KR101194334B1 - Anchoring element and stabilization device for the dynamic stabilization of vertebrae or bones using such anchoring elements - Google Patents

Abstract

The present invention provides a bone fixation element 1, 1 ′, 100, 415, 420 for use in a stabilizer 200 for bone or vertebra. This bone fixation element allows the vertebrae or bones to be connected relative to the rod shaped elements 21, 417. As the rod and fixation elements 2, 4 are firmly connected to the bone or vertebra with at least one rotatable arrangement of each other, the torsional torque M is transmitted to the bone fixation elements 2, 4. It is possible to prevent the loosening or detachment of the fixing element in the bone or vertebra. The present invention also provides a stabilizer 200 using such bone fixation elements 1, 100, 415, 420.

Bone fixation element, vertebrae, rod geometry element, rotatable arrangement, stabilizer

Description

Anchor element and stabilization device for dynamic stabilization of the vertebrae or bones using the anchor element {ANCHORING ELEMENT AND STABILIZATION DEVICE FOR THE DYNAMIC STABILIZATION OF VERTEBRAE OR BONES USING SUCH ANCHORING ELEMENTS}

1a is an exploded view of a fixing element according to a first embodiment of the invention;

1B is a partial cross-sectional view of the fixing element according to the first embodiment of the present invention showing a state where a rod is inserted.

2 is a perspective view of a bearing part used in the first embodiment of the present invention.

3 shows a variant of the fixing element according to the first embodiment;

4 is an exploded view of a fixing element according to a second embodiment of the invention.

5 is a partial cross-sectional view of the fixing element according to the second embodiment of the present invention.

6A shows a side view of the rod mounting portion of the fastening element according to the second embodiment, in which the rod is inserted and the inner screw is not yet fully threaded;

6B is a side view of the rod mounting portion of the fastening element according to the second embodiment, showing that the rod is inserted and the internal screw is fully screwed in. FIG.

7A and 7B are cross-sectional views of a fixing element according to a second embodiment of the invention showing two different angular positions of the rod-shaped element with respect to the receiving part.

8A is an exploded view of a fixing element according to a third embodiment of the invention.

FIG. 8B shows a bone screw rotatably connected between a head and a fixing section as used in the third embodiment of the present invention. FIG.

8c shows a variant of the fastening element according to FIGS. 8a and 8b.

9 shows the generation torque on the bone screw in a known dynamic stabilizer.

Description of the Related Art

1, 1 ', 100, 415, 420: bone fixation element

21, 407: rod shape element

7, 412: shaft

3, 102, 408, 421: receiving parts

4, 109, 410: internal thread

The present invention relates to a fastening element and a stabilizing device for achieving dynamic stabilization of the vertebrae or bones using the fastening element.

Rigid fixation and stabilization devices are known for the fixation of fracture bones or for the stabilization of the spinal column, which devices comprise at least two bone screws secured to each bone and / or vertebra and a rigid connection connecting these bone screws to each other. It consists of a load of. For example, EP 0 483 242 discloses a fixing element according to the preamble of claim 1 below, which is used together with a rigid rod to constitute a stabilizer of the type described above. Such rigid systems are used when relative movements between bone fragments or vertebrae to be stabilized are undesirable, such as when fractures occur or when the positional relationship between other bones is incomplete.

U. S. Patent No. 5,474, 555 discloses a bone fixation element in the form of a multi-axis bone screw with a screw element and an accommodating part for connection with a rod. In this disclosed bone fixation element, the screw element is fixed to the bone. It is connected to an accommodating part in the state which can move to a certain extent with respect to. However, in the case of this disclosed configuration, there is no function of controlling relative motion between such components during stable operation.

In certain cases, such as when the intervertebral disc is damaged or when the artificial intervertebral disc is used, it is desirable that the stabilizer be able to allow some limited relative movement between the vertebrae to be stabilized. Dynamic stabilizers of this type are disclosed, for example, in US Pat. No. 5,733,284.

Stabilizers, in particular dynamic stabilizers, known from the above US patents, however, carry the risk that the rod may cause torsional torque on the bone fixation element. Torsional torque can cause the bone fixation element to loosen or eventually separate from the bone.

FIG. 9 shows the generated torque M centered on the screw axis in the known stabilizer 200. In this illustrated stabilizer 200, two bone fixation elements 202, 202 ′ are connected to each other by a curved rod 201 with a predetermined bending elastic force. This bone fixation element is firmly secured to two neighboring vertebrae (not shown) using bone screws. In the state shown in FIG. 9, two bone fixation elements 202, 202 ′ are pressed together under force F, which causes a bending moment on the rod, resulting in a bone fixation element. Torques M around the screw axis are generated on 202 and 202 '. Thereby, two bone holding elements separated by the force F are pulled out so that torque M occurs in the opposite direction about the screw axis.

It is therefore an object of the present invention to provide a bone fixation element which is free from risk of loosening or detachment from the bone during surgery and a dynamic stabilizer having such a bone fixation element for stabilizing adjacent vertebrae or bones and inhibiting their relative movement. will be.

This object of the present invention is achieved by a fixing element according to claim 1 and a stabilization device according to claim 12.

Further refinements of the invention are defined in the dependent claims.

An advantage of the present invention is that a predetermined area of the fastening element fixed to the bone is connected so as to be rotatable relative to the rod, thereby effectively preventing loosening or detachment of the fastening element even if torque is applied to the fastening element. The stabilizer of the present invention has the advantage of allowing independent control of the fixation of the rod or the shaft rotation of the head with respect to the dynamic stabilization of the vertebrae.

Further features and advantages of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings.

First Embodiment

As shown in FIGS. 1A and 1B, according to a first embodiment of the invention, the fastening element connected to the rod 21 having a bone fragment or vertebra and preferably a rectangular cross-sectional shape is provided with a screw element 2. And an accommodating part 3, an internal screw 4 screwed to the accommodating part, and a bearing part 5.

The screw element 2 comprises an ellipsoid segment-shaped head 6 and a threaded shaft 7 fixed to the bone or vertebra. On the opposite side of the threaded shaft 7 the head 6 of the screw element 2 is flattened and provided with a hexagon socket screw keying groove 8.

The receiving part 3 is a substantially cylindrical body with a first end 9 and a second end 10 opposite this first end. In such a receiving part, a bore hole 11 extending coaxially with the main axis line is formed. A rectangular groove 12 is formed towards the first end 9 to accommodate the rod 21, which also forms two free legs 40, 41. The width of the rectangular groove 12 is only slightly longer than the length of the short side of the rod having a rectangular cross section, and the depth is longer than the length of the long side of the rod. An internal thread 13 is formed in the bore hole 11 on the inner side surfaces of the legs 40, 41 adjacent to the first end 9. The bore hole has a substantially constant inner diameter over the first section adjacent the first end, which is slightly larger than the diameter of the head 6 of the screw element 2. The portion adjacent to the first section of the receiving component 3 is tapered from the first end 9 to the second end 10 so that a spherical seating portion 14 is formed adjacent the second end. . The diameter of the second end side orifice 32 is larger than the diameter of the threaded shaft 7 of the screw element 2.

The bearing part 5 comprises a cylindrical section on which the front side 15 is flat. This cylindrical section is formed with a diameter sufficient to press-fit to the first section of the receiving part 3 in the assembled state. The bearing part 5 also comprises a ball socket shaped section 31 adjacent the cylindrical section. The contour of this section 31 coincides with the shape of the spherical seating portion 14. A spherical groove 17 is defined in the bearing part 5 to accommodate the head 6 of the screw element 2. Depending on the desired resistance characteristics of the rotating and pivoting movement of the screw element relative to the bearing part, the inner diameter of the groove 17 is determined in a range that is approximately equal to or only slightly larger than the diameter of the head of the screw element. A bore hole 18 is formed extending from the flat front side 15 and terminating in the groove 17, the diameter of which is a hexagon socket screw key guided through this bore hole to tighten the screw element 2. It is determined to be smaller than the diameter of the head 6 of the screw element 2. The ball socket shaped section is formed with a coaxial bore hole 19 terminating in the groove 17, the threaded section having a diameter smaller than the diameter of the head 6 of the screw element 2. It is larger than the diameter of (7). As shown in FIG. 2, the bearing part 5 comprises a slit 30 in a ball socket shaped section adjacent to the opposite side of its flat front side 15. This slit 30 serves to increase the elastic force of the bearing part. Preferably, the bearing part 5 is formed of a body compatible plastic material with good sliding properties, preferably polyethylene (PE). Herein, for example, LDPE and LLDPE having a molecular weight of 50,000 g / mol and HDPE having a molecular weight of 200,000 g / mol or ultra-high molecular weight polyethylene (UHMWP) having a molecular weight of approximately 6,000,000 g / mol; ultra high Various levels of crosslinking can be used resulting in various molecular weights, such as molecular weight polyethylene). UHMWP is preferred for use as a constituent material of bearing components because of its low wear and tear even after prolonged use.

The inner screw 4 has a coaxial groove 42 for hexagon socket screw key engagement.

At the time of operation, the head 6 of the screw element 2 is first inserted into the groove 17 of the bearing part 5, and the screw element 2 and the bearing part 5 together are inserted into the receiving part 3. do. Following this preassembly, the screw element 2 is screwed into the bone or vertebra. Thereafter, the rod-shaped element 21 is disposed in the receiving component 3 so that the receiving component 3 is correctly aligned with respect to the rod-shaped element 21. Subsequently, the rod-shaped element 21 and the receiving part 3 are fixed to each other by the internal screw 4.

According to the above-described procedure, a connection is formed between the screw element 2 and the rod-shaped element 21 which are screwed firmly into the bone or vertebra, in which the head 6 of the screw element 2 is It is seated on the bearing part 15 so as to be rotatable within the angular range. The angular range is, on the one hand, by the diameter of the threaded shaft 7, on the other hand by the diameter of the orifice 32 on the second end 10 side of the receiving part 3 or of the bearing part 5. It is determined by the diameter of the coaxial bore hole 19. Depending on the relativity of the diameter of the spherical groove 17 and the diameter of the head 6, the friction force acting between the head and the bearing part may vary. The frictional force here is the force that must be overcome in order for the head 6 of the screw element 2 to rotate or pivot in the groove 17 of the bearing part 5.

3 shows a variant 1 ′ of the fastening element 1 according to the first embodiment, in which the bearing part 5 ′ is divided into two of the first bearing element 5 a and the second bearing element 5 b. It is formed as a part of. The two-piece bearing part 5 'is similar to the bearing part 5 except that it is divided into two parts in a direction parallel to the front side thereof. By forming in two parts in this way, the head 6 of the screw element 2 can be inserted into the groove 17 'without increasing the size of the orifice 19'. As a result, the bearing part 5 'can be formed of a hard material having no slit.

Second Embodiment

4 to 7b, there is shown a fixing element 100 according to a second embodiment of the invention. The same reference numerals are assigned to the same elements as those of the first embodiment.

4 and 5, the fastening element 100 according to the second embodiment of the invention comprises a screw element 2, a receiving part 102, a pressing element 103, and a first one. A ring 104, a second ring 105, a first bearing component 106, a second bearing component 107, a rod mounting portion 108, and an internal thread 109.

The screw element 2 of the fastening element 100 according to the second embodiment is identical to the screw element 2 of the fastening element 1 according to the first embodiment.

The receiving part 102 is a substantially cylindrical body having a first end 112 and a second end 113 opposite the first end. A coaxial bore hole 120 extends from the first end 112 to the second end 113 of the receiving component 102, with a substantially U-shaped groove 140 at the first end 112. It is formed adjacent. This U-shaped groove 14 forms two free legs 114 and 115. Internal threads 122 are formed adjacent to the first end 112 on the inner surfaces of these free legs 114 and 115. The bore hole 120 has a substantially constant inner diameter in the section adjacent the first end 112 of the receiving part 102, which is larger than the diameter of the head 6 of the screw element 2. In the second section extending to the second end of the receiving component 102 adjacent to the first section, the bore hole 120 is tapered toward the second end 113. The region adjacent the second end 113 is formed of a spherical section 121 that matches the shape of the head 6 of the screw element 2. The diameter of the bore hole in the second section is smaller than the diameter of the head 6 of the screw element 2 at the portion adjacent the second end but larger than the diameter of the threaded shaft 7 of the screw element 2.

On the outer side of the first ring 104 is formed an outer thread 123 which cooperates with the inner thread 122 on the inner side of the free legs 114, 115 of the receiving component 102. In addition, the front side 146 of the first ring 104 is formed with a groove 124 extending in the radial direction, so that a tool for screwing the first ring 104 into the receiving component 102 is formed therein. It can be combined.

The second ring 105 has a tubular shape with a constant outer diameter, and has a first section having a first inner diameter adjacent the first end 141 and a second inner diameter adjacent the second end 142. It consists of a second section. The second inner diameter is larger than the first inner diameter, and a shoulder 147 is formed between the first section and the second section. The outer diameter of the second ring 105 constant along the entire length of the ring is a bore hole in the section adjacent the first end 112 of the receiving component 102 so that the ring 105 can slide into the bore hole 120. Slightly smaller than the diameter of 120. Rectangular grooves 143 forming two free legs 144 and 145 are formed adjacent to the first end 141. The width of this groove 143 is similar to the width of the U-shaped groove 140 of the receiving part 102 and is longer than the short side of the rectangular cross section of the rod, so that the rod 21 disposed in the groove has a predetermined angle range, preferably It is preferably configured to be able to swing back and forth over approximately ± 10 °.

The pressing element 103 is formed in the form of a substantially flat cylindrical body with a spherical groove on the side facing the screw head, the shape of which coincides with the head 6 of the screw element 2. This pressing element 103 is provided with a coaxial bore hole 110, which is terminated in the groove 111 so that the screwdriver can pass through the hole. The outer diameter of the pressing element 103 is slightly smaller than the diameter of the bore hole 120 of the receiving component 102 so that the pressing element 103 can slide into the bore hole of the receiving component.

The first and second rings 104, 105 apply a force to the pressing element 103 to secure the head 6 of the screw element 2 in the spherical section 121.

The first bearing part 106 is formed in a disc shape and has a coaxial bore hole 135 and a ring-shaped protrusion 148 for guiding the passage of the screwdriver. The protrusion extends in the circumferential direction on the opposite side of the pressing element in the inserted state. This ring-shaped protrusion includes two rectangular grooves 149 opposite each other.

The second bearing component 107 is formed from a tubular section with a flanged protrusion 151, the diameter of which is smaller than the diameter of the first bearing component 106 and the outer diameter of the flanged protrusion 151 is It is equal to the diameter of the first bearing part 106. Adjacent to the flange-like protrusion 151, two rectangular grooves 150 opposite to each other are formed.

In the inserted state, the first and second bearing parts 106 and 107 are arranged coaxially such that the ring-shaped protrusion 148 of the first bearing part 106 is the flanged protrusion 151 of the second bearing part 107. ), And the rectangular grooves 149, 150 of these two bearing parts 106, 107 are aligned with each other so that two orifices for receiving the rod therein are provided by the two bearing parts 106, 107. It is defined. These two orifices have opposite configurations to each other and terminate inside the bearing. The width of the orifices formed by the grooves 149 and 150 in the assembled state is selected so that the rod 21 disposed through these orifices can pivot back and forth over a predetermined angle range, preferably in a range of ± 10 °. do. The height of the orifice formed by the grooves 149 and 150 in the assembled state is slightly longer than the corresponding side of the rod 21. Such a bearing part has an outer diameter such that it can be press-fitted to the first and second clamp rings. In the assembled state, the flanged protrusion 151 is placed against the shoulder 147 of the second ring 105.

Preferably, the first and second bearing parts 106, 107 are formed of a body compatible plastic material with good sliding movement properties, preferably polyethylene (PE) is used. In the present specification, various molecular weights, for example, LDPE and LLDPE having molecular weights of 50,000 g / mol and HDPE having molecular weights of 200,000 g / mol or UHMWP (ultra high molecular weight polyethylene) having molecular weights of approximately 6,000,000 g / mol Various levels of crosslinking can be used that result in the following. UHMWP is preferred for use as a constituent material of bearing components because of its low wear and tear even after prolonged use. The remaining parts of the fastening element are preferably formed of a body compatible material with good mechanical properties such as titanium.

As shown in FIGS. 5, 6A and 6B, the rod mount 108 is formed as a cylindrical body having a first end 130 and a second end 131, and is formed from the first end 130. It has a continuous coaxial bore hole 132 extending to two ends 131. An inner thread 155 may be formed on the inner circumferential surface of the bore hole 132 adjacent to the first end 130, so that the inner screw 109 may be screwed to the inner thread. The outer diameter of the rod mount 108 is slightly smaller than the inner diameter of the second bearing part 107. The second end 131 of the rod mounting portion 108 is provided with a flange-shaped protrusion 152 whose outer diameter is slightly smaller than the inner diameter of the first bearing part 106. The side wall of the rod mount 108 is provided with two orifices 133 having opposite rectangular cross sections from each other. The width B of the orifice is slightly wider than the width of the rod, and the height H of the orifice is higher than the height of the rod.

The inner screw 109 includes an outer thread 154 that cooperates with an inner thread 155 of the rod mounting portion 108, and a coaxial bore hole 134 extends through the inner thread 109. This coaxial bore hole has a cross-sectional shape suitable for hexagon socket screw key engagement.

As shown in FIGS. 6A and 6B, the axial length of the section of the internal thread 155 of the rod mount 108 and the height of the orifice 133 are defined by the orifice 133 from one position where the rod is displaceable within the orifice. It is selected to be displaceable to another position where it is pressed against the lower edge 153 and fixed according to the tightening of the inner screw 109.

At the time of operation, for preassembly of the fastening element, the screw element 2 is first inserted into the receiving part 102 with the threaded shaft 7 facing forward so that the head 6 is inserted into the spherical region 121. To be deployed. Then, from the side of the first end 112 of the receiving component 102, the pressing element 103 is inserted into the coaxial bore hole 120 of the receiving component 102 with its spherical groove 111 facing the head. Next, the first bearing part 106 is inserted into the receiving part 102 with its coaxial bore hole coming to the front, and then the rod mounting portion 108 in which the internal screw 109 is incompletely screwed on is first mounted. It is disposed in the bearing part 106. Thereafter, the second bearing part 107 and the second ring 105 are inserted back and forth with each other between the side wall of the receiving part 102 and the first and second bearing parts 106 and 107. Finally, the first ring 104 is screwed into the receiving component 102 only to prevent separation of the element inserted into the receiving component 102. In this way, the preassembly of the fixing element 100 is completed.

However, optionally, the rod mounting 108, the first and second bearing parts 106 and 107, the first and second rings 104 and 105 and the inner screw 109 are first assembled outside the receiving part. It can then be assembled in such a way that it is inserted into the receiving part, and other types of assembly are also possible.

In surgery, a hexagon socket screw key is guided through the bore holes 134, 132, 135, 110 to be used to screw the screw element 2 into the vertebra or bone during surgery. Subsequently, the rod slides from one side of the receiving component 102 between the two free legs 114, 115, in turn, the orifice 133 of the rod mounting 108, and the first and second bearing components 106. 107, and slides through the groove of the first ring (105). Thereafter, a force is applied to the pressing element 103 by tightening the first ring 104 and the receiving part 102 is fixed in one position relative to the screw element 2. Subsequently, the rod 21 is fixed to one position of the rod mounting portion 108 by inserting and tightening the internal screw 109.

In this way, a connection is effectively formed between the rod-shaped element 21 and the bone or vertebra, and in this connection, the rod mounting portion 108 to which the rod-shaped element 21 is fixed is used for the receiving part 102 over a predetermined angle range. Can rotate around the main axis. The angular range includes the dimensions of the rod 21, the width of the grooves 140 of the receiving part 102, the width of the rectangular grooves 149, 150 of the first and second bearing parts 106, 107, and the second. It is determined by the width of the groove 143 of the ring 105. The rod mount 108 rotates with the rod 21, while the bearing parts 106, 107 are firmly seated in the first and second rings 104, 105 by press fit. The angular position of the screw fastening axis with respect to the receiving component 102 remains fixed.

7a and 7b show two different limiting angle positions α and β of the rod-shaped element 21 with respect to the receiving component 102.

Unlike the fastening element 1 according to the first embodiment, in which the rod provides three different rotatable arrangements with respect to the screw element, according to the connection configuration of the fastening element 100 according to the second embodiment the rod is screwed. Provide only one rotatable arrangement for the element.

Third Embodiment

According to a third embodiment of the invention, the rotatable connection between the rod and the bone or vertebra is made using multiaxial screws. In such a multi-axial screw, the angle between the rod 407 and the receiving part 408 and between the screw element and the receiving part is fixed as shown in Fig. 8A, and the screw element 400 is composed of two parts. have. Head 401, which is part of the screw element, is rotatably connected to threaded shaft 412, which is the other part. As shown in FIG. 8A, the multi-axis screw includes a receiving component 408, a pressing element 409, an inner screw 410 and an outer screw 411.

As shown in FIG. 8B, the head 401 of the screw element 400 consists of a cylindrical neck 403 and a spherical segment shaped head section 402. In addition, a pin 404 may be provided on the side of the neck 403 to be pressed along the longitudinal axis into the neck 403 by an elastic force.

On the side facing the head 401 of the screw element 400, the threaded shaft 412 has a coaxial groove 405 for engaging the neck 403. Longitudinal holes 406 for coupling the pins 404 are formed in the sidewalls of the grooves 405.

During surgery, the pin is first pressed into the neck such that the neck 403 can slide into the groove 405 of the threaded shaft 412. Thereafter, the neck 403 slides into the groove 405 such that the pin 404 engages the longitudinal hole 406 formed in the sidewall of the groove 405 under the action of the elastic force. In this way, the head 401 of the screw element 400 and the threaded shaft 412 are connected. In this connection the head 401 is rotatable about a coaxial line with respect to the threaded shaft 412 of the threaded element over a predetermined angular range by the length of the longitudinal hole 406.

The screw element 400 is then inserted into the receiving part 408 and screwed into the bone. The relative position of the screw element relative to the receiving part is then fixed and the rod 407 is inserted and fixed in a known manner.

Similar to the second embodiment, the connection of the securing element according to the third embodiment also provides only one rotatable arrangement.

In a variant of the third embodiment shown in FIG. 8C, a bone fixation element 420 in the form of a single screw is provided, such that the receiving part 421 is rigidly connected to or fixed to the head of the two-piece screw element. It is formed as an integral component of. This bone fixation element 420 is the same as in the third embodiment described above for the other parts.

The following modifications of the embodiments of the invention as described above are also possible.

Although the orifice 19 of the bone fixation element according to the first embodiment is described as having a diameter smaller than the diameter of the head 6 but larger than the diameter of the threaded section 7, the screw element is formed of two parts. The diameter of the orifice 19 may be smaller than the diameter of the threaded shaft 7 so that it is not necessary to guide the threaded shaft through the orifice 19 during assembly. It is also possible to form an orifice so that the screw element can be screwed through the orifice.

In the fastening element according to the first embodiment, a head which is not spherical but rotationally symmetrical about the screw axis may limit the rotational movement of the screw element relative to the receiving part to only one arrangement. In the case of the bearing part 5 according to the first embodiment, and also in the case where the head 6 of the screw element 2 can be inserted even in the absence of the slit 20 because the constituent material itself has elastic force. It is not necessary to include the same one or multiple slits 20.

The diameter of the bore hole 120 of the second section of the receiving component 102 according to the second embodiment is larger than the diameter of the threaded shaft 7 of the screw element 2 in the region adjacent the second end 113. Although described as large, the diameter of the bore hole 120 adjacent the second end may be determined such that the threaded element may be screwed through the bore hole, or if the diameter of the bore hole consists of a plurality of parts, It may be smaller than the diameter of the threaded shaft 7. In this case, the screw element need not be guided through the bore hole 120 but can be connected to the outside of the head disposed in the receiving part.

In addition, the protrusion 148 may not be provided in the first bearing component 106.

The fastening element 100 according to the second embodiment may be formed in the form of a single screw, in which case the receiving part 102 may be rigidly connected to the screw element 2 or may be formed as an integral element.

In all of the above-mentioned fastening elements, instead of the fastening method using screw elements, other fastening methods, for example hooks or the like, may be used to fasten the bone or vertebrae.

Although the bone fixation element according to the first and second embodiments of the present invention has been described for rod-shaped elements having a rectangular cross section, by appropriately modifying the shape of the bore hole and groove for accommodating the rod, Bone fixation elements may be used with rod-shaped elements having a circular or other shaped cross section. Similarly, the bone fixation element according to the third embodiment can also be modified for use with rod-shaped elements having a rectangular or other shaped cross section.

It is described in connection with the third embodiment that the pin 404 can be pressed into the neck 403 using an elastic force, but is inserted by a pressure fit into the hole of the neck 403 or 422 to allow the neck 403 or 422 may be rigidly connected. In this case, the neck is inserted into the groove 405 without the pin during surgery, and then the pin is inserted through the longitudinal hole 406 into the hole in the neck. In addition, an external thread may be formed in the pin to form the pin and the neck so that the external thread may be screwed into the internal thread provided in the hole of the neck. In addition, the screw head 401 and the threaded section 402 may be rotatably connected in various other ways.

The stabilization device according to the invention for achieving dynamic stabilization of a bone or vertebra, similar to the known stabilization device shown in FIG. 9, consists of at least two bone anchoring elements and rod-shaped elements connecting these anchoring elements. At least one of the elements is a bone fixation element according to the first to third embodiments of the invention.

According to the bone fixation element and dynamic stabilizer of the present invention, it is possible to completely prevent the bone fixation element fixed to the bone or the vertebrae from loosening or detaching from the bone during surgery, and such neighboring vertebrae or bones are stable to each other. The relative movement can be effectively suppressed.

Claims (14)

As a fastening element 1, 1 ′, 100, 415, 420 for fastening the rod shaped elements 21, 407 to a bone or vertebrae, Shafts 7 and 412 fixed to the bone or vertebra; Receiving parts 3, 102, 408, 421 connected to the shafts 7, 412 to receive the rod-shaped elements 21, 407, and Such fastening elements 1, 1 ′, 100, 415, comprising fastening devices 4, 109, 410 for fastening the rod shaped elements 21, 407 to the receiving parts 3, 102, 408, 421. 420, wherein In the fixed state of the rod-shaped elements 21, 407, the shafts 7, 412 are connected to the rod-shaped elements 21, 407 by the receiving parts 3, 102, 408, 421 in a movable manner. And the shaft (7, 412) is movable relative to the rod-shaped element (21, 407) in a state in which translational motion is not possible but provides at least one rotatable arrangement. 2. The shaft (1) according to claim 1, characterized in that the shaft (7) is rigidly connected to the receiving component (102) and the rod-shaped element (21) is held in the mounting portion (108) in the receiving component (102) so as to be rotatable. Fixed elements. 3. A fastening element according to claim 2, wherein the mounting portion (108) is seated in a bearing component (106, 107) so as to be rotatable. 4. A screw according to claim 3, provided in the form of a multi-axial screw with a bone fixation element (2) consisting of the shaft (7) and a spherical segmented head (6), A spherical seating portion 121 is formed adjacent to one end of the receiving component 102 for receiving a spherical segment-shaped head 6 of the bone fixation element 2, Two opposite grooves 140 are formed opposite to the other end of the receiving part 102, and these grooves form two free legs 114 and 115, Threads 122 may be formed on the inner surfaces of the free legs 114 and 115 such that ring-shaped elements 104 may be screwed into the threads such that pressure is applied directly or indirectly to the pressure element ( Applied on 103, the pressure applied in this way is transferred back to the head 6 of the bone fixation element 2 so that the bone fixation element 2 is relative to the receiving part 102 at a predetermined angular position. Fixed in position, The bearing element (106, 107) is characterized in that it is located inside the ring-shaped element (104). 5. A fastening element according to claim 4, characterized in that the bearing part (106, 107) is firmly connected to the ring-shaped element (104) by a press fit. A head (6) according to claim 1, which is provided adjacent to the shaft (7), is held in the receiving part (3) in a bearing part (5, 5 ') and is arranged to be rotatable relative to the rod-shaped element. Fixed element characterized in that there is. 7. Fastening element according to one of the claims 3 to 6, characterized in that the bearing part (5, 106, 107) is formed of a body compatible plastic material. 2. The head 401 of claim 1 provided adjacent the shaft 412 may be secured within the receiving component 408 such that the shaft 412 is positioned at a predetermined angular position relative to the receiving component 408, And said head (401) and shaft (412) are formed as separate components rotatably connected to each other. 2. The head of claim 1 wherein the head provided adjacent to the shaft 412 is rigidly connected to the receiving component 412 or is formed as an integral element, And the shaft (412) and the head are formed as separate components rotatably connected to each other. 10. A fastening element according to claim 1, wherein a limit stop (149, 150, 406) is provided for limiting the rotational movement. 10. A fastening element according to claim 1, wherein the shaft (7, 412) fixed to the bone or vertebra comprises threads. 11. 10. Stabilizer 200 having at least two fastening elements 202, 202 'and rod-shaped elements 201 connecting them, any of claims 1 to 6, 8 and 9. Stabilizer, characterized in that at least one fixing element according to claim is provided. As a fastening element 1, 1 ′, 100, 415, 420 for fastening the rod shaped elements 21, 407 to a bone or vertebrae, Shafts 7 and 412 fixed to the bone or vertebra; Receiving parts 3, 102, 408, 421 connected to the shafts 7, 412 to receive the rod-shaped elements 21, 407, and In such fastening elements comprising fastening devices 4, 109, 410 for fastening the rod-shaped elements 21, 407 to the receiving parts 3, 102, 408, 421. In the stationary state of the rod shaped elements 21, 407, the shafts 7, 412 are connected to the rod shaped elements 21, 407 by the receiving parts 3, 102, 408, 421 in a rotatable manner. And a guide surface for limiting the relative movement of the shaft (7, 412) and the rod-shaped element (21, 407) in a state of providing one rotatable arrangement. 7. Fastening element according to one of the claims 3 to 6, characterized in that the bearing part (5, 106, 107) is formed of polyethylene.

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