Source: https://patents.google.com/patent/ES2378588T3/en
Timestamp: 2019-12-14 02:46:25
Document Index: 738162827

Matched Legal Cases: ['art 5', 'art 5', 'art 5', 'art 5', 'art 9', 'art 9', 'art 9', 'art 9', 'art 5', 'art 5', 'art 16', 'art 16', 'art 16', 'art 9', 'art 16', 'art 16', 'art 9', 'art 16', 'art 16', 'art 9', 'art 9', 'art 16', 'art 16', 'art 5', 'art 81', 'art 81', 'art 16', 'art 16', 'art 82', 'art 5', 'art 83', 'art 9', 'art 16', 'art 16', 'art 9', 'art 5', 'art 16', 'art 5', 'art 9', 'art 16', 'art 16', 'art 5', 'art 16', 'art 5', 'art 5', 'art 16', 'art 16', 'art 9', 'art 16', 'art 83', 'art 81', 'art 81', 'art 81', 'art 16', 'art 91', 'art 9', 'art 81', 'art 16', 'art 5', 'art 101', 'art 100', 'art 5', 'art 16']

ES2378588T3 - Receiving part for receiving a rod for coupling the rod in a bone anchoring element and bone anchoring device with such receiving part - Google Patents
Receiving part for receiving a rod for coupling the rod in a bone anchoring element and bone anchoring device with such receiving part Download PDF
ES2378588T3
ES2378588T3 ES08022553T ES08022553T ES2378588T3 ES 2378588 T3 ES2378588 T3 ES 2378588T3 ES 08022553 T ES08022553 T ES 08022553T ES 08022553 T ES08022553 T ES 08022553T ES 2378588 T3 ES2378588 T3 ES 2378588T3
ES08022553T
2012-04-16 Publication of ES2378588T3 publication Critical patent/ES2378588T3/en
Receiving part for receiving a rod in order to engage the rod in a bone anchoring element, the receiving part including a body of the receiving part (5, 5 ', 5 ") with a rod receiving part (9 ) with a channel (12) for receiving the rod, and a head receiving part (16) for receiving a head (3) of the bone anchoring element, the head receiving part (16) has an open end (17 ) and is flexible to allow the introduction and clamping of the head, and a fixing ring (8, 80, 800) surrounding the head receiving part, where the fixing ring exerts a force on the receiving part of head for locking the head, characterized in that the fixing ring (8, 80) or the body of the receiving part (5 ") comprises a spring part (83, 90, 101) cooperating with a part (9, 30 , 31, 41, 42) of the body of the receiving part or the fixing ring (800), respectively, in order to hold take the head in a presetting position of the fixing ring
Receiving part for receiving a rod for coupling the rod in a bone anchoring element and bone anchoring device with such receiving part
The present invention relates to a receiving part for receiving a rod in order to couple the rod in a bone anchoring element and to a bone anchoring device with such receiving part. The receiving part includes a body of the receiving part and a fixing ring. The head of the bone anchoring element is fixed in the body of the receiving part by the compression of a head receiving part of the receiving part that surrounds the head laterally by means of the fixing ring. The fixing ring includes a spring part that cooperates with a body part of the receiving part to exert a claim that holds the head in a preset position for safe handling during surgery. The bone anchoring device can be made, for example, in the form of a polyaxial bone screw.
Several designs of polyaxial bone screws are known where the head is secured from the side to fix the rotational position of the bone screw.
US 5,672,176 describes a bone screw with a receiving part having a conical seat and a conical pressure element that exerts pressure on the head from above and from the side. If the conicity angle has a value within a specific range, a self-fixation of the pressure element within the receiving part occurs, which allows the head to be initially fixed within the receiving part, while the rod remains mobile to allow adjustment of its position.
US 5,728,098 describes a bone screw for connection to a spinal rod comprising a screw element and a receiving element having grooves provided at the bottom of the rod receiving channel and where two ring-shaped compression elements made of a shape memory alloy, they are provided in the lower and upper part of the receiving element, respectively. The compression elements are compressed around the parts of the receiving element when the temperature is high so that the rod is secured in the channel.
WO 2007/038350 A2 describes an apparatus for connecting a bone anchor to a support rod, the apparatus including a connector body and a cover. The connector body has a cavity to insert, angular and remove a bone anchor. A sleeve is provided configured to fit over the connector body in a temporary position, where the sleeve allows the insertion of the bone anchor to move to a provisional fixation position in which the sleeve allows angulation, although it prevents the removal of the bone anchor and to move to a fixation position, in which the sleeve prevents both angulation and removal of the bone anchor. The sleeve extends over the entire length of the cavity.
US 2002/0032443 A1 describes a spinal fixation assembly comprising a receiving element and a bone screw that can pivot within the receiving element. In one embodiment, two ring-shaped compression elements are provided, each being formed of a temperature sensitive material that is compressed around a part of the receiving element to thereby compress the receiving element around both the head of the bone screw that is inside the cavity like the spinal rod that is inside the channel of the receiving element.
US 2005/0080415 A1 describes a polyaxial bone anchor for attaching a rod to a bone, comprising an anchoring element for bone attachment, a body element having a U-shaped channel for receiving the rod and a cavity compressible to receive a head of the anchoring element so that the anchoring element can be angled polyaxially at the beginning with respect to the body element, a collar arranged slidably around the body element and which can compress the cavity around the head, and a clamping piece that can press the rod against the collar.
It is the purpose of the invention to provide an improved receiving part for receiving a rod in order to engage it in a bone anchoring element and a bone anchoring device with such a receiving part that has a small size and at the same time allows safe handling. during surgery and a safer final fixation.
The purpose is solved with a receiving part according to claim 1 and a bone anchoring device according to claim 18. Other improvements are shown in the dependent claims.
The fixing ring can be placed in three positions. In the insertion position, the head can be inserted into the head receiving part. In the preset position, the fixing ring prefixes the head in the head receiving part which prevents accidental removal of the head from the body of the receiving part, and prevents accidental movement of the head relative to the body of the reception part during surgery. This allows safer handling of the bone anchoring device during surgery. In the fixation position, the head is finally fixed in the receiving part. The fixing ring can be released releasably in the insertion position and in the presetting position. This makes handling more convenient.
The presetting and final fixation of the head are achieved with a single fixing ring. Therefore, the receiving part and the bone anchoring device according to the invention comprise fewer elements, which reduces manufacturing costs and facilitates handling. It makes use of the principle of securing the head of the bone anchoring element circumferentially from the sides, which reduces the force necessary to securely hold the head. The design of the receiving part further reduces the dimension in terms of height, as well as the lower outer diameter, which makes it especially suitable for applications where small bone anchoring devices are needed, for example in the field of cervical spine surgery, in pediatric applications or in traumatic and minimal opening applications.
By providing several bone anchors with different receiving parts, a modular system is available before surgery.
The receiving part can be designed with a small diameter. The pressure exerted through the fixing ring on the head receiving part is the largest in a position of the largest diameter of the head of the bone anchoring element. Therefore, the fixing ring does not have to extend to the open end of the head receiving part which allows to have a fixing ring with a reduced diameter at the lower end.
When the fixing ring has a curved internal surface part, no interference occurs between the fixing ring and the head receiving part.
Other features and advantages of the invention are clear in the description of the embodiments, with reference to the attached drawings.
Figure 1 shows an exploded perspective view of a first embodiment of the bone anchoring device.
Figure 2 shows a perspective view of the bone anchoring device of Figure 1 in the assembled state.
Figure 3 shows a perspective view of the body of the receiving part according to the first embodiment.
Figure 4 shows a side view of the body of the receiving part of Figure 3.
Figure 5 shows a sectional view of the body of the receiving part of Figure 3, the section being made perpendicular to the axis of the rod.
Figure 6 shows a top view of the body of the receiving part of Figure 3.
Figure 7 shows a perspective view of the fixing ring of the first embodiment.
Figure 8 shows a top view of the fixing ring of Figure 7.
Figure 9 shows a side view of the fixing ring of Figure 7.
Figure 10 shows a sectional view of the fixing ring of Figure 7, the section being taken along line A-A of Figure 7.
Figure 11 shows a sectional view of the bone anchoring device of the first embodiment in a first
position, the section being made perpendicular to the axis of the rod.
Figure 12 shows a sectional view of the bone anchoring device of Figure 11 in a second position.
Figure 13 shows a sectional view of the bone anchoring device of Figure 11 in a third position.
Figure 14 shows an exploded perspective view of a second embodiment of the bone anchoring device.
Figure 15 shows a perspective view of the bone anchoring device of Figure 14 in the assembled state.
Figure 16 shows a perspective view of the body of the receiving part according to the second embodiment.
Figure 17 shows a side view of the body of the receiving part of Figure 16. Figure 18 shows a sectional view of the body of the receiving part of Figure 16, the section being Perpendicular to the shaft of the rod.
Figure 19 shows a top view of the body of the receiving part of Figure 16.
Figure 20 shows a perspective view of the fixing ring of the second embodiment.
Figure 21 shows a sectional view of the fixing ring of Figure 20, the section being taken along the line
A-A in Figure 20.
Figure 22a shows a sectional view of the bone anchoring device of the second embodiment in a first
Figure 22b shows an enlarged view of a detail of Figure 22a.
Figure 23a shows a sectional view of the bone anchoring device of Figure 22a in a second position.
Figure 23b shows an enlarged view of a detail of Figure 23a.
Figure 24a shows a sectional view of the bone anchoring device of Figure 22a in a third position.
Figure 24b shows an enlarged view of a detail of Figure 24a.
Figure 25 shows an exploded perspective of a third embodiment of the bone anchoring device.
Figure 26 shows a perspective view of the bone anchoring device of Figure 25 in the assembled state.
Figure 27 shows a top view of the body of the receiving part of the third embodiment.
Figure 28 shows a sectional view of the bone anchoring device of the third embodiment in a first
position, the section being made perpendicular to the axis of the rod. Figure 29 shows a sectional view of the bone anchoring device of Figure 28 in a second position. Figure 30 shows a sectional view of the bone anchoring device of Figure 28 in a third position. Detailed description of the invention As shown in Figures 1 and 2, the bone anchoring device according to a first embodiment comprises a
bone anchoring element 1 in the form of a bone screw with a threaded rod 2 and a head 3 with a part
curved surface, in this embodiment a spherical segment-shaped head. Head 3 has a cavity
4 to attach a screwing tool. The bone anchoring device further comprises a body of the receiving part 5 for receiving a rod, in order to connect it to the bone anchoring element 1. In addition, a closure element 7 is provided in the form of an internal screw to secure the rod 6 on the body of the receiving part 5. In addition, the bone anchoring device includes a fixing ring 8 for fixing the head on the body of the receiving part 5.
As can be seen in particular in Figures 3 to 6, the body of the receiving part 5 comprises a substantially cylindrical rod receiving part 9 with a first end 9a and a second opposite end 9b. The rod receiving part 9 has a first coaxial bore 10 provided at the second end 9b. The diameter of the first bore 10 is smaller than the diameter of the head 3 of the bone anchoring element. The rod receiving part 9 also comprises a second coaxial bore 11 that extends from the first end 9a at a distance from the second end 9b. The diameter of the second bore 11 is larger than that of the first bore 10 and larger than the diameter of the rod 6. A substantially U-shaped cavity 12 is provided in the rod receiving portion 9, which extends from the first end 9a to the second end 9b, the diameter of the cavity 12 being slightly larger than the diameter of the rod 6 such that the rod 6 can be placed in the cavity and guided therethrough. By means of the cavity 12, two free legs 12a, 12b are formed, in which an internal thread is provided 13. The internal thread can be a metric thread, a flat thread, a negative angle thread, a sawtooth thread, or any other type of thread. Preferably, a thread form such as a flat thread or a negative angle thread is used which prevents the legs 12a, 12b from opening when the internal screw is screwed 7. The depth of the cavity 12 is such that the rod 6 and the internal screw 7 can be inserted between the legs. Between the bottom of the cavity and the legs 12a, 12b, a flat section 14 is provided which forms the end of the hole 11.
As can be seen in Figures 1, 2, 3 and 6, cuts 24 are provided in the rod receiving part at each end of the channel formed by the cavity 12.
The rod receiving part 9 of the body of the receiving part 5 further comprises a plurality of coaxial grooves 15 extending from the second end 9b at a certain distance from the first end, distance approximately corresponding to the length of the internal thread 13. The grooves 15 open towards the second end 9b and extend, as can be seen in particular in Figures 1, 3 and 6, through the flat section 14 of the substantially U-shaped cavity 12. At least a groove 15, preferably more than one, is provided on each side of the cavity 12. The number of grooves is selected based on the degree of elasticity that the grooves will provide. It may depend on the material and wall thickness and / or other factors.
The rod receiving part has an annular cavity 30 next to its second end 9b by means of which a flange 31 is formed at a certain distance from the second end. The depth of the cavity 30 is such that it can cooperate with a part of the fixing ring 8 described below.
Next to the second end 9b, the body of the receiving part 5 comprises a head receiving part 16 that provides a housing space for the head 3 of the bone anchoring element 5. The head receiving part 16 has a surface external which decreases towards the second end 9b and which has an open end 17 opposite the second end 9b. The external surface of the head receiving part 16 may be partially or totally conical. It is conical, at least in the area of greater diameter of the head 3. The open end 17 may have a rounded edge.
As can be seen in particular, in Figures 3 to 5, the outside diameter of the rod receiving part 9 at the second end 9b is larger than the outside diameter of the head receiving part 16 adjacent to the second end 9b and is also larger than the outer diameter of the head receiving part at the open end 17. Therefore, the head receiving part 16 is lowered with respect to the rod receiving part 9.
As can be seen in particular, in Figure 5, the head receiving part 16 has an internal hollow section 18 that forms a head seat 3 of the bone anchoring element 1. The hollow section 18 has its shape adapted to the shape of the head 3, in the embodiment shown is a spherical section to receive the spherical head 3. The hollow section 18 is sized to surround the head 3 of the bone anchoring element from the side that covers an area that includes the largest head diameter 3.
A plurality of grooves 19 are provided in the head receiving part 16, open to the open end 17 and extending from the open end 17 to the second end 9b of the rod receiving part and continue in the cuts 15 of the rod receiving part 9, to form continuous grooves extending from the open end 17 of the head receiving part to the rod receiving part 9. The number of grooves 19 may be equal to the number of grooves 15, without However, it may be greater or lesser depending on the desired elasticity of the head receiving part 16. In addition, slits 20 are provided on the side of the head receiving part adjacent to the substantially U-shaped cavity 12 of the part of the rod reception, as shown in Figure 6. The slits 20 terminate at a distance from the second end 9b. The elasticity of the head receiving part 16 is such that the head 3 of the anchoring element can be inserted by expanding the head receiving part and can be secured by compressing the head receiving part. The grooves 15 of the rod receiving part facilitate the assembly of the body of the receiving part 5 on the head 3 manually.
Next, the fixing ring 8 is described with reference to Figures 1, 2 and 7 to 13. The fixing ring 8 is substantially cylindrical and has a first part 81 with an internal conical surface 81a. The outer surface of the first part can also be tapered to reduce the outer bottom diameter. The size of the first part 81 is such that the conical inner surface 81a can be coupled with the conical part of the outer surface of the head receiving part 16 to exert a compressive force on the head receiving part 16. The surface Internal 81a of the first part can also be curved, with a curvature that is directed to the center of the fixing ring.
In addition, the fixing ring has a second cylindrical part 82, whose free end forms an annular surface 82 that can rest on the second end 9b of the rod receiving part, as shown in Figure 11.
Two protrusions 21 diametrically opposed to each other extend from the annular surface 82a in the direction of the second end. The projections 21 have a height such that they protrude above the bottom of the substantially U-shaped cavity 12 and extend to the cuts 24 when the fixing ring 8 is in a position where the head 3 has not yet fixed, as shown in Figures 11 and 12. The free ends 22 of the projections 21 can be curved, especially with a curvature corresponding to that of the rod 6. The fixing ring is arranged around the receiving part of head 16 of the body of the receiving part 5, so that the projections 21 are in the positions of the cavity 12. Due to this, the projections 21 protruding into the cavity 12 prevent the fixing ring from rotating when the rod It has not been inserted.
A third part 83 of the fixing ring is formed by a slightly conical annular flange protruding from the outer edge of the annular surface 82. A plurality of coaxial grooves 84 are provided on the flange that open towards the free end and which cause the flange is, to some extent, radially flexible. The height of the flange is, as shown in Figure 11, greater than the height of the cavity 30 of the rod receiving part 9. The inner diameter of the flange is such that, as shown in Figure 11, the ring of fixation, it can hold the receiving part of rod 9 and is maintained by means of the pretension generated by the flexible ring.
The elasticity of the head receiving part 16 and the size of the head receiving part at the open end 17 allow the fixing ring 8 to be fitted by fitting the free end 17 towards the head receiving part 16. Given that the outer diameter of the head receiving part is smaller than that of the rod receiving part 9, the fixing ring barely protrudes beyond the rod receiving part in radial direction.
The internal screw 7 has a thread that cooperates with the internal thread 13 provided on the legs. If a thread form is used that prevents the legs from opening, a single closing element such as the internal screw 7 is sufficient. This reduces the size of the bone anchoring device in radial direction. Other closing elements such as, for example, an outer nut can also be used.
The body of the receiving part 5, the fixing ring 8, the internal screw 7 and the bone anchoring element are made of a biocompatible material, for example, titanium or stainless steel or a biocompatible alloy, or of a plastic material Biocompatible with sufficient resistance.
The bone anchoring device can be preassembled with the fixing ring 8 which is mounted on the head receiving part 16 of the body of the receiving part 5 and with the screw head 3 inserted.
The function of the fixing ring is now explained with reference to Figures 11 to 13. As shown in Figure 11, a first position P1 of the fixing ring 8 is defined such that the fixing ring is in its position higher, where the annular surface 82a rests on the second end 9b of the rod receiving part 9. In this position, the fixing ring 8 is maintained by the pretension exerted by the flexible flange 83 on the receiving part of rod 9. The head receiving part 16 is not compressed. In this position, the introduction of the screw head 3 is possible.
A second position P2 is the preset position, as shown in Figure 12. In position P2, the fixing ring has moved down until the flexible flange 83 elastically fits into the cavity 30 provided in the receiving part of rod 9 and its upper edge rests on the flange 31 of the cavity. Since the flange 83 is slightly tapered, the fixing ring is held in this position by the pretension exerted by the flexible flange 83. The conical inner surface 81a of the fixing ring exerts a claim on the head receiving part 16 which prefix the head 3. A presetting means, in conditions that arise during surgery, maintains the angular position of the bone anchoring element with respect to the body of the receiving part 5 and can only be loosened by exerting additional force on the body of the receiving part or the screw element. Therefore, it is not possible to involuntarily remove the head. The presetting position of the fixing ring 8 can be achieved manually, by pushing down the fixing ring or by inserting the rod and by screwing the internal screw so that the rod presses on the projections 21.
A third position P3, which is the fixing position, is shown in Figure 13. The fixing position is defined as the position in which the head 3 of the screw is finally locked within the head receiving part. In position P3, the conical inner surface 81a is coupled with the outer surface of the head receiving part 16 such that the head 3 is fixed by compression of the head receiving part. This is achieved by tightening the internal screw 7 at the last moment, which presses the rod 6. At the same time, another downward movement of the fixing ring 8 can be prevented.
The cavity 30 of the body of the receiving part can be suppressed. It is also possible for the flange 83 to cooperate with the second end 9b of the body of the receiving part.
In use, the preassembled bone anchoring device comprising the body of the receiving part, the bone anchoring element and the fixing ring, are screwed into the bone. The cavity 4 of the head can be accessed with a screwing tool, through the first hole 10. The fixing ring 8 can already be in the preset position P2. To properly align the receiving part with respect to the rod to which it is to be connected, an additional force is exerted on the receiving part, either manually or by applying an instrument. Once the correct position of the rod with respect to other bone anchoring devices is achieved, the internal screw 7 is tightened thus moving down the fixing ring 8, to the fixing position P3. When the fixing ring 8 moves towards the free end 17 of the head receiving part, it compresses its head receiving part, thereby closing the head. The final tightening of the internal thread fixes the rod and the head at the same time.
The bone anchoring device can be pre-assembled by the manufacturer or can be pre-assembled during the course of preparing the surgery or at any other time. Conveniently, the surgeon selects the necessary reception parts and bone anchoring elements before surgery based on the specific requirements of the clinical application. The design of the bone anchoring device makes it possible to select the appropriate bone anchoring element as regards the diameter, length and other characteristics of the anchoring section. Therefore, a modular system is provided that includes receiving parts and various bone anchoring elements, which can be chosen and adapted individually.
In the preset condition, the head remains attached when the internal screw is loosened. This allows you to continue adjusting the rod.
A second embodiment of the bone anchoring device is now described with reference to Figures 14 to 24. Parts that are identical to those of the first embodiment are designated with the same reference numbers and their description is not repeated. The second embodiment of the bone anchoring device differs from the first embodiment in the design of the body part of the receiving part and the fixing ring. The body of the receiving part 5 'does not have the cavity 30 at the second end 9b. Instead, the body of the receiving part 5 'has two notch-shaped cavities 40, near the open end 17 of the head receiving part 16 and an annular cavity 41 adjacent to the open end 17 of the head receiving part 16. The notch-shaped cavities 40 are located diametrically opposite each other on both sides of the U-shaped cavity 12 of the rod receiving part 9. They are arranged at a distance from the open end 17. The cross-section of the notch-shaped cavities 40 can be V-shaped, preferably with an angle of 45 ° included in the two side walls of the cavity in a more or less notch . Because of this, as best seen in Figures 22 to 24, a surface 40a inclined downward is formed. By means of the inclined surface 40a and the cavity 41, a projection 42 is formed which cooperates with a flexible part of the fixing ring, as described below. The number of cavities 40 is not limited to two. A larger number of cavities can also be provided. The cavities are preferably located in places of the head receiving part 16, between recesses 19.
The fixing ring 80 differs from the fixing ring 8 in that the third part 83 'formed by the annular flange has no grooves, so that it is not flexible. In addition, the inner surface part 81a of the first part 81 is not conical, but curved inwardly, as shown in Figures 20 to 24. However, it can also be conical.
In the first part 81 of the fixing ring 80, two radially inwardly directed elastic peaks 90 are formed diametrically opposite each other and on both sides of the projections 21, in positions where they can fit into the cavities more or less than notch 40 of the head receiving part 16. Between the peaks and the external surface, a hollow part 91 is provided which allows the peaks 90 to be elastically deformed. The dimension of each peak is such that it can fit into the shaped cavity more or less notch 40.
The function of the bone anchoring device according to the second embodiment is now described with reference to Figures 22a to 24b. In the first position P1, which is the insertion position, the fixing ring rests, with its annular surface 82a, on the second end 9b of the rod receiving part 9, as shown in Figures 22a and 22b. In this position, the tip 90 fits into the cavity in a more or less notch 40 shape. The fixing ring 80 is held in this position by the pretension exerted by the elastic peak 90. In this position, the head 3 can be inserted from the open end 17.
As shown in Figures 23a and 23b, the second position P2 is the preset position, which is defined so that the peak 90 fits into the annular cavity 41 adjacent to the open end 17. This position is achieved by moving the ring down. of fixing 80. Thus, the inclined surface 40a guides the beak 90 until it fits behind the projection 42. Obtaining the presetting position P2 is facilitated, if the angle of the side walls of the cavity is more or less shaped. Notch is approximately 45 °. The fixing ring 80 can be released from the preset position only by applying an instrument or manually, whereby the spout 9 has to be released from the coupling with the annular cavity 41.
As shown in Figures 24a and 24b, another downward movement of the fixing ring 80 by tightening the internal screw that presses the rod 6, brings the fixing ring 80 to a third position P3, which is the fixing position. In the fixation position, the beak moves out of the cavity 41 so that it is placed under the open end. In this position, the internal surface part 81a 'of the fixing ring 80 compresses the head receiving part 16, so that the head 3 is finally fixed.
It should be noted that flange 83 can be suppressed in this embodiment.
A third embodiment of the bone anchoring device is now described with reference to Figures 25 to 30. The parts that are identical to those of the first embodiment have the same reference numbers and their descriptions are not repeated. The third embodiment of the bone anchoring device differs from the first embodiment in the design of the body of the receiving part and the fixing ring. The receiving part 5 "has a spring part in its outer wall that cooperates with the fixing ring 800. The spring part is formed by a longitudinal element 100, which extends coaxially, diametrically opposite to the outer wall of the part for receiving the rod, for example in the legs 12a, 12b. The element 100 is a leaf-like part with a curved outward part 101, which is formed in the outer wall of the rod receiving part. curved outwardly 101 protrudes from the wall and can be pressed elastically into a corresponding wall cavity.
The fixing ring 800 differs from the fixing ring 8 of the first embodiment in that the flange 83 "is not flexible.
In the first position, as shown in Fig. 28, the fixing ring 800 is maintained by the pretension that the spring part 100 exerts on the flange 83 ". The head receiving part is not compressed, which allows the insertion of the head 3. In the second position, the preset position shown in Figure 29, the fixing ring is released from the spring element 100 and moves downwards.The spring element can act as a stop defining the position of presetting In the third position shown in Figure 30, the fixing ring 800 is still displaced downwards and the head is fixed.
Other shapes and numbers of the spring part are also possible.
Other modifications of the embodiments shown are possible. For example, the head of the bone anchoring element may have any other shape, for example, cylindrical, whereby a monoaxial bone screw is provided that allows the rotation of the screw element with respect to the receiving part around a single axis The head 3 can also be conical or have any other shape and the internal hollow section 18 of the head receiving part adapts to this shape. In another modification, the body of the receiving part 5 or at least the head receiving part 16 is made of a biocompatible plastic material, which provides a certain degree of elasticity. In this case, the slits can be suppressed.
The projections of the fixing ring that are coupled with the rod may have another shape. For example, the surface of the free end may be flat or have another shape. The outgoing can be deleted.
The head receiving part may have an inclined open end 17 to allow greater angulation of the head in one direction.
The external surface of the head receiving part may be spherical, and the internal surface of the fixing ring may be conical.
1. Receiving part to receive a rod in order to couple the rod in a bone anchoring element, including the receiving part
a body of the receiving part (5, 5 ', 5 ") with
a rod receiving part (9) with a channel (12) for receiving the rod, and
a head receiving part (16) for receiving a head (3) of the bone anchoring element, the head receiving part (16) has an open end (17) and is flexible to allow the introduction and clamping of the head , Y
a fixing ring (8, 80, 800) surrounding the head receiving part, wherein the fixing ring exerts a force on the head receiving part to block the head; characterized because
the fixing ring (8, 80) or the body of the receiving part (5 ") comprises a spring part (83, 90, 101) cooperating with a part (9, 30, 31, 41, 42) of the body of the receiving part or the fixing ring (800), respectively, in order to hold the head in a preset position of the fixing ring.
Reception part according to claim 1, wherein the spring part (83, 90) is provided on an edge of the fixing ring.
Receiving part according to claim 1 or 2, wherein the fixing ring can adopt a presetting position (P2) in which the head is held in the head receiving part by means of a pretension exerted on the receiving part of head (16) and a fixation position (P3) in which the head is fixed.
Reception part according to one of claims 1 to 3, wherein the fixing ring (8, 80) can adopt an insertion position (P1) in which the head can be inserted into the head receiving part.
Reception part according to one of claims 1 to 4, wherein the fixing ring (8) has a lower edge facing the open end (17) of the head receiving part and an upper edge facing away from the open end and where the spring part (83) is arranged at the upper edge.
Reception part according to claim 5, wherein the spring part is formed by a radially flexible upper flange (83).
Reception part according to claim 5 or 6, wherein the spring part (83) is formed by at least one coaxial groove (84) provided on the flange.
Receiving part according to one of claims 5 to 7, wherein the spring part (83) cooperates with a cavity (30, 31) of the rod receiving part (9) or an end face (9b) of the Reception part of rod.
Reception part according to one of claims 1 to 4, wherein the fixing ring (80) has a lower edge facing the open end (17) of the head receiving part and an upper edge facing away from the open end and where the spring part (90) is arranged at the bottom edge.
Reception part according to claim 9, wherein the spring part (90) is formed by a radially flexible projection, preferably by at least two radially flexible peaks (90).
Reception part according to claim 10, wherein the projection cooperates with a cavity in the head reception part, preferably arranged near the open end.
Reception part according to claim 11, wherein the cavity (40) is more or less notched and has a side wall inclined downwards (40a) to facilitate the release of the flexible projection (90) in order to loosen the preset condition.
Reception part according to one of claims 1 to 12, wherein the head reception part (16) has an external surface with a conical part and the fixing ring (8) has an internal surface with a conical part (81a ) or curved (81a '), the curvature being directed to the center of the fixing ring.
Receiving part according to one of claims 1 to 13, wherein the fixing ring (8, 80, 800) can be moved by exerting pressure on it through the rod.
Receiving part according to one of claims 1 to 14, wherein the rod receiving part has a first end (9a) and a second end (9b) and a cavity (12) extending from the first end into the direction of the second end that form the channel for the rod.
Receiving part according to one of claims 1 to 15, wherein the rod receiving part (9) has a first end (9a) and a second end (9b) and the head receiving part (16) is arranged on the side of
second end (9b) and wherein the outer diameter of the head receiving part (16), on the side of the second end, is smaller than the diameter of the rod receiving part (9) at the second end ( 9b).
Receiving part according to one of claims 1 to 16, wherein the body of the receiving part (5) comprises a plurality of openings (19) open towards the open end (17), preferably extending to the
5 minus a slit (15, 19) from the open end and continuously to the part of the rod reception (9).
18. Receiving part according to claim 1 or one of claims 13 to 17, wherein the spring part
(100) is provided in the body of the receiving part (5 ").
19. Bone anchoring device comprising a receiving part according to one of claims 1 to 18 and
10 a bone anchoring element (1) with a threaded shaft and a head (3) and in which preferably a closure element (7) is provided which is preferably an internal screw to secure the rod (6) in the cavity (12).
ES08022553T 2008-12-30 2008-12-30 Receiving part for receiving a rod for coupling the rod in a bone anchoring element and bone anchoring device with such receiving part Active ES2378588T3 (en)
ES2378588T3 true ES2378588T3 (en) 2012-04-16
ES08022553T Active ES2378588T3 (en) 2008-12-30 2008-12-30 Receiving part for receiving a rod for coupling the rod in a bone anchoring element and bone anchoring device with such receiving part
AT300245T (en) * 2002-02-11 2005-08-15 Synthes Ag Device for connecting a counter with a bone
ES2353033T3 (en) 2011-02-24 Bone anchorage device.
EP2286747A2 (en) 2011-02-23 Enchoring element and dynamic stabilisation device for vertebral bodies or bones
ES2609079T3 (en) 2017-04-18 Housing piece to accommodate a rod in order to couple the rod to a bone anchoring element