BONE REPAIR SYSTEM

Abstract

Disclosed is a bone repair system, in particular for treatment of fractures or defects of the pars interarticularis. In an embodiment, the bone repair system comprises a support member and a fastening member. The support member is configured to be fixed to a first bone or bone fragment. The fastening member includes a first and a second end portion and an elongate portion extending between the first and the second end portions. The first end portion is coupled to the support member, and the elongate portion is configured to loop around at least one second bone or bone fragment. The support member includes fixation means for adjustably securing the second end portion of the fastening member so as to stabilize and/or fix the first and the second bone or bone fragment with respect to each other.

Claims

1. A bone repair system, the system comprising: a support member comprising a bone mounting part configured to be fixed to a first bone or bone fragment by means of a bone screw so as to mount the support member at the first bone or bone fragment, and a fastening member including a first and a second end portion and an elongate portion extending between the first and the second end portions, wherein the first end portion of the fastening member is coupled to the support member, wherein the support member comprises a fastening member fixing part, wherein a coupling between the first end portion of the fastening member and the fastening member fixing part is implemented in form of an articulated joint, wherein the elongate portion is configured to loop around at least one second bone or bone fragment, and wherein the fastening member fixing part of the support member includes fixation means for adjustably securing the second end portion of the fastening member so as to stabilize and/or fix the first and the second bone or bone fragment with respect to each other, wherein the fixation means include a locking element for receiving the second end portion of the fastening member, wherein the locking element is rotatably mounted with respect to the fastening member fixing part to receive the second end portion of the fasting member from different angular positions.

2. The bone repair system according to claim 1, wherein the bone mounting part of the support member includes a substantially ring-shaped portion adapted for receiving the head of a bone screw.

3. The bone repair system according to claim 1, wherein a coupling between the support member and the head of a bone screw is effected by means of an interference fit, by means of a form fit, or by means of plastic deformation.

4. The bone repair system according to claim 1, wherein the fixation means are configured to effect securing of the second end portion of the fastening member by means of a form fit, by means of a clamping mechanism, or by means of a crimping mechanism.

5. The bone repair system according to claim 1, wherein the elongate portion of the fastening member is formed as a notched or toothed strap, band, or flexible rack.

6. The bone repair system according to claim 1, wherein the support member comprises a fastening member fixing part including a first fixing portion for anchoring the first end portion of the fastening member, and a second fixing portion including the fixation means for the second end portion of the fastening member.

7. The bone repair system according to claim 6, wherein the first fixing portion and the second fixing portion are substantially arranged one above the other.

8. The bone repair system according to claim 6, wherein the first end portion of the fastening member comprises a spherical head, and wherein the first fixing portion of the fastening member fixing part includes a cavity adapted to accommodate the spherical head of the first end portion of the fastening member.

9. The bone repair system according to claim 6, wherein the locking element of the fixation means is shaped substantially cylindrically, wherein the locking element is rotatably mounted within a corresponding recess formed within the second fixing portion of the fastening member fixing part.

10. The bone repair system according to claim 9, wherein the locking element includes a case having a ratchet mechanism integrated therein, wherein the case is adapted for receiving the second end portion of the fastening member, and wherein the ratchet mechanism is configured to act on notches or teeth of the fastening member so as to prevent the fastening member from being pulled back.

11. The bone repair system according to claim 9, wherein the second fixing portion of the fastening member fixing part comprises an opening window, the opening window being adapted to allow insertion of the second end portion of the fastening member into the locking element under different angles.

12. The bone repair system according to claim 1, wherein the fastening member is fabricated of chrome, molybdenum, or titanium, or of an alloy thereof, or of a composite, in particular titanium with polyetheretherketone (PEEK) or a carbon fiber reinforced plastic.

13. The bone repair system according to claim 1, wherein at least one of the support member and the fastening member is fabricated of a resorbable material.

14. The bone repair system according to claim 1, wherein the fastening member includes a reinforcement within a neck portion adjoining the first end portion.

15. The bone repair system according to claim 1, wherein the support member is adapted to be fixed to a human vertebral arch, and wherein the fastening member is adapted to be looped around the associated pars interarticularis, the associated Processus spinosus, the lamina, the Processus transversus, or a rib for treatment of a spondylolysis.

16. The bone repair system according to claim 2, wherein the substantially ring-shaped portion is adapted for receiving the head of a pedicel screw.

Description

[0033] There are several ways how to design and further develop the teaching of the present invention in an advantageous way. To this end, it is to be referred to the dependent patent claims on the one hand and to the following explanation of preferred examples of embodiments of the invention, illustrated by the drawing on the other hand. In connection with the explanation of the preferred embodiments of the invention by the aid of the drawing, generally preferred embodiments and further developments of the teaching will be explained. In the drawing

[0034] FIG. 1 is a perspective side view illustrating a bone repair system according to an embodiment of the invention,

[0035] FIG. 2a is a front view of the bone repair system of FIG. 1,

[0036] FIG. 2b is an enlarged front view of the support member of the bone repair system shown in FIG. 2a,

[0037] FIG. 3a is a side view of the bone repair system of FIG. 1,

[0038] FIG. 3b is an enlarged side view of the support member of the bone repair system shown in FIG. 3a,

[0039] FIG. 4 is a perspective side view of a support member of a bone repair system according to an embodiment of the invention,

[0040] FIG. 5 is a perspective side view of a support member of a bone repair system according to another embodiment of the invention,

[0041] FIG. 6 is another perspective side view of the support member of FIG. 5,

[0042] FIG. 7 is a rear view of the support member of FIG. 5,

[0043] FIG. 8 is a first side view of the support member of FIG. 5,

[0044] FIG. 9 is a second side view of the support member of FIG. 5,

[0045] FIG. 10 is a perspective view from above of the locking element of the bone repair system in accordance with an embodiment of the invention,

[0046] FIG. 11 is a perspective view from below of the locking element of FIG. 10,

[0047] FIG. 12 is a side view of the locking element of FIG. 10,

[0048] FIG. 13 is a schematic dorsal view of an implanted bone repair system in accordance with an embodiment of the invention,

[0049] FIG. 14 is another schematic dorsal view of an implanted bone repair system in accordance with an embodiment of the invention,

[0050] FIG. 15 is a schematic lateral view of the implanted bone repair system of FIG. 13,

[0051] FIG. 16 is another schematic lateral view of the implanted bone repair system of FIG. 14, and

[0052] FIG. 17 is schematic lateral view of an implanted bone repair system in accordance with a further embodiment of the invention.

[0053] In the following description of embodiments, like reference numeral designate like components.

[0054] While a bone repair system according to embodiments of the present invention can be generally utilized in various scenarios where two or more bones or bone fragments have to be fixed and/or stabilized against each other, the embodiments described hereinafter predominantly relate to the treatment of a spondylolysis, which is known as a defect or stress fracture in the pars interarticularis of the human vertebral arch.

[0055] FIG. 1 shows a bone repair system 1 according to an embodiment of the present invention, including a support member 100 and a fastening member 200 coupled to the support member 100. The support member 100 is configured to be fixed to a first bone or bone fragment 400, as will be described in greater detail below. The fastening member 200 is configured to be looped around at least one second bone or bone fragment 410, and to be adjustably secured at the support member 100 so as to stabilize and/or fix the first and the second bone or bone fragment 400, 410 with respect to each other.

[0056] As will be appreciated by those skilled in the art, it is one of the major advantages of the bone repair system 1 according to the invention compared to prior art techniques that only a minimum of components has to be handled by the surgeon during surgery. As the support member 100 and the fastening member 200 can be pre-assembled prior to operative surgery, essentially, the operation requires only a single component (together with a bone screw for fastening of the support member 100 at the first bone or bone fragment 400) has to be handled. This means that the actual operative surgery is completely relieved from the requirement of any laborious assembly of individual parts. This advantage comes along with the further advantage of achieving shortened surgery durations, which minimizing the surgical risk and makes the operation less stressful and hazardous for the patient. In addition, the risk of improper assembly or incorrect coupling between individual components is significantly reduced.

[0057] FIGS. 2 and 3 show of the embodiment of the bone repair system of FIG. 1 from further perspectives. FIGS. 2b and 3b are enlarged views of sections A and B, respectively, of FIGS. 2a and 3a. As can be seen, the fastening member 200 comprises a first and a second end portion 210, 220 and an elongate portion 230 extending between the first and the second end portions 210, 220. As can be best obtained from FIG. 3b, the elongate portion 230 is formed as a toothed strap or band. As such, the structure of the fastening member 200 is comparable to that of conventional cable ties. Being formed as a strap or band, the fastening member 200 has sufficient flexibility to adapt to the specific anatomic conditions.

[0058] The first end portion 210 of the fastening member 200 is coupled to the support member 100, while the second end portion 220 lies free. After fastening of the support member at 100 a first bone or bone fragment 400 and looping the elongate portion 230 of the fastening member 200 around a second bone or bone fragment 410, the second end portion 220 can be coupled and securely fixed to the support member 100, as will be described in greater detail below.

[0059] FIG. 4 illustrates the support member 100 of the embodiment of FIG. 1-3 from a perspective view. Essentially, the support member 100 comprises two functional components, namely a bone mounting part 120 and a fastening member fixing part 140. According to preferred embodiments, the support member 100 is formed in one piece, with the bone mounting part 120 and the fastening member fixing part 140 adjoining each other.

[0060] The bone mounting part 120 includes an essentially ring-shaped portion 130 that is configured to receive a bone screw 300 (shown in FIGS. 13-16), such as a pedicle screw, for fastening of the support member 100 at the respective first bone or bone fragment 400. In the embodiment shown in FIG. 4, a form fit (or, alternatively, a clamping or crimping mechanism) may be used to effect secure coupling between the bone mounting part 120 and the head 310 of the bone screw 300.

[0061] FIG. 5 illustrates a support member 100 according to a similar embodiment. The only difference compared to the embodiment of FIG. 4 is that the coupling between the bone mounting part 120 and the head of the bone screw 300 is realized by a threaded pin 132 provided in a side wall of the essentially ring-shaped portion 130 of the bone mounting part 120. The threaded pin 132 acts as a set screw that exerts a sideward force on the head 310 of the bone screw 300, thereby fixing the bone screw 300 in its desired position. FIGS. 6-9 depict the support member 100 of FIG. 5 from further perspectives.

[0062] As can be best obtained from FIG. 3b, the fastening member fixing part 140 of the support member 100 includes a first fixing portion 150 for anchoring the first end portion 210 of the fastening member 200, and a second fixing portion 160 for receiving the second end portion 220 of the fastening member 200 after looping the elongate portion 230 around the bone or bone fragments to be stabilized. As seen in a direction perpendicular to the surface of the bone to which the support member 100 is mounted, the first fixing portion 150 and the second fixing portion 160 are substantially arranged one above the other. In this way, any interference between the first and the second end portions 210, 220 of the fastening member 200 is inhibited. Consequently, the direction under which the second end portion 220 can be received within the second fixing portion 160 is completely independent of, i.e. decoupled from the orientation of the first end portion within the first fixing portion 150.

[0063] According to the illustrated embodiments, the coupling between the first end portion 210 of the fastening member 200 and the first fixing portion 150 of the support member 100 is realized by means of a ball and socket joint. To this end, the first end portion 210 of the fastening member 200 comprises a spherical head 240 and, correspondingly, the first fixing portion 150 of the fastening member fixing part 140 includes a cavity 170 adapted to accommodate the spherical head 240 of the first end portion 210 of the fastening member 200.

[0064] This configuration allows for flexible alignments of the fastening member 200. During surgery, the surgeon may determine the orientation of the fastening member 200 in first instance by proper alignment of the support member 100 itself, i.e. prior to fully tightening the bone screw 300. However, even after having fully tightened the bone screw 300, the ball and socket joint still allows for minor adjustments and corrections of the alignment of the fastening member 200 relative to the involved bones or bone fragments.

[0065] As already mentioned above, the fastening member fixing part 140 of the support member 100 includes a second fixing portion 160 for receiving the second end portion 220 of the fastening member 200 after looping the elongate portion 230 around the bone or bone fragments to be stabilized. Specifically, the second fixing portion 160 comprises fixation means 110 for adjustably securing the second end portion 220 of the fastening member 200 so as to stabilize and/or fix the first and the second bone or bone fragment 400, 410 with respect to each other.

[0066] According to the illustrated embodiments, the fixation means 110 include a locking element 180, the locking element 180 having a mainly cylindrical body 182, as shown from different perspectives in FIGS. 10-12. Correspondingly, the second fixing portion 160 includes an essentially cylindrical recess 162 in which the locking element 180 is rotatably mounted. Specifically, the recess 162 includes a circumferential groove 164 formed for engagement with a respective bulge portion 184 of the cylindrical body 182 of the locking element 180, so as to prevent the locking element 180 from getting disengaged from the support member 100.

[0067] As can be obtained from FIGS. 10-12, the locking element 180 comprises a case 186 including a first opening window that is adapted for receiving the second end portion 220 of the fastening member 200, and a second opening window, disposed on the opposite side of the first opening window, for leading the fastening member 200 out of the locking element 180. A ratchet mechanism 188 is integrated within the case 186, wherein the ratchet mechanism 188 is configured to act on the notches or teeth of the fastening member 200 so as to prevent the fastening member 200 from being pulled back. In other words, once the second end portion 220 of the fastening member 200 has been pulled through the case 186 and past the ratchet 188, it is prevented from being pulled back, i.e. the resulting loop may only be pulled tighter.

[0068] As can be best seen in FIGS. 4, 5 and 9, the second fixing portion 160 of the fastening member fixing part 140 comprises an ingress opening 190 for receiving the second end portion 220 of the fastening member 200 within the second fixing portion 160 and for its insertion into the locking element 180. Likewise, the second fixing portion 160 comprises an egress opening 192 for leading the second end portion 220 of the fastening member 200 out of the second fixing portion 160. For instance, the openings 190, 192 may be formed as recesses within an outer wall of the second fixing portion 160. According to embodiments, both openings 190, 192 may have an opening size sufficiently large that angular alignment of the fastening element in a lateral direction of about at least ±10° can be accomplished. As already mentioned above and as appreciated by those skilled in the art, depending on the anatomic conditions, opening windows with larger opening angels (e.g. ±30°) or with an asymmetry between ingress opening 190 and egress opening 192 may be realized. In order to bring the opening windows of the case 186 of the locking element 180 into alignment with the openings 190, 192 of the second fixing portion 160, a slit 188 is formed in the upper surface of the locking element 180. The slit 188 (or, according to alternative embodiments, a cross slot, a hexagon socket, an internal torx/stardrive, or the like) is adapted for engagement with a respective tool by which the surgeon can easily effect appropriate rotation of the locking element 180.

[0069] FIGS. 13-16 schematically depict an implanted bone repair system in the specific case of treatment of a fracture and/or defect of the pars interarticularis vertebrae (lytic, traumatic, degenerative, due to growth, etc.) in accordance with embodiments of the invention. FIGS. 13 and 15 illustrate the implant in dorsal views, while FIGS. 14 and 16 show the respective lateral views. In this case, the support member 10 is mounted to the affected vertebral arch as the first bone or bone fragment 400, and the fastening member 200 is looped around the associated pars interarticularis as the second bone or bone fragment 410.

[0070] FIG. 17 depicts a different implant situation. While the support member 10 is still mounted to the vertebral arch as the first bone or bone fragment 400, the fastening member 200 is not looped around the associated pars interarticularis but, instead, around the associated Processus spinosus as the second bone or bone fragment 410. According to still further embodiments, not shown in the drawings, the fastening member 200 may be looped around the lamina, the Processus transversus, and also around a rib as the second bone or bone fragment 410.

[0071] By the implantation of a bone repair system in accordance with embodiments of the present invention, one or more of the following advantages can be achieved: [0072] time saving for the surgeon through easy application; [0073] secure fixation of the involved bone fragments by looping with the fastening member; [0074] minimization of loosening, which could lead to protracted or failing bone healing; [0075] reduction of the risk of misplacement and the risk of injury of nerve roots, spinal cord and spinal membrane; [0076] cost-effective manufacturing.

[0077] Many modifications and other embodiments of the invention set forth herein will come to mind to the one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing description and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

LIST OF REFERENCE NUMBERS

[0078] 1 bone repair system [0079] 100 support member [0080] 110 fixation means [0081] 120 bone mounting part [0082] 130 ring-shaped portion [0083] 132 threaded pin [0084] 140 fastening member fixing part [0085] 150 first fixing portion [0086] 160 second fixing portion [0087] 162 cylindrical recess [0088] 164 circumferential groove [0089] 170 cavity [0090] 180 locking element [0091] 182 cylindrical body [0092] 184 bulge portion [0093] 186 case [0094] 188 ratchet mechanism [0095] 189 slit [0096] 190 opening window (ingress opening) [0097] 192 opening window (egress opening) [0098] 200 fastening member [0099] 210 first end portion [0100] 220 second end portion [0101] 230 elongate portion [0102] 240 spherical head [0103] 250 neck portion [0104] 300 bone screw [0105] 310 screw head [0106] 400 first bone or bone fragment [0107] 410 second bone or bone fragment