Cage and positioning instrument for a cage positioning system
11471304 · 2022-10-18
Assignee
Inventors
- Farzam Vazifehdan (Stuttgart, DE)
- C. Michael Nilsson (Moreland Hills, OH, US)
- Helmut Schoenhoeffer (Erbach, DE)
Cpc classification
A61F2/4455
HUMAN NECESSITIES
A61F2002/4627
HUMAN NECESSITIES
A61F2/4465
HUMAN NECESSITIES
International classification
Abstract
A surgical cage positioning system for the implantological replacement of an intervertebral disk, in the region of the lumbar spine of humans, has a positioning instrument with a first coupling prong and with a first manipulator prong, each provided with a coupling element. The manipulator prong can be displaced in the axial direction relative to the coupling prong by means of a handle. The cage positioning system has a cage with an insertion opening for the instrumentation segment and with coupling means, via which the coupling elements of the instrumentation segment, each pivotally connected to the cage, can be coupled so that the cage can be pivoted by means of the manipulator prong about an axis of rotation defined by the coupling element of the coupling prong and the coupling means of the cage relative to the longitudinal axis of the positioning instrument.
Claims
1. A surgical cage positioning system for an implantological replacement of an intervertebral disk, in an area of the lumbar spine of humans, comprising: a positioning instrument having an actuating segment and having an instrumentation segment which extends away from the actuating segment in a direction of a longitudinal axis of the positioning instrument; wherein the instrumentation segment has a first coupling prong and a first manipulator prong, each of which is provided with a coupling element, wherein the manipulator prong is displaceable in an axial direction relative to the coupling prong by means of a handle; and a cage to be implanted, having an insertion opening for the instrumentation segment and having a coupling means via which the coupling elements of the instrumentation segment can each be pivotally coupled to the cage; wherein the coupling means and the coupling elements of the positioning instrument coupled to the cage interact in such a way that the cage is pivotable relative to the longitudinal axis of the positioning instrument by means of the manipulator prong about a first axis of rotation D defined by the coupling element of the coupling prong and the coupling means of the cage; wherein the actuating segment and the instrumentation segment can be plugged into each other and locked against each other by means of a rocker-like locking means.
2. The cage positioning system according to claim 1, wherein the coupling means of the cage assigned to the coupling element of the manipulator prong produces a translational movement of the coupling element of the manipulator prong along a non-linear movement path B relative to the cage when the cage is pivoted, wherein the coupling means of the cage assigned to the coupling element of the manipulator prong is designed as a non-linear groove or a non-linear elongated hole.
3. The cage positioning system according to claim 1, wherein the cage can be pivoted relative to the longitudinal axis of the positioning instrument by actuation of the manipulation prong over a pivot angle β, where 0°≤β≤80°.
4. The cage positioning system according to claim 1, wherein the positioning instrument has a first locking slide which is mounted in a longitudinally displaceable manner in or on a base body of the instrumentation segment and which can be slid relative to the coupling prong in the axial direction between a releasing position in which the coupling prong coupled to the cage can be disconnected from the cage and a locking position in which the coupling prong coupled to the cage is locked on the cage, wherein the first locking slide can be actuated by means of the handle arranged on the instrumentation segment or on the actuating segment.
5. The cage positioning system according to claim 1, wherein the instrumentation segment has a second coupling prong which is arranged running parallel to the first coupling prong, wherein a first locking slide, when in a locking position, is arranged at least in sections between the two coupling prongs and blocks the two coupling prongs from nearing each other.
6. The cage positioning system according to claim 1, wherein the positioning instrument has a second locking slide which is mounted in a longitudinally displaceable manner in or on a base body of the instrumentation segment and which can be slid relative to the manipulator prong in the axial direction between a releasing position in which the manipulator prong coupled to the cage can be disconnected from the cage and a locking position in which the manipulator prong coupled to the cage is locked on the cage.
7. The cage positioning system according to claim 1, wherein the instrumentation segment has a second manipulator prong, wherein the second manipulator prong and the first manipulator prong are synchronously displaceable in the axial direction, and wherein a second locking slide, when in a locking position, is arranged at least in sections between the two manipulator prongs and blocks the same from nearing each other.
8. The cage positioning system according to claim 1, wherein the instrumentation segment and the actuating segment are each designed as separate structural units which are detachably coupled to each other.
9. The cage positioning system according to claim 1, wherein the instrumentation segment is designed for single use and the actuating segment is designed for multiple use, wherein the actuating segment can be reversibly disassembled into its individual parts and can be autoclaved multiple times.
10. The cage positioning system according to claim 1, wherein the cage has a foot segment and a head segment which are arranged so as to be pivotable relative to each other.
11. The cage positioning system according to claim 10, wherein the foot segment and the head segment are guided on each other and connected to each other via at least one tongue and groove connection.
12. The cage positioning system according to claim 10, wherein the cage has a fixing element by which the foot segment and the head segment can be fixed in position relative to each other in their respective set angle α, wherein the fixing element is designed as a fixing screw which can be screwed into a screw-in area of the cage, which is corrugated at least in sections.
13. The cage positioning system according to claim 12, wherein the fixing element can be actuated by means of a locking slide and is releasably connected to the same, via a predetermined breaking point or a tool profile engaging in the fixing element of the locking slide, being an Allen key, wherein the locking slide is coupled or can be coupled in a torque-proof manner to the handle of the actuating section.
14. The cage positioning system according to claim 1, wherein the actuating segment of the positioning instrument has the handle for actuating the manipulator prong, wherein the actuating segment has a display by means of which a respective pivot angle β of the cage can be read relative to the longitudinal axis of the positioning tool.
15. The cage positioning system according to claim 1, wherein each coupling prong is integrally formed on a base body of the instrumentation segment.
16. The cage positioning system according to claim 1, wherein the cage has a head segment and a foot segment which can be pivoted relative to each other about a pivot axis.
17. The cage positioning system according to claim 1, having the actuating segment and having the instrumentation segment which extends from the actuating segment in the direction of the longitudinal axis of the positioning instrument, wherein the instrumentation segment has the first coupling prong and the first manipulator prong, each of which is provided with the coupling element, wherein the manipulator prong is displaceable in the axial direction relative to the coupling prong by means of the handle, and wherein its instrumentation segment is designed for single use and its actuating segment is designed for multiple use.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Further advantages of the invention result from the description and the drawings. The embodiments shown and described are not to be understood as an exhaustive enumeration but rather have exemplary character for the description of the invention.
(2) In the drawings:
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
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(30) The actuating segment 16 comprises a plurality of handles 26, 28, 30, 32, the individual functions of which are explained below.
(31)
(32) The instrumentation segment 18 and the actuating segment 16 are each formed in this case as separately manipulable and preassembled units or instrument modules which can be detachably coupled to each other for the operational use of the positioning instrument 14.
(33) The instrumentation section 18 is preferably designed for single use. In contrast, the actuating segment 16 is preferably designed for multiple use. The actuating segment 16 consists at least partially, preferably entirely, of metal, in particular stainless steel. Alternatively, the actuating segment can consist of a particularly high-quality plastic that is suitable for repeated sterilization measures.
(34) In
(35) The first handle 26 is arranged on the actuating segment 16 at a distal position in the axial direction. This first handle 26 serves as a locking knob for the instrumentation segment 18 to be inserted into the second handle 28. For this purpose, the first handle 26 has an insertion opening 42 on its end face for the instrumentation segment 18. The insertion opening 42 has a cross-sectional shape corresponding to the proximal end section 44 of the instrumentation segment 18. As a result, the instrumentation section can be enclosed in a rotationally fixed manner by the first handle. Locking means 46 are arranged on the first handle 26 and, as shown in
(36) According to
(37) A third handle 30 adjoins the second handle 28 in the axial direction. The third handle 30 can be rotated about the longitudinal axis 20 relative to the second handle 28 in the assembled state of the actuating segment 16. A bearing sleeve 56 with a bearing pin 58 is arranged within the second and third handles 28, 30 and extends here proximally away from the bearing sleeve 56 in the axial direction. The bearing sleeve 56 is pinned to the second handle 28. The bearing pin 58 has a flattened peripheral region 60. Reference number 62 indicates a movement sleeve which, in the assembled state of the actuating segment 16, has a threaded connection via its external thread 64 to the third handle 30. The movement sleeve 62 has a partially circumferentially flattened plunger 66 which, in the assembled state of the positioning instrument, abuts in sections the bearing pin 58 of the bearing sleeve 56 and is guided in a longitudinally displaceable manner.
(38) A driver which projects inwards away from the movement sleeve 62 in the radial direction is arranged on the inside of the plunger 66 of the movement sleeve 62. When the instrumentation segment 18 is coupled to the actuating segment 16, the driver engages in a holding groove 68 of the manipulator 36 in order to couple its movement in the axial direction with the movement sleeve 62. The movement sleeve 62 is held within the third handle 30 by means of a cover ring 70. The cover ring 70 can be pinned to the third handle 30. The cover ring 70 has an axial passage 72 through which a fourth handle 32 designed as a rotary knob can be inserted into the second handle 28 of the actuating segment 16, by a driver pin 74. The driver pin 74 has at its distal end a driver profile 76—in this case, an inner polygonal profile. The inner polygonal profile serves to accommodate the first locking slide, designated as 34 in
(39) In
(40) The second handle 28 has first markings 80 via which the locked state of the first handle 26, along with the instrumentation segment 18, can be read relative to the second handle 28—in this case, the locking means 46 thereof. The third handle 30 has second markings 82 with angle information that can be read relative to a reference mark 84 of the second handle.
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(42) An enlarged detail of the distal end of the instrumentation segment 18 is shown in
(43) A coupling element 92 is arranged on the free end section of the coupling prong 88. The coupling element 92 extends laterally away from the coupling prong 88 in the radial direction. In the present case, the coupling element 92 is designed in the shape of a circular cylinder. The first locking slide 34 (upper side) explained in connection with
(44) A fixing element 94, here in the form of a grub screw, for example, can be arranged at the free end of the first locking slide 34. The fixing element 94 can have a driving profile (not shown in more detail), for example in the form of a hexagon socket, in which the locking slide 34 engages in a rotationally fixed manner (with an external hexagon or so-called Allen key). Alternatively, the fixing element 94 can also be integrally connected to the locking slide 34. In this case, the locking slide 34 and the fixing element 94 are advantageously connected to each other via a predetermined breaking point 96 in order to be able to separate the locking slide 34 from the fixing element 94 after the fixing element 94 has been placed. It is also conceivable that the fixing element 94 is glued to the first locking slide 34 or arranged on the locking slide 34 in a press fit. The locking slide 34 can alternatively have a tool profile, for example an Allen key, which detachably engages in a corresponding driving profile (=drive profile) of the fixing element 94. The fixing element 94 is preferably designed as a screw.
(45) The manipulator 36 has a manipulator prong at one end, designated by 98. The manipulator prong 98 has, in a manner corresponding to the coupling prong 88, a coupling element 92 which extends from the manipulator prong 98 in the radial direction—i.e. extends away from the same. The coupling elements 92 of the two prongs can extend in the same direction from the given prong as shown in
(46) A second locking slide 38 is assigned to the manipulator 36. The second locking slide 38 can lie directly against the manipulator prong 98 and can be supported thereon in a radial direction. The free end of the locking slide 38 can have an insertion chamfer 100. The cumulative height h of the coupling prong 88 and the first locking slide 34 assigned to the coupling prong 88, as well as the cumulative height h of the manipulator prong 98 and the assigned second locking slide 38, can be clearly seen in
(47) The positioning instrument 14 can have a second coupling prong 88 and/or a second manipulator prong 98 according to the embodiment shown in detail in
(48) The second manipulator prong 98 is arranged parallel or substantially parallel to the first manipulator prong 98. As a result, an intermediate space Z is formed between the two manipulator prongs 98, into which the second locking slide 38 can be advanced. The coupling elements 92 of the two manipulator prongs 98 point away in opposite directions from the respective manipulator prongs 98. If the locking slide 38 is pushed forward between the two manipulator prongs 98 in the axial direction, this blocks the two manipulator prongs 98 (coupled to the cage) from nearing each other. The second locking slide 38 can, if necessary, spread the manipulator prongs 98 apart (slightly), so that they diverge towards the free end.
(49) In
(50) The cage 12 has an insertion opening, designated by 114, for the instrumentation segment 18 of the positioning instrument 14. The insertion opening 114 extends in the circumferential direction from one of its lateral surfaces 108 to the rear lateral surface 110. A clear height of the insertion opening 114 is denoted by H. The insertion opening 114 is delimited in the direction of the vertical axis 116 of the cage on the upper side by a top wall 118 and on the underside by a bottom wall 120.
(51) The bottom wall 120 is provided with a first coupling means 122. The coupling means 122 in this case is in the form of a recess for the engagement of the coupling element 92 of the coupling prong 88 of the positioning instrument 14. The top wall 118 of the insertion opening 114 is provided with a second coupling means 124 in the form of a non-linear recess, which serves for the engagement of the coupling element 92 of the manipulator prong 98.
(52) According to
(53) It is understood that the orientation of the coupling elements 92 of the coupling prong 88 and the manipulator prong 98 and the arrangement of the corresponding coupling means 122, 124 of the cage 12 are adapted to each other.
(54) Thus, the coupling means 122 for the one coupling element 92 of the manipulator prong 88 can also be arranged or formed on the bottom wall 120 of the insertion opening 114. In a corresponding manner, the coupling means 124 for the one coupling element 92 of the coupling prong 88 can be formed on the top wall 118 of the insertion opening. The second coupling means 124 forms a non-linear movement path B (
(55) If the positioning instrument 14 (
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(57) The foot segment 126 and the head segment 128 have mutually facing joint surfaces 130, by means of which the foot segment 126 and the head segment 128 abut each other. The joint surfaces 130 are each arched in the sagittal direction of the cage 12. The two segments 126, 128 can be pivoted relative to each other about a pivot axis designated by 132. The curvature of the two joint surfaces 130 is such that the pivot axis 132 is arranged far outside of the cage. With an increasing set angle α between the head segment 128 and the foot segment 126, the anterior edge 134 of the head segment is moved in the direction of the sagittal axis S of the cage 12 beyond the front lateral surface 106 of the cage 12, as is illustrated by the arrow P in
(58) The head segment 126 and the foot segment 124 of the cage 12 are preferably guided on each other via at least one tongue and groove connection 136, here purely by way of example via two tongue and groove connections 136, and held captively against each other. This eliminates the need for separate joint components.
(59) In
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(61) The fixing element 94 is still fixed on the first locking slide and can be screwed into the screw-in area 138 of the foot segment 126 and the head segment 128 in order to fix them relative to each other after setting a desired set angle α (
(62) Functional Description:
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(64) In
(65) According to
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(70) The mode of operation of the cage positioning system 10 is explained below with additional reference to the steps of the method 200 for implanting the cage 12 shown in
(71) In order to implant the cage 12 in the intervertebral disk compartment 142 of the preferably lumbar spine, arranged between two vertebral bodies 144, 146, the positioning instrument 14 is coupled in a first step 202 to the cage 12 with its coupling prongs 88 and its manipulator prongs 98 of the instrumentation section 18.
(72) In a further step 204, the instrumentation section 18 coupled to the cage is secured by moving the first locking slide 34 into its locking position in its position coupled to the cage 12. The instrumentation segment 18 can be provided with the cage 12 pre-assembled in the form of a sterile set.
(73) In a further step 206, the actuating segment 16 is coupled to the instrumentation segment 18 by an operator. For this purpose, the instrumentation segment 18 is inserted into the insertion opening (cf. Fig.) of the actuating section 16 up to the stop in sub-step 206a. The locking means 46 (=pawls) are unlocked in sub-step 206b and the manipulator 36 of the instrumentation segment 18 is brought into engagement with the third handle 30 by its rotational movement about the longitudinal axis 22. In sub-step 206c, the locking means 46 are transferred into their locking position and the instrumentation segment 18 is thus fixed on the fastening segment 16 in a torque-proof manner and fixed in position in the axial direction.
(74) The cage positioning system 10 is thus ready for use.
(75) In a further step 208, the cage 12 can now be introduced into the surgical site in the direction of its transverse axis 140 and introduced into the intervertebral disk compartment 142 of the spine to be supplied with the cage 12.
(76) By here, for example, rotationally adjusting 210 the third handle 30, the manipulator prong 98 is adjusted in a further step relative to the coupling prong(s) 88 of the instrumentation section 18 in the axial direction translationally (toward the distal end), and thus the cage 12 is forced to pivot about the coupling element 92 of the coupling prong 88 or the coupling elements 98 of the coupling prongs 88 until the cage 12 is arranged in its prespecified position in the intervertebral disk compartment 142.
(77) If the cage 12 is designed to be articulated in itself, the set angle α of the head segment 128 relative to the foot segment 126 can be set to a corresponding value by a corresponding lordosis of the spine and a corresponding deflection of the head and foot segments relative to each other. To lock 212 the set angle α, the fixing element 94 or the fixing screw is screwed into the screw-in area 138 of the cage 12 by means of the fourth handle and the first locking slide which is coupled to the movement.
(78) In a further step, the first locking slide 34 is translationally moved back from its locking position into its releasing position in the axial direction. The second locking slide 38 is translationally moved back from its locking position into its releasing position by actuating the handle 40 arranged on the instrumentation segment 18 in the direction of the longitudinal axis 22 of the positioning instrument 14. The instrumentation section 18 is now unlocked with regard to its mechanical coupling to the cage and can be disconnected in a further step with axial pull from the cage 12 and moved out of the surgical site.
(79) In summary, the invention relates to a surgical cage positioning system (10) for the implantological replacement of an intervertebral disk, preferably in the region of the lumbar spine of humans, having a positioning instrument (14) with a first coupling prong (88) and with a first manipulator prong (98), each provided with a coupling element (92). The manipulator prong (98) can be displaced in the axial direction relative to the coupling prong (88) by means of a handle (26, 28, 30, 32, 40); The cage positioning system comprises a cage (12) with an insertion opening (114) for the instrumentation segment (18) and with coupling means (122, 124) via which the coupling elements (92) of the instrumentation segment (18), each pivotally connected to the cage (12), can be coupled so that the cage (12) is pivotable by means of the manipulator prong (98) about an axis of rotation D defined by the coupling element (92) of the coupling prong (88) and the coupling means (122, 124) of the cage (12) relative to the longitudinal axis (22) of the positioning instrument (14). The invention also relates to a cage and a positioning instrument.