WO2023021249A1 - Tool set for placing intervertebral disc implants in position - Google Patents

Abstract

Tool set for placing an intersomatic implant in position, said tool set comprising a tool (1) for placing said implant in position, said tool comprising a shaft (11) for positioning said implant, an implant holder (2) and an implant holder rod (15) for holding a cage (4) of the implant, said shaft being provided with a first end (12) forming a handle and with a second end (13) fixed to said implant holder, said implant holder rod being received movably in rotation in a tubular portion (14) of said shaft and being provided with a distal end (16) passing through said implant holder in order to engage in said cage, said implant holder being provided with a stub (22) for orientation of said cage with respect to said implant holder.

Description

TOOLS FOR PLACEMENT OF INTERVERTEBRAL DISC IMPLANTS

Technical area

This disclosure relates to the field of spine operations and in particular the placement of implants comprising an intersomatic cage intended to replace a defective intervertebral disc.

[0002] An intersomatic cage is an implantable medical device filling the intervertebral space allowing fusion between two adjacent vertebrae and supplementing the mechanical support function of a failing disc.

The present disclosure relates more particularly to a medical device allowing the establishment of an intersomatic cage during an anterior surgical intervention for a failure of an intervertebral disc. One of the goals sought is to optimize the approach, positioning and stabilization of the intersomatic cage. Indeed, especially when placing a lumbar intersomatic cage by an anterior approach, the anatomical relationships and the limited working space make the placement of this cage complex and risky. The present device will make it possible to simplify and secure the procedure by limiting the number of manipulations in a restricted space close to noble structures such as blood vessels, digestive tract, nerves.

Prior technique

[0004] There already exist devices for placing implants comprising an intersomatic cage, but these tools remain complex and occupy a voluminous space.

[0005] The document EP2 945 574 A1 describes for example a device comprising a guide for an intersomatic cage, on which can slide a fixing plate of the cage between the vertebrae, a drilling guide provided with guide tubes to successively receive a drilling tool then screws and a screwdriver. This device remains an assembly requiring a large place in the workspace and requiring successive positioning of tools.

Technical problem

[0006] Currently, the existing devices intended to place intervertebral implants do not make it possible to completely secure and simplify the gesture of setting up a cage, a plate holding the cage and screws for fixing the plate on the vertebrae, while reducing the working space needed for the operation. The present invention aims to improve this situation.

Disclosure of Invention

[0007] In view of the prior art, the present invention relates to an interbody implant and its installation tool for which the installation tool comprises a tool adapted to position together an interbody cage, a plate for holding this cage and screws for holding the plate, without having to change instruments, the tool also being adapted to ensure the stabilization of these implantable elements in the same surgical gesture.

[0008] To do this according to a first aspect, the present disclosure provides a tool for placing an interbody implant comprising a cage, screws for fixing the implant in the vertebrae, a screw holder plate provided with holes for passing said screws on either side of the cage, said tool comprising a tool for placing said implant, comprising a handle for positioning said implant, an implant holder and an implant holder rod for holding the cage of the implant, said handle being provided with a first end forming a handle and a second end fixed to said implant holder, said implant holder rod being received rotatably in a tubular portion of said handle and provided with a distal end, passing through said implant to be inserted into said cage, said implant holder being provided with an orientation pin for said cage relative to said implant holder, for which said implant holder comprises, opposite passage holes for said screws of said p lacquer, tubular housings, for receiving and temporarily retaining said screws, the axes of which form axes for inserting said screws into said vertebrae. [0009] Preferably, the distal end of the implant holder rod is threaded.

[0010] The implant-carrying rod may include a wheel for maneuvering the implant-carrying rod in rotation, accessible in a cutout made in a widened intermediate part of the handle.

[0011] The handle may comprise a first part carrying the first end forming a handle and a second tubular part receiving the implant holder rod and carrying the second end of the handle, said first part and second part being separated at the level of the cutout before insertion. of the implant holder rod in the second part of the handle then assembled to form the handle and retain the implant holder rod.

[0012] According to a particular embodiment, the tool may comprise one or more preparation tools comprising one or more punches and one or more test jigs, said test jigs each being provided with a guide provided, at a distal end, with a cage template and a plate template, said plate template being provided with cutouts for passing a said punch.

[0013] The guide rod can constitute an anti-rotation coded guide for a tool holder, adapted to slide on the guide rod, carrying at a distal end said punch, and provided with a handle at a proximal end .

[0014] The punch may comprise blades adapted to pass through said cutouts during a sliding movement of the tool holder on the guide rod, said blades being shaped to define the outline of a portion of bone to be removed and provided with a sharp free end.

[0015] The handle may comprise a free termination adapted to receive an impact from a hammer.

[0016] The present disclosure further relates to an interbody implant which can be implanted by means of a tool as described previously, comprising a cage, screws and a retaining plate for the cage, for which the cage is wedge-shaped with inclined upper and lower faces, a rear face forming a base of the wedge and a front face forming a point of the wedge, said plate positioned between the cage and a front face of the implant holder of said tool and being provided with at least one passage hole of said pin.

[0017] The screw passage holes of the plate can be inclined passages for said screws.

[0018] Said screws may have a double thread and the holes in the plate include a shoulder for supporting the screw heads and a thread for locking the screws in the plate.

[0019] The upper and lower faces of the cage may include cutouts for passing the screws.

[0020] The plate may be a plate curved along an arc, the center of which is located on a side opposite the cage.

[0021] The present disclosure further relates to an interbody implant placement tool assembly and an interbody implant as described above for which said plate is positioned between the cage and a front face of the implant holder and is provided with passage holes said pin, the distal end of the implant-holder rod and the screws, said cage itself being provided with a tapped hole for receiving said threaded distal end of said rod and with a smooth hole for receiving said pin orientation and for which the screwing of the threaded distal end of said rod in the tapped hole of the cage maintains the plate axially and angularly between the cage and the front face of the implant holder.

[0022] The screws can be received in the tubular housings, for receiving and temporarily retaining said screws before implanting the implant.

Brief description of the drawings

Other characteristics, details and advantages of the invention will appear on reading the detailed description below of non-limiting embodiments, and on analyzing the appended drawings, in which:

[0024] [Fig. 1] shows a schematic view of a placement tool and an implant according to a first aspect; [0025] [Fig. 2] shows a perspective view of an embodiment of a tool according to the block diagram of Figure 1;

[0026] [Fig. 3] shows an implant holder of a placement tool;

[0027] [Fig. 4] shows a plate of an implant;

[0028] [Fig. 5] shows a perspective view of a jig and a punch according to a second aspect;

[0029] [Fig. 6] shows a cross-sectional perspective view of the punch of Figure 5 and the jig assembled;

[0030] [Fig. 7] shows the cookie cutter of figure 6 in three-quarter face.

Description of embodiments

The drawings and the description below contain elements that can not only serve to better understand the present invention, but also contribute to its definition, where appropriate.

[0032] Figure 1 shows a block diagram summarizing the different parts of a placement tool and an implant according to the principle used in the present disclosure and its interaction with the environment and the vertebrae. According to this diagram, a tool for placing an implant comprises a handle 1 and an implant holder 2. The implant for its part comprises a cage 4 which is positioned between two vertebrae A and B, a plate holding the cage 3 and screws 5, 6 for positioning and fixing the plate which are screwed diagonally into the vertebrae A and B. The correct positioning and fixing of the implant (plate and cage) are essential for the success of the surgery .

The implant holder 2 is provided with cutouts or tubular housings 24 for guiding screws 5, 6 for fixing.

[0034] This tool will make it possible to simplify and secure the procedure by limiting the number of manipulations in a restricted space close to noble structures (vessels, digestive tract, nerves, etc.).

Figure 2 shows the tool and the implant in more detail. The handle 11 for positioning said implant comprises a tubular portion 14 to receive an implant holder rod 15 holding the cage 4 of the implant. Said handle is provided with a first end 12 forming a handle and with a second end 13 fixed to the implant holder 2. The implant holder rod 15 is rotatable in the tubular portion 14 of the said handle and provided with an end distal 16, crossing the implant holder 2 to fit into said cage 4. Thus, the handle is fixed in the implant holder and the implant holder rod is fixed in the cage, the tool making it possible to position the cage between the patient's vertebrae.

The end 16 of the implant holder rod 15 is threaded and received in a tapped hole 42 of the cage 4.

In addition, the implant holder 2 is provided with a pin 22 for orientation of said cage parallel to said distal end which comes out of a hole 21 in the front face of the implant holder as shown in Figure 3. Thus the cage is precisely positioned angularly relative to the implant holder 2.

[0038] The implant holder rod comprises a wheel 17 for maneuvering the implant holder rod in rotation accessible in a cutout 141 made in a widened intermediate part of the handle 11. This wheel will make it possible to screw the end of the holder rod -implant in the cage to position it on the implant holder then unscrew the implant holder rod when the cage is in position.

According to an important aspect, the implantable device consists of a cage 4, a plate 3, and screws 6.

[0040] The intervertebral or intersomatic cage 4 makes it possible to replace a defective disc and is inserted between two vertebrae by resting on the two adjacent plates of said vertebrae. It must adapt to the morphology of the patients. The cages can therefore be of different shapes (wedge-shaped, with parallel faces, of convex shape) and are generally made of a biocompatible material such as, for example, titanium or PEEK. Their dimensions will depend on the morphology of the patient and are between approximately 32 mm and 38 mm in width, 28 mm and 32 mm in depth and between 10 mm and 18 mm in height, the lordotic angulation marked a in figure 1 being between 8° to 18°. The plate 3, an example of which is given in FIG. 4, must make it possible to ensure very good retention of the cage 4 between the vertebrae in cooperation with screws 6 which are represented in FIG. 2. According to FIG. 4, the plate has holes 33 in order to ensure the passage and maintenance of the screws 6. The positions and orientations of these holes are very important. The holes must allow the screws to be inserted and fixed at the correct angle in the vertebrae to optimize support and mechanical strength. According to the example shown, in order to optimize both the angulation constraints imposed by the screws and the size of the system, the plate is triangular with two screw passages facing the lower vertebra and a screw passage in view of the upper vertebra. The plate can be made of a biocompatible metal or metal alloy such as titanium or chrome-cobalt with a thickness of 3 or 4 mm with a height and a width adapted to the dimensions of the cage and the position of the screws.

The plate described here is a three-screw triangular plate and the cage described is a wedge-shaped quadrilateral cage, but the concept of the present disclosure could be extended to other forms of cages and plates. Likewise, the screws could be made with different diameters and lengths depending on the dimensions of the plate and have a different thread than that described in the example.

Another aspect resides in the implant holder 2 presented in FIGS. 2 and 3. This is fixed to the handle 11 and makes it possible to maintain the plate 3 and cage 4 assembly. The implant holder also contains the screws 6 ready to be screwed into the plate. To do this, the implant holder comprises tubular housings 24 formed by bores, for receiving and temporarily retaining the screws 6 for fixing the implant in the vertebrae A, B on either side of the cage. The tubular housings are designed with specific angles allowing the screws to be screwed directly with the correct orientations in relation to the vertebrae. The axes of the tubular housings thus correspond to the axes for introducing the screws into the vertebrae. These guidelines also provide a easy access for screwing the screws with a screwdriver usually used for the placement of implants of this type.

[0044] The introduction of screws into an operating field is often tedious and can prove to be dangerous (wound of vessels responsible for haemorrhage, loss of screws in the small pelvis, etc.) and the pre-assembly of screws in the implant holder of the present disclosure avoids these complications. For this pre-assembly, the screws are received in the tubular housings 24, for receiving and temporarily retaining said screws 6 before implantation of the implant. The surgeon only has to insert and screw these screws, previously placed in the implant holder, into the vertebrae once the implant is positioned.

[0045] The cage system 4 associated with a screwed plate 3 for which the assembly is mounted on a fitting tool 1, 2 with screws 6 housed in an implant holder 2 so that they encroach on the The graft space is advantageous because it is easy to set up. In addition, because access to the operating field is very limited and it is not always easy to angle the screws with conventional tools in the operating room, the present implant holder system, designed to protect the screws and allow fixing of the screws with the correct angle of departure without however exceeding the zone of action offered to the surgeons during such an operation, is particularly advantageous.

During the positioning time of the cage-plate device and the screwing of the three screws in the vertebrae, the implant holder is linked to the plate-cage device by the threaded end 16 of the implant holder rod 15 screwed in the tapped hole 42 of the plate 4. Once the screws have been put in place, the handle and the implant holder are removed together by unscrewing the implant holder rod 15 to separate it from the cage 4. The pin 22 then comes out of its housing 41 and the hole 31 of the plate which completely releases the implant.

To ensure solid fixation of the implant, according to Figure 4, the plate 3 has tapped holes 33 331, receiving and passing the screws, to allow the locking of the screws in the plate. Shoulders 332 at the entrance to the screw passages provide support for the screw heads and prevent the latter from entering completely into the vertebrae. Not only the heads no screws protrude from the plate, the latter can be curved between its lower part which comprises two tapped holes for passing screws and its upper part comprising a tapped hole for passing screws. This keeps the plate thickness below 4 mm while maintaining correct screw orientation.

[0048] The screws must allow the plate to be fixed in the two vertebrae. Their end must be very pointed to facilitate insertion into the cortical wall of the bone. The screws will have a double thread: a main thread for insertion and maintenance of the screws in the bone tissue and a secondary thread at the level of the screw head for tightening and locking of the screws in the plate.

The lengths of the screws will be adapted to the morphology of the vertebrae, their diameters are for example 5 mm for the two lower screws and 6 mm for the upper screw. The screws can be made of a resistant and biocompatible metal such as titanium.

To increase the compactness of the implant, according to the example of Figure 2, the cage 4 has cutouts 43 allowing the passage of screws to reduce the dimensions of the implant.

[0051] The implant holder can be made of different materials such as plastics, composites or biocompatible metals. Different manufacturing processes are possible such as machining, molding or additive manufacturing.

[0052] The positioning and holding of the implant holder is carried out using a specific handle. The handle is long enough for easy access to the spine regardless of the approach.

According to Figure 2, the handle 1 comprises for example a first part comprising the first end forming a handle 12 and a second tubular part 11 to receive the implant holder rod 15 and ending with the second threaded end 13 of the handle which will be fixed on the implant holder 2. The first part and second part are assembled at the level of the cutout 141 for access to the knob 17 to allow the insertion of the implant holder rod in the second part of the handle before assembly of said first part and second part.

[0054] The positioning handle of the implant holder may be made of a metal or plastic material which is always biocompatible, it will be reusable and must therefore withstand one or more sterilizations in an oven.

The concept of the invention could also be used in other surgical indications, in particular in cervical disc replacement surgery as well as tibial varus or valgus osteotomies (knee surgery).

The present disclosure also provides for a second tool consisting of one or more preparation tools 50 making it possible to choose a suitable implant and to carry out the preparation for the placement of this implant.

[0057] The preparation tool 50 includes one or more test jigs which can be used in addition to the implant placement tool or with other types of implant placement tools. These preparation tools can be used to prepare the implantation of a cage and a plate of the present disclosure by means of the placement tool described here but also of cages and plates implanted with other types of laying tools.

The trial template as shown in Figure 5 has two functions: to choose a cage, of dimensions adapted to the intervertebral space to be equipped, and to prepare the area for the implantation of the plate and the screws.

The test jig comprises a cage jig 53 and a plate jig 52.

The preparation tool 50 further comprises a guide rod 51 comprising at a distal end a cage template 53 and a plate template 52 of given size.

The plate template has cutouts 54, 55 which define the locations of the plate on the vertebrae between which the cage template is positioned then the cage. It is planned to have several preparation tools corresponding to several sizes of cage templates and plate templates corresponding to the different sizes of cages and plates to be implanted according to the patient's morphology. These templates can be tried on the patient before placement in order to choose the implant size best suited to the patient's morphology.

[0062] Once the size of the implant has been chosen, the guide rod equipped with the cage template 53 and the plate template 52 is positioned on the vertebral site of the patient to be treated so that the cage template 53 takes the real place of the cage and that the plate template 52 comes to rest against the two vertebrae above and below the location of the cage. The guide rod 51 will then serve as a support for a tool holder 56 sliding on the guide rod. The tool holder carries at a distal end the punch 58 provided with blades 59, 60 fixed on a plate 58a of the punch. The tool holder has a handle 57 at a proximal end. The blades fit into the cutouts 54, 55 of the plate jig and define the contours of the plate at the level of the vertebrae surrounding the wedge jig.

The cutouts 54, 55 thus allow the blades 59, 60 of the punch to pass while guiding them. The guide rod 51 then constitutes an anti-rotation code guide 56a, 51a for the tool holder 56 sliding back and forth relative to the guide rod to effect the cut. This makes it possible to guide the punch 58 longitudinally in an axial direction without risking rotation or lateral movements of this tool.

[0064] Figure 6 shows in perspective section the sliding tool holder 56 installed on the guide rod 51 along which it will slide while being angularly retained by the coding device which is here a device with groove 51a and rib 56a . The punch 58 is cut at its end to the size of the cage and will make it possible to shape the surface of the bone tissue of the vertebrae so as to cut the imprint of the plate so that it takes its place perfectly in accordance with the position of the cage.

[0065] The cookie cutter is a cutting tool which, following a shock, cuts out a piece of bone and removes it. It is a stainless steel, titanium or polymer tool, possibly for single use. The punch comprises, as shown in Figure 7, blades 59, 60 fixed on a plate 58a of the tool holder and formed according to the contours of the bone parts to be removed from the vertebra above the insert and the vertebra below the insert. The blades each have a sharp termination 59a, 60a all around. The cut is made by impaction by striking the free end 57a of the handle 57 of the tool holder, possibly flattened, with a hammer when the punch is positioned and guided on the guide rod 51 and in contact with the vertebrae. The bone fragments cut by the blades 59, 60 will be retained by the contour of the blades and extracted when removing the punch.

The blades 59, 60 have a height of the order of the thickness of the plate 3 to be implanted, generally of the order of 3 mm to 5 mm.

The combination of the trial template forming the guide and the punch mounted on its handle 57 which makes it possible to maintain the assembly while the surgeon strikes on the top of the handle 57, is an important point of this test tool whose blades can be adapted to any type of retention plate of a known or unknown cage and independently of the installation tool described above.

The invention is not limited to the examples described above, only by way of example, but it encompasses all the variants that a person skilled in the art may consider in the context of the protection sought, the plate which may include three or four screw holes depending on the space available on the vertebrae.

Claims

Claims [Claim 1] Tooling for placing an intersomatic implant comprising a cage, screws for fixing the implant in the vertebrae (A, B), a screw-carrying plate provided with passage holes for said screws on either side of the cage, said tool comprising a tool (1) for placing said implant, comprising a handle (11) for positioning said implant, an implant holder (2) and an implant holder rod (15) for holding the cage ( 4) of the implant, said handle being provided with a first end (12) forming a handle and with a second end (13) fixed to said implant holder, said implant holder rod being received rotatably in a portion tubular (14) of said handle and provided with a distal end (16), passing through said implant holder to be inserted into said cage, said implant holder being provided with a pin (22) for orienting said cage by relation to said implant holder, characterized in that said implant holder comprises, opposite passage holes for said screws of the plate, tubular housings (24), for receiving and temporarily retaining said screws (6), the axes of which form axes for inserting said screws into said vertebrae. [Claim 2] Interbody implant placement tool according to claim 1, wherein the distal end (16) of the implant holder rod is threaded. [Claim 3] Interbody implant placement tool according to claim 1, or 2, for which the implant holder rod comprises a knob (17) for maneuvering the implant holder rod in rotation accessible in a cutout (141) made in an enlarged intermediate part of the handle (11). [Claim 4] Interbody implant placement tool according to claim 3, for which the handle comprises a first part carrying the first end forming a handle (12) and a second tubular part receiving the implant holder rod and carrying the second end ( 13) of the handle, said first part and second part being separated at the level of the cutout (141) before insertion of the implant holder rod in the second part of the handle and then assembled to form the handle and retain the implant holder rod. [Claim 5] Interbody implant placement tool according to any one of claims 1 to 4, characterized in that it comprises one or more preparation tools comprising one or more punches (58) and one or more test (50), said test jigs each being provided with a guide rod (51) provided, at a distal end, with a cage jig (53) and a plate jig (52), said plate template being provided with cutouts (54, 55) for the passage of a said punch (58). [Claim 6] Interbody implant placement tool according to claim 5, for which the guide rod (51) constitutes an anti-rotation code guide for a tool holder (56), adapted to slide on the guide rod, carrying at a distal end said punch (58), and provided with a handle (57) at a proximal end. [Claim 7] Interbody implant placement tool according to claim 5 or 6, wherein the punch (58) comprises blades (59, 60) adapted to pass through said cutouts (54, 55) during a sliding movement of the tool holder on the guide rod, said blades being shaped to define the outline of a portion of bone to be removed and provided with a free sharp end (59a, 60a). [Claim 8] Interbody implant placement tool according to claim 6, wherein the handle (57) has a free termination adapted to receive an impact from a hammer. [Claim 9] Interbody implant implantable by means of a tool according to any one of claims 1 to 4, comprising a cage (4), screws (6) and a plate (3) for retaining the cage, for which the cage is wedge-shaped with sloping top and bottom faces, a rear face forming a base of the wedge and a front face forming a tip of the wedge, said plate being positioned between the cage and a front face (25) of the carrier implant of said tool and being provided with at least one hole (31) for passage of said pin (22). [Claim 10] Interbody implant according to claim 9 wherein the plate screw holes (33) are inclined passages for said screws. 15 [Claim 11] Interbody implant according to claim 9 or 10, for which said screws have a double thread and for which the holes (33) of the plate comprise a shoulder (332) for supporting screw heads and a thread (331 ) locking the screws in the plate. [Claim 12] Interbody implant according to claim 9, 10 or 11 for which the upper and lower faces of the cage have cutouts (43) for passing the screws. [Claim 13] Interbody implant according to any one of Claims 9 to 12, for which the plate (3) is curved in an arc whose center is located on a side opposite the cage. [Claim 14] Interbody implant placement tool assembly according to any one of claims 1 to 4 and interbody implant according to any one of claims 9 to 13 for which said plate (3) is positioned between the cage and a face front (25) of the implant holder and is provided with holes (31, 32, 33) for passing said pin (22), the distal end (16) of the implant holder rod and screws (6), said cage being itself provided with a threaded hole (42) for receiving said threaded distal end (16) of said rod and with a smooth hole (41) for receiving said orientation pin and for which the screwing of the The threaded distal end (16) of said rod in the tapped hole (42) of the cage holds the plate (3) axially and angularly between the cage and the front face (25) of the implant holder. [Claim 15] Interbody implant placement tool assembly according to claim 14 for which the screws are received in the tubular housings (24), for receiving and temporarily retaining said screws (6) before implantation of the implant.