact with the upper and lower members 106, 108 at any location within the implant 100.

Various views of other embodiments of expandable interbody spinal fusion implants suitable for use with the instrumentation of the present invention are illustrated in Figures 11-14. As seen in Figures 11 and 12, implants 200 and 300 are similar to implant 100, except that they are designed to be inserted in an anterior to posterior direction and fill more than half the width of the disc space. Implants similar to the 200 and 300 could have a tilting point at the initial end and one or more expansion devices at the final end, as in the posterior insertion implant described above, so that the implants will increase in height by the final extremes rather than the initials to regain a lordosis.

As actually shown in Figure 11, the implant 200 has two expansion devices 220 to move at least one part of the upper and lower elements, separating it from the other and thus increasing the height of the implant 200. All characteristics described above for a single expansion device 120 of implant 100 of Figures 1-7 are also applicable to both expansion devices 220 of implant 200. Additionally, the second expansion device 220 can be located near the end of the implant 200, adjacent to the other expansion device 220, which provides the implant 200 with the ability to expand at both ends 202, 204 of the implant 200. The increased height of the implant 200, the result of moving two expansion devices 220 can be constant or it can vary along the length of the implant 200, depending on the configuration that it is desired to give to the implant 200. The implant 200 can also take an embodiment with a single expansion device at its end end and a pivot point at its initial end.

Figure 12 shows another preferred embodiment of the non-arcuate and expandable interbody spinal fusion implant to be used from an anterior approach with the instruments of the present invention, generally referenced with the number 300. In the implant 300, they are used two sets of expansion devices 320, each located on one side of the median longitudinal axis of implant 300. Depending on the type of joint used, the expansion devices 320 can be rotated to provide a transverse angle or a longitudinal angle to the

ES 2 298 665 T3 upper and lower elements 306, 308 in cases where angles are required. The four expansion devices 320 can be used to expand the upper and lower elements 306, 308, to the same or different measures from each other. This can be done to allow the surgeon to expand the leading and trailing ends or the laterals by changing the degrees.

As illustrated in FIG. 13, a plug 334 with an outer surface and an inner surface can be used to close the trailing end 302 of implant 300. As will be appreciated by those skilled in the art, plug 334 can be adapted to will engage implant 300 in a number of different ways. Thus, for example, the inner surface of plug 334 could have grooves spaced around its circumference to facilitate a snap fit between plug 334 and implant 300, or the edge of plug 334 could be threaded for rotary engagement with the trailing end 302 of the implant 300. Furthermore, the plug 334 could be solid or perforated and made of a surgical grade plastic of the resorbable type or any other suitable material. The plug 334 could also be suitable to prevent the overexpansion of the implant 300. Some examples of plugs to prevent the overexpansion of implants are described in Michelson, provisional patent application uS-60 / 274,869, the disclosure of which is incorporated into the present application by reference. .

Figure 14 shows another preferred embodiment of an implant to be used from a posterior approach with the instruments and methods of the present invention, generally referenced with the number 400. The implant 400 is provided with an expansion device 420 at its leading end 402. The initial end 402 is formed to generally conform to the anatomical configuration of the anterior aspect of the vertebral body and prevent the anterior lateral aspect of the implant from protruding from the spine. The implant 400, with slight modifications, is also useful for anterior bilateral insertion of a hemi-implant (half width), something that would be desirable for laparoscopic insertion.

Although it has been described in connection with posterior and anterior approaches, the pressure implant of the present invention can also be used for insertion from the translateral aspect of the spine, as described by Michelson in US Pat. No. 5,860,973, which is incorporated herein by reference. In this case, the implants would be expanded at least anteriorly to increase the height of the disc space and / or restore lordosis.

Figures 15-18 show various views of instrumentation suitable for inserting and expanding spinal fusion implants as described above. Unless otherwise indicated, such instrumentation and how to use it will be described in relation to implant 100 and other expandable implants.

A preferred embodiment of an implant holder 500 for inserting an implant 100 into a disc space is depicted in Figures 15 and 16. The implant holder 500 is provided with a shaft 502 and an outer sleeve 504. The shaft 502 has a distal end 506, a proximal end 508 and a reduced portion 510 extending towards the distal end 506, a reduced middle portion 511 and an enlarged portion 512 between the intermediate reduced portion 511 and the proximal end 508. The transition between the enlarged portion 512 and the reduced intermediate portion 511 preferably forms an angle suitable to embed the proximal end 524 of the outer sleeve 504. The shaft 502 is preferably hollow and suitable to allow the passage of other instruments through it, depending on described later. Reduced portion 510 features an elbow 514 at distal end 506, sized and shaped to engage with distal end and outer sleeve 504 and lock implant holder 500 on implant 100, in order to hold and manipulate the implant during insertion. in the disc space. As used herein, the term "locking" refers to the fixation of an implant in the implant holder, so that the implant holder can be rotated or pushed, or can be pulled or otherwise oriented within implantation space, without the risk of inadvertent disconnection between the implant and the implant holder. From the intermediate reduced zone 511 starts a pin 516 close to the initial edge of an enlarged part 512 to be inserted into a slot 540 of the outer sleeve 504. The proximal end 508 of the enlarged part 512 has an increased diameter suitable to receive the enlarged part. 612 of an expansion unit 600. Proximal end 508 has a cutout 518 to accommodate a spike 622. The cutout 518 has a slot 520 to accommodate the shank 622 of an expansion unit 600 to prevent the expansion unit 600 from rotating with respect to the implant holder 500.

The outer sleeve 504 has a distal end 522 and a proximal end 524. The distal end 522 has upper and lower extensions 526, 528, and lateral extensions 530 capable of engaging together with the end end 104 of implant 100. The lateral extensions 530 are each provided with a flange 532 to engage in combination with a slot 126 of the implant 100 and a plug 534, in order to limit the implant holder 500 from further advancing towards the end end 104 of the implant 100.

As illustrated in Figures 15, 19 and 20, each of the lateral extensions 530 has an inner surface 536 with an inclined part 538. The inclined part 538 interacts with the peak of the elbow 514 of the shaft 502, preferably serrated. to facilitate the opening of the lateral extensions 530 and the engagement of the tabs 532 with the grooves 126 of the implant 100.

A preferred embodiment of expansion unit 600 is shown in Figures 17 and 18 for engaging expansion device 120 and rotating. Expansion unit 600 contains a shaft 602 with a distal end 604, a proximal end 606, a reduced portion 608, an implant holder engaging portion 610, and an enlarged portion 612. The shaft 602 generally has a circular cross section and is suitable for coaxial engagement, preferably with the inside of the shaft 502 of the circular implant holder 500 in order to hold

ES 2 298 665 T3 have vertical alignment between the expansion unit 600 and the implant holder 500. The distal end 604 has a tip 614 capable of engaging the opening 130 of the expansion device 120. In a preferred embodiment, tip 614 is hexagonal in shape, but could take any suitable shape to engage expansion device 120.

The implant holder engagement portion 610 has a first distal stop 616 and a second proximal stop 618 to lock engagement with the implant holder 500, which is described in greater detail below, in connection with Figures 23, 24. , 28 and 29. The enlarged portion 612 is sized and shaped to engage the proximal end 508 of the implant holder 500 and rotate it. The enlarged portion 612 has an elbow 620 and a shank 622 to assist the cut 518 and slot 520 of the implant holder 500 to limit the rotation of the expansion unit 600 while they are engaged in the implant holder 500. The proximal end 606 It has a "T" shaped handle 624 for manual rotation of the expansion unit 600. The handle 624 may be removable, for example a quick release handle. In cases where the expansion units 600 must be used simultaneously, it might be preferable that each of the two separate expansion units 600 uses an “L” -shaped handle, so that both implants could expand simultaneously without the handles interfere with each other. Other hands could be used, for example oriented in different planes, and a combination of hands suitable for the purposes that will be apparent to any person skilled in the art, within the scope of the present invention.

Figures 19-38 show various phases of a preferred method of inserting an implant 100 and using the associated instrumentation described in this patent from a posterior approach to the spine.

The surgeon first identifies the appropriate disc space to operate, by direct ocular inspection or using radiographic means such as the radiopacity marker and an X-ray or image intensifier. The disc is then surgically accessed from a position posterior to the transverse processes of the vertebrae to be fused. Sufficient laminar bone is removed to allow access to the posterior aspect of the disc space. The surgeon can then remove material from the disc that is sufficient, at a minimum, to create the disc portion of an implant receptor space. Optionally, the surgeon can insert a shield first and then, using the shield, remove enough disc space to, at a minimum, create the disc portion of an implant receptor space. With the dural sac conveniently retracted and protected in the area opposite the insertion, and with the nearby nerve roots adequately protected, the surgeon may choose to insert a shield, such as the 700 shield filed in the pending US patent application, with serial number US60 / 272,381, entitled "Dynamic lordotic protection with mobile extensions to create a posterior implantation space in the lumbar spine and method of using it." Shield 700 is provided with an extended pivoting outer sleeve to protect adjacent delicate neurological structures and induce lordosis in adjacent vertebral bodies, as illustrated in Figure 26. Although guard 700 is preferred for use in the restoration of lordosis in adjacent vertebral bodies, it will be appreciated by those of ordinary skill that other protections may be used to protect the dural sac in cases where it is desired to use a guard to protect the dural sac.

The disc space is then prepared, with a bone removal instrument, so that it can accommodate an implant 100 of suitable dimensions. Michelson discloses some preferred instruments and methods for preparing the disc space in patent applications US-09 / 972,560, entitled "Spinal interspace spacer", US-6,083,228 entitled "Device and method for preparing a space between adjacent vertebrae that can host an implant ”, US Patent 6,224,607, entitled“ Instrument and method for creating a disc space that can accommodate an implant ”, and WIPO publication WO-99/63891, entitled "Device for preparing a space between adjacent vertebrae that can accommodate an implant." When it is required to leave the shield 700 in place, to protect the adjacent delicate neurological structures, after the disc space has been prepared, the described operation can be carried out with the shield 700, which will be removed once completed. It is generally preferable that the procedure be performed on both sides of the spinal midline and that two implants 100 be inserted, each less than half the width of the disc space, from a posterior approach to anterior either broadly parallel or alternatively from a general posterior approach to anterior in a toed-in configuration.

Preferably prior to insertion, implant 100 could be loaded with fusion enhancing materials, including any of the following, or any combination of them: bone in any of its forms, bone-derived materials, bone morphogenetic proteins, mineralizing proteins, genetic materials programmed for the production of bone or any substance capable of inducing bone formation or useful to achieve fusion according to the proposed purposes.

In order to better accommodate the presence of the fusion-enhancing materials, the implant 100 preferably has a gap 118, as shown in Figure 6, between its ends, which is not obstructed by the expansion device 120, so that unobstructed loading of the interior of the implant is allowed. Furthermore, this preferred configuration of the implant 100 enables the entire volume of the gap to be used to contain the fusion enhancing materials and thus facilitate bone growth directly into the gap, free from obstructions from any expansion mechanism, into the bodies. adjacent vertebral bodies. The method and instrument of the present invention could be useful for expandable implants that are not as free of obstructions. Fusion enhancing materials could preferably be loaded compressed into the implant

ES 2 298 665 T3

100, using an instrument such as, for example, a tampon, a press or a piston, at any point in the process, as decided by the surgeon.

As illustrated in Figures 19 and 20, the distal end of the implant holder 500 is inserted into the end end 104 of the implant 100, so that the tabs 532 of the outer sleeve 504 are positioned to engage the slots 126 of implant 100. In FIG. 20, shaft 502 is moved to an extended position within outer sleeve 504 by linearly advancing reduced portion 510 of shaft 502 through outer sleeve 504. This allows the elbow 514 to be in contact with the inclined portion 538 of each lateral extension 530 and forces each of the lateral extensions 530 to separate until the flanges 532 engage in the grooves 126 of the implant 100 to engage the outer sleeve 504 implant 100. It will be appreciated that instead of forcing the lateral extensions 530 to separate from each other, the implant holder can be adapted so that the lateral extensions are forced towards each other and lock the implant attached to the implant holder. Such an embodiment is described below with reference to FIG. 67.

In Figure 21, shaft 502 is rotated relative to outer sleeve 504 so that pin 516 moves to a locked position within the "L" shaped slot 540 of outer sleeve 504, thereby locking shaft 502 in an extended position within the outer sleeve 504. With implant holder 500 hooked and locked to implant 100, the surgeon can manipulate implant 100 (eg, push or pull) without the risk that implant 100 and implant holder 500 will lose their union. When the implant holder 500 is attached to the trailing end 104 of the implant 100, the material within the implant 100 can continue to be compressed and / or extruded through the openings in the engaging surfaces of the vertebrae of the implant 100 using, for example , an instrument such as an expansion unit 600 for introducing bone growth enhancing material through the implant holder 500.

As illustrated in Figures 22-24, distal end 604 of expansion unit 600 inserts into proximal end 508 of shaft 502 and advances through implant holder 500 into implant 100. The leading end of tip 614 of expansion unit 600 is formed to facilitate advancement of the instrument by rotating movements through implant filling material in implant 100 until it reaches and engages expansion device 120. The depth of penetration of the expansion unit 600 into and through the expansion device 120 is limited by the larger cross-sectional dimensions of the engaging portion 610 of the implant holder and the enlarged portion 612 of the expansion unit. 600. Expansion unit 600 is then locked to implant holder 500 in a first locking position to prevent expansion unit 600 from further rotating relative to implant holder 500. This is accomplished by placing the spike 622 of the expansion unit 600 in the housing slot 520 at the proximal end 508 of the implant holder 500, and placing the first and second snap fasteners 546, 548 of the inner surface 542 of the shaft. 502 within the first and second fasteners, 616, 618 of the engaging portion 610 of the implant holder. Locking the expansion unit 600 in the implant holder 500 in the first locking position allows the handle 624 of the expansion unit 600 to control the handling of the implant itself and to allow the introduction of the implant holder 500 and the implant 100 within the disc space without displacing the expansion device, so that the implant remains in the collapsed position during insertion.

In Figures 25 and 26, the implant 100 is pushed into the prepared receptor disc space by a pressing movement, an impact force, or a combination of both by the guard 700. According to a preferred method of preparing a receptor space, they are worked vertebral endplates and at least the outermost cell layers of bone are removed from adjacent vertebral bodies to allow fusion. However, the bone in the endplate region could be preserved, as otherwise required by the surgeon. The protection 700 preferably has a shaft 702 suitable to allow the insertion through it of the instruments used in the preparation and implantation of spinal implants, a distal end 704 and a proximal end 706. The proximal end 706 has upper and lower elements. lower 708, 710 suitable for a mobile coupling between the two. The distal end 704 is provided with upper and lower projections 712, 714 for disc penetration and a pivot point 716 configured such that, when the proximal end 706 is folded, the upper and lower disc penetration projections 712, 714 separate. and they induce lordosis in the adjacent vertebral bodies when inserted into the disc space. Optionally, other protections could be used that meet the same objectives. The implant 100 is inserted to a suitable depth which, preferably, might be necessary so that the end end 104 of the implant 100 does not protrude beyond the posterior faces of the adjacent vertebral bodies, and that no substantial part of the implant 100 protrudes from the outer perimeter of adjacent vertebral bodies between which implant 100 has been installed. It may be desirable to "countersink" or "recess" the end end 104 of the implant within the posterior perimeter of the adjacent vertebral bodies. The implant 100 could be inserted such that it lies between two adjacent vertebral bodies or at least partially within adjacent vertebral bodies. Although the use of shield 700 is preferable, the invention is not limited thereto, so that the implant could be inserted directly into the disc space, as illustrated in FIG. 27A.

As shown in Figures 27A and 27B, it is noted that adjacent vertebral bodies do not necessarily have to maintain an angular relationship with each other prior to insertion of implant 100. Thus, for example, implant 100 could be inserted into the disc space oriented parallel to the vertebral bodies, parallel to each other, as illustrated in Figures 27A and 27B. Advancement of implant 100 would then continue into the disc space in a parallel direction P until the initial end 102 of implant 100 meets the upper and lower elbows S.

ES 2 298 665 T3

At this point, the surgeon has a number of options to complete the procedure, two of which are preferable and are described below.

One option is to complete the procedure from one side, left or right, of the spine, before repeating the entire process on the other side of the spine. Another option is to implant two implants in the unexpanded position and then expand each one, preferably simultaneously. Although both methods will be described, it is necessary to first pay attention to the method by which implantation and expansion are carried out on a first lateral before introducing the implant on the second lateral.

In Figures 28 and 29, the expansion unit 600 is partially folded from the first locking position to a second locking position, such that the second spring lock 548 of the implant holder 500 engages the first latch 616 of the expansion unit 600. The expansion unit 600, in this position, is rotatable relative to the implant holder 500, so that the pin 622 of the expansion unit 600 exits the slot 520 and is free to rotate within the cut portion 518 of the implant holder. 500. Preferably, the cut portion 518 has a shape and size that, as it exits the slot 520, the path of the pin 622 is limited to approximately 90 degrees, clockwise, from the top of the slot 520. This Configuration based on a cut portion 518 facilitates a properly guided rotation of the expansion device 120, which is configured to rotate clockwise only when it is expanding the implant.

As illustrated in Figures 30-34, when implant 100 is properly seated in the disc space, expansion unit 600 is rotated to move expansion device 120 so that at least the initial end 102 of the implant 100 expands and increases the maximum implant height in the area near the initial end 102. One of the purposes for which implant 100 is expanded is to position adjacent vertebral bodies at an angle to each other, or in lordosis in the example at hand. During the rotation of the expansion device 120, the upper and lower elements 106, 108 move from a parallel orientation P, as illustrated in Figure 27B in which the implant 100 is in a first position, to an orientation in Angle A, as illustrated in FIG. 31, in which implant 100 is in a second position.

As shown in Figures 10, 33 and 34, the expansion device 120 in an embodiment hereof a cross section with side surfaces 136 intersecting the top and bottom surfaces 138, 140 at two junctions that can be diametrically opposite corners 142 and two diametrically opposite arches 144. The arcs 144 each preferably have the same radius, and the modified hypotenuse MH between the opposing arches 144 generally approximates the distance between the upper and lower surfaces 138, 140 so that when the device is rotated expansion 120 from an initial insertion position to the final deployed position, no substantial over-separation occurs between adjacent vertebral bodies. Speaking of "no substantial over-separation" is being expressed that the length of the modified hypotenuse MH is closer to the Y dimension of the expansion device than the unmodified hypotenuse UH; and has been chosen to allow the implant to operate preferentially in the elastic deformation range of the tissues around the disc space in which it is operated. It can be seen that the expansion device can also move the upper and lower elements 106, 108 from a first height at each end to a second and greater height at each end. Thus, for example, expansion device 120 can be used to expand an implant oriented at an angle at the time of insertion into a parallel or more angled orientation after expansion; or to expand an implant with a parallel orientation at the time of insertion into an expanded parallel orientation after expansion.

A given implant might be able to receive an expansion device chosen by the surgeon at the time of surgery, from a series of graduated expansion devices of different dimensions, so that the surgeon could choose the future spacing and / or height. implant maximum.

When such methods and instruments are used to place these types of implants later, the technique could also include the application of substances that inhibit scar tissue after the end of the implant and at the base of the spinal canal.

As illustrated in Figure 35, after implant 100 has been placed in an expanded position, expansion unit 600 is removed from implant holder 500. During this phase of the surgical procedure, proximal end 508 of implant holder 500 will generally be face up, as the patient will normally be lying face down on the operating table. The proximal end 508 of the implant holder 500 is preferably funnel-shaped or, in other cases, the shape suitable to receive the filling material of the implant M, for example only, ground bone graft, bone paste, demineralized bone gels or putties. or any other fusion enhancing substance or a combination of all of them. The axis 602 of the expansion unit 600 occupies a volume along the median longitudinal axis of the implant 100 that extends essentially the entire length of the graft-bearing portion of the implant 100 from and through the end end 104 of the implant 100. After implant 100 has been expanded, a notch C is formed in the filler graft, which is generally wedge-shaped and is larger at the initial end than at the distal end, along the channel of the expansion unit. and on both sides of said channel.

ES 2 298 665 T3

As illustrated in FIG. 36, bone growth enhancing materials are pressed through implant holder 500 using expansion unit 600 or other instrument, for example a piston or impact mechanism. Notch C and channel can then be filled with fusion enhancing materials from leading end 102 toward end 104 of implant 100. When appropriate, the fusion enhancing materials or the graft can be compressed into the implant 100 so as to be conveyed into the vertebral bodies. Material can still be loaded with the implant holder 500 attached or unattached. The shaft 502 of the implant holder 500 is then rotated relative to the outer sleeve 504 to move the pin 516 to an unlocked position in the "L" shaped slot 540. The shaft 502 can then be partially removed from the outer sleeve 504 by moving the elbow 514 from the distal end 522 of the outer sleeve 504 and allowing the lateral extensions 530 to fold inwardly and allow the implant 100 to be separated from the implant holder 500.

As illustrated in FIG. 37, implant holder 500 is disengaged from implant 100 and removed. At the surgeon's discretion, a plug can be installed to close at least a part of the end of the implant and prevent bone growth into the spinal canal, or to limit the adherence of neurological structures to the base of the canal or even to protect the structures. neurological. Additionally, scar tissue inhibiting materials can be applied to the disc space and / or the implant. The method includes the use of various materials such as membranes and gels that may be suitable for these purposes. These materials can be used at any time after the implant has been inserted. Among the reasons for using a plug are to limit the passage of fusion enhancing materials so that they remain loaded within the implant. Another reason for using a plug would be to provide structural support to the implant.

After completing the procedure on a first side, it can then be repeated as described, on the opposite side of the same disc space, resulting in the implantation of two implants 100 in the same disc space, as illustrated in the figure. 38.

In summary, a preferred method of the present invention from a posterior spine approach includes: identifying the appropriate disc space to be fused; folding and protection of the dural sac; performance of at least one partial laminectomy sufficient to access the disc space; performing at least one partial discectomy, which preferably provides sufficient space to accommodate the depth of the implant; insertion of a protection in the disc space; preferably induction of lordosis in the adjacent vertebral bodies before perforation, and optionally afterwards, using the implant for this; and insertion of a bone removal device through the guard to a desired insertion depth to create the implantation space. The insertion depth can be controlled by radiography.

After creating the implantation site, the method could proceed by loading the implant with bone growth enhancing materials; mounting the implant, implant holder, and expansion unit together so that the expansion unit is in the first locking position relative to the implant holder; inserting the implant into the implantation space; retracting the expansion unit towards the second locking position; rotating the expansion unit to move the expansion device and expand the implant. The procedure could proceed by removing the implant expansion unit and implant holder; inserting fusion enhancing material into the implant holder; using the expansion unit as a piston to move the bone growth enhancing material into the implant; separating the expansion unit from the implant holder; unlocking the implant holder and implant; and removing the implant holder from the implant.

From here, an end cap and scar tissue inhibitor material can be applied to the implant, if desired. Those skilled in the ordinary art will deduce that the above method may vary according to the preferences of the operating surgeon, without thereby departing from the general scope of the present invention. Thus, for example, it is possible to omit the use of a protection, or to use it only during one phase of the procedure. The method can be carried out without separation of the disc space or without induction of lordosis between adjacent vertebral bodies. Disc space preparation can be accomplished by known bone drilling or removal devices, such as the device for preparing a space between adjacent vertebrae to accommodate an implant, described by Michelson and referenced above. The implant can be loaded with bone growth enhancing material before and / or after implantation. If the bone growth enhancing material is loaded into the implant after implantation, other instruments could be used in place of the expansion unit to move the bone growth enhancing material into the implant. Other steps could be included as needed, for example when using bone screw implants and bone screw closures. In these cases, the surgeon could carry out the phases of inserting a bone screw through the implant and into an adjacent vertebral body, and locking the bone screw with a bone screw closure. Additionally, other steps could be included to achieve adequate dimensions for the implant, such as radiographs, computed tomography tests, or MRIs to obtain measurements of the disc space and process the implant accordingly before inserting it.

According to an alternative method, both implants are placed in the disc space in a juxtaposed and aligned configuration, generally from a posterior face to an anterior face. Both implants can then expand simultaneously, or in very rapid succession.

ES 2 298 665 T3

In this method, both implants can be inserted using the implant holder 500 without the expansion unit 600 attached. Instead, the implant holder 500 can be adapted to engage a handle to facilitate insertion of the implant 100. Once inserted, both implants receive the expansion units 600 hooked to each of the expansion devices 120 within the implants, but preferably without the presence of the implant support 500 during the expansion phase. Given the small cross-sectional dimensions of the expansion unit shafts 608 and their spacing distance, the dural sac can be safely driven between them. As mentioned above, it might be preferable for each expansion unit 600 to have an "L" shaped handle, so that both implants could expand simultaneously without the handles hitting each other. Other hands could also be used, for example oriented in different planes, and any combination of hands suitable for the purposes, as will be apparent to one skilled in the art, in the context of the description of the present invention.

While it is preferable to have an implant holder 500 installed while expanding implant 100, the invention is not limited thereto. Expansion unit 600 can also expand implant 100 without the presence of implant holder 500. If the implants are expanded without the implant holder 500 being installed, then the graft can be inserted manually into the expansion unit canal and into the graft expansion notch, or preferably using an instrument that allows for alignment and preferably engage the distal end of the implant, which is hollow and ends proximally in an opening formed to facilitate graft reception. A piston, plunger, press, or other instrument could then be used to drive the graft through the loading instrument and insert it into implant 100.

According to another alternative method, both implants could be implanted from an anterior approach to the spine. The surgeon first identifies the appropriate disc space to operate on by direct inspection or through radiographic means, such as a radiopaque marker and an X-ray or image intensifier. The disc is then surgically accessed from a position anterior to the transverse processes of the vertebral bodies to be fused. Sufficient laminar bone is removed to facilitate access to the anterior aspect of the disc space, preserving the annular fibrosis portion of the disc along at least both sides of the disc space.

The interspace created in this way is deflected, although not a requirement, preferably to its optimum height, which height is determined by the known normal spatial relationship between said area and adjacent soft tissue structures. The interspace is then preferably measured to determine its height, depth and width. The width of the interspace could be determined relative to the bottom of the vertebral base plate of the upper vertebrae, and this determines the choice of a suitable width for a milling block or other protection should it be necessary to use it. Michelson discloses a preferred milling block in US Pat. No. 6,159,214, entitled "Drilling Instruments and Method for Preparing a Space Between Adjacent Vertebral Bodies." The measured depth of the interspace, ie the distance between the front and back of the vertebral body, will determine the selection of a slightly lower depth spacer and milling means. The height and depth of the interspace will determine the selection of the appropriate height and length of the spacer element, the shape of which will be determined both by the need to maintain or restore lordosis, and by the shape of the implant, which may or may not be wedge-shaped. .

The appropriate spacer element is then chosen, which may be of a known fixed length or, preferably, adjustable and the optimum fixed length of which is adjusted using a caliper, integral marking or similar means. The spacer device is then attached to the milling block, previously chosen based on the appropriate width.

The combined spacer and milling block unit is then brought to the melting point and the spacer element is inserted into the disc space. The spacer element can be inserted into the disc space in a lateral rotation position, to facilitate its introduction, and then rotated 90 degrees to separate the space; or the separating element can be inserted perpendicular to the plane of the disc space, thanks to its initial rounded head end, to separate the vertebral bodies. The angular relationship of the two vertebral bodies adjacent to said disc space is then determined as a function of the shape of the spacer element. It is noted that, although this is not a preferred option, a spacer element could be inserted into the disc space first, and then the milling block unit is placed in place, relative to the spine.

The reamer block is then fixed to the anterior face of the spine preferably, engaging each of the adjacent vertebral bodies. The width and depth of the bone resection can then be easily confirmed visually, prior to any actual bone resection. The spacer element and the spacer device are then removed from the disc space.

The surgeon can then remove material from the disc that is at least sufficient to form a part of the implant receptor space.

Although a reamer block is preferable for use in restoring lordosis in adjacent vertebral bodies, it will be apparent to those of ordinary skill that other devices can be used to induce lordosis in adjacent vertebral bodies where necessary. do it.

The disc space is then prepared with a bone removal instrument to receive an implant of the appropriate dimensions. The medium of suitable dimensions is chosen for bone removal, corresponding

ES 2 298 665 T3 to the previously used spacer element, and, using the housing depth gauge, the depth of the bone removal means is adjusted and locked in this position. The bone removal means is fixed in the drill entry of the drill block, after which the space necessary to remove a portion of the bone from the base plates adjacent to the disc space is reamed. The reamer is removed and the prepared space can be irrigated and aspirated via the reamer block or, optionally, the entire reamer unit, including the reamer block, can be removed to irrigate and then aspirate the prepared space.

The prepared space is separated using conventional means and the appropriate implant or implants are then inserted into the prepared space.

Preferably prior to insertion, the implant could be loaded with fusion enhancing materials, such as those described for the post-spine approach method. Fusion enhancing materials can be loaded or preferably compressed into the implant using instruments such as buffers, presses, or pistons at any time during the procedure, depending on the surgeon's choice.

Hereafter, the method could be continued by inserting the implant into the implantation space and moving the expansion device to expand the implant. Optionally, if the implant is inserted laparoscopically, the method could include mounting the implant, implant holder, and expansion unit all together so that the expansion unit is in the first locking position relative to the holder. of the implant; inserting the implant into the implantation space; retracting the expansion unit towards the second locking position; rotating the expansion unit to displace the expansion device and expand the implant. The procedure could be continued by removing the implant expansion unit and implant holder; inserting fusion enhancing material through the implant holder; using the expansion unit as a piston to move the bone growth enhancing material into the implant; removing the expansion unit from the implant holder; unlocking the implant support from the implant; and separating the implant holder from the implant.

As illustrated in Figures 39 and 40, if implant 200 is used with expansion devices at its initial and final ends, then one or both expansion devices 220 could be used to expand implant 200 to achieve the desired angle. for adjacent vertebral bodies. Additionally, bone screws 232 could be inserted into the adjacent vertebral bodies to better anchor implant 200 in the spine.

Subsequently, an end plug can be fitted and scar tissue inhibitor materials can be applied into the spinal canal. The steps of the method based on the anterior approach to the column can be varied as mentioned for the method based on the posterior approach of the column.

Figures 41-68 show various views of embodiments of arcuate interbody spinal fusion implants suitable for use with the instrumentation of the present invention.

As used in this text, the term "arcuate" describes the shape of an implant capable of being inserted into a disc space between two adjacent vertebral bodies, each of which has an area, after preparation of the disc space, that describes arcs of the same circle. Thus, for example, in the case of implants with a circular cross section, such as threaded implants, the curvature of the upper and lower surfaces in contact with the adjacent vertebral bodies is the radius equivalent to half the width of the implant.

As shown in Figures 41-48, implant 800 is similar to implant 100, except that upper and lower members 806, 808 are preferably arcuate and are suitable for placement toward, and at least partially, the interior of the upper and lower part of two adjacent vertebral bodies, respectively. Additionally, the outer surface 812 of each of the opposed upper and lower members 806, 808 has at least one projection 814, threadedly, to join the bone. The holes 826 that receive the pins in the final end 804 of the implant 800 are suitable for receiving an implant holder (described later).

As illustrated in Figures 41 and 48, a plug 834 can be used to close the leading end 802 of implant 800. As those skilled in the art will deduce, a plug 834 can be adapted to mate with implant 800 in a variety of ways. procedures. Thus, for example, the inner surface of plug 834 could have grooves 835 spaced between flanges 837 around its entire circumference to facilitate snap closure between plug 834 and implant 800, or the edge of plug 834 could be threaded to a rotary coupling with the initial end 802 of the implant 800. Furthermore, the plug 834 could even be compact or perforated and made from resorbable surgical grade plastic or any other suitable material.

Figures 49-54 show various stages of a preferred method of inserting an implant 800 using the associated instrumentation disclosed herein for the anterior approach to the spine.

The surgeon first identifies the appropriate disc space in which to operate by direct inspection or radiographic means, such as a radiopaque marker and an X-ray or image intensifier. The disc is then surgically accessed from a position anterior to the transverse processes of the vertebrae to be fused. The surgeon can then remove disc material that is at least sufficient to create a portion of the implant receptor space. Optionally, the surgeon can first insert a shield, such as the

ES 2 298 665 T3 protection 700 which is illustrated in Figure 26, but suitable to be used with arcuate implants and then, using the protection, remove at least enough disc material to create the part of a receptor space of the implant.

The disc space is then prepared by a bone removal instrument to receive an implant 800 of the appropriate dimensions. In cases where it is desirable to leave the shield in place to preserve the delicate adjacent neurological structures, after preparing the disc space, the operation described can be carried out through the shield, which will be removed after the operation is completed. . The insertion depth can be controlled radiographically.

Once the disc space is prepared, fusion enhancing materials can be loaded; preferably, tablets are loaded into implant 800 using an instrument such as a tampon, press, or piston, at any time during the procedure, at the discretion of the surgeon.

As shown in Figure 49, a preferred embodiment of the functional end of an implant holder 900 for holding the implant 800 and for use in inserting the implant 800 into the disc space, has a shaft 902 and a distal end 904, with an enlarged head 906. The head 906 has an area for coupling the implant 908 with projections 910. The protrusions 910 could be formed as pins, pins, or any type of protrusion suitable for the intended purposes. The distal end 904 is configured to be inserted into the trailing end 804 of the implant 800, so that the pins 910 are positioned to engage the pin receiving holes 826 in the implant 800. The pins 910 hold the upper and lower elements 806, 808 of implant 800 attached during implant insertion. One skilled in the art will understand that other means may be used to couple implant holder 900 to implant 800, such methods being within the scope of the present invention. Some of them are tabs, threads or magnetism.

As illustrated in Figures 50 and 51, pins 910 engage pin receiving holes 826 and implant 800 is inserted into the disc space in the unexpanded position. Pins 910 engage implant 800 to preferably allow rotation of implant 800 within the disc space. After implant 800 is inserted into the disc space, implant holder 900 is separated from implant 800.

As seen in Figure 52, the procedure can be continued by aligning the expansion unit 1000 with the trailing end 804 of the implant 800. A preferred expansion unit 1000 for engaging the expansion device 820 and causing it to rotate would have a shaft 1002 with a distal end 1004 provided with a tip 1006. The tip 1006 has a coupling zone for expansion 1008 suitable for coupling combined to the opening 830 of the expansion device 820. In a preferred embodiment, tip 1006 is hexagonal in shape, although it could be any suitable shape to engage expansion device 820.

As illustrated in FIG. 53, tip 1006 of expansion unit 1000 is inserted into and advanced through end 804 of implant 800. The penetration depth of the expansion unit 1000 at the trailing end 804 is slowed by a larger cross-sectional arrangement of the shaft 1002.

As illustrated in FIG. 54, expansion unit 1000 is rotated to move expansion device 820 from its initial position to its final position, where it expands implant 800. During the rotation of the expansion device 820, the upper and lower elements 806, 808 advance parallel in direction P, as illustrated in Figure 51 in which the implant 800 is in a first position, up to an angle arrangement A, as illustrated in FIG. 53, where implant 800 is in a second position. The implant 800 could also be loaded with bone growth enhancing materials in order to fill the spaces that were left empty when the expansion unit 1000 was removed from the implant 800. As illustrated in Figures 41 and 54, channels 822, 824 are configured to allow expansion device 820 to rotate therein and then move back and forth within channel 822, 824 as shown. indicated with arrows B, to allow greater access to the hollow interior 818.

As best seen in FIG. 54, for example, more than one implant 800 placed in a side-by-side configuration could be used to advantageously occupy more disc space than could be occupied by a single arcuate interbody spinal fusion implant.

Later, at the surgeon's discretion, it is possible to install a plug to close at least a part of the end of the implant and prevent bone growth towards the spinal canal, or to limit the adhesions of neurological structures to the base of the canal, or to otherwise protect neurological structures. One of the purposes for which you use a plug is to reduce the passage of fusion enhancing materials, so that they remain loaded within the implant. Another objective that justifies the use of a plug is to add structural support to the implant.

Figures 55-60 show another embodiment of an arcuate and expandable interbody spinal fusion implant, suitable for use from a posterior approach with the instruments and methods of the present invention, generally referenced with the number 1100. Implant 1100 is similar to Implant 800 except that it is designed to be inserted at the implantation site from a posterior approach to the spine. The implant 1100 preferably has an expansion device 1120 at the initial end 1102 and a pivot point 1116 at the end end 1104. In this way, the implant 1100 will have a greater height at the initial end 1102 than at the end end 1104. implant 1100, preferably, includes a variety of holes 1128 in the end end 1104 to enhance if possible bone growth through said implant 1100. Holes 1128 have

ES 2 298 665 T3 preferably has a diameter smaller than that of the pin receiving holes 1126, so that the pins 1210 of the implant holder 1200 (described below) do not pass through. Those skilled in the art will deduce that the holes 1128 could have different shapes without thereby departing from the broader scope of the present invention.

As best illustrated in Figure 55, channels 1122, 1124 of upper and lower elements 1106, 1108 of implant 1100 present a support surface 1125, and expansion device 1120 has a corresponding support surface 1127 that is in contact. with the support surface 1125 of the channels 1122, 1124 in order to orient the expansion device 1120 in a predetermined location. Assist surfaces orient expansion device 1120 within implant 1100 so that the axis of rotation of expansion device 1120 is parallel to the longitudinal axis of implant 1100 and, more especially, center expansion device 1120 within implant 1100 to that the axis of rotation of the expansion device 1120 coincides with the longitudinal axis L of the implant 1100.

As illustrated in Figures 55-57, the implant holder 1200 includes a shaft 1202 with a distal end 1204 and an enlarged head 1206. The head 1206 comprises an implant mating area 1208 with pins 1210. The pins 1210 they serve a function similar to that described in connection with the pins 910 above. The implant holder 1200 has a 1212 gauge suitable to additionally house a 1300 expansion unit through it.

Expansion unit 1300 features a shaft 1302 with a distal end 1304 provided with a tip 1306 with a coupling area for expansion 1308. The initial end of tip 1306 is shaped to facilitate advancement of the instrument by rotational movements through of the implant filling material into implant 1100 until it reaches and engages expansion device 1120. Expansion unit 1300 is capable of extending into implant 1100 and moving expansion device 1120 from an initial position to a final position that expands implant 1100, as will be disclosed in greater detail in the method described below.

As illustrated in Figures 58-60, the method for inserting implant 1100 from a posterior approach to the spine is similar to that described in connection with Figures 19-38, except that the pins 1210 of the implant holder 1200 they engage in holes 1126 and implant 1100 is pushed into the prepared receptor disc space by exerting a rotary force, a pushing motion, an impact force, or a combination of all of these, through a guard and being in the unexpanded position.

As illustrated in FIG. 60, after implant 1100 has been properly seated in the disc space the procedure can proceed preferably by keeping implant holder 1200 attached to end end 1104 and extending expansion unit 1300 through implant 1100. until tip 1306 is conjointly coupled to expansion device 1120. The expansion unit 1300 is rotated to move the expansion device 1120 so that the initial end 1102 of the implant 1100 expands to increase the maximum height of the implant, close to the initial end 1102.

Those skilled in the art will deduce that many of the phases described in relation to the subsequent filling of implants introduced with bone growth enhancing materials are applicable to the subsequent filling of arcuate implants with bone growth enhancing materials, therefore they will not be repeated here.

Once the procedure is completed on a first side, it is repeated, as already described, on the opposite side of the same disc space, resulting in the insertion of two implants 1100 in the same disc space.

Those skilled in the art will deduce that, while the preferred option, the presence of implant support 1200 is not essential to expand the implant. Thus, for example, as illustrated in Figure 61, it is possible to insert an implant 1400 into the implantation space using a variety of known implant insertion devices and then expand it with the expansion unit 1300.

Illustrated in Figures 62-66 is another preferred embodiment of an expandable arcuate interbody spinal fusion implant for use from an anterior approach with the instrumentation and methods of the present invention, generally referenced at 1500.

As illustrated in Figure 62, implant 1500 tapers from initial end 1502 toward end 1502, in the unexpanded position, and preferably has a second expansion device 1520 at its initial end 1502 to separate at least one from the other. a part of the upper and lower elements and increase the height of the implant 1500. The advantages derived from using a second expansion device are described in relation to implant 200 of Figure 11.

As illustrated in Figures 64-66, another aspect of the implant 1500 consists in that its upper and lower elements 1506, 1508 have threaded holes 1548 that pass through them, capable of receiving a bone screw 1550 that passes from the interior of the implant. 1500 to the adjacent vertebral bodies and anchor the 1500 implant to an adjacent vertebral body. One of the objectives of the opposed bone screws is to rigidly fix the implant within the vertebral segment. Another objective is to bring each of the adjacent vertebral bodies closer to the implant and also to each other. If the joint device holds the upper and lower elements together, as in the posterior implant 100 embodiment of Figures 1-7, tightly wrapping a

ES 2 298 665 T3 strut, then the implant cannot expand at this location. Bone screws are not essential to the operation of the invention, but are preferable to provide additional fixation between the implant and adjacent vertebral bodies.

As illustrated in FIG. 65, the lateral surface of implant 1500 'facing implant 1500 has a C-shaped contour to allow the central longitudinal axes of implants 1500, 1500' to remain close. Michelson illustrates some examples of these implants in US-5,593,409 entitled "Interbody Spinal Fusion Implants" and in pending patent US-09 / 566,272, entitled "Inserted Interbody Spinal Fusion Implants."

As illustrated in Figure 66, the end ends 1504, 1504 'of the implants 1500, 1500', respectively, are designed to generally conform to the anatomical configuration of the anterior aspect of the vertebral body and prevent the anterior lateral aspect from of the implant protrudes from the spine.

As shown in Figures 62-64, a preferred method for installing and expanding an implant with multiple expansion devices is similar to that described for an implant with an expansion device such as the one shown in Figures 49-54. except that a 1600 expansion unit is used. Expansion unit 1600 is similar to expansion unit 1000, except that expansion unit 1600 features an elongated tip 1606 suitable for extending through the holes of various expansion devices along implant 1500, as illustrated in Figure 63. Tip 1606 allows multiple expansion devices 1520 to be simultaneously displaced to expand implant 1500. After placement of implants 1500, bone screws 1550 can be inserted through bone tapped holes 1548 using known methods.

Figure 67 shows a diagram that represents another embodiment of an arcuate interbody spinal fusion implant generally referenced with the number 1700 and provided with a final end suitable for use with another embodiment of the instruments and methods. of the present invention. The implant 1700 is similar to the implant 1100 described above, except that in addition to the holes 1726 for receiving the pins, the end 1704 also preferably includes opposing grooves 1752 along the inside surface of the end end 1704. The grooves 1752 are suitable for receive and lock the tabs 1820 of the implant holder 1800.

The implant holder 1800 includes a shaft 1802 having a distal end 1804. The distal end 1804 includes an implant engagement area 1808 provided with pins 1810 and an 1812 gauge. Preferably around the perimeter of the 1812 gauge are upper and lower extensions. 1814, 1816, respectively, and a pair of lateral extensions 1818. The lateral extensions 1818 each have a flange 1820, capable of engaging in combination with the grooves 1752 of the implant 1700 when in the locked configuration.

In use, the lateral extensions 1818 are pushed to advance together and displace the flanges 1820 in the slots 1752 of the implant 1700, before releasing from them subsequently locking in support of the implant 1800 attached to the implant 1700. Subsequently, an expansion unit as described in relation to Figure 55 may be inserted through the 1812 gauge and into the implant 1700 to displace an expansion device (not illustrated) and expand the implant 1700.

When implant 1700 is expanded, the height of endpoint 1702 decreases, as upper and lower members 1706, 1708, respectively, articulate around pivot point 1716. The upper and lower projections, 1814, 1816, respectively, are capable of moving inward and in the direction of the longitudinal axis of the implant holder 1800, so that the implant holder 1800 can remain attached to the implant 1700 while the implant is expanding implant. It will be appreciated that other configurations of the implant holder are possible to allow the implant holder to remain attached to the implant during any change in implant dimensions; All of these configurations are covered by the broad scope of the present invention.

Shown in Figure 68 is another preferred embodiment of an expandable arcuate interbody spinal fusion implant for use from an anterior approach to the spine with the instrumentation and methods of the present invention, generally referenced at 1900. The 1900 implant is similar to the 800 implant except that the bone-engaging extensions 1914 are ratchet-like facing frontally, which facilitates linear insertion and prevents expulsion of the implantation space. Implant 1900 can be inserted using methods such as those described in connection with implant 100 and instrumentation described in connection with implant 800.

Although the instruments of the present invention have been described in relation to spinal fusion implants, it will be appreciated that said instruments can also be used with other implants, for example inert spacers, artificial discs, bone grafts and any other inserted element suitable for the purpose of significantly reduce, or eliminate, movement between two adjacent bone volumes.

Various implants and the instrumentation that can be used with them have been disclosed in the foregoing description and in the drawings, fully and effectively meeting the objectives of the present invention. However, it will be appreciated that it is possible to introduce variations and modifications to the disclosed embodiments without thereby departing from the scope of the invention, defined by the claims.