Aiming device

Abstract

The present invention relates to an aiming device (1) for forming a fixation of a prosthesis (8) to a bone by means of a bone anchoring element (5), comprising holding means (15) for positioning the prosthesis (8) in a first axis (X1), a receiving part (20) oriented along a second axis (X2), passing through the aiming device and forming a guide opening (22) designed to receive a protective sleeve, and locking means (40) comprising at least one elastically deflectable finger (50) which can be deflected axially and / or radially relative to the second axis (X2), where the first axis (X1) and the second axis (X2) intersect and the at least one finger (50) protrudes into the guide opening (22).

Description

[Technical field]

[0001] The invention relates to an aiming device for forming a fixation of a prosthesis, in particular an intramedullary nail, to a bone by means of a bone anchoring element with the features of claim 1. [Background technology]

[0002] Such aiming devices are already known in various forms from the prior art and are used for the precise positioning of bone fixation elements in corresponding recesses of a prosthesis, for example an intramedullary nail, in order to firmly connect and fixate the prosthesis to the bone. Such aiming devices are widely used for stabilizing bones (for example the femur, tibia, etc.) after fracture.

[0003] For this purpose, the prosthesis used comprises a recess into which a bone fixation element can be introduced in order to fix the prosthesis or the intramedullary nail to the bone. A corresponding recess can be made in the bone by means of a tool, which is made precisely to match the recess in the prosthesis by means of an aiming device with a guide opening. When using the aiming device to make the corresponding recess, a distance is maintained between the tissue and the tool in order to prevent damage to the surrounding tissue.

[0004] In addition to the tissue spreader, a protective sleeve is also used which shields the tool when making the corresponding recess in the bone. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention is directed to the task of proposing an expediently improved aiming device, the use of which, when a corresponding recess is produced in the bone by means of a tool, prevents damage to the surrounding tissue by a protective sleeve, and in the process makes the handling of the aiming device simple and reliable. [Means for solving the problem]

[0006] The above problem is solved by an aiming device having the features of claim 1. Further advantageous embodiments of the aiming device according to the invention are set forth in the dependent claims. The aiming device according to the invention with the features of claim 1 for forming a fixation of a prosthesis, in particular an intramedullary nail, in a bone comprises a holding means for positioning the prosthesis, in particular an intramedullary nail, on a first axis, at least one receiving part oriented along a second axis, passing through the aiming device and forming at least one guide opening designed to receive at least one protective sleeve, and at least one locking means comprising at least one elastically deflectable finger that can be deflected axially and / or radially relative to the second axis. It is provided that the first axis and the second axis intersect and further that the at least one elastically deflectable finger projects into the guide opening. The at least one elastically deflectable finger is designed to fix the protective sleeve along the second axis.

[0007] The invention is based on the idea that the protective sleeve is fixed in the guide opening by means of at least one elastically deflectable finger, so that the protective sleeve does not have to be held by medical personnel and there is no risk of it being unintentionally removed from the guide opening.

[0008] It is noted here that the aiming device has a plurality of receiving sections forming guide openings. Each guide opening can be oriented along a second axis, and the second axes are spaced apart from each other. The second axes can be oriented parallel to each other or can intersect at a common intersection. The angle between the second axes is preferably between 30° and 60°.

[0009] The at least one elastically deflectable finger can be in operative contact with a protective sleeve inserted into the guide opening and can achieve a frictionally-locking connection with the protective sleeve, the at least one elastic finger being deflected axially and / or radially when the protective sleeve is inserted into the guide opening, providing a holding force that fixes the protective sleeve.

[0010] By correspondingly designing the stiffness of the at least one resilient finger, the magnitude of the holding force can be determined, so that the holding force can be adapted to the respective application or user preference.

[0011] The guide opening and / or the protective sleeve are preferably cylindrical and pass completely through the aiming device. The guide opening is preferably designed so that the protective sleeve can be smoothly inserted therethrough, for example by means of a clearance fit.

[0012] A preferred development of the invention provides for the locking means to comprise a bushing, which may preferably be a hollow cylinder with a through-opening, which preferably has its shape and / or dimensions adapted to or identical to the guide opening and may further form part of the guide opening.

[0013] The penetration can have a polygonal, circular or figure-of-eight cross section, the penetration being designed to allow the at least one guide sleeve to pass through. The figure-of-eight cross section can allow the at least one guide sleeve to be passed through in at least two positions: parallel and spaced apart with respect to the second axis.

[0014] At least one resilient finger projects radially inwardly or radially inwardly and axially from the locking means or bushing. The bushing can be attached to the aiming device in any manner, more preferably the through-hole and the guide opening are coaxially arranged on the second axis.

[0015] According to a further preferred embodiment, the locking means or bushing can be arranged, in particular completely, in the receiving part of the aiming device. It is particularly preferred if the bushing can be arranged non-removably in the receiving part. The receiving part preferably has an extension, such as a cylindrical threaded bore, into which the bushing can be inserted. The bushing is held in the receiving part in coaxial alignment with the guide opening.

[0016] It has further proved to be advantageous if an annular space is formed in the receiving part and if at least one finger can project freely into the annular space, in particular if the annular space is formed on the end face of the locking means or the bush and is surrounded, preferably in a U-shape, by the receiving part on the one hand and by the bush on the other hand.

[0017] A preferred development of the invention provides for a flushing channel to open into the annular space. In order to clean the aiming device after or before use, a cleaning agent can be introduced into the annular space through the flushing hole.

[0018] According to one development, the flushing channel opens into the annular space with an orientation oriented tangentially to the second axis, whereby the annular space can be effectively rinsed with cleaning agent during cleaning.

[0019] According to a preferred development of the invention, the bushing has a U-shaped cross section. The bushing has an inner leg, an outer leg and a central leg, the central leg connecting the inner leg and the outer leg. The U-shaped design of the bushing allows an annular space to be formed by the legs of the U-shaped bushing.

[0020] Advantageously, connecting means can be provided which can arrange and hold the locking means in the receiving part in a force-locking, form-locking and / or material-locking manner. A preferred development of the invention provides that the inner leg surrounds at least one finger.

[0021] According to a preferred development, at least two, in particular three or more, free-standing fingers are provided. The free-standing elastically deflectable fingers can be distributed circumferentially around the second axis, arranged at a distance from one another and protrude into the guide opening like spokes or a comb. Furthermore, at least two elastic fingers can be arranged along the second axis. The holding force of the protective sleeve can also be designed by the number of elastic fingers.

[0022] A preferred development of the invention provides that the free-standing elastic fingers are arranged circumferentially symmetrically relative to the second axis. In particular, a circumferentially symmetric arrangement of the free-standing fingers makes it possible to center the protective sleeve in the guide opening.

[0023] One development of the invention provides that at least one elastically deflectable finger has a contact area at its free end. The contact area can be configured to generate the highest possible holding force and the highest possible static friction. For example, the contact area can be made of a suitable material and / or have a suitable finished surface with the highest possible coefficient of friction.

[0024] According to another development of the invention, the contact area can be angled with respect to the orientation of the at least one finger, the contact area being configured for surface contact with the protective sleeve. Exemplary embodiments of the aiming device according to the invention and developments of the aiming device are explained in more detail below with reference to the attached drawings. [Brief description of the drawings]

[0025] [Figure 1a] FIG. 2 shows a perspective view of an aiming device according to the invention, comprising a retaining means for positioning the prosthesis on the first shaft and a protective sleeve which is retained in the guide opening by a locking means of the first shaft. [Figure 1b] FIG. 2 shows a perspective view of an aiming device according to the invention, comprising a retaining means for positioning the prosthesis on the first shaft and a protective sleeve which is retained in the guide opening by a locking means of the first shaft. [Figure 1c] FIG. 2 shows a perspective view of an aiming device according to the invention, comprising a retaining means for positioning the prosthesis on the first shaft and a protective sleeve which is retained in the guide opening by a locking means of the first shaft. [Figure 2a] 2A-2C are different views of the locking means according to FIG. 1; [Figure 2b] 2A-2C are different views of the locking means according to FIG. 1; [Figure 2c] 2A-2C are different views of the locking means according to FIG. 1; [Figure 3a] 2A-2C are different views of a second embodiment of the locking means according to FIG. 1; [Figure 3b] 2A-2C are different views of a second embodiment of the locking means according to FIG. 1; [Figure 3c] 2A-2C are different views of a second embodiment of the locking means according to FIG. 1; [Figure 4a] 3A-3C are different views of a third embodiment of the locking means according to FIG. 1; [Figure 4b] 3A-3C are different views of a third embodiment of the locking means according to FIG. 1; [Figure 4c] 3A-3C are different views of a third embodiment of the locking means according to FIG. 1; [Figure 5a] 4A-4D are different views of the fourth embodiment of the locking means according to FIG. 1; [Figure 5b] 4A-4D are different views of the fourth embodiment of the locking means according to FIG. 1; [Figure 5c] 4A-4D are different views of the fourth embodiment of the locking means according to FIG. 1; [Figure 6a] 5A to 5C are different views of the fifth embodiment of the locking means according to FIG. [Figure 6b] 5A to 5C are different views of the fifth embodiment of the locking means according to FIG. [Figure 6c] 5A to 5C are different views of the fifth embodiment of the locking means according to FIG. [Figure 6d] 5A to 5C are different views of the fifth embodiment of the locking means according to FIG. [Figure 7] FIG. 6 shows a sixth embodiment of the locking means according to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] In the following, identical or functionally identical parts in the exemplary embodiments are provided with the same reference numerals. For the sake of clarity, not all identical or functionally identical parts are provided with the same reference numerals in the individual figures.

[0027] FIG. 1a shows a diagram of an aiming device 1 according to a preferred embodiment of the present invention. The aiming device 1 is formed in an arcuate shape and may comprise a single-piece or multi-piece body 10, referred to as a whole, having a first end region 11 and a second end region 12. Additionally, the aiming device 1 has a proximal side 13 and a distal side 14, with the proximal side 13 located in a concave region of the arcuate aiming device 1 and the distal side 14 located in a convex region opposite the concave region.

[0028] The first end region 11 is provided with a retaining means 15 for positioning a prosthesis, not shown, in particular an intramedullary nail, which can be held oriented along a first axis X1. The retaining means 15 can form a detachable connection with the prosthesis.

[0029] In the second end region 12, at least one receiving portion 20 is formed which forms at least one guide opening 22, which passes completely through the aiming device 1 or the body 10, said receiving portion 20 connecting the proximal side 13 to the distal side 14. The receiving portion 20 is oriented along a second axis X2, and as shown in the exemplary embodiment according to Fig. 1, a plurality of receiving portions 20 are provided. For the sake of clarity, in the attached figures, further receiving portions 20, further guide openings 22 and further second axes X2 are marked with "'".

[0030] The first axis X1 and the second axis X2 have a common intersection point, and preferably the intersection angle on the side facing the aiming device 1 should be about 45° to 135°. As shown in Figures 1c, 2a, 3a, 4a and 5a in particular, the protective sleeve 60 can be inserted or threaded into the receiving part 20 or the guide opening 22, and it is preferable that the protective sleeve 60 can be smoothly inserted into the receiving part 20 and the guide opening 22 along the second axis X2. For this purpose, the shapes of the protective sleeve 60 and the guide opening 22 correspond to each other.

[0031] It is also possible to insert or pass through the receiving section 20' or the guide opening 22', in a manner not shown, two protective sleeves 60 in the same way or one protective sleeve in various different positions.

[0032] The receiving portion 20 and / or the guide opening 22 may have a circular or figure-of-eight cross section, the guide opening 22 further pre-orienting the protective sleeve 60 on the second axis X2. The guide opening 22 has a diameter D22 and the protective sleeve 60 has a diameter D60, which is preferably slightly smaller than the diameter D22 in order to form a clearance fit.

[0033] Furthermore, the aiming device 1 comprises locking means 40, which are configured to fix the protective sleeve 60 in the receiving part 20 in order to avoid unwanted or unintentional falling out. 1a-7 comprises at least one elastic finger 50, which can be elastically deflected in the axial and / or radial direction relative to the second axis X2 and can come into working contact with at least one protective sleeve 60. The at least one elastically deflectable finger 50 protrudes freely into the guide opening 22 and can perform an elastic escape movement in case of the insertion of the protective sleeve 60 into the guide opening 22 and subsequently holds the protective sleeve 60 with a holding force and fixes it in the desired position in the guide opening 22.

[0034] At least one resilient finger 50 projects radially or radially and axially relative to the second axis X2 into the guide opening 22. When the resilient fingers 50 are in their undeflected state, a free end 52 of each finger 50 is in the guide opening 22. It is noted here that in the attached figures, for reasons of simplifying the illustration, the fingers 50 are shown in their undeflected state. Only in Fig. 5a is a deflection movement suggested by dashed lines and by means of a double-headed arrow.

[0035] The free end 52 may preferably have a contact area 54 that provides enhanced traction characteristics. For example, the elastic, deflectable fingers 50 according to the exemplary embodiment according to Figures 2a to 3c protrude radially into the guide opening 22, while the elastic fingers 50 according to the exemplary embodiment according to Figures 4a to 5c are oriented at an angle inclined at about 45° with respect to the second axis X2 and therefore protrude radially and axially into the guide opening 22.

[0036] As shown in the illustrated exemplary embodiment, the locking means 40 may comprise a bushing 42 that can be inserted into the receiving part 20. Resilient fingers 50 protrude from the bushing 42 radially with respect to the second axis X2 or radially and axially in the direction of the second axis X2.

[0037] The receiving portion 20 may have an extension 24 on the proximal side 13 and / or the distal side 14 configured to receive the bushing 42. The extension 24 has a diameter D24, which is larger than the diameter D22.

[0038] The bushing 42 has an outer diameter D42a and the through-hole of the bushing 42 has an inner diameter D42i. The outer diameter D42a corresponds to the diameter D24 of the extension 24 and the inner diameter D42i is larger than the diameter D60 of the protective sleeve 60.

[0039] The connecting means can hold the bushing 42 in a force-locking, form-locking and / or material-locking arrangement in the receiving part 20. It can be advantageous to arrange the bushing 42 in a force-locking manner in the receiving part 20, for example, to avoid the ingress of dirt into the interface between the bushing 42 and the body of the aiming device 1.

[0040] For this purpose, the bushing 42 may have a recess 45 into which a sealant and / or adhesive can be introduced. The extension 24 may further include a stop 25 formed as a step, by means of which the position of the bush 42 in the receiving part 20 may be predetermined. One of the end faces 43, 44 of the bush 42 may abut against the stop 25.

[0041] Referring to FIG. 2 a , an annular space 26 is further formed in the receiving portion 20 next to the extension portion 24 , into which at least one resilient finger 50 can extend. The annular space 26 may be formed by a conical section connecting the extension 24 or the stopper 25 to the guide opening 22. To allow an unhindered flexing movement of the resilient fingers 50, the maximum diameter D25 of the conical or cylindrical annular space 26 must be greater than the inner diameter D42i.

[0042] In figures 2a to 7 different embodiments of the locking means 40 generally described above are shown and which will be described in detail below also having the above mentioned characteristics. 2a-c has a plurality of resilient fingers 50 arranged circumferentially symmetrically around the second axis X2, which project radially in the direction of the second axis X2 into the through-hole 41 of the bush 42 or into the guide opening 22. The distance A52 between two diametrically arranged free ends 52 is smaller than the diameter D60.

[0043] 2a-c further suggest that a flushing channel 30 may be provided opening into the annular space 26. The flushing channel 30 is configured to introduce a cleaning agent into the annular space 26, for example for cleaning or sterilizing the aiming device 1 after use. The flushing channel 30 may preferably open into the annular space 26 in an orientation oriented tangentially to the second axis X2, which allows for an effective rinsing of the annular space 26 during cleaning.

[0044] The locking means 40 according to Figures 3a to 3c is designed similarly to the locking means 40 according to Figures 2a to 2c and has a number of closely spaced elastic fingers 50. In the circumferential direction, the distance between the elastic fingers 50 is smaller than their width. The free spaces between the elastic fingers 50 have relief holes on the side opposite to the free ends 52. The relief holes can reduce the notch effect of the notch-shaped free spaces.

[0045] Figures 4a-4c show a U-shaped cross-section of the locking means 40. The locking means 40 is designed equivalently to the locking means 40 already presented according to figures 2a-3c. Here, however, the bush 42 is formed U-shaped in cross-section and has an inner leg, an outer leg and a central leg. The central leg connects the inner leg and the outer leg, which at least partially surround the annular space 26.

[0046] The inner legs form resilient fingers 50, by means of which a particularly compact form of the locking means 40 can be achieved. An alternative embodiment of the locking means 40 can be seen in figures 5a to 5c, in which resilient fingers 50 project from the end faces 43, 44 of the annular bushing 42.

[0047] The bushing 42 forming the locking means 40 can be inserted into the receiving part 20 in any orientation, the elastically deflectable fingers 50 being able to point in both directions relative to the second axis X2.

[0048] A fifth embodiment of the locking means 40 and a development of the body 10 are shown in figures 6a to 6d. The body has an undercut 28 in the extension 24, which is away from the distal side and / or the proximal side 14. The undercut 28 can form an annular space 26. A deflectable finger 50 stands in the annular space 26 in a free-floating manner and can perform an unhindered avoidance movement.

[0049] As can be seen from FIG. 6a, flushing channels 30 opening into the annular space 26 can be provided in a manner equivalent to that already described. The locking means 40 according to Figures 6a-6d is designed equivalently to the already presented locking means 40 according to Figures 4a-5c. Here, however, the bush 42 is made longer along the second axis X2 and the elastic fingers 50 project from the end faces 43, 44 of the bush 42. The opposite end face 43 or 44 has a flange portion 48 which can cooperate with a stopper 25 to fix the position of the locking means 40 in the receiving part 20 on the second axis X2.

[0050] From the detailed view according to Fig. 6d it can be seen that the connection means of the locking means 40 can comprise at least one projection 46 for forcefully holding the locking means 40 in the receiving part 20. The projection 46 can be designed as a circumferential flange and is configured to clamp and hold the locking means 40 in the receiving part 20 by means of an interference fit. A number of tooth-shaped projections 46 can also be provided distributed around the circumference.

[0051] The protrusion 46 is preferably arranged next to the deflectable finger 50. In the illustrated exemplary embodiment, the protrusion 46 is formed along the second axis X2 in the area from which the fingers 50 protrude, or more precisely in the area that is arranged next to the end face 43, 44 from which at least one finger 50 protrudes.

[0052] FIG. 7 shows a sixth exemplary embodiment of the locking means 40 according to FIG. 1b, where the locking means is marked with the reference sign 40′. The locking means 40 according to FIG. 7 differs from the locking means 40 shown in FIGS. 6a-6d in that it has a through-hole 41 with a figure-of-eight cross-section, which allows a protective sleeve 60 (not shown) to be inserted and held in two positions: parallel and spaced apart with respect to the second axis X2′. The through-hole 41 with a figure-of-eight cross-section can be designed such that two circles enclosing the cross-section intersect at one or two intersection points. The enclosing circles can also be arranged spaced apart from each other. In such a case, two protective sleeves 60 can be held simultaneously by the locking means 40. [Explanation of symbols]

[0053] 1...aiming device, 5...bone fixation element, 8...prosthesis, 10...main body, 11...first end region, 12...second end region, 13...proximal side, 14...distal side, 15...retaining means, 20...receiving portion, 22...guide opening, 24...extension, 25...stopper, 26...annular space, 30...flushing channel, 40...locking means, 41...penetration portion, 42...bush, 43...first end face, 44...second end face, 45...recess, 46...protrusion, 48...flange, 50...finger, 52...free end of 50, 54...contact area, 60...protective sleeve, X1...first axis, X2...second axis.

Claims

1. An aiming device (1) for forming a fixation of a prosthesis (8) to a bone by means of a bone fixation element (5), comprising: a retaining means (15) for positioning said prosthesis (8) on a first axis (X1); a receiving part (20) oriented along a second axis (X2), passing through said aiming device and defining a guide opening (22) designed to receive a protective sleeve (60); and locking means (40) including at least one elastically deflectable finger (50) deflectable axially and / or radially with respect to said second axis (X2), The first axis (X1) and the second axis (X2) intersect, The at least one finger (50) projects into the guide opening (22).

2. 2. The aiming device (1) according to claim 1, wherein said locking means (40) comprises a bushing (42).

3. 3. The aiming device (1) according to claim 1 or 2, wherein the bush (42) is arranged in the receiving portion (20).

4. The housing portion (20) is formed with an annular space (26), Aiming device (1) according to any one of claims 1 to 3, wherein said at least one finger (50) is protrudable into said annular space (26) so as to be free to move.

5. Aiming device (1) according to any one of the preceding claims, wherein a flushing channel (30) opens into said annular space (26).

6. Aiming device (1) according to any one of the preceding claims, wherein the flushing channel (30) opens into the receiving portion (20) in an orientation oriented tangentially to the second axis (X2).

7. Aiming device (1) according to any one of the preceding claims, wherein said locking means (40) is U-shaped in cross section.

8. The aiming device (1) according to any one of claims 1 to 7, further comprising connecting means capable of arranging and holding the locking means (40) in the receiving part (20) in a force-locking, form-locking and / or material-locking manner.

9. Aiming device (1) according to any one of the preceding claims, wherein said locking means (40) is made of plastic.

10. Aiming device (1) according to any one of the preceding claims, wherein a plurality of free-standing fingers (50) are provided.

11. Aiming device (1) according to any one of the preceding claims, wherein said free-standing fingers (50) are arranged circumferentially symmetrically with respect to said second axis (X2).

12. Aiming device (1) according to any one of the preceding claims, wherein said at least one finger (50) has a contact area (54) at a free end (52).

13. Aiming device (1) according to any one of the preceding claims, wherein the contact area (54) of the at least one finger (50) is angled to make face contact with the protective sleeve.

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