KR20120056215A - Polyaxial bone anchoring device with enlarged pivot angle - Google Patents

Abstract

PURPOSE: A multi-shaft bone fixing device having an expanded pivot angle is provided to easily adjust orientation of the expanded pivot angle while offering high fixed power efficiency. CONSTITUTION: A fixed element comprises a head(3) having a shaft and a spherical outer surface unit(3a). The shaft is fixed within a bone. A receiving unit is connected with the head which can be pivoted. The receiving unit comprises an accommodation space(11) having a bottom opening(12) at the bottom edge(4b). A sleeve type insertion piece(5) is pivoted within the receiving unit. A pressurization member(6) comprises a lower surface unit(63). The lower surface unit is partly arranged within the receiving unit. The lower surface unit contacts to the head and adds pressure to the head.

Description

POLYAXIAL BONE ANCHORING DEVICE WITH ENLARGED PIVOT ANGLE}

The present invention relates to a multi-axis bone fixation device having an extended pivot angle. The bone fixation device includes a bone fixation element for fixation into a bone or spine and a receptacle that couples the bone fixation element to a stabilizing element such as a spinal rod, wherein the bone fixation element is pivotable within the receptacle. And pivoted from the central axis with an extended pivot angle. The orientation of the extended pivot angle can be selected within the range of 360 ° with respect to the central axis and is automatically achieved by pivoting the receptacle with respect to the bone fixation element.

US Pat. No. 6,736,820 describes a multiaxial bone fixation device having an extended pivot angle. This bone fixation device comprises a receptacle having a bone screw and a seat for the head of the bone screw. In order to enable the screw member to be pivoted by at least an angle extended to one side, the edge abutting the free end of the receiver has an asymmetrical configuration. In a variant embodiment, an insert with a spherical bottom for the head of the screw member is provided.

United States Patent Application Publication No. 2007/0118123 A1 describes multiaxial bone fixtures of increased tilt angle. The multiaxial bone fixture has a locking member that is shaped and configured to rotate in a multiaxial direction at a large angle with respect to the central axis of the bone fixture before the securing member, such as a screw or a ring, is compressed in the securing head.

While the multiaxial bone fixation device described above provides an extended tilt angle in the desired orientation, there is still a need for an improved multiaxial bone fixation device in terms of simplicity of construction.

It is an object of the present invention to provide a multi-axis bone fixation device that can equally provide high fixation efficiencies while allowing the adjustment of the orientation of the extended pivot angle with a simple configuration.

This object is achieved by the multiaxial bone fixation device of claim 1. Further advanced constructions are set forth in the dependent claims.

The multiaxial bone fixation device of the present invention has a small number of elements in a simple configuration. Thus, the bone fixation device of the present invention is easy to manufacture and cost effective. The bone fixation device of the present invention provides a secure fixation since the pressure to fix the angular position of the fixation element relative to the receptacle is effectively applied only in the axial direction. The bone fixation device of the present invention does not have any flexible elements or parts. Therefore, it is reliable even if the extended pivot angle changes several times during the adjustment of the angular position.

The pivot angle of the bone fixation element relative to the receptacle is at least 45 ° as measured from a straight position. Thereby, the bone fixation device of the present invention is particularly suitable for the use of fixing masses laterally in the cervical spine, for example.

The locking mechanism for securing the fastening element and the sleeved insert provides a great fastening force on a small surface. Therefore, the locking mechanism is efficient.

Even if an insertion member requiring an arrangement space is disposed below the accommodation portion, the upper portion of the accommodation portion can be configured in a small size.

The bone fixation device may be configured as an upper loading device into which the fixing element is inserted from the top or a lower loading device into which the fixing element is inserted from the bottom.

Further features and advantages of the present invention will become apparent from the description of the embodiments by the accompanying drawings.

1 is an exploded perspective view of a multi-axis bone fixation device having a spinal rod according to the first embodiment.
FIG. 2 is a perspective view of the bone fixation device of FIG. 1 in an assembled state. FIG.
3 is a cross-sectional view of the bone fixation device of FIGS. 1 and 2, taking a cross section along the axis of the spinal rod, omitting the spinal rod and the fixation screw.
4A is a side view of the pressing element of FIG. 1.
4B is a cross-sectional view of the pressing element taken along the line AA of FIG. 4A.
4c is a bottom view of the pressing element.
4d is a perspective view of the pressing element.
5A is a side view of the sleeved insert of FIG. 1.
5B is a perspective view of the sleeve-like insert.
FIG. 5C is a cross-sectional view of the sleeve-shaped insert piece taken along the line BB of FIG. 5A.
FIG. 5D is an enlarged cross-sectional view of a part of the insertion piece shown in FIG. 5C.
6A-6E illustrate various steps of aligning a multiaxial bone fixation device with respect to the extended pivot angle orientation.
7 is an exploded perspective view of a second embodiment of a multi-axis bone fixation device.
8 is a perspective view of the bone fixation device of FIG. 7 in an assembled state.
FIG. 9A is a cross sectional view of the bone anchoring device in the assembled state, taking a cross section perpendicular to the axis of the spinal rod, with the bone anchoring element in a first position with respect to the receptacle; FIG.
9B is a cross-sectional view of the bone anchoring device in an assembled state, with the bone anchoring element in a second position with respect to the receptacle;
10A is a perspective view from below of the receiving portion of the bone fixation device according to the second embodiment;
FIG. 10B is a cross-sectional view of the receiving portion taken along the line CC of FIG. 10A.
10C is a side view of the receiver.
10D is a cross-sectional view of the receiving portion taken along the line DD of FIG. 10C.
11A-11G show the assembly steps of the sleeved insert and the receptacle.
12 is a perspective view showing the assembly of the receptacle and the sleeved insertion piece and the bone fixation element and the pressing element.
13 is an exploded perspective view of a multi-axis fixing device according to a modified embodiment.
14 is a cross-sectional view of the multi-axis bone fixation device of FIG. 13 in an assembled state.
15 is an exploded perspective view of a third embodiment of a multi-axis bone fixation device.
FIG. 16 is a cross-sectional view of the multi-axis bone fixation device of FIG. 15 in an assembled state with a spinal rod but without a fixation mechanism and taking a cross section perpendicular to the axis of the spinal rod.
17A-17C are different views of the pressing member of the multi-axis bone fixation device according to FIGS. 15 and 16.
18A and 18B are different views of the receptacle of the multi-axis bone fixation device according to FIGS. 15 and 16.
19A-19G are different views showing the assembly steps of the multi-axis bone fixation device according to FIGS. 15 and 16.
20 is a side view showing a step of using the multi-axis bone fixation device after assembly.

As shown in FIGS. 1-3, the multiaxial bone anchoring device according to the first embodiment comprises a bone anchoring element 1 in the form of a bone screw with a helical shaft 2 and a head 3. The head 3 includes a spherical outer surface portion 3a and has a recess 3b at its free end that is engaged with the driver. The head 3 is retained in the receptacle 4 which couples the bone fixation element 1 to the stabilization rod 100. In the receiving part 4 there is arranged a sleeve-like insert 5 which provides a seat for the head 3 and a pressing member 6 for applying pressure to the head 3 of the bone fixation element. In addition, a fastening element in the form of a fastening screw 7 is provided for fastening and fixing the stabilizing rod 100 in the receptacle 4.

The receiving portion has an upper end 4a and a bottom end 4b, a central axis C and a coaxial hole 8 extending from the upper end 4a in the direction of the bottom end 4b. Adjacent the top 4a is provided with a substantially U-shaped recess 9 which forms a channel for the reception of the stabilizing rod. By this recess 9, two leg portions having a female threaded portion 10 interacting with the set screw 7 are formed.

The coaxial hole 8 opens into the accommodation space 11 provided in the lower portion of the accommodation portion 4. The accommodation space 11 further includes a seat portion 13 on which the sleeve-like insert 5 is seated near the bottom end 4b of the accommodation portion 4. The seat portion 13 has a spherical shape to provide a socket for a ball-socket joint formed by the sleeve-like insert 5 and the receiving portion 4. It should be noted that the seat portion 13 may have other shapes that may be tapered or used to implement a ball-socket joint. The inner diameter of the lower opening 12 is smaller than the inner diameter of the accommodation space 11. It should be noted that the inner diameter of the coaxial hole 8 does not need to be constant between the upper end 4a and the accommodation space 11. Coaxial holes may have different portions of different diameters.

The sleeved insert 5 is shown in particular in FIGS. 3 and 5a-5d. The sleeved insert has an upper edge 5a and a lower edge 5b. The sleeved insert has a spherical outer surface 51 between the upper edge and the lower edge. The maximum outer diameter of the sleeve-like insert is larger than the inner diameter of the lower opening 12 of the receiving portion 4. Thus, the sleeved insert cannot escape through the lower opening 12 when seated in the receptacle. The size of the spherical outer surface portion 51 corresponds to the size of the spherical sheet portion 13 in the receiving portion so that the sleeve-like insert 5 can pivot and rotate in the receiving portion when seated in the seat portion 13. When the sleeve-like insert 5 is seated in the seat portion 13 such that its central axis 5c is coaxial with the central axis C of the receiving portion, the lower edge 5b protrudes from the lower opening 12. When the sleeved insert 5 is provided in the receiving portion, as shown in FIG. 3, the lower edge 5b protrudes at least partially from the lower opening 12.

The sleeved insertion piece 5 is hollow and has a spherical center portion 52 having a radius corresponding to the radius of the spherical outer surface portion 3a of the head 3 of the fixing element 1. The lower end of the central portion 52 forms the shoulder 53. Similar to the ball-socket joint, the inner diameter of the shoulder 53 is larger than the maximum outer diameter of the spherical head 3 so that the head 3 can be rotated and pivoted within the spherical center portion 52 of the sleeve insert 5. small. Between the shoulder 53 and the lower end 5b a tapered portion 54 is tapered outward so that the bone fixation element 1 is tilted until the shaft 2 is in contact with the lower end 5b. Between the spherical center part 52 and the upper end 5a, the taper part 55 tapered outward is provided. The inner diameter of the tapered portion and the inner diameter of the transition portion between the tapered portion 55 and the spherical center portion 52 are always larger than the maximum outer diameter of the head 3 so that the head 3 can be inserted from the upper edge 5a. The upper edge 5a is provided with a chamfered portion 56 which can act as a braking part for the pressing member 6.

The center points of the spherical center portion 52 and the spherical outer surface portion 51 may be shifted in such a manner that the center point of the inner spherical center portion 52 is moved in the direction of the bottom end 4b. Thus, the range of tilt angle adjustment of the bone fixation element 1 can be further increased. The axial height of the sleeved insert 5 is such that a portion of the spherical outer surface 3a of the head 3 is still at the top of the sleeved insert 5 when the head 3 is inserted into the sleeved insert 5. It is smaller than the axial height of the head 3 to protrude from the edge 5a.

The pressing member 6 is shown in particular in FIGS. 1, 3 and 4a-4d. The pressing member 6 has a substantially cylindrical shape having an outer diameter that allows movement within the coaxial hole 8 and the receiving space 11. The pressing member has an upper end 6a and a lower end 6b. The joining member 6 comprises a spherical recess 61 having a spherical coincidence with a spherical shape of the spherical outer surface portion 3a of the head 3, adjacent to the lower end 6b. Adjacent to the lower end 6b there is a tapered portion 62 which can abut the chamfer 56 of the sleeve-like insert 5. The pressing member 6 includes a cylindrical recess 63 for accommodating the rod 100 therein at the upper end 6a. In addition, the pressing member 6 is provided with a coaxial hole 64 to be connected to the screw head 3 using a tool. The coaxial hole 64 is also configured such that a portion of the head 3 extends therethrough when the bone fixation element is in a pivoted state as shown in FIG. 3. The axial height of the pressing member 6 is formed such that when the fixing screw 7 is tightened, the pressing member 6 acts only on the head 3 of the bone fixing element while pressing the upper end 6a of the pressing member 6. .

The bone fixation device according to the first embodiment can be preassembled in such a way that the sleeved insert 5, the head 3 of the bone fixation element 1 and the pressing member 6 are arranged in the receptacle 4. have. For the assembly of the bone fixation device, both the bone fixation element 1 and the pressing member 6 are inserted through the upper end 4a. The pressing member 6 is arranged in an alignment position in which the cylindrical recess 63 is aligned with the U-shaped recess 9 of the receiver for accommodating the rod. The pressing member 6 can be temporarily held in this position, for example by crimping.

The bone fixation device is composed in whole or in part of a biocompatible material such as a biocompatible metal such as a biocompatible alloy such as titanium, stainless steel, or nitinol, or a biocompatible plastic material such as polyetheretherketone (PEEK). Can be.

The steps of using the bone fixation device according to the first embodiment are shown in Figs. 6A-6E. First, a fixation element is inserted into a bone portion or spine of a stabilization object. Usually some bone fixation devices require securing the stabilizing rod to the bone portion or spine of the stabilizing object. For example, after insertion of the bone fixation element as shown in FIG. 6A, the receptacle 4 is adjusted by pivoting and / or rotating to allow handling of the stabilizing rod.

In the state shown in FIGS. 6A-6E both the sleeved insertion piece 5 and the head 3 of the bone fixation element 1 are freely pivotable independently. The sleeved insert 5 is rotatable and pivotable within the receptacle 4, while the receptacle 4 and the sleeved insert 5 rotate and pivot relative to the head 3 of the bone fixation element. It is possible. The sleeved insert 5 protrudes from the lower opening 12 in the receiving portion 4 because it extends the distance between the shaft 2 of the bone fixation device and the contact provided by the edge of the lower opening 12. Compared to the case where the head 3 is directly received, the inclination angle adjustment range is extended. Since the sleeved insert 5 is rotatable and pivotable within the receptacle, the adjustment of the inclination angle of the extended range can be carried out at any position of the receptacle with respect to the bone fixation element within 360 ° about the central axis C of the receptacle. Can be achieved. As shown in FIG. 6B, the pivoting of the receptacle relative to the bone fixation element initially maintains the position of the sleeved insert 5 essentially. As soon as the shaft 2 of the bone fixation element contacts the lower edge 5b of the sleeved insert, as shown in FIG. 6C and in an enlarged portion of FIG. 6D, the sleeved insert 5 is pivoted. do. The shaft 2 pushes the insertion piece 5 until the shaft abuts the edge of the lower opening 12 of the receptacle as shown in FIG. 6E. Thus, in FIG. 6E the receptacle is pivoted at the maximum pivot angle with respect to the bone fixation element 1. The maximum pivot angle obtained depends on the size of the sleeved insert 5, the receptacle and the bone fixation element, but is usually at least 45 ° when measured from a straight line, ie an angle position of 0 degrees.

6A-6E show an example in which the pivoting motion is carried out in a plane comprising the rod axis, but the same movement is at 90 ° of the plane containing the rod axis or about the central axis C of the receptacle 4. It should be noted that it may be done in any direction within 360 degrees.

After the rod is finally inserted, the head and the sleeve-like insert are fixed at the same time by tightening the inner screw 7 to press the pressing member 6 toward the head 3 side.

7-12 show a second embodiment of a bone fixation device. Elements or parts which are the same as or similar to those in the first embodiment are designated by the same reference numerals and the description is not repeated. In the bone fixation device of the second embodiment, the configuration of the receiving portion and the pressing member is different from the bone fixation device of the first embodiment. All other elements are the same as in the first embodiment.

The presence of the sleeved insertion piece 5 may result in a larger outer diameter than the receiving part having a lower portion of the accommodation portion in order to have space for the insertion piece. However, at the position of the rod the receiving portion needs to have a small size. 7, 8 and 10, the receiving portion 4 'according to the second embodiment has a smaller outer diameter than the upper part supporting the rods as compared with the receiving portion of the first embodiment. The receiving portion 4 'has two tapered outer surfaces 41a, 41b tapered to the upper end 4a side to reduce the size. The tapered outer surface portions 41a and 41b are arranged to be offset by 180 ° from each other across the longitudinal axis corresponding to the longitudinal axis of the U-shaped recess 9. Therefore, the size of the receiving portion 4 'in the direction of the rod axis is reduced compared to that of the first embodiment. In order to obtain sufficient wall strength, the coaxial hole 8 'has a smaller diameter than the coaxial hole 8 of the first embodiment. The diameter of the coaxial hole 8 'is smaller than the maximum outer diameter of the sleeved insert 5. The coaxial hole 8 'opens to the accommodation space 11' side. The receiving space 11 'has a seat portion 13 and a lower opening 12 as in the first embodiment. In addition, the accommodation space includes a dome-shaped portion 14 between the seat portion 13 and the coaxial hole 8 '. The domed portion 14 and the sheet portion 13 form the maximum inner diameter of the accommodation space 11 'larger than the inner diameter of the coaxial hole 8'. The receptacle 4 ′ may also have an outwardly tapered portion 15 tapered outward from the opening 12 to further extend the tilt angle adjustment range of the bone fixation element. The size of the receiving space 11 'is formed such that the sleeve-like insert 5 can be inclined upon introduction from the upper end 4a in an inclined position as described below.

In order to allow the sleeved insert to be introduced from the top 4a, two opposing recesses 42a and 42b are provided on the inner wall of the coaxial 8 'and the receiving space 11'. The recesses 42a and 42b are aligned with the U-shaped recesses 9. The recess extends from the bottom of the U-shaped recess 9 into the receiving space 11 '.

The size of the recesses 42a and 42b is formed so that the sleeved insert 5 can be introduced from the top at a 90 ° inclined position, that is, the width of the recess is greater than the axial height of the sleeved insert. The recesses 42a and 42b extend into the accommodation space to the extent that the insertion piece 5 into the seat 13 can be inclined.

The receptacle also includes at least one pin hole 16 to receive the pin 17 as shown in FIGS. 7-10. The pin holes 16 are arranged at an angle of 90 ° to the channel axis. A second pin (not shown) may be provided on the other side of the receiver, but it is not necessary to provide the second pin.

As shown in FIGS. 7 and 9A-9B, the pressing member 6 ′ is pressurized in that it has a cylindrical portion 62 ′ having a diameter somewhat smaller than the diameter of the cylindrical main portion instead of the tapered portion 62. It is different from the member 6. The outer diameter of the lower cylindrical portion 62 'is such that the lower cylindrical portion 62' is arranged at least partially within the upper tapered portion 55 of the sleeved insert 5, and the upper tapered portion of the sleeved insert 5 It is smaller than the inner diameter of 55). Thus, the pressing member 6 'does not contact the sleeve-like insert 5.

The pressing member 6 'is provided on its outer wall with a coaxial recess 65 closed on the bottom edge 6b side and open to the upper end 6a side on one side perpendicular to the cylindrical axis of the cylindrical recess 63. . The bottom of the recessed part 65 on the lower edge 6b side is rounded. The recess 65 functions to receive the pin 17 holding the receiver in a position aligned so that the cylindrical axis of the cylindrical recess 63 and the channel axis of the U-shaped recess receiving the rod are aligned. The recessed portion 65 and the pin 17 form a mechanism for preventing rotation and release of the pressing member 6 '.

The position and size of the pin holes, pins and recesses 65 can be configured such that the pressing member 6 'is temporarily fixed to apply a small preload to the head 3. Accordingly, the head 3 is clamped by friction before it is finally fixed by tightening the fixing screw 7 to press the pressing member 6 '. Thus, the receptacle can be maintained in an adjustable angular position relative to the bone fixation element. The pivot of the receptacle against the bone fixation element is still operable by applying a force greater than the frictional force.

The step of assembling the bone fixation device of the second embodiment is illustrated with reference to FIGS. 11A-11G. First, as can be seen in FIGS. 11A and 11B, the sleeve-like insert is tilted 90 ° and inserted into the receiving portion at the position of the U-shaped recess 9. Then, as shown in Fig. 11D, which is a cross-sectional view of Figs. 11C and 11C, the insertion piece 5 is moved downward into the accommodation space 11 '. Since the outer diameter of the insertion piece 5 is larger than the inner diameter of the lower opening 12, the insertion piece cannot be separated through the lower edge of the opening 12. Thereafter, as shown in FIG. 11G, which is a cross-sectional view of the receiving portion according to FIG. 11F, the insertion piece 5 is finally inclined so as to be seated in the seat portion 13 as shown in FIG. 11G. Then, the bone fixation element 1 with the pressing member 6 'on the top of the head 3 is inserted from the top 4a. Then, the pin 17 is introduced into the pin hole to hold the pressing member 6 'until the recess 65 is restrained.

The use of the bone fixation device of the second embodiment is similar to the use of the first embodiment.

13 and 14 show modifications of the second embodiment. All elements that are the same as in the second embodiment are designated by the same reference numerals and description thereof is not repeated.

The modified second embodiment differs from the second embodiment in the configuration of the pressing member and the fixing mechanism. The bone fixation device has a separate head and rod fixation. It is provided with a U-shaped recess 63 ′ instead of a cylindrical recess 63 and a leg extending over the rod 100 when the rod is inserted into the channel formed by the U-shaped recess 63. Achieve the axially high pressing member 6 "so that 63a 'and 63b' are formed. Moreover, the pressing member 6" is inclined concave part closer to the upper end 6a and the lower edge 6b side. It may have 65 '.

The fastening mechanism 70 is a two-part fastening mechanism that includes an internal screw 71 that interacts with the female thread of the receptacle 4 '. The inner screw 71 has a coaxial screw hole for receiving the set screw 72. The set screw 72 acts on the rod 100. Tightening the inner screw 71 forces the upper end 6a of the pressing member 6 "to apply pressure only to the head 3 of the bone fixation element. The rod 100 is independently fixed by the stop screw 72. Can be.

The assembly and use of the bone fixation device according to the modified second embodiment is similar to that of the second embodiment. It should be noted that the fastening mechanism and the deformed pressing member can also be used for the bone fixing device of the first embodiment.

A third embodiment of a bone fixation device is shown in FIGS. 15-20. The third embodiment differs from the bone fixation device of the previous embodiment in that the sleeved insert is introduced from the bottom end 4b of the receptacle. The bone fixation device of the third embodiment differs from the bone fixation device of the previous embodiment in that the fixation element is a so-called bottom-loaded multiaxial bone fixation device in which the fixation element is introduced from the bottom end 4b. As in the previous embodiment, the same or similar features are designated by the same reference numerals and the description is not repeated.

The multiaxial bone fixation device according to the third embodiment has a receptacle 4 "having a size and shape for receiving the fastening element 1 from the bottom end 4b together with the sleeved insert and the pressing member 6" '. ) For this purpose, the receiving portion includes two recesses 43a and 43b which are disposed 180 ° apart from each other at the bottom end thereof and are disposed at a position perpendicular to the rod axis. The recesses 43a and 43b are opened toward the bottom end 4b and the receiving space 11 " is received from the bottom end 4b in a posture in which the sleeve-like insert 5 is tilted 90 degrees as shown in Fig. 19A, for example. The recesses 43a and 43b need not be positioned at an angle of 90 ° with respect to the rod axis, but can be located at 0 ° or any other angle with respect to the rod axis. It should be noted that when the recess is disposed at 90 ° with respect to the rod axis, the overall strength of the receptacle is lessened. The receiving space 11 "has a sleeve-like insert and a pressing member 6" 'inside. It has a generally hollow hemispherical shape to allow insertion of the head in the mounted state. This is the introduction of the head with the receiving space 11 "in the sleeve-like insert 5 and the pressing member 6" 'installed thereon. And it means having the size and shape to enable the rotation. The lower part of the coaxial hole 8 "'which opens into the working space 11" has the taper part 18 tapered outward toward the bottom end 4b. This is a sleeve-shaped insertion piece and the pressing member 6 "'. Allows the installed head 3 to be rotated in the accommodation space 11 ".

The coaxial hole 8 "'does not necessarily have to guide the pressing member and / or sleeve-like insert therethrough, so it may have a smaller diameter than the coaxial holes 8, 8' of the previous embodiment. The size of the receiving portion 4 'of the region can be made smaller. As shown in Fig. 16, the diameter of the coaxial hole 8 "' is smaller than the maximum outer diameter of the pressing member 6" '. It is not necessary to temporarily fix the pressing member 6 'in order to prevent the detachment of 6 "'.

The sleeved insert 5 of the third embodiment is substantially the same as the sleeved insert of the previous embodiment.

The pressure member 6 "'is a rotational symmetry having an upper end 6a and a lower edge 6b as shown in Figures 17A-17C. The pressing member is adjacent to the lower edge as in the previous embodiment. It has a spherical recess 61. There is no cylindrical recess for accommodating a rod so that the upper end 6a is planar. In addition, the pressing member 6 "'is connected to the head 3 using a driver. A coaxial hole 64 is included to allow the connection to the screw head while lowering the head 3 so that the head partially extends through when the bone fixation element is pivoted at a large angle. The outer portion 62 is tapered at a portion adjacent the lower edge 6b as in the first embodiment. Adjacent to the top 6a is a small spherical shape having a size and shape that matches the domed portion 14 'of the receiving space 11' to facilitate rotation of the head 3 with the pressing member installed thereon. An outer surface 67 is provided. The spherical outer surface 67 may be small, for example the outer surface may be only a chamfer that facilitates rotation.

The assembly process will be described with reference to FIGS. 19A-19G. 19A is a side view of the receptacle and bone fixation element before assembly. The bone fixation element is provided with the sleeved insert 5 and the pressing member 6 "'. The sleeved insert 5 and the pressing member 6"' have a central axis C in the center of the receiving portion. Inclined to be perpendicular to. There may be a tool for holding the bone fixation element in which the sleeved insert 5 and the pressing member 6 "'are placed in this position. Thereafter, as shown in the side view of FIG. 19B, the sleeved insert is also shown. Bone fixation element 1 with 5 and pressing member 6 "'is introduced into the accommodation space 11" from the bottom end through lower opening 12 in this inclined position. The sleeved inserts 5 are oriented with respect to each other in such a way that the sleeved inserts can be introduced into a position in which the recesses 43a and 43b are provided in the receiving portion, Fig. 19C shows the rod axis in the posture shown in Fig. 19B. Fig. 19D is a cross sectional view along the EE line of Fig. 19C. As can be seen in Fig. 19D, the sleeve-like insert 5 is further inserted from the bottom end with a coaxial hole 8 " And may partially extend into (18).

Next, as shown in FIGS. 19E and 19F, which are side views of the bone fixation device, the sleeved insert 5 and the pressing member are rotated in the receiving space 11 ″ through pivoting of the bone fixation element. When the shaft 2 of the fixing element 1 abuts the lower edge 5b of the sleeved insert, the sleeved insert 5 is pivoted together with the bone fixation element. At the same time, the pressing member 6 "'. Is guided along the wall of the receiving space 11 ". As a result, the sleeve-like insert and the pressing member are in the zero angle position, as shown in the cross section according to Fig. 19G, so that the central axis thereof is the receiving portion 4. It becomes coaxial with the central axis C of ").

When the multiaxial bone fixation device is finally assembled, the pressing member 6 "'protrudes slightly above the bottom of the U-shaped recess 9. When the rod 100 is inserted, the rod is placed on the flat top surface of the pressing member ( 6a). Tightening the inner screw or other fastening mechanism acts on the rod to pressurize the pressure member 6 ", which in turn presses the head of the bone fixation device into the sleeve insert 5 The angle adjustment position of the head in Esau and the angle adjustment position of the sleeve-like insertion piece 5 in the receiving portion 4 "are fixed.

Further variations on the embodiments described above are conceivable. For example, in the case of a bone fixation element, all kinds of fixation elements can be used to attach to the receptacle. These fastening elements include, for example, screws of different lengths and diameters, cannulated screws, screws of other thread types, nails, hooks, and the like. The head and the shaft may be separate elements connectable with each other.

A variant of the receiver includes a recess for the rod in the form of an inclined, laterally open or closed channel, instead of a U-shaped recess perpendicular to the central axis. Other kinds of fasteners are also possible, including outer nuts, outer caps, engagement locks, and the like. In all embodiments the inner surface portion of the pressing member in contact with the head 3 need not necessarily be spherical. The inner surface may have another form suitable for applying pressure to the head.

It should be further noted that the elements of the other embodiments described above can be combined with each other.

Claims (18)

As a multiaxial bone fixation device:
A fixing element 1 having a shaft 2 fixed in the bone and a head 3 having a spherical outer surface portion 3a;
Receptacles 4, 4 ′, 4 ″ pivotably connected to the head 3, the upper end 4a and the bottom end 4b through which the longitudinal axis C extends, and the rod 100. Receiving portion having accommodation spaces 11, 11 ', 11 "having a lower opening 12 in the bottom end 4b as space for accommodating the transverse channel 9 and the head 3 for receiving (4, 4 ', 4 ");
A sleeve-like insert 5 enclosing a portion of the head 3, having a spherical outer surface portion 51, configured to pivot within the receiving portion, and having a lower edge of the sleeve-shaped insert 5. 5b) is a sleeved insert 5 configured to extend through the lower opening 12 when the sleeved insert is seated in the receiving portion in a position where the sleeve axis of the sleeved insert is coaxial with the longitudinal axis C. )and;
Pressing members 6, 6 ', 6 "having at least partially disposed in said receiving spaces 11, 11', 11" and having a lower surface portion 63 in contact with said head 3 to apply pressure to said head. , 6 "');
The fastening element 1 is pivotable with respect to the receiving portions 4, 4 ′, 4 ″ and pressurizes the head 3 with the pressing members 6, 6 ′, 6 ″, 6 ″ ′. Multi-bone bone fixation device, characterized in that can be fixed at a predetermined angle by simultaneously applying the head and the sleeve-like insert (5) in the receiving portion. 2. The sleeve-like insert (5) and the fastening element (1) according to claim 1, wherein the shaft (2) of the fastening element (1) and the lower edge (5b) of the sleeve-like insert (5). Multi-axis bone holding device characterized in that the pivoting independently when the contact is not in contact. 3. The shaft (2) of claim 1, wherein the shaft (2) of the fastening element (1) is pivoted to restrain the lower edge (5b) of the sleeve-like insert (5), the addition of the fastening element (1). By means of the pivoting movement of the sleeve-like insert (5), characterized in that the pivot with the fixing element (1). 4. The lower surface portion 61 of the pressurizing member 6, 6 ′, 6 ″, 6 ″ ′ in contact with the head 3 is at least partially spherical. Multiaxial bone fixation device characterized in that. 5. The press member 6, 6 ′, 6 ″, 6 ″ ′ is in contact with the head 3, and the press member 6, 6 ′, 5. 6 ", 6" ') and a gap between said sleeved insert (5). 6. Multiaxial bone fixation device according to one of the preceding claims, characterized in that the sleeve insert (5) has a spherical inner surface portion (52) that forms a seat portion for the head (3). 7. The multi-axis bone anchoring device according to claim 6, wherein the center points of the spherical outer surface portion (51) and the spherical inner surface portion (52) of the sleeve-like insertion piece (5) are shifted from each other in the axial direction of the sleeve axis. 8. A multiaxial bone fixation device according to claim 7, characterized in that the center point of the spherical inner surface portion (52) is moved to the bottom end (4b) side of the receiving portion (4). 9. The pressing member 6 ', 6 ", 6"' according to one of the preceding claims preliminarily tightens the head by friction before the angular position of the fixing element 1 is finally fixed. Multiaxial bone anchoring device, characterized in that it is maintained in the receiving portion (4 ') to apply a load to the head. 10. Device according to one of the preceding claims, characterized in that the sleeved insert (5) is a rotational symmetry. The lower opening 12 has a circular cross section, and the maximum outer diameter of the sleeve-like insert 5 is larger than the inner diameter of the lower opening 12. Multi-axis bone fixture. The pressure element (6, 6 ', 6 ", 6"') is opened into the accommodation space (11, 11 ', 11 ") and the fastening element is according to one of the preceding claims. Multiaxial bone fixation device, characterized in that it has a passage (64) adapted to receive at least a portion of the head (3) during the pivoting operation. 13. The receiving part (4) according to one of the preceding claims, wherein the receiving part (4) has a passage (8) extending from the upper end (4a) into the receiving space (11), the passage at the upper end (4a). The inner diameter of (8) is a multi-axis bone fixing device, characterized in that the sleeve-shaped insertion piece (5) is formed so that it can be inserted from the upper end (4a). 13. The receiving device according to one of the preceding claims, wherein the receiving portion has passages 8 ', 8 "extending from the upper end 4a into the receiving spaces 11', 11", and the upper end 4a. ), The inner diameter of the passage (8 ', 8 ") is smaller than the maximum outer diameter of the sleeved insert (5). 15. The method according to claim 13 or 14, wherein the channel (9) for receiving the rod is formed by a U-shaped recess adjacent to the upper end (4a), and the sleeve-like insert (5) is inclined. Multi-axial bone anchoring device, characterized in that the two recesses (42a, 42b) extend downward from the U-shaped recess in the direction of the bottom end (4b) to be inserted from the upper end (4a) in a true posture . Device according to one of the preceding claims, characterized in that the pressing member (6, 6 ', 6 ") has a recess adapted to receive the rod. 13. The receiving space according to claim 1, wherein the receiving space 11 ″ extends into the wall of the receiving space 11 ″ from an edge in contact with the lower opening 12, while the sleeved insert Multi-axial bone fixation device, characterized in that the piece (5) has two opposing recesses (43a, 43b) configured to be inserted from the lower opening. 18. The receiving space (11) according to claim 17, wherein the receiving space (11) is sized so that the sleeved insert (5) can tilt when introduced from the lower opening (12) with the sleeved insert (5) tilted. Multiaxial bone fixation device characterized in that it has a form.

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