Instruments for use with bone fixation devices

Abstract

This invention provides an instrument for use in conjunction with a bone fixation device. [Solution] An instrument is provided for use with a bone fixation device (2), the bone fixation device (2) comprising a bone fixation element (4) and a receiving portion for connecting a rod (3) to the bone fixation element (4). The instrument (1) comprises at least one tube (30) that is attachable to the bone fixation device and defines a longitudinal axis, and at least one alignment member (20) configured to assist in attaching the tube to the bone fixation device.

Description

Technical Field

[0001] The present invention relates to an instrument for use with a bone fixation device, as well as a system of such an instrument and a bone fixation device. In particular, the instrument may be an instrument for locking and unlocking the head of a bone fixture at a receiving portion of the bone fixation device, and / or the instrument may be an instrument for positioning and repositioning the receiving portion of the bone fixation device relative to a bone fixation element.

Background Art

[0002] In spinal surgery, it is often necessary to correct and / or stabilize multiple segments of the spine using spinal rods and multi-axis bone fixtures. During such procedures, it may be necessary to repeatedly adjust the bone fixation elements and rods relative to the receiving portions of each multi-axis bone fixation device.

[0003] Typically, a multi-axis bone fixation device includes a coupling device and a bone fixation element having a head, the head being rotatably received within the coupling device and capable of locking the head to set the angle of the bone fixation element relative to the coupling device at a desired angle. The coupling device also houses a rod configured to connect the multi-axis bone fixation device to further bone fixtures.

[0004] US10,470,805B2 describes an instrument suitable for repeatedly adjusting a bone fixation element to a rod in this manner. The instrument includes a tube assembly comprising an inner tube and an outer tube, the tube assembly having a longitudinal axis, the outer tube being displaceable relative to the inner tube from a first axial position to a second axial position and vice versa, the first axial position being associated with an unlock configuration of the multiaxial bone fixation device in which the head of the bone fixation device is rotatable, and the second axial position being associated with a lock configuration of the multiaxial bone fixation device in which the head is locked. The apparatus further comprises an actuator assembly having an operating mechanism for displacing an inner tube relative to an outer tube, the actuator assembly being rotatable about a longitudinal axis to a first rotational position, in which case the actuator assembly acts to move the tube assembly to a first axial position, the actuator assembly being rotatable about a longitudinal axis to a second rotational position, in which case the actuator assembly acts to move the tube assembly to a second axial position.

[0005] There may be a need to further simplify the handling of such equipment and / or accommodate a wider range of applications. [Overview of the project] [Problems that the invention aims to solve]

[0006] An object of the present invention is to provide an improved instrument for modifying, further positioning, or repositioning a multiaxial bone fixation device relative to a rod during surgery, the instrument being easy for the user to handle and enabling a wider range of corrective procedures during surgery. Another object is to provide a system of such instruments, as well as a multiaxial bone fixation device adapted for use with such instruments. [Means for solving the problem]

[0007] The above objectives are achieved by the apparatus described in claim 1, the apparatus described in claim 14, and the system described in claim 15. Further developments are provided in the dependent claims.

[0008] According to one embodiment, the device is adapted for use with a bone fixation device comprising a bone fixation element and a receiving portion for connecting a rod to the bone fixation element, the device comprising at least one tube that can be attached to the receiving portion of the bone fixation device, the tube having a longitudinal axis, and the device further comprising at least one alignment member configured to assist in attaching the tube to the receiving portion.

[0009] According to another embodiment, a device for locking and unlocking the head of a bone fixator in a receiving portion of a bone fixator comprises a tube assembly that can be attached to the bone fixator, the tube assembly comprising at least a first tube and a second tube defining a longitudinal axis, the first tube and the second tube configured to engage with the bone fixator and movable relative to each other between a first axial position associated with a unlocking configuration in which the head is unlocked in the receiving portion and a second axial position associated with a locking configuration in which the head is locked in the receiving portion, the device further comprises at least one alignment member configured to assist in attaching the tube assembly to the bone fixator, and the device further comprises an actuator assembly including an actuation mechanism configured to move the first tube and the second tube of the tube assembly from the first axial position to the second axial position and vice versa.

[0010] The alignment member may assist in attaching and / or removing the tube or tube assembly from the bone fixation device by guiding the tube or tube assembly to the receiving portion of the bone fixation device.

[0011] In one embodiment, the alignment member may be an outer alignment member, such as an outer sleeve, that surrounds the tube or the first and second tubes at least partially in their circumferential direction. The outer alignment member may indicate a rotational position of the tube or tube assembly, which is a rotational position in which the tube or tube assembly engages with the receiver so as to be coupled to the receiver, or a rotational position in which the engagement with the receiver is released so as to be detachable from the receiver. In this way, it is possible to facilitate the attachment of the tube or tube assembly to the receiver of the bone fixation device. Alternatively or in addition thereto, the alignment member may be an inner alignment member, such as a plunger, which is at least partially positioned within the tube of the tube assembly or within the first and second tubes. Preferably, the inner alignment member is configured to press against a rod inserted into the receiver. This facilitates the attachment of the tube or tube assembly onto the receiver, in particular by bringing the rod to or holding it in its lowest position within the receiver, and / or by providing further guidance when positioning the tube assembly on the receiver.

[0012] According to another embodiment, a device for locking and unlocking the head of a bone fixator in a receiving portion of a bone fixator includes a tube assembly that can be attached to the bone fixator, the tube assembly comprising at least a first tube and a second tube defining a longitudinal axis, the first and second tubes being configured to engage with the bone fixator and being movable relative to each other between a first axial position associated with a unlocking configuration in which the head is unlocked in the receiving portion and a second axial position associated with a locking configuration in which the head is locked in the receiving portion, the device further comprising an actuator assembly including an actuation mechanism configured to move the first and second tubes of the tube assembly from the first axial position to the second axial position and vice versa, the actuator assembly being configured to be at least a third configuration in which the actuator assembly is connectable to and / or detachable from the tube assembly, and a locking mechanism preventing the actuator assembly from becoming the third configuration. Preferably, the locking mechanism is configured to be released by loosening a handle portion of the actuator assembly.

[0013] The fixation mechanism can improve the handling and safety of surgical instruments, particularly by preventing the actuator assembly from unintentionally releasing from the tube assembly.

[0014] In yet another embodiment, the actuator assembly may be detachably connected to the tube assembly, thereby enabling the adjustment of multiple bone fixation devices, particularly multiaxial bone fixation devices, each connected successively to a tube assembly with a single actuator assembly. Since the tube assemblies may be positioned close to one another, operating with a single actuator assembly is advantageous in that it reduces the available space. All tube assemblies may be identical or different in terms of their length or other features such as engagement functions for engaging with (multiaxial) bone fixation devices. Thus, the device can also provide a modular system including an actuator assembly and various tube assemblies adapted for use with this actuator assembly.

[0015] Furthermore, along with the apparatus according to the embodiment, a sensor member and / or navigation member is provided, which is configured to detect at least one of the unlocking and locking configurations of the head in the receiving portion, or the first and second axial positions of the first and second tubes. The apparatus or sensor member may further generate a signal, in particular an optical and / or audible signal, when one of the different configurations of locking, unlocking, or removing is performed. This further enhances safety and user convenience.

[0016] The sensor member and / or navigation member may include a base member connectable to an instrument and a movable element such as a sensor element or pin that is movable relative to the base member. The sensor member and / or navigation member may be configured to move the movable element relative to the base member by the relative movement of the first and second tubes of the tube assembly between a first axial position and a second axial position, or vice versa. The movement of the movable element may be detected by a sensor device, which may be a position sensor configured to measure the distance of the sensor element to a reference position, and / or the displacement of the sensor element, and / or the pressure acting on the sensor element, and / or to detect the position of the sensor element. Alternatively or in addition, the movable element may be provided with a navigation sphere, and the navigation member may be configured to detect the relative or absolute displacement of the navigation sphere.

[0017] In addition, this device simplifies the adjustment of the bone fixation elements and rods, as well as the corrective steps required to adjust the position of one or more vertebrae. Temporary locking of the bone fixation elements in the receiving portion can be achieved simply by using the device with the rods already inserted into the receiving portion, without the need for locking elements such as set screws. As a result, the multi-axis bone fixation device allows for several adjustments or readjustments of the angular position of the receiving portion relative to the bone fixation device with the rods already inserted. Temporary locking of the head using the device allows the multi-axis bone fixation device to be used in the same way as a single-axis bone fixation device.

[0018] Further features and advantages of the present invention will become apparent from the description of embodiments based on the accompanying drawings. [Brief explanation of the drawing]

[0019] [Figure 1] A perspective view of the apparatus and bone fixation device according to the embodiment is shown. [Figure 2] Figure 1 shows an exploded perspective view of the tube assembly of the device. [Figure 3] Shows a perspective view of the tube assembly of FIG. 2 in an assembled state. [Figure 4] Shows a perspective view of the outer tube of the tube assemblies of FIGS. 2 and 3. [Figure 5] Shows a perspective view of the inner tube of the tube assemblies of FIGS. 2 and 3. [Figure 6a] Shows an enlarged perspective view of the upper part of the tube assembly of FIG. 3 in the first configuration. [Figure 6b] Shows an enlarged perspective view of the upper part of the tube assembly of FIG. 3 in the second configuration. [Figure 7] Shows an exploded perspective view of the plunger of the tube assemblies of FIGS. 2 and 3. [Figure 8] Shows a perspective view of the plunger of FIG. 7 in an assembled state. [Figure 9] Shows a first perspective view of the outer sleeve of the tube assemblies of FIGS. 2 and 3. [Figure 10] Shows a second perspective view of the outer sleeve of the tube assemblies of FIGS. 2, 3 and 9. [Figure 11] Shows a cross-sectional view of a part of the tube assembly of FIG. 3, and this cross-section is a plane including the longitudinal axis of the tube assembly. [Figure 12] Shows enlarged cross-sectional views of the upper and lower parts of the tube assembly of FIG. 11. [Figure 13] Shows an exploded perspective view of the actuator assembly of the instrument of FIG. 1. [Figure 14] Shows a perspective view of the actuator assembly of FIG. 13 in an assembled state. [Figure 15] Shows an enlarged view of a part of the actuator assembly of FIG. 14. [Figure 16] Shows a perspective view of the second inner tube of the actuator assemblies of FIGS. 13 and 14. [Figure 17] Shows a perspective view of the first inner tube of the actuator assemblies of FIGS. 13 and 14. [Figure 18a]Figures 13 and 14 show a perspective view of the adjustment member of the actuator assembly, viewed from slightly above at a certain angle. [Figure 18b] Figure 18a shows a perspective view of the adjustment member from a slightly downward angle. [Figure 19] Figures 18a and 18b show top views of the adjustment members. [Figure 20] Figure 1 shows an exploded perspective view of the bone fixation device. [Figure 21] Figure 20 shows a perspective view of the bone fixation device in its assembled state. [Figure 22] Figure 21 shows a magnified perspective view of a portion of the bone fixation device. [Figure 23] Figures 23a to 23c show perspective views of the steps involved in connecting the device in Figure 1 to the bone fixation device in Figure 21. [Figure 24] Figures 24a to 24c show enlarged views of the lower part of the device in Figure 1 and the upper part of the bone fixation device in Figure 21 during the steps in Figures 23a to 23c. [Figure 25] Figures 25a and 25b show cross-sectional views of the lower part of the device in Figure 1 and the upper part of the bone fixation device in Figure 21, with the inserted head locked and unlocked. This cross-section is a plane that passes through the central axis of the receiving portion and is perpendicular to the axis of the inserted rod. [Figure 26] A perspective view of the device according to a further embodiment is shown. [Figure 27] Figure 26 shows a perspective view of the device with the sensor component assembled. [Figure 28] Figure 26 shows an enlarged perspective view of a part of the device. [Figure 29] Figures 26-28 show enlarged perspective views of parts of the device with the sensor components assembled. [Figure 30] Figures 26 to 29 show perspective views of the outer surface of the sensor component of the device, and the sensor component is viewed from slightly above. [Figure 31] Figure 30 shows a perspective view of the inner surface of the sensor component, and is a view of the sensor component from slightly above. [Figure 32] Figure 30 shows a top view of the sensor component. [Figure 33] Figure 30 shows a side view of the outer surface of the sensor component. [Figure 34] Figure 30 shows a side view of the inner surface of the sensor component. [Figure 35] Figures 35a and 35b show cross-sectional views of a portion of the device from Figure 26 with the sensor member assembled, during locking and unlocking of the inserted head in the bone fixation device. This cross-section is a plane passing through the longitudinal axis of the tube assembly. [Figure 36] Figures 36a and 36b show perspective views of the inner surface of the sensor member of Figure 30 while the head is locked and unlocked. [Figure 37] A perspective view of the device according to a further embodiment is shown. [Figure 38] Figure 37 shows a perspective view of the navigation component of the device, viewed from slightly below. [Figure 39] Figure 38 shows a side perspective view of the navigation component. [Figure 40] Figure 38 shows a rear perspective view of the navigation component. [Figure 41] Figure 40 shows an enlarged perspective view of a portion of the navigation component. [Figure 42] Figure 1 shows a perspective view of a spine equipped with multiple multi-axis bone fixation devices, a device connected to a first multi-axis bone fixation device among these devices, and a device according to a further embodiment connected to a second multi-axis bone fixation device among these devices. [Figure 43] Figure 42 shows a perspective view of the device in its assembled state, according to a further embodiment of the device. [Figure 44] Figure 43 shows a perspective view of the tubing of the device. [Figure 45] Figure 43 shows a perspective view of the outer sleeve of the device. [Modes for carrying out the invention]

[0020] Figure 1 shows an embodiment of the instrument 1 for use with a multi-axis bone fixation device 2, which is configured to connect a rod 3 to a bone fixation element 4. The instrument 1 comprises a tube assembly 10 and an actuator assembly 100 that is detachably connected to the tube assembly 10. As shown in Figure 1, the tube assembly 10 is mountable on the multi-axis bone fixation device 2.

[0021] The tube assembly 10 will be described with further reference to Figures 2 to 12. The tube assembly 10 comprises an outer sleeve 20, an outer tube 30, an inner tube 40, and a plunger 50. The inner tube 40 may be a first tube, and the outer tube 30 may be a second tube. The outer tube 30 and the inner tube 40 define a longitudinal axis or tube axis L. When the tube assembly 10 is assembled, the outer sleeve 20 surrounds the entire lower portion of the outer tube 30 in its circumferential direction, the inner tube 40 is positioned inside the outer tube 30, and the plunger 50 is positioned inside the inner tube 40. The outer sleeve 20 is rotatable about the longitudinal axis L relative to the outer tube 30 to a certain extent that allows the tube assembly 10 to engage with the multi-axis bone fixation device 2. In addition, when the tube assembly 10 is assembled, the plunger 50 is configured to enter at least a portion of the multi-axis bone fixation device 2 and to press down on the rod 3 from above if the rod 3 is present within the bone fixation device 2. Furthermore, when the tube assembly 10 is assembled, the outer tube 30 and the inner tube 40 are axially displaceable relative to each other along the longitudinal axis L to a certain extent that allows a portion of the multi-axis bone fixation device 2 to move from the unlocked position of the bone fixation element 4 to the locked position of the bone fixation element 4 and vice versa. The relative axial displacement of the inner tube 30 and the outer tube 40 is provided by the actuator assembly 100, as will be described in more detail below.

[0022] As shown in detail in Figures 2, 4, 11, and 12, the outer tube 30 comprises a front end 30a and a rear end 30b opposite to the front end 30a. The outer tube 30 includes an internal channel that extends between the front end 30a and the rear end 30b and is configured to receive the inner tube 40. In the front portion of the outer tube 30 adjacent to the front end 30a, in section 31, the outer surface of the outer tube may taper toward the front end 30a, thereby reducing the total space required by the device when attached to the multiaxial bone fixation device 2.

[0023] A recess 32 is formed extending from the front end 30a of the outer tube 30 to a certain distance. The circumferential width of the recess 32 is greater than the upper width of the multi-axis bone fixation device 2, and its axial height is such that the rod 3 shown in Figure 1 can pass through and move axially within the recess 32. As is best seen in Figure 12, an engagement structure 34 is provided at a certain distance from the front end 30a of the outer tube 30, adapted to engage with the corresponding engagement structure of the multi-axis bone fixation device 2. The engagement structure 34 may be in the form of a circumferentially extending rib formed on the inner surface of the outer tube, which cooperates with the corresponding groove of the multi-axis bone fixation device 2. A stepped portion or a circumferentially extending shoulder portion 35 is provided on the inner surface of the outer tube at a certain distance from the engagement structure 34 toward the rear end 30b of the outer tube, forming a contact portion with the inner tube 40.

[0024] As is best seen in Figures 4, 6a, and 6b, notches or recesses 37 are formed on both sides of the longitudinal axis L adjacent to the rear end 30b of the outer tube 30. The recesses 37 open at the rear end 30b and extend to a certain distance from the rear end 30b. Each recess 37 has a substantially stepped shape, forming a first recessed region 37a that opens at the rear end 30b in the perspective view shown in Figures 6a and 6b, and a second recessed region 37b adjacent to it in the circumferential direction, having a smaller circumferential width compared to the first recessed region 37a, and extending further downward from the rear end 30b, i.e., toward the front end 30a. The recesses 37 serve to house the drive unit of the actuator assembly and the driven unit of the inner tube 40. The orientation of the recesses 37 is such that the recesses 37 are substantially aligned in the circumferential direction with the engagement structure 34 at the front end 30a.

[0025] The corner formed between the first recessed region 37a and the second recessed region 37b may be rounded or inclined, as shown in Figures 6a and 6b.

[0026] A projection 38 is formed on the outer surface of the outer tube 30 at a distance from the rear end 30b, and this projection 38 serves to engage with the elongated slot of the actuator assembly 100. The projection 38 is positioned circumferentially, substantially aligned with the recess 37 at the rear end 30b and the engagement structure 34 at the front end 30a.

[0027] A mounting function portion in the form of a circumferentially extending groove 39 and recess 39a is provided on the outer tube 30, located at an axial distance from the protrusion 38 toward the front end 30a. The circumferentially extending groove 39 is provided on the outer surface of the outer tube 30 and serves to receive the clip portion 60 shown in Figures 2 and 3. The circumferentially extending groove 39 may extend along the entire circumference of the outer tube, or it may extend along at least the portion corresponding to the circumferentially extending portion of the clip portion 60. More specifically, the recess 39a is formed as a through hole extending through the entire wall of the outer tube 30. The recess 39a serves to receive a pin 61 provided on the inner surface of the clip portion 60, and this pin 61 has a length exceeding the thickness of the outer tube 30 and the inner tube 40 so that it can engage with the plunger 50 when the tube assembly 10 is assembled. The recess 39a is located in the circumferential direction of the groove 39 that extends in the circumferential direction, slightly offset from the center of the recess 32 at the front end 30a.

[0028] Two optional recesses 139a and 139b are provided in the wall of the outer tube 30, located axially at a distance from the groove 39 toward the front end 30a of the outer tube 30. The recesses 139a and 139b are provided on both sides of the outer tube in the circumferential direction, i.e., substantially 180° apart from each other, and each recess may be positioned circumferentially offset by about 90° from recess 39a. The recesses 139a and 139b extend throughout the entire wall of the outer tube and may serve to mount additional navigation and / or sensor elements to the tube assembly or to provide access to the inner tube 40. Each recess 139a, 139b may have a substantially elongated or elliptical contour when viewed on the outer surface of the outer tube, with the major axis of this contour extending circumferentially along the outer tube 30.

[0029] A marking 71 may be provided at an axial distance from the groove 39 and / or recesses 139a, 139b toward the front end 30a of the outer tube 30, which serves to indicate the rotational position of the outer sleeve 20 relative to the outer tube 30. The marking 71 may be an elongated stripe or straight line extending axially along the outer tube 30. The marking 71 may be positioned circumferentially, substantially aligned with the recess 39a of the mounting function portion.

[0030] Further axially from the marking 71 toward the front end 30a of the outer tube 30, two engaging functional parts in the form of recesses 36 are provided on the outer surface of the outer tube 30, although only one of the recesses 36 is visible in the drawing. These recesses 36 are spaced apart in the circumferential direction of the outer tube and, as will be described in more detail below, serve to receive corresponding engaging functional parts of the outer sleeve 20, such as engaging latches, at each rotational position of the outer sleeve 20.

[0031] Next, referring again to Figure 2, and further to Figures 5, 11 and 12, the inner tube 40 comprises a front end 40a, a rear end 40b, and an internal channel, the internal channel extending from the front end 40a along at least a portion of the inner tube toward the rear end 40b and configured to receive the plunger 50 therein. The inner diameter of the inner tube 40, i.e., the diameter of its internal channel, is such that a fixing element such as a set screw or any other device can pass through it.

[0032] A recess 42 is formed in the front portion of the inner tube 40 adjacent to the front end 40a, substantially corresponding to a recess 32 in the outer tube 30, such that the recess 32 and recess 42 are aligned when the inner tube 40 is inside the outer tube 30 (see Figure 3 for example). An engagement structure 44 is provided at a distance from the front end 40a, configured to cooperate with a corresponding engagement structure in the multi-axis bone fixation device 2. In the shown embodiment, the engagement structure 44 is a circumferentially extending groove provided on the inner surface of the inner tube 40, which can cooperate with a circumferentially extending rib in the multi-axis bone fixation device 2.

[0033] In the upper region 43a adjacent to the rear end 40b of the inner tube 40, first projections 45a and 45b are formed on its outer surface. These first projections function as driven parts, driven by the drive unit of the actuator assembly 100 to displace the inner tube 40 relative to the outer tube 30. Two sets of first projections 45a and 45b are provided on both sides of the longitudinal axis L in the circumferential direction of the inner tube 40. As shown in Figures 2, 5, 6a, and 6b, one projection 45a is positioned at a first distance from the rear end 40b, and the other projection 45b is positioned at a second distance greater than the first distance from the rear end 40b, and is circumferentially offset from and adjacent to projection 45a. The projections 45a and 45b may have a substantially square profile with optionally inclined edges and may have a radial height such that they are substantially flush with the outer cylindrical surface of the outer tube 30 when the inner tube 40 and the outer tube 30 are assembled. To achieve this, the inner tube 40 may have a reduced outer diameter in the upper region 43a, including the first projections 45a and 45b, compared to the outer diameter of the inner tube in the lower region 43b of the inner tube. As shown in detail in Figures 6a and 6b, in the assembled state, the projection 45a closer to the rear end 40a of the inner tube 40 is located in the first recess region 37a of the recess 37 of the outer tube 30, and the second projection 45b is located at the bottom of the second recess region 37b of the recess 37 of the outer tube 30. The distance between the circumferential protrusions 45a and 45b is such that, in the assembled state, there is a gap G between the first protrusion 45a and the side wall of the opposing recess 37 that helps to insert the drive unit of the actuator assembly into the recess 37. The inner tube 40 and the outer tube 30 can be assembled by first introducing the lower protrusion 45b into the recess 37, rotating the inner tube 40 relative to the outer tube 30, and then inserting the upper protrusion 45a into the recess 37.

[0034] A recess 49 is provided at an axial distance from the upper region 43a of the inner tube 40 toward the front end 40a. The recess 49 is formed as a through-hole that penetrates the entire wall of the inner tube 40 and serves to receive the pin 61 of the clip portion 60. Furthermore, when the tube assembly is assembled, the recess 49 is positioned in the axial and circumferential directions of the inner tube, corresponding to the axial and circumferential positions of the recess 39a of the outer tube 30. More specifically, the recess 49 has an elongated, for example, elliptical shape, and the major axis of this elongated shape extends axially along the inner tube 40, allowing the inner tube 40 and the outer tube 30 to be axially displaced relative to each other in the direction of the longitudinal axis L, even though the pin 61 of the clip portion 60 extends from the clip portion 60 through the recesses 39a and 49 of both the outer tube and the inner tube.

[0035] An optional recess 48 is provided at an axial distance from the recess 49 of the inner tube, extending through the entire wall of the inner tube 40. The area of ​​the inner tube wall around the recess 48 may be locally thinned so that the contour 48a of the recess 48 on the outer surface of the inner tube is larger than the contour of the recess 48 on the inner surface, and / or so that there are inclined wall portions 48b at the upper and / or lower ends of the recess 48 in the axial direction. The recess 48 may have a substantially elongated or elliptical contour, the long axis of which extends axially along the inner tube 40, i.e., along the longitudinal axis L. When the tube assembly is assembled, the recess 48 is positioned in the axial and circumferential positions of the inner tube 40 corresponding to the axial and circumferential positions of the recess 139a or 139b of the outer tube 30. The inner tube 40 may have two such recesses 48 located on either side of the inner tube in its circumferential direction.

[0036] Referring again to Figure 2, and further to Figures 7, 8, 11, and 12, the plunger 50 comprises a front end 50a and a rear end 50b. The outer diameter of the plunger 50 is such that it can be accommodated within the internal channel of the inner tube 40 of the tube assembly. The front region 51 of the plunger 50 adjacent to the front end 50a may have a reduced outer diameter such that, in the assembled state of the tube assembly as shown in Figures 11 and 12, a circumferentially extending gap is provided between the outer surface of the front region 51 of the plunger 50 and the inner surface of the inner tube 40 in at least one portion along the longitudinal axis L. This gap may be sized to accommodate a portion of the receiving part of the multiaxial bone fixation device 2, allowing the front region 51 of the plunger 50 to enter the receiving part. In the rear region of the plunger 50, the plunger 50 may have an outer cylindrical surface that contacts the inner surface of the inner tube when the inner tube and the plunger are assembled.

[0037] An elongated opening 52 is provided in the axial direction between the rear end 50b of the plunger 50 and its front region 51, and this opening penetrates the plunger 50 in a direction perpendicular to the longitudinal axis L. The opening 52 extends between a first end 52a closer to the front end 50a of the plunger and a second end 52b closer to the rear end 50b of the plunger. The size of the opening 52 is determined to accommodate an elastic element such as a coil spring 53 within it. Between the second end 52b of the opening 52 and the coil spring 53, a mounting function is provided in the form of a cylindrical mounting element 54 with a through hole 54a. The through hole 54a of the mounting element 54 accommodates a sleeve 55 with a through hole 55a configured to receive a pin 61 of a clip portion 60 (see Figures 2 and 3) for mounting the plunger 50 to the inner tube 40 and the outer tube 30.

[0038] When the tube assembly is assembled, as shown in Figures 3, 11, and 12, the plunger 50 has its front end 50a extending axially into the recesses 32 and 42 of the outer and inner tubes 30 and 40, preferably with its front end 50a projecting axially from the outer tube 30 and / or outer sleeve 20. When the tube assembly 10 is mounted to the multiaxial bone fixation device 2 while the rod 3 is in the receiving portion, as shown in Figure 1, the plunger 50 is displaced axially toward the rear end 40b of the inner tube 40 because of the presence of the rod 3, so that the coil spring 53 is compressed within the elongated opening 52, generating a reaction force acting on the plunger 50 in a downward direction, i.e., toward the front end 40a of the inner tube, and thus pressing the rod 3 downward within the receiving portion.

[0039] Referring again to Figures 2 and 3, and further to Figures 9 to 12, the outer sleeve 20 comprises a front end 20a, a rear end 20b, and an internal channel extending from the front end 20a to the rear end 20b. The inner diameter of the outer sleeve 20, i.e., the inner diameter of the internal channel, is such that the front portion of the outer tube 30 can be received therein.

[0040] A recess 22 is formed in the front region adjacent to the front end 20a of the outer sleeve 20, extending to a certain distance from the front end 20a. The recess 22 has an axial height that allows the rod 3 to extend through it and be movable axially within the recess 22 (Figure 1). The circumferential width of the recess 22 is substantially equivalent to, or slightly greater than, the diameter of the rod 3, and smaller than the widths of the recesses 32 and 42 of the outer tube 30 and inner tube 40, respectively.

[0041] The axial length of the outer sleeve 20 between its front end 20a and rear end 20b may be shorter than the axial lengths of the inner tube 40 and the outer tube 30. The axial length of the outer sleeve 20 may be such that, when the outer sleeve 20 is assembled with the outer tube 30, its rear end 20b is substantially located within the area of ​​the marking 71 on the outer tube 30.

[0042] An engaging part in the form of a latch tab 23 is provided at a certain distance from the rear end 20b of the outer sleeve 20, and is configured to selectively engage with one of two recesses 36 provided on the outer surface of the outer tube 30. The engagement of the latch tab 23 with the corresponding recess 36 of the outer tube 30 mounts the outer sleeve 20 to the outer tube 30 at a specific rotational position. Specifically, the engagement of the latch tab 23 with the first recess of the recess 36 determines the first rotational position of the outer sleeve relative to the outer tube, and the engagement of the latch tab 23 with the second recess of the recess 36 determines the second rotational position of the outer sleeve relative to the outer tube.

[0043] Markings 72a and 72b indicating the position and / or function of the tube assembly 10 are provided on the outer surface of the outer sleeve 20 adjacent to the rear end 20b. The markings 72a and 72b are offset from each other in the circumferential direction of the outer sleeve 20, so that when the latch tab 23 engages with the first recess 36 of the outer tube 30 in the first rotational position, the first marking 72a on the outer sleeve 20 is aligned circumferentially with the marking 71 on the outer tube 30, and when the latch tab 23 engages with the second recess 36 of the outer tube 30 in the second rotational position, the second marking 72b on the outer sleeve 20 is aligned circumferentially with the marking 71 on the outer tube 30. The first marking 72a may be provided with the function indication "INTRODUCE", and the second marking 72b may be provided with the function indication "OPERATE".

[0044] As will be described in more detail below, when the outer sleeve 20 is in a first rotational position indicated by the "INTRODUCE" marking, with the first marking 72a of the outer sleeve 20 aligned with the marking 71 of the outer tube 30, the tube assembly can be placed on and removed from the receiving part of the multi-axis bone fixation device 2. In a second rotational position of the outer sleeve 20, indicated by the "OPERATE" marking, with the second marking 72b of the outer sleeve 20 aligned with the marking 71 of the outer tube 30, the tube assembly is engaged with the receiving part of the multi-axis bone fixation device 2 and cannot be removed from it.

[0045] The circumferential widths of the recesses 32 and 42 of the outer tube 30 and inner tube 40, respectively, exceed the width of the recess 22 of the outer sleeve 20. Therefore, in both the "INTRODUCE" and "OPERATE" positions of the outer sleeve 20 relative to the tubes 30 and 40, all of the recesses 22, 32, and 42 of the outer sleeve 20, tube 30, and tube 40 overlap circumferentially, allowing the rod to pass through.

[0046] Next, the actuator assembly will be described in more detail with reference to Figures 13 to 19. The actuator assembly 100 comprises a first inner sleeve 110, a second inner sleeve 120, an outer sleeve 130, an adjustment member 140, a handle portion 150, and a lever assembly 160 in the form of a toggle lever.

[0047] The outer sleeve 130 has a front end 130a and a rear end 130b. A female thread 131 is provided at or near the rear end 130b, which allows the handle portion 150 to be connected to the outer sleeve 130.

[0048] Adjacent to the rear end 130b is a first hinge 132 which helps to mount one of the lever arms of the lever assembly 160, more specifically providing a point of rotation for a toggle lever. Multiple elongated openings 133 may be provided circumferentially to facilitate cleaning. In addition, at the same circumferential position as the first hinge 132, an elongated slot 134 extends from the front end 130a to a point axially distanced from the front end. The slot 134 allows a second hinge provided on the first inner sleeve 110 and a projection 38 provided on the outer tube 30 of the tube assembly 10 to protrude through the slot.

[0049] Approximately 90° circumferentially from the first hinge 132, an opening or recess 135 is provided in the wall of the outer sleeve 130, allowing the adjustment lever 141 of the adjustment member 140 to protrude through it. As shown in more detail in Figure 15, the opening 135 is closed to the rear end 130b of the outer sleeve 130. In the perspective view, the opening 135 has a substantially stepped shape, forming a first opening region 135a and a second opening region 135b adjacent to it in the circumferential direction, the first opening region 135a and the second opening region 135b extending equally in the axial direction, with the first opening region 135a being closer to the rear end 130b than the second opening region 135b.

[0050] The circumferential width of the second opening region 135b is determined to allow the adjustment lever 141 of the adjustment member 140, described later, to move to some extent along the circumferential direction of the outer sleeve. The distance between the rear end 130b of the outer sleeve 130 and the first opening region 135a is such that the adjustment lever 141 of the adjustment member 140 can be received into the first opening region only when the handle portion 150 is moved further away from the rear end 130b, for example, when it is twisted out from the outer sleeve 130, thereby providing additional space for moving the adjustment lever 141 upward from the second opening region 135b into the first opening region 135a.

[0051] Functional indicators "REMOVE," "LOCK," and "UNLOCK" may be provided at an axial distance from the opening 135 toward the front end 130a of the outer sleeve. For example, a marking may be provided on the "REMOVE" indicator to indicate the removal position of the actuator assembly 100, and / or arrows may be provided to indicate the rotation direction of the adjustment member 140 to achieve the locked and unlocked positions. The "REMOVE" indicator is located axially below the first opening region 135a, while the "LOCK" and "UNLOCK" indicators are located axially below the second opening region 135b of the outer sleeve 130 at different circumferential positions.

[0052] The handle portion 150 is provided with a threaded projection 151 that cooperates with the female thread 131 of the outer sleeve 130 to enable the handle portion 150 to be screwed into the outer sleeve 130. The handle portion 150 may further include a gripping structure 152, such as a circumferential lobe or top, to facilitate gripping. In addition, the handle portion 150 may be provided with multiple through holes 153 to facilitate cleaning.

[0053] Referring further to Figure 17, the first inner sleeve 110 has a front end 110a and a rear end 110b, and has an axial length shorter than the axial length of the outer sleeve 130 and an outer diameter smaller than the inner diameter of the outer sleeve 130, so that the first inner sleeve 110 can be fully housed within the outer sleeve 130. A second hinge 112 is provided on the outer surface of the first inner sleeve 110 at the same circumferential position as the first hinge 132 of the outer sleeve 130, adjacent to the front end 110a. When the actuator assembly 100 is assembled, the second hinge 112 protrudes outward from the first inner sleeve 110 through a slot 134 in the outer sleeve 130. The second hinge 112 functions as the second pivot point of the toggle lever.

[0054] Furthermore, the first inner sleeve 110 includes a latching function in the form of a latch tab 115 that locally protrudes into the internal channel of the first inner sleeve 110 and helps engage with the second inner sleeve 120.

[0055] The second inner sleeve 120, shown in detail in Figure 16, has a front end 120a and a rear end 120b, and has an outer diameter smaller than the inner diameter of the first inner sleeve 110 so that the second inner sleeve 120 can be housed inside the first inner sleeve 110. The second inner sleeve 120 has a circumferentially extending projection 121 on its outer surface, adjacent to the front end 120a and forming a contact portion with the front end 110a of the first inner sleeve 110. In the front region 125a adjacent to the circumferentially extending projection 121, the outer diameter of the second inner sleeve is made slightly smaller than that of the rear region 125b adjacent to the rear end 120b, thereby forming a contact portion or shoulder portion 125c on the outer surface of the second inner sleeve that is configured to engage with the latch tab 115 of the first inner sleeve 110. The shoulder portion 125c engages with the latch tab 115, and the front end 110a of the first inner sleeve 110 abuts against the circumferentially extending projection 121 of the second inner sleeve 120, thereby fixing the first inner sleeve and the second inner sleeve together with respect to their axial position.

[0056] Two inner projections 122 are formed on the inner surface of the second inner sleeve 120, adjacent to the rear end 120b, and these projections 122 are located on both sides of the longitudinal axis, i.e., offset by 180° in the circumferential direction. The projections 122 form a second projection that is comparable to the first projection of the tube assembly 10. They may have a substantially square profile and may function as drive units for transmitting the operating motion of the lever assembly 160 to the tube assembly 10, as will be described in detail below. Also, two recesses 123 are provided at the rear end 120b, which are offset by 180° from each other in the circumferential direction and are located substantially at 90° to the projections 122. Each recess 123 extends a certain distance from the rear end 120b and may have a substantially square profile. The recesses 123 serve to receive the extended portion of the adjustment member 140.

[0057] The adjustment member 140 is shown in detail in Figures 18a, 18b, and 19. The adjustment member 140 comprises an annular ring 144 sized to be received within the outer sleeve 130. An adjustment lever 141 is provided on the outer surface of the annular ring 144, connected to the annular ring 144 via a projection 141a. The projection 141a is sized to protrude outside the outer sleeve 130 through an opening 135 when the adjustment member 140 is received within the outer sleeve 130. Thus, the adjustment lever 141 is accessible from outside the outer sleeve for manual operation by the user.

[0058] The adjustment member 140 has two inner projections 142 on the inner surface of the annular ring 144 that are offset by 180° from each other. The inner projections 142 are similar to the inner projections 122 of the second inner sleeve 120, that is, they have a substantially square contour. The inner projections 142 protrude from the inner surface of the annular ring 144 such that its inner width is locally narrowed.

[0059] Furthermore, two extensions 143 are provided on the lower side of the annular ring 144, and these extensions project downward from the annular ring 144, i.e., toward the front end 130a of the outer tube 130 when the actuator assembly 100 is assembled. The extensions 143 are offset from each other by 180° in the circumferential direction of the annular ring 144 and are positioned substantially at 90° with respect to the projections 142. The extensions 143 have a shape similar to the shape of the recess 123 of the second inner sleeve 120; that is, each extension 143 may have a substantially square contour so that it can be at least partially accommodated within the corresponding recess 123 of the second inner sleeve 120. The circumferential width of the extension 143 corresponds to the circumferential width of the recess. Therefore, when the adjustment lever 141 is rotated circumferentially within the opening 135 of the outer sleeve 130, the adjustment member 140 rotates circumferentially together with the second inner sleeve 120, which engages with the adjustment member via the extension portion 143.

[0060] When the actuator assembly 100 is assembled, the extension portion 143 of the adjustment member 140 engages with the recess 123 of the second inner sleeve 120 such that the inner projection 142 of the adjustment member 140 is aligned circumferentially with the inner projection 122 of the second inner sleeve 120. Similar to the inner projection 122 of the second inner sleeve 120, the inner projection 142 of the adjustment member 140 is a second projection in comparison to the first projections 45a and 45b of the tube assembly 10, and also functions as a drive unit configured to transmit the operating motion of the actuator assembly 100 to the tube assembly 10.

[0061] Referring again to Figures 13 and 14, the lever assembly 160 comprises a first lever arm 162 that is hinged at one end to a second hinge 112 provided on a first inner sleeve 110 via a pin 163. The longer end portion or gripping portion 162a of the first lever arm 162 may have a gripping structure on the opposite side of the sleeves 110, 120, 130 to facilitate manual operation. The second lever arm 164 of the lever assembly 160 is hinged at one end to a first hinge 132 via a pin 165 and at its second end is hinged to the first lever arm 162 via a pin 166. The latter connection provides a third point of rotation for the toggle lever. In the embodiment shown, the second lever arm 164 is shorter than the first lever arm 162. The first lever arm 162 has a slightly angled shape. More specifically, the length of the gripping portion 162a of the first lever arm 162 is such that the height position of the first lever arm substantially corresponds to the height position of the handle portion 150.

[0062] Furthermore, an elastic member in the form of a spring 168 is provided on the first lever arm 162. The spring 168 is supported by a pin 167 on the first lever arm 162, with its first end in contact with another pin 169 provided on the first lever arm 162, and its second end in contact with the outer sleeve 130. Therefore, when the first lever arm 162 is moved toward the handle portion 150 to a more upright position, i.e., when the lever assembly 160 is configured in a straight line (not shown) in which the first lever arm 162 and the second lever arm 164 are more parallel or at a smaller angle, the spring 168 generates a force that pushes the first lever arm 162 away from the handle portion 150, returning the lever assembly 160 to its initial position as shown in Figure 14, which is an angled configuration, in which the first lever arm 162 and the second lever arm 164 are angled relative to each other, and the gripping portion 162a extends at an angle away from the handle portion 150. This angled configuration is the default configuration of the lever assembly 160 due to the preload generated by the spring 168.

[0063] When the first lever arm 162 is pushed toward the handle portion 150, the lever assembly 160 becomes a linear configuration in which the first lever arm 162 and the second lever arm 164 are more parallel or at a smaller angle (not shown). As a result, the first inner sleeve 110 abuts against the circumferential projection 121 of the second inner sleeve 120, and both inner sleeves 110 and 120 are pushed downward toward the front end 130a of the outer sleeve 130, causing the inner projection 122 of the second inner sleeve 120 to move axially away from the inner projection 142 of the adjustment member 140, thereby increasing the axial distance between the projection 122 of the second inner sleeve 120 and the projection 142 of the adjustment member 140. The relative axial movement of the two projections 122 and 142, which are the driving parts of the actuator assembly 100, is transmitted to the projections 45a and 45b of the tube assembly 10, i.e., the driven parts, to displace the inner tube 40 of the tube assembly 10 relative to the outer tube 30, as will be described in more detail below.

[0064] This instrument is made from biocompatible materials. Titanium or stainless steel, in particular, are suitable materials, but other materials can also be used, as long as they are biocompatible.

[0065] Next, referring again to Figures 1 to 3, 6a, 6b, and 13 to 15, the installation of the tube assembly 10 and the actuator assembly 100, as well as the operation of the tube assembly 10 by the actuator assembly 100, will be described.

[0066] The actuator assembly 100 is mounted as follows: The plunger 50 is located inside the inner tube 40, which is located inside the outer tube 30, and the clip portion 60 is housed in a circumferentially extending groove 39, so that its pin 61 extends through the inner and outer tubes into the through-hole 55a of the plunger 50, thereby holding the plunger 50 within these tubes. The first projections 45a and 45b of the inner tube 40 are located in recessed areas 37a and 37b of the recess 37 of the outer tube 30, respectively.

[0067] Next, the outer sleeve 20 is slid onto the outer tube 30 to mount it onto the outer tube 30. In this position, the outer sleeve 20 is in a first rotational position relative to the outer tube 30, and in this position, the "INTRODUCE" marking 72a of the outer sleeve 20 is aligned circumferentially with the marking 71 of the outer tube 30. The outer sleeve 20 is slid onto the outer tube 30 until the latch tab 23 of the outer sleeve 20 engages with the recess 36 of the outer tube 30.

[0068] The adjustment lever 141 of the actuator assembly 100 is in the circumferential position indicating the "REMOVE" position, i.e., within the first opening region 135a of the opening in the outer sleeve 130, which is made possible by loosening the handle portion 150 from the outer sleeve 130 to some extent. The actuator assembly 100 is mounted on the tube assembly 10 in an orientation such that the projection 38 on the outer surface of the outer tube 30 enters the elongated slot 134 of the outer sleeve 130 of the actuator assembly. In this orientation of the actuator assembly 100, the second projections 122 and 142 of the actuator assembly, which are aligned with each other in the circumferential direction, can pass downward through the gap G in the tube assembly 10, which is formed between the first projection 45a of the inner tube 40 and the opposing side walls of the recess 37 of the outer tube 30. In the same position, the actuator assembly 100 is removed from the tube assembly 10, in which case the second projections 122 and 142 of the actuator assembly move upward through the gap G in the tube assembly.

[0069] The locking configuration of device 1 is implemented as follows: First, the adjustment lever 141 of the actuator assembly 100 is rotated counterclockwise and moved downward within the second opening region 135b of the opening of the outer sleeve 130, thereby screwing the handle portion 150 fully into the outer sleeve 130, preventing the adjustment lever 140 from unintentionally reaching the "REMOVE" position where it is housed within the first opening region 135a. While housed within the second opening region 135b, the adjustment lever 141 can be rotated circumferentially to selectively align with the "LOCK" or "UNLOCK" indicator. When the adjustment lever 141 is moved to the "LOCK" position, the second protrusions 122 and 142 of the actuator assembly 100 move into the first recess region 37a of the tube assembly 10, which is below the first protrusion 45a on the upper part of the inner tube 40. When the lever assembly 160 is actuated by pushing the first lever arm 162 toward the handle portion 150 to form the linear configuration described above (not shown), the second protrusions 122 and 142 move apart from each other as described above, thereby creating or increasing a gap between them in the axial direction. When the lower wall of the recess 37 contacts the second protrusion 122 of the inner sleeve 120, the second protrusion 142 of the adjustment member 140 pushes the first protrusion 45a of the inner tube 40 upward toward the rear end 30b of the outer tube 30, and the first protrusion 45b also moves upward relative to the outer tube (Figure 6b). As a result, the front ends 30a and 40a of the tubes are displaced axially relative to each other so as to increase the distance between the engagement structures of the inner and outer tubes.

[0070] The unlock configuration is achieved by moving the adjustment lever 141 of the actuator assembly 100 to the "UNLOCK" position. The second projections 122 and 142 of the actuator assembly 100 enter the second recessed area 37b of the tube assembly 10 above the lower first projection 45b. When the lever assembly 160 is actuated by pushing the first lever arm 162 toward the handle portion 150 to achieve the above linear configuration (not shown), the second projections 122 and 142 move apart from each other, and the second projection 122 of the inner sleeve 120 pushes down the first projection 45b of the inner tube 40. The opposite (upper) wall of the recess 37 acts as a contact point for the second projection 142 of the adjustment member 140 (Figure 6a). As a result, the front ends 30a and 40a of the tubes are displaced axially from each other so that the distance between the engagement structure of the inner tube and the outer tube is reduced.

[0071] Next, with reference to Figures 20 to 22, a multi-axis bone fixation device 2 suitable for use with the instrument 1 will be described. In one embodiment, the multi-axis bone fixation device 2 comprises a bone fixation element 4, the bone fixation element having a shank 12 and a head 13 having a spherical outer surface portion. The bone fixation element 4 may be a bone screw having a threaded shank. The head 13 may have a recess 14 provided for engaging with a tool such as a screwdriver. A receiving portion 5 is provided to house the head 13 and connect the bone fixation element 4 to the rod 3 via the head 13. In addition, a fixing element 7 in the form of an internal thread or set screw may be provided to fix the rod 3 to the receiving portion 5. The bone fixation device 2 also includes a locking ring 8 for locking the head 13 to the receiving portion 5.

[0072] The receiving portion 5 has a first end or upper end 5a and a second end or lower end 5b. A rod receiving portion 90 is provided adjacent to the upper end 5a, and a head receiving portion 96 is provided adjacent to the lower end 5b. The rod receiving portion 90 is substantially cylindrical and includes a coaxial bore 91 extending from the upper end 5a into the head receiving portion 96. The bore 91 includes, at least in its area, a female thread for receiving the fixing element 7. A substantially U-shaped recess 92, forming a channel for receiving the rod 3, extends from the upper end 5a to roughly where the head receiving portion 96 begins. A groove or weakened portion 93 may be provided at a distance from the upper end 5a, which allows for the separation of the upper portion of the receiving portion 5 formed by the U-shaped recess, which functions as an extension tab. The long extension tab allows for pulling, for example, a vertebra relative to the rod by operating the multiaxial bone fixation device 2 with the inserted rod 3, which is at a higher position compared to the final position.

[0073] The outer surface of the rod receiving portion 90 is provided with an engagement structure for engaging with the tube assembly 10. The engagement structure may include circumferentially extending ribs 94. The ribs 94 are arranged asymmetrically with respect to a plane containing the central axis C of the receiving portion 5 and the channel axis of the substantially U-shaped recess 92. This means that a first rib 94 extends from one side of the U-shaped recess 92 over a certain distance around the receiving portion, and a second rib 94 extends from the opposite side of the U-shaped recess with respect to the central axis C over a certain distance around the receiving portion 5. This creates ribless surfaces 95 on both sides of the U-shaped recess.

[0074] The head receiving portion 96 has a substantially cap-like shape with a hollow, substantially spherical inner portion 97 (see Figures 25a and 25b) for rotatably receiving the head 13 therein. Multiple slits 98 make the head receiving portion flexible, so that when pressure is applied to the head receiving portion by the locking ring 8, the head 13 can be clamped and ultimately locked.

[0075] The lock ring 8 is designed to surround the head receiver 96, and its internal structure works in cooperation with the head receiver to fully lock the head 13 within the head receiver 96 when the lock ring 8 is in its lowest position, and to pre-lock when the lock ring 8 is slightly above its lowest position, which allows the head 13 to still rotate within the head receiver but prevents the head 13 from disengaging from the head receiver 96.

[0076] The lock ring 8 further has a plurality of upright flexible portions 81 that can engage with the receiving portion to pre-hold the lock ring 8 in a pre-locked position. The upper side of the lock ring is also provided with two opposing projections 82 that serve to support the rod 3. In the shown embodiment, the lock ring 8 also includes two upright arms 83 that are asymmetrical with respect to a plane extending through the central axis C and the center of the projections 82, similar to the arrangement of the ribs 94 on the rod receiving portion 90. The upper ends of the arms 83 are provided with engaging structures in the form of grooves 84 configured to engage with the tube assembly 10 of the device 1. As shown in Figures 21 and 24, when the multiaxial bone fixation device 2 is assembled, the engaging structures in the form of ribs 94 on the receiving portion 5 and the engaging structures in the form of grooves 83 on the lock ring 8 are circumferentially aligned, and the ribless surface 95 of the head receiving portion 90 remains exposed. The upright arms 83 of the lock ring 8, along with the engaging structures 84 at or near their upper ends, facilitate the discovery of the engagement structures with the device.

[0077] The use of the device will now be described. Referring further to Figures 23a to 24c, the first step of attaching the device 1 to the multi-axis bone fixation device 2 will be described. The bone fixation element 4 can be embedded in a vertebra or other bone. The locking ring 8 is positioned axially relative to the receiver 5, not completely locking the head but preventing the head 13 from coming off the head receiver 96. The rod 3 is inserted into a substantially U-shaped recess 92. The extension tab allows the rod 3 to move not only along the rod axis but also axially.

[0078] The tube assembly 10 of the device 1 is in a first rotational position of the outer sleeve 20 relative to the outer tube 30, which is the position where the first marking 72a of the outer sleeve 20 aligns with the marking 71 of the outer tube 30, as shown in Figures 23a and 24a, and is indicated by the "INTRODUCE" marking. Also, the engagement structure 34 of the outer tube 30 and the engagement structure 44 of the inner tube 40 are closest together, which is determined by bringing the front portion 40a of the inner tube 40 into contact with the inner shoulder portion 35 of the outer tube 30 (see Figure 12). In this configuration, the device 1 is placed on the receiving portion 5 of the bone fixation device 2 and moved downward in a orientation in which the recess 22 of the outer sleeve 20 aligns with the substantially U-shaped recess 92 of the receiving portion 5 that forms a channel for the rod 3. This allows the device 1 to be placed on the receiving portion 5 with the rod 3 housed inside. In this orientation of the device 1, the engagement structures 34 and 44 of the outer tube 30 and inner tube 40 are circumferentially aligned with the ribless outer surface portion 95 of the receiving portion 5. The outer sleeve 20, along with its recess 22, assists in positioning the device 1 correctly on the receiving portion. The plunger 50 of the tube assembly also enters the coaxial bore 91 of the receiving portion, which further assists in positioning the device on the receiving portion and pushes the inserted rod 3 downward within the U-shaped recess 92. Thus, both the outer sleeve 20 and the plunger 50 can function as alignment members that assist in mounting the tube assembly 10 to the bone fixation device 2. This facilitates handling of the device because the device can be positioned on the receiving portion with the recess 22 of the outer sleeve 20 aligned with the rod already inserted in the receiving portion. In this way, the recess 22 indicates the correct mounting position to the user.

[0079] Next, as shown in Figures 23b and 24b, the engaging structures 34 and 44 of the tube assembly 20 of the fixture move along the ribless surface portion 95 of the receiving portion 5 until the engaging structures in the form of ribs 34 of the outer tube 30 and grooves 44 of the inner tube 40 are in the same axial position as the corresponding engaging structures in the form of grooves 84 of the lock ring 8 and ribs 94 of the receiving portion 5.

[0080] As shown in Figures 23c and 24c, the device 1 is then rotated to a second rotational position of the outer sleeve 20 relative to the outer tube 30, which is indicated by the "OPERATE" marking where the second marking 72b on the outer sleeve 20 aligns with the marking 71 on the outer tube 30. In this position, the recesses 32 and 42 of the outer and / or inner tubes 30 and 40 can contact the inserted rod 3 at their periphery. This causes the outer tube 30 and inner tube 40 of the tube assembly 10 to rotate relative to the receiving part within the outer sleeve 20, thereby engaging the engagement structure in the device 1 with the engagement structures in the lock ring 8 and the receiving part 5. More specifically, the rib 34 of the outer tube 30 engages with the groove 84 of the lock ring 8, and the rib 94 of the receiving part 5 engages with the groove 44 of the inner tube 40. To disengage the tube assembly 10, the outer tube 30 is rotated back to the "INTRODUCE" position on the outer sleeve 20 so that the engaging structures 34 and 44 of the tubes 30 and 40 can be removed along the ribless portion 95 of the receiving portion 5.

[0081] Next, with reference to Figures 25a and 25b, the function of locking and unlocking the head 13 in the head receiving portion 96 of the receiving portion 5 using the device 1 will be described. In Figure 25a, the device 1 has the engagement configuration shown in Figures 23c and 24c, in which the engagement structure 34 of the outer tube 30 engages with the engagement structure 84 of the lock ring 8, and the engagement structure 44 of the inner tube 40 engages with the engagement structure 94 of the receiving portion 5. The lock ring 8 is in an axially upward position, in which position the head 13 can still rotate within the head receiving portion 96, but is prevented from coming out of the head receiving portion 96. The front ends 40a and 30a of the inner tube 40 and outer tube 30 of the tube assembly 10 are closest to each other. The plunger 50 presses against the rod housed in the U-shaped recess 92 of the receiving portion 5. The actuator assembly 100 is in configuration "UNLOCK". In this configuration, the angle of the receiving portion 5 and the locking ring 8 relative to the bone fixation element 4 can be adjusted using the device 1.

[0082] Figure 25b shows the locked position of the lock ring 8 relative to the receiving portion 5. In the locked position, the lock ring 8 is moved lower than in the unlocked position, fully clamping and locking the head 13 in the head receiving portion 96. This is achieved by moving the lock ring 8 downward along with the outer tube 30, which is driven downward by the actuator assembly 100 when the actuator assembly 100 is operated in configuration "LOCK". As can be seen from Figure 25b, the distance between the engagement structure of the receiving portion 5 and the lock ring 8 has increased. The front end 40a of the inner tube 40 is no longer in contact with the inner shoulder portion 35 of the outer tube 30. In the locked configuration, it is possible to pull upward toward the rod 3 into which the associated vertebra or bone is inserted using the instrument 1.

[0083] The head 13 can be repeatedly locked and unlocked while the device 1 is engaged with the bone fixation device 2. To achieve the locked configuration, the adjustment lever 141 of the actuator assembly 100 is rotated circumferentially within the second opening region 135b of the outer sleeve 130 to align with the "LOCK" indicator. By pressing the first lever arm 162 toward the handle portion 150, the head 13 is locked, as shown in Figure 25b. To release the locked configuration, the first lever arm 162 of the actuator assembly 100 is no longer pressed toward the handle portion 150, and the return force generated by the spring 168 returns it to the default configuration shown in Figure 14. Next, the adjustment lever 141 of the actuator assembly 100 can be rotated circumferentially within the second opening region 135b to align with the "UNLOCK" indicator. By pressing the first lever arm 162 toward the handle portion 150, the head 13 is unlocked, as shown in Figure 25a.

[0084] Ultimately, the device 1 can be removed from the bone fixation device 2, and the fixation element 7 can be tightened to secure the locking mechanism (not shown). Removal of the device 1 can be achieved by rotating the outer tube 30 back to the "INTRODUCE" position of the outer sleeve 20, allowing the engaging structures 34 and 44 of the tubes 30 and 40 to be removed along the ribless portion 95 of the receiving part 5.

[0085] Furthermore, when using the device, multiple bone fixation devices 2 can be embedded in each vertebra (not shown). The rod 3 can be inserted into the receiving portion 5 of these bone fixation devices, and each tube assembly 10 can be connected to the bone fixation device. Several steps of positioning and repositioning the receiving portion can be performed using a single actuator assembly 100 that can be selectively connected to different tube assemblies 10. Because the actuator assembly 100 is easy to handle, the time required for adjustment steps that require adjusting multiple bone fixation devices can be reduced. It is possible to reduce the space required for the device. In addition, the actuator assembly can be removed to facilitate cleaning of the device.

[0086] Next, further embodiments of the device will be described with reference to Figures 26 to 35b. Device 1' according to this further embodiment is similar to device 1 of the first embodiment, and in addition includes a sensor member 200. Parts and elements of device 1' that are the same as or similar to those of device 1 of the first embodiment are given the same reference numerals, and their descriptions are omitted.

[0087] The sensor member 200 of device 1' is a separate component that can be attached to the tube assembly 10 of device 1'. More specifically, as shown in Figures 28 and 29, the sensor member 200 can be attached to the outer surface of the outer tube 30 by engaging with the recess 139a of the outer tube 30 and the corresponding recess 48 of the inner tube 40 at a position below the clip portion 60.

[0088] The sensor member 200 is shown in more detail in Figures 30 to 34. The sensor member 200 comprises a base member 210 that has a general ring shape and extends between a first end 200a and a second end 200b. The circumferential extension of the base member 210 between the first end and the second end may exceed half of the circumferential extension on the outer surface of the outer tube 30. The inner surface of the base member 210 is substantially complementary to the outer surface of the outer tube 30 so that when the sensor member 200 and the tube assembly 10 are assembled, the inner surface of the base member 210 can contact the outer surface of the outer tube, which may be, for example, a cylindrical surface portion. An opening is provided between the first end 200a and the second end 200b to allow the sensor member 200 to be mounted on the outer tube. Because the base member 210 has this open shape, the base member 210 has a restoring force, so that the first end 200a and the second end 200b can spread out when mounted on the outer tube 30 and immediately return to their initial positions once mounted, which provides a force that holds the base member 210 on the outer tube. The base member 210 may have thickened end portions such as protrusions at its first end 200a and second end 200b, and these protrusions extend radially away from the outer surface of the base member 210.

[0089] The base member 210 extends axially from the lower boundary 201a to the upper boundary 201b, and the axial dimension of the base member 210 between the lower boundary 201a and the upper boundary 201b exceeds the axial dimension of the recess 139a of the outer tube 30 (see Figure 28).

[0090] A projection 202 is formed on the inner surface of the base member 210, preferably in the intermediate portion between the first end 200a and the second end 200b, projecting from the inner surface. The projection 202 has a shape and size that can be accommodated within the recess 139a or 139b of the outer tube. The projection 202 is bounded by a peripheral edge 203 that extends away from the inner surface of the base member 210, and the peripheral edge 203 has a contour corresponding to the contours of the recesses 139a, 139b of the outer tube 30, and may have a substantially elongated or elliptical contour, for example, having a major axis of the contour extending circumferentially of the base member 210. Thus, when the sensor member 200 and tube assembly 10 are assembled, the peripheral edge 203 contacts the wall of the outer tube 30 that defines the boundary of the recess 139a. The rear surface 205 of the projection 202, which faces away from the inner surface of the base member, may be substantially flat.

[0091] The thickness of the projection 202 in a direction perpendicular to the inner surface of the base member 210 may exceed the thickness of the wall of the outer tube 30 so that, when assembled, the projection 202 extends into the recess 48 of the inner tube 40, as shown in Figures 35a and 35b.

[0092] The sensor member 200 further comprises a sensor device, which is not shown, and which may be located within the projection 202. For example, the sensor device may be a sensor configured to measure the distance of the sensor element to a reference position, or the displacement of the sensor element, and / or a position sensor configured to detect the position of the sensor element. Alternatively or in addition, the sensor device may be a pressure sensor configured to detect the pressure acting on the sensor element. The sensor element of the sensor device, such as a pin 204, extends from the sensor device to the outside of the projection 203. The pin 204 can move to some extent relative to the projection 202 in the axial direction of the base member 210, i.e., toward the lower boundary 201a and / or upper boundary 201b. When the sensor member 200 is mounted on the tube assembly 10, the pin 204 protrudes into the recess 48 of the inner tube, as shown in Figures 35a and 35b, and can contact the inclined lower wall portion 48b at the lower end of the recess 48. The sensor device is configured to detect at least whether the inclined lower wall portion 48b of the recess 48 is in contact with the pin 204. The sensor device may further be configured to measure the pressure exerted by the inclined lower wall portion 48b on the pin 204 and / or to measure the relative or absolute displacement of the pin 204.

[0093] A display device 206 is provided on the outer surface of the base member 210, that is, on the surface facing away from the outer tube 30 when the sensor member 200 and the tube assembly 10 are assembled. The display device 206 is configured to output optical and / or audible signals in response to the measurement values ​​of the sensor device. For example, the display device may be configured to display two visible states, such as light of different colors or light that can be switched on or off, with the first of these visible states assigned to a first position of the pin 204 closest to the lower boundary 201a of the base member 210 (see Figure 36a), and the second of these visible states assigned to a second position of the pin 204 furthest from the lower boundary 201a (see Figure 36b). Alternatively or in addition, the display device 206 may be configured to output an audible signal, such as a beep, when the pin 204 is in the second position furthest from the lower boundary 201a (see Figure 36b).

[0094] Next, with reference to Figures 25a and 25b, and Figures 35a, 35b, 36a and 36b, the function of the sensor member 200 when locking and unlocking the head 13 in the receiving portion 5 using the device 1' will be described. Figure 35a shows the tube assembly 10 of the device 1', on which the sensor member 200 is mounted, and the head is in an unlocked configuration, i.e., the distance between the front ends 40a and 30a of the inner tube 40 and outer tube 30 of the tube assembly 10 is minimized (see Figure 25a). In this configuration, the lower wall portion 48b of the recess 48 of the inner tube is located at a distance axially below the pin 204 of the sensor member 200, i.e., it does not contact the pin 204 (see Figure 35a). The pin 204 is in a first position closest to the lower boundary 201a of the base member 210, as shown in Figure 36a. When the device 1' is activated to lock the head 13 (Figure 25b), the inner tube 40 moves axially upward relative to the outer tube 30, and the lower wall portion 48b of the recess 48 of the inner tube contacts the pin 204 of the sensor member 200, moving the pin to its second position toward the upper boundary 201b of the base member 210 (see Figures 35b and 36b). As a result, the display device 206 outputs an optical and / or audible signal to indicate the locked position of the bone fixation device to the user.

[0095] Thus, the sensor member can serve to indicate the locked and / or unlocked state of the head within the receiving portion, thereby facilitating the handling of the instrument during surgery. Furthermore, if the sensor device is configured to measure the pressure exerted by the inclined lower wall portion 48b on the pin 204 and / or the displacement of the pin 204, instrument wear may be detected, for example, based on a reduction in pressure or displacement determined by the sensor device when the head is locked.

[0096] The sensor component may be configured to transmit data to external devices such as computers, navigation devices, trackers, and the like. Preferably, the sensor component is configured to wirelessly transmit data to external devices via, for example, WiFi®, Bluetooth®, radio frequency identification (RFID) signals, and the like.

[0097] Next, further embodiments of the device will be described with reference to Figures 37 to 41. This further embodiment of device 1'' is similar to device 1 of the first embodiment and further includes a navigation member 300. Parts and elements of device 1'' that are identical or similar to those of devices 1 and 1' of the above embodiments are given the same reference numerals and their descriptions are omitted.

[0098] The navigation member 300 is a separate component that can be attached to the tube assembly 10 of the device 1'', that is, the navigation member 300 can be attached to the outer surface of the outer tube 30 in a position below the clip portion 60 by engaging with the recess 139a of the outer tube 30 and the corresponding recess 48 of the inner tube 40, similar to the sensor member 200 of the device 1'. The navigation member 300 also comprises a base member 210 provided with a projection 202 and a movable pin 204, similar to the sensor member 200 of the device 1'. The navigation member 300 comprises a navigation device in the form of a navigation star 301 instead of the sensor device of the sensor member 200. The navigation star 301 is mounted on the outer surface of the base member 210 and comprises four arms, each arm having a navigation sphere 302 at its free end. An additional navigation sphere 303 is provided on the outer surface of the base member 201 and coupled to the pin 204, so that when the pin 204 is in the first position as described above, the navigation sphere 303 can take the first position closest to the lower boundary 201a of the base member 210, and when the pin 204 is in its second position as described above, the navigation sphere 303 can take the second position furthest from the lower boundary 201a.

[0099] Based on the position of the additional navigation sphere 303 relative to the navigation sphere 302, the locking and unlocking configuration of the head in the receiving section can be determined, and / or the relative displacement between the inner and outer tubes of the tube assembly can be determined. In addition, the position of the instrument can be determined based on the positions of the four navigation spheres 302.

[0100] The navigation member 300 does not necessarily have to have four navigation spheres 302 fixedly connected to the base member 210, and may have more or fewer than four navigation spheres 302. For example, the navigation member 300 may generally have one or more navigation spheres 302 fixedly connected to the base member 210 and at least one further navigation sphere 303, the further navigation sphere being movable relative to the base member 201 and whose movement is linked to the movement of the pin 204. The relative position or displacement between the navigation sphere 303 linked to the movement of the pin 204 and the at least one fixed navigation sphere can be optically determined, for example, by the light beams reflected by each of the navigation spheres 302, 303.

[0101] Next, further embodiments of the device will be described with reference to Figures 42 to 45. The device 1000 according to this further embodiment comprises a tube 1030 and an outer sleeve 20, which may be the same as the outer tube 30 and outer sleeve 20 of the tube assembly 10 of the above embodiment of the device. The tube 1030 of the device 1000 is attachable to the multi-axis bone fixation device 2. The device 1000 plays a role in positioning and repositioning the receiving portion 5 of the multi-axis bone fixation device 2 with respect to the bone fixation element 4.

[0102] Referring to Figure 42, the multiple multi-axis bone fixation devices 2 shown are embedded in each vertebra 2000. A rod 3 (not shown) can be inserted into at least some of the receiving parts 5 of these multi-axis bone fixation devices 2. The tube assembly 10 of the instrument 1 of the first embodiment is connected to the first multi-axis bone fixation device of the multi-axis bone fixation devices 5, and the tube 1030 of the instrument 1000 is connected to the second multi-axis bone fixation device of the multi-axis bone fixation devices 5. Several steps of positioning and repositioning the receiving parts 5 can be performed by using the instrument 1 and / or instrument 1000 of the first embodiment. For example, the instrument 1000 coupled to the second bone fixation device 2 can be tilted and / or rotated to adapt the position of the multi-axis bone fixation device 2 to the bone fixation element 4 already inserted in the corresponding vertebra 2000.

[0103] Referring further to Figures 43 to 45, the tube 1030 of the device 1000 defines the longitudinal axis or tube axis L of the device 1000. When the device 1000 is assembled, the outer sleeve 20 completely encloses the lower portion of the tube 1030 in its circumferential direction, and the outer sleeve 20 is rotatable to a certain extent relative to the tube 1030 about the longitudinal axis L, enabling the tube 1030 to engage with the multi-axis bone fixation device 2.

[0104] The tube 1030 has a front end 1030a and a rear end 1030b opposite to the front end 1030a. A recess 1032 is formed, which extends from the front end 1030a of the tube 1030 to a certain distance. The circumferential width of the recess 1032 is greater than the width of the upper part of the multi-axis bone fixation device 2, and the axial height of the recess 1032 is such that a rod 3 (not shown) can pass through and move axially within the recess 1032. At a certain distance from the front end 1030a of the tube 1030, an engagement structure 1034 is provided, for example, a circumferentially extending rib formed on the inner surface of the tube, which is adapted to engage with the corresponding engagement structure of the multi-axis bone fixation device 2, for example, with the groove 84 of the lock ring 8.

[0105] Adjacent to the rear end 1030b of the tube 1030, a mounting function portion 1031 may be formed to facilitate attachment to a further instrument or handle portion (not shown). The mounting function portion 1031 may have a polygonal shape on the outer surface of the tube 1030 so that the further instrument or handle portion can transmit rotational and / or tilting motion onto the instrument 1000. An opening 1033 may be provided at a distance from the rear end 1030b to facilitate cleaning or to allow insertion of other instruments or parts.

[0106] A marking 1071 may be provided at an axial distance from the mounting function portion 1031 and / or the opening 1033 toward the front end 1030a of the tube 1030, similar to the marking 71 on the outer tube 30 of the tube assembly 10, to indicate the rotational position of the outer sleeve 20 relative to the tube 1030.

[0107] Two engaging parts in the form of recesses 1036 are provided on the outer surface of the tube 1030, located at an axial distance from the marking 1071 toward the front end 1030a of the tube 1030, although only one of the recesses 1036 is visible in the drawing. These recesses 1036 are spaced apart in the circumferential direction of the tube 1030 and, similar to the recesses 36 of the outer tube 30 of the tube assembly 10, serve to receive corresponding engaging parts such as the engaging latches of the outer sleeve 20 at each rotational position of the outer sleeve 20.

[0108] The outer sleeve 20 is similar to the outer sleeve of the above-described device. As shown in Figure 45, the outer sleeve 20 comprises a front end 20a, a rear end 20b, and an internal channel extending from the front end 20a to the rear end 20b, allowing the front portion of the tube 1030 to be received within the internal channel of the outer sleeve 20. The recess 22 formed in the front region of the outer sleeve 20 adjacent to the front end 20a has a circumferential width that substantially corresponds to or is slightly larger than the diameter of the rod 3, and is smaller than the width of the recess 1032 of the tube 1030. The axial length of the outer sleeve 20 between the front end 20a and the rear end 20b may be shorter than the axial length of the tube 1030, and the rear end 20b may be substantially located within the area of ​​the marking 1071 on the tube 1030 when the outer sleeve 20 is assembled to the tube 1030 as shown in Figure 43.

[0109] As previously described for the outer sleeve 20 and outer tube 30 of the tube assembly, the latch tab 23 of the outer sleeve 20 is configured to selectively engage with one of two recesses 1036 provided on the outer surface of the tube 1030, thereby mounting the outer sleeve 20 onto the tube 1030 in a first rotation position and a second rotation position, respectively. In the first rotation position of the outer sleeve 20, indicated by the "INTRODUCE" marking, where the first marking 72a of the outer sleeve 20 is aligned with the marking 1071 of the tube 1030, the tube 1030 can be placed on and removed from the receiving portion 5 of the multi-axis bone fixation device 2. In the second rotation position of the outer sleeve 20, indicated by the "OPERATE" marking, where the second marking 72b of the outer sleeve 20 is aligned with the marking 1071 of the tube 1030, the engagement structure 1034 of the tube 1030 engages with the corresponding engagement structure of the multi-axis bone fixation device 2 and cannot be removed from it.

[0110] When in use, the device 1000 is first attached to the multiaxial bone fixation device 2, in which the bone fixation element 4 is already embedded in the vertebra 2000 or other bone. The rod 3 may be inserted into the receiving portion. The device 1000 is in the first rotational position of the outer sleeve 20 relative to the tube 1030, the position indicated by the "INTRODUCE" marking, where the first marking 72a on the outer sleeve 20 is aligned with the marking 1071 on the tube 1030. In this configuration, as described for device 1, the device 1000 is placed on the receiving portion 5 of the bone fixation device 2 and moved downward in a orientation such that the recess 22 of the outer sleeve 20 is aligned with the substantially U-shaped recess 92 of the receiving portion 5 that forms a channel for the rod 3. In this configuration, as described for device 1, the engagement structure 1034 of the tube 1030 is aligned circumferentially with the ribless outer surface portion 95 of the receiving portion 5. The outer sleeve 20, along with its recess 22, can assist in positioning the instrument 1000 on the receiving portion in the correct orientation, and thus function as an alignment member to assist in attaching the tube 1030 to the bone fixation device 2.

[0111] Next, when the engagement structure 1034 of the tube 1030 is in the same axial position as the corresponding engagement structure of the bone fixation device, the instrument 1000 is rotated to a second rotational position of the outer sleeve 20 relative to the tube 1030. This position is indicated by the "OPERATE" marking, where the second marking 72b of the outer sleeve 20 is aligned with the marking 1071 of the tube 1030. In this position, the recess 1032 of the tube 1030 can contact the inserted rod 3 at its circumferential edge. In this way, the tube 1030 is rotated relative to the receiving portion within the outer sleeve 20 so that the engagement structure in the instrument 1000, i.e., the rib 1034 of the tube 1030, engages with the engagement structure in the bone fixation device, i.e., the groove 84 of the lock ring 8. In the engagement configuration of the instrument 1000 and the bone fixation device 2, the instrument 1000 can be tilted and / or rotated so that the position of the receiving portion conforms to the bone fixation element.

[0112] To disengage the device 1000, rotate the tube 1030 back to the "INTRODUCE" position of the outer sleeve 20 so that the engagement structure 1034 of the tube 1030 can be removed along the ribless portion 95 of the receiving portion 5, as described for device 1.

[0113] Furthermore, one or more tubes 1030 can be used in addition to or instead of the tube assembly 1, each with its corresponding outer sleeve 20.

[0114] Various modifications to the above embodiments of the instrument and bone fixation device are possible. For example, the arrangement, number, configuration, and shape of the protrusions constituting the drive and driven parts may differ. The instrument is shown with a bottom-loading type multiaxial bone fixation device with an external locking ring, but the instrument is not limited to use with such a device. For example, the instrument can be used with any type of multiaxial bone fixation device in which the clamping means is axially displaceable to clamp the inserted head, or with a uniaxial or uniplane bone fixation device.

Claims

1. An instrument for use with a bone fixation device (2), wherein the bone fixation device (2) comprises a bone fixation element (4) and a receiving portion (5) for connecting a rod (3) to the bone fixation element (4), and the instrument (1, 1', 1'', 1000) is The bone fixation device comprises at least one tube (10, 30, 40, 1030) that can be attached to the bone fixation device, the tube having a longitudinal axis (L), and the device further comprises A device comprising at least one alignment member (20, 50) configured to assist in attaching the tube to the bone fixation device (2).

2. The device according to claim 1, wherein the alignment members (20, 50) are separate members from the tubes (10, 30, 40, 1030) and are preferably attachable to the tubes.

3. The device according to claim 1 or 2, wherein the alignment member is preferably an outer alignment member in the form of an outer sleeve (20), and surrounds the tubes (10, 30, 40, 1030) at least partially, preferably entirely, in their circumferential direction.

4. The device according to claim 3, wherein the alignment member (20) is movable between a first rotation position and a second rotation position with respect to the tubes (10, 30, 40, 1030), the first rotation position is a position in which the tubes (10, 30, 40, 1030) can be attached to and detached from the bone fixation device (2), and the second rotation position is a position in which the tubes (10, 30, 40, 1030) are configured to engage with the bone fixation device (2) and prevent them from coming off the bone fixation device.

5. The outer alignment member (20) has a first end (20b) and a second end (20a), and the second end (20a) has a recess (22) opening therein, and the recess (22) is formed with a defined orientation so as to align with a substantially U-shaped recess (92) provided in the receiving portion (5) for accommodating the rod (3). Preferably, the tube (10, 30, 40, 1030) has first ends (30b, 40b, 1030b) and second ends (30a, 30b, 1030b), and the second ends have recesses (32, 42, 1032) opening therein, the circumferential width of the recess (22) of the alignment member (20) is smaller than the width of the recess (32, 42, 1032) of the tube (10, 30, 40, 1030), and the recess (22) of the alignment member and the recess (32, 42, 1032) of the tube overlap at both the first and second rotation positions so that an inserted rod (3) can pass through, the device according to claim 3 or 4.

6. The instrument is an instrument (1, 1', 1'') for locking and unlocking the head (13) of the bone fixation device (2) at the receiving portion (5), and the tube is the first tube (40) or the second tube (30) of the tube assembly (10) of the instrument (1, 1', 1''), The tube assembly (10) is The tube assembly (10) includes at least the first tube (40) and the second tube (30) that define the longitudinal axis (L), the first tube and the second tube being configured to engage with the bone fixation device (2), and being movable relative to each other between a first axial position associated with an unlocking configuration in which the head (13) is unlocked in the receiving portion (5) and a second axial position associated with a locking configuration in which the head (13) is locked in the receiving portion (5), and the tube assembly (10) further, The tube assembly (10) includes at least one alignment member (20, 50) configured to assist in attaching it to the bone fixation device (2), The device further comprises an actuator assembly (100) which includes an operating mechanism configured to move the first tube and the second tube of the tube assembly (10) from a first axial position to a second axial position and vice versa. Preferably, the actuator assembly (100) is a separate component that is connectable to and detachable from the tube assembly (10), according to any one of claims 1 to 5.

7. The apparatus according to any one of claims 1 to 6, wherein the alignment member is an internal alignment member, preferably in the form of a plunger (50), at least partially, preferably entirely, positioned within the at least one tube (10, 30, 40, 1030).

8. The device according to claim 7, wherein the internal alignment member (50) is configured to enter the coaxial bore (91) of the receiving portion (5) of the bone fixation device when the at least one tube is attached to the bone fixation device, and preferably the internal alignment member (50) is configured to press against the rod (3) inserted into the receiving portion.

9. The apparatus according to any one of claims 6 to 8, wherein the actuator assembly (100) is configured to take a first configuration such that the tube assembly (10) is in a first axial position when the operating mechanism is activated, a second configuration such that the tube assembly (10) is in a second axial position when the operating mechanism is activated, and a third configuration such that the actuator assembly (100) is connectable to and / or detachable from the tube assembly (10).

10. The apparatus according to claim 9, wherein the actuator assembly (100) comprises an adjustment member (140) configured to rotate in the circumferential direction to selectively configure the actuator assembly (100) to the first configuration, the second configuration, or the third configuration, and preferably the adjustment member (140) is fixed against movement to a position associated with the third configuration.

11. The apparatus according to claim 10, wherein the actuator assembly (100) comprises a handle portion (150) connectable to an outer sleeve (130) of the actuator assembly, and the adjustment member (140) is movable to a position associated with the third configuration, particularly when the handle portion (150) is loosened, when it is separated from the outer sleeve (130) to a certain extent.

12. The apparatus according to any one of claims 9 to 11, wherein the actuator assembly (100) comprises at least two drive units (122, 142) configured to be displaceable relative to each other parallel to the longitudinal axis in response to the operation of the operating mechanism, the tube assembly (10) includes at least two driven units (45a, 45b) configured to be driven by the drive units (122, 142), the at least two driven units (45a, 45b) are spaced apart in the circumferential direction to correspond to the first and second configurations of the actuator assembly (100), preferably the spaced apart driving units (45a, 45b) provide a gap (G) which allows the drive units (122, 142) to enter the tube assembly (10) and defines the third configuration of the actuator assembly (100).

13. The apparatus according to any one of claims 6 to 12, further comprising a sensor member (200) and / or a navigation member (300) configured to detect the unlocking configuration and the locking configuration of the head (13) in the receiving portion (5), or at least one of the first axial position and the second axial position of the first tube and the second tube.

14. A device for locking and unlocking the head (13) of a bone fixation device at the receiving portion (5) of the bone fixation device (2), wherein the device (1, 1', 1'') is The bone fixation device includes a tube assembly (10) that can be attached to the bone fixation device, The tube assembly comprises at least a first tube (40) and a second tube (30) defining a longitudinal axis (L), the first tube and the second tube being configured to engage with the bone fixation device (2), and being movable relative to each other between a first axial position associated with an unlocking configuration in which the head (13) is unlocked in the receiving portion (5) and a second axial position associated with a locking configuration in which the head (13) is locked in the receiving portion (5). The device further comprises an actuator assembly (100) which includes an operating mechanism configured to move the first tube and the second tube of the tube assembly (10) from a first axial position to a second axial position and vice versa. The actuator assembly (100) is configured to have at least a third configuration in which the actuator assembly (100) is connectable to and / or detachable from the tube assembly (10), and a fixing mechanism that prevents the actuator assembly (100) from becoming the third configuration. Preferably, the fixing mechanism is releaseable by loosening the handle portion (150) of the actuator assembly.

15. A system of instruments and bone fixation devices according to any one of claims 1 to 14, wherein the bone fixation device (2) comprises a bone fixation element (4) for fixing to a bone and a receiving portion (5) for housing the head (13) of the bone fixation element, and is provided with a clamping device (8) that acts on the head (13) in the receiving portion to lock the head (13) in the receiving portion, and the bone fixation device (2) comprises engaging structures (84, 94) configured to engage with engaging structures (34, 44, 1034) in the tubes (10, 30, 40, 1030), Preferably, the system comprises an engagement structure (84, 94) configured to engage with engagement structures (34, 44) in the first tube (40) and the second tube (30), respectively, in each of the receiving portion (5) and the clamping device (8).

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