TARGET DEVICE

Description

[0001] The present invention relates to a targeting device for forming a fastening of a prosthesis, in particular an intramedullary nail with a bone fastening element to a bone, having the features of patent claim 1.

[0002] Such targeting devices are known in various designs from the prior art and serve to precisely position a bone fastening element in a corresponding recess of a prosthesis, for example, an intramedullary nail, in order to firmly connect and anchor the prosthesis to the bone. Such targeting devices are widely used to stabilize bones (e.g., femur or tibia) after a fracture. For example, such a targeting device is previously known from US2012 022 533 A1.

[0003] For this purpose, the prostheses used include a recess through which the bone fastener can be inserted to anchor the prosthesis or intramedullary nail in the bone. A corresponding recess can be created in the bone using a tool. The corresponding recess is precisely aligned with the recess in the prosthesis using the targeting device with a guide opening. To prevent damage to the surrounding tissue when using the targeting device to create the corresponding recess, the tissue is kept at a distance from the tool.

[0004] In addition to tissue spreaders, protective sleeves are also used to shield the tool when the corresponding recess is made in the bone.

[0005] The present invention is dedicated to the task of proposing a suitably improved targeting device. When using a previously described targeting device, damage to the surrounding tissue should be prevented by means of a protective sleeve when the tool creates the corresponding recess in the bone, while the handling of the targeting device should be simple and reliable.

[0006] These objects are achieved by a targeting device having the features of patent claim 1.

[0007] Further advantageous embodiments of the aiming device according to the invention are specified in the subclaims.

[0008] The aiming device according to the invention with the features of patent claim 1 for forming a fastening of a prosthesis, in particular an intramedullary nail, to a bone has a holding means for positioning the prosthesis, in particular the intramedullary nail, in a first axis, at least one receptacle forming at least one guide opening, which is oriented along a second axis and penetrates the aiming device and is designed to receive the 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 with respect to the second axis. The first axis and the second axis intersect, wherein it is further provided that the at least one elastically deflectable finger protrudes into the guide opening. The at least one elastically deflectable finger is configured to secure the protective sleeve along the second axis.

[0009] The present invention is based on the idea of ​​securing the protective sleeve within the guide opening by at least one elastically deflectable finger. The protective sleeve therefore does not need to be held by medical personnel and is also not at risk of accidentally falling out of the guide opening.

[0010] At this point, it should be noted that the aiming device may have more than one receptacle forming a guide opening. The respective guide openings may each be oriented along a second axis, wherein the second axes are spaced apart from one another. The second axes may be oriented parallel to one another or intersect at a common intersection point. The angle enclosed by the second axes is preferably 30° to 60°.

[0011] The at least one elastically deflectable finger can come into operative contact with the protective sleeve inserted into the guide opening, creating a frictional connection with the protective sleeve. Upon insertion of the protective sleeve into the guide opening, the at least one elastic finger is deflected axially and / or radially, exerting a holding force that secures the protective sleeve.

[0012] By appropriately designing the stiffness of at least one elastic finger, the holding force can be dimensioned and thus adapted to the respective application or to the user's preferences.

[0013] The guide opening and / or the protective sleeve are preferably cylindrical, and the guide opening completely penetrates the aiming device. The guide opening is preferably designed so that the protective sleeve can be easily inserted, for example, by means of a clearance fit.

[0014] The invention provides that the locking means comprises a bushing. The bushing can preferably be a hollow cylinder with an opening, wherein the opening is preferably adapted to the guide opening in shape and / or dimensions or identical to it and can further form a portion of the guide opening.

[0015] The opening may have a polygonal, circular, or figure-eight-shaped cross-section, wherein the opening is configured such that at least one guide sleeve can be passed through. The figure-eight-shaped cross-section may allow the at least one guide sleeve to be guided through at least two positions parallel to and spaced from the second axis.

[0016] The at least one elastic finger protrudes radially inward or radially inward and axially from the locking means or the bushing. The bushing can be attached to the aiming device in any desired manner, with the aperture and the guide opening preferably being arranged coaxially along the second axis.

[0017] According to a further preferred embodiment, the locking means or the bushing can be arranged—preferably completely—in the receptacle of the aiming device. It is particularly preferred if the bushing can be arranged captively in the receptacle. The receptacle preferably has a widened portion similar to a cylinder head screw countersunk head, into which the bushing can be inserted. The bushing is held in the receptacle coaxially aligned with the guide opening.

[0018] Furthermore, it has proven advantageous if an annular space is formed in the receptacle, and if the at least one finger can protrude freely into the annular space. In particular, it is preferred if the annular space is formed at the end face of the locking means or the bushing and is enclosed, preferably in a U-shape, by the receptacle on one side and the bushing on the other.

[0019] A preferred embodiment of the present invention provides for a flushing channel to open into the annular space. A cleaning agent can be introduced into the annular space through the flushing bore to clean the target device before or after use.

[0020] According to a further development, the flushing channel opens into the annular space in a direction oriented tangentially to the second axis, whereby the annular space can be effectively flushed with a cleaning agent during cleaning.

[0021] According to a preferred embodiment of the present invention, the bushing is U-shaped in cross-section. The bushing has an inner leg, an outer leg, and a middle leg, with the middle leg connecting the inner leg and the outer leg. Due to the U-shaped configuration of the bushing, the annular space can be formed by the legs of the U-shaped bushing.

[0022] Preferably, a connecting means can be provided by which the locking means can be held in the receptacle in a force-fitting, form-fitting and / or material-fitting manner.

[0023] A preferred development of the present invention provides that the inner leg comprises the at least one finger.

[0024] According to a preferred development, at least two, preferably three or more, freestanding fingers are provided. The freestanding, elastically deflectable fingers can be distributed around the circumference of the second axis and spaced apart from one another, and can extend into the guide opening in a spoke-like or comb-like manner. Furthermore, at least two elastic fingers can be arranged along the second axis. The holding force for the protective sleeve can also be designed by the number of elastic fingers.

[0025] A preferred embodiment of the present invention provides that the freestanding and elastic fingers are arranged circumferentially symmetrically to the second axis. In particular, the circumferentially symmetrical arrangement of the freestanding fingers enables centering of the protective sleeve in the guide opening.

[0026] A further development of the present invention provides that the at least one elastically deflectable finger has a contact area at a free end. The contact area can be configured to generate the greatest possible holding force and the greatest possible static friction. For example, the contact area can be formed from a suitable material and / or have a correspondingly equipped surface that has the highest possible coefficient of friction.

[0027] According to a further development of the present invention, the contact area can be angled relative to an orientation of the at least one finger, wherein the contact area is configured to lie flat on the protective sleeve.

[0028] An embodiment of the aiming device according to the invention and further developments of the aiming device are described in detail below with reference to the accompanying drawings. They show: Figure 1a-1c shows a perspective view of a targeting device according to the invention with a holding means which positions a prosthesis in a first axis, and a protective sleeve which is held in a guide opening by locking means in a first axis, Figures 2a-2c show different views of the locking means according to Figure 1 , Figures 3a-3c different views of a second embodiment of the locking means according to Figure 1 , Figures 4a-4c different views of a third embodiment of the locking means according to Figure 1 , Figures 5a-5c different views of a fourth embodiment of the locking means according to Figure 1 , Figures 6a-6d different views of a fifth embodiment of the locking means according to Figure 1 , and Figure 7 a sixth embodiment of the locking means according to Figure 1 .

[0029] In the following, identical or functionally equivalent components in an exemplary embodiment are identified by the same reference numerals. For the sake of clarity, not all identical or functionally equivalent parts are provided with a reference numeral in the individual figures.

[0030] Figure 1a shows a representation of a target device 1 according to a preferred embodiment of the invention.

[0031] The aiming device 1 is bow-shaped and has a first end region 11 and a second end region 12 and can comprise a single-part or multi-part main body 10, referred to as a whole. Furthermore, the aiming device 1 has a proximal side 13 and a distal side 14, wherein the proximal side 13 lies on a concave region of the bow-shaped aiming device 1 and the distal side 14 lies on a convex region opposite the concave region.

[0032] In the first end region 11, a holding means 15 is provided for positioning a prosthesis (not shown), in particular an intramedullary nail, wherein the prosthesis can be held oriented along a first axis X1. The holding means 15 can establish a detachable connection with the prosthesis.

[0033] In the second end region 12, at least one receptacle 20 forming at least one guide opening 22 is formed, wherein the receptacle 20 completely penetrates the targeting device 1 or the main body 10 and the receptacle 20 connects the proximal side 13 with the distal side 14. The receptacle 20 is oriented in a second axis X2, wherein, as in the embodiment according to Figure 1 shown, several receptacles 20 are provided. For clarity, the additional receptacle 20, the additional guide opening 22, and the additional second axis X2 are marked with a "'" in the accompanying figures.

[0034] The first axis X1 and the second axis X2 have a common intersection point, wherein the intersection angle on the side facing the target device 1 should preferably be approximately between 45° and 135°.

[0035] In the receptacle 20 or in the guide opening 22, as shown, among other things, in the Figure 1C , 2A , 3A , 4A and 5A As shown, a protective sleeve 60 can be inserted or guided through, wherein the protective sleeve 60 can preferably be inserted smoothly into the receptacle 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 one another.

[0036] In a manner not shown, two protective sleeves 60 can also be inserted or passed through in an analogous manner into the receptacle 20' or into the guide opening 22', or one protective sleeve in different positions.

[0037] The receptacle 20 and / or the guide opening 22 can have a circular or figure-eight-shaped cross-section, with the guide opening 22 further defining the orientation of the protective sleeve 60 along the second axis X2. The guide opening 22 has a diameter D22, and the protective sleeve 60 has a diameter D60, with the diameter D60 preferably being slightly smaller than the diameter D22 to form a clearance fit.

[0038] Furthermore, the aiming device 1 comprises a locking means 40 which is configured to fix the protective sleeve 60 in the receptacle 20 in order to prevent unwanted or unintentional falling out.

[0039] The locking means 40 according to the Figure 1 - 7comprises at least one elastic finger 50, which can be elastically deflected axially and / or radially with respect to the second axis X2 and can come into operative contact with the at least one protective sleeve 60. The at least one elastic, deflectable finger 50 projects freely into the guide opening 22 and, upon insertion of the protective sleeve 60 into the guide opening 22, can perform an elastic evasive movement and subsequently press against the protective sleeve 60 with a holding force in order to fix it in a desired position in the guide opening 22.

[0040] The at least one elastic finger 50 projects radially or radially and axially into the guide opening 22 with respect to the second axis X2. A free end 52 of the respective finger 50 is located within the guide opening 22 in the non-deflected state of the elastic finger 50. At this point, it is noted that in the accompanying figures, the fingers 50 are shown in the non-deflected state for reasons of simplified representation. Only in Figure 5a A deflection movement is indicated by dashed lines and a double arrow.

[0041] The free end 52 may have a contact area 54 which preferably has increased static friction properties.

[0042] For example, the elastic deflectable fingers 50 according to the embodiments according to the Figure 2 and 3 radially into the guide opening 22, while the elastic fingers 50 according to the embodiments according to the Figure 4 and 5 are oriented at an angle of approximately 45° to the second axis X2, and thus protrude radially and axially oriented into the guide opening 22.

[0043] The locking means 40 may, as shown in the illustrated embodiments, comprise a bushing 42 that can be inserted into the receptacle 20. The elastic fingers 50 protrude freely from the bushing 42 in the radial direction or in the radial and axial directions in the direction of the second axis X2.

[0044] The receptacle 20 may have a widened portion 24 on the proximal side 13 and / or on the distal side 14, which is configured to receive the bushing 42. The widened portion 24 has a diameter D24, wherein the diameter D24 is larger than the diameter D22.

[0045] The bushing 42 has an outer diameter D42a, and the opening of the bushing 42 has an inner diameter D42i. The outer diameter D42a corresponds to the diameter D24 of the expansion 24, and the inner diameter D42i is larger than the diameter D60 of the protective sleeve 60.

[0046] The bushing 42 can be held in the receptacle 20 by means of connecting means in a force-fitting, form-fitting, and / or material-fitting manner. For example, the material-fitting arrangement of the bushing 42 in the receptacle 20 can be advantageous to prevent the penetration of contaminants into the interface between the bushing 42 and the main body of the targeting device 1. For this purpose, the bushing 42 can have a recess 45 into which a sealant and / or an adhesive can be introduced.

[0047] The widened portion 24 may further comprise a stop 25 formed as a shoulder, which may determine the position of the bushing 42 in the receptacle 20. One of the end faces 43, 44 of the bushing 42 may engage the stop 25.

[0048] With reference to the Figure 2a It can be seen that an annular space 26 is further formed in the receptacle 20 adjacent to the widening 24, into which the at least one elastic finger 50 can dip.

[0049] The annular space 26 can be formed by a conical section connecting the widened portion 24 or the stop 25 with the guide opening 22. The largest diameter D25 of the conical annular space 26 or a cylindrical annular space 26 should be larger than the inner diameter D42i to allow unimpeded deflection of the elastic finger 50.

[0050] In the Figure 2-7Different embodiments of the locking means 40 described above in general terms are shown, wherein the locking means 40 described below in detail have the properties described above in common.

[0051] The locking means 40 according to the Figure 2 has a plurality of elastic fingers 50 arranged circumferentially symmetrically around the second axis X2, which project radially in the direction of the second axis X2 into an opening 41 of the bushing 42 or into the guide opening 22. The distance A52 between two diametrically arranged free ends 52 is smaller than the diameter D60.

[0052] Furthermore, the Figure 2It is indicated that a flushing channel 30 can be provided, which opens into the annular space 26. The flushing channel 30 is configured to conduct a cleaning agent into the annular space 26, for example, to clean or sterilize the target device 1 after use. The flushing channel 30 can preferably open into the annular space 26 in a direction oriented tangentially to the second axis X2, whereby the annular space 26 can be effectively flushed during cleaning.

[0053] The locking means 40 according to Figure 3 is analogous to the locking means 40 according to Figure 2formed, wherein a plurality of elastic fingers 50 are provided in a close mesh. In the circumferential direction, the distance between the elastic fingers 50 is smaller than the width of the elastic fingers 50. A free space between the elastic fingers 50 has a relief bore on the side facing away from the free end 52. The relief bore can reduce the notch effect of the notch-shaped free space.

[0054] Figure 4 shows a locking means 40 which is U-shaped in cross section. The locking means 40 is comparable to the locking means 40 already presented according to the Figure 2 and 3However, here the bushing 42 is U-shaped in cross-section and has an inner leg, an outer leg, and a middle leg. The middle leg connects the inner leg and the outer leg, with the legs enclosing the annular space 26 at least in part. The inner leg forms the elastic fingers 50, which allows for a particularly compact design of the locking means 40.

[0055] A further embodiment of the locking means 40 can be seen in Figure 5, wherein the elastic fingers protrude from an end face 43, 44 of the annular bushing 42.

[0056] The bushing 42 forming the locking means 40 can be inserted into the receptacle 20 in any orientation, wherein the elastically deflectable fingers 50 can point in both directions with respect to the second axis X2.

[0057] A fifth embodiment of the locking means 40 and a further development of the main body 10 is described in Figure 6 shown. The main body has an undercut 28 in the widened portion 24, which is spaced from the distal and / or proximal side 14. The undercut 28 can form the annular space 26. The deflectable fingers 50 are freely movable within the annular space 26 and can thus perform an unhindered evasive movement.

[0058] How Figure 6a As can be seen, a flushing channel 30 can be provided in a similar manner as already described, which opens into the annular space 26.

[0059] The locking means 40 according to the Figure 6a - 6d is comparable to the locking devices 40 already presented according to the Figure 4 and 5However, here the bushing 42 is more elongated along the second axis X2, and the elastic finger 50 protrudes from an end face 43, 44 of the bushing 42. The opposite end face 43 or 44 has a flange portion 48 that can cooperate with the stop 25 to fix the position of the locking means 40 along the second axis X2 in the receptacle 20.

[0060] From the detailed representation according to Figure 6d It can be seen that the connecting means of the locking means 40 can comprise at least one projection 46 to hold the locking means 40 in the receptacle 20 in a force-fitting manner. The projection 46 can be designed as a circumferential flange and is configured to hold the locking means 40 clamped in the receptacle 20 by an interference fit. A plurality of tooth-shaped projections 46 can also be provided distributed over the circumference.

[0061] The projection 46 is preferably arranged adjacent to the deflectable fingers 50. In the illustrated embodiment, the projection 46 is formed along the second axis X2 in the region from which the finger 50 protrudes, or more precisely, adjacent to the end face 43, 44 from which the at least one finger 50 protrudes.

[0062] Figure 7 shows a sixth exemplary embodiment of the locking means 40, according to Figure 1b which is provided there with the reference number 40'. The locking means 40 according to Figure 7, in contrast to the one in Figure 6The locking means 40 shown has an opening 41 with a figure-eight shape in cross-section, which is intended to enable a protective sleeve 60 (not shown) to be inserted and held in two positions parallel to and spaced from the second axis X2'. The figure-eight shape in cross-section 41 can be designed such that the two circles framing the cross-sectional area intersect at one or two intersection points. The framing circles can also be arranged spaced from one another. In such a case, two protective sleeves 60 can be held by the locking means 40. List of reference symbols

[0063] 1Targeting device 5Bone fixation element 8Prosthesis 10Main body 11First end area 12Second end area 13Proximal side 14Distal side 15Holding means 20Receptacle 22Guide opening 24Wide opening 25Stop 26Annular space 30Irrigation channel 40Locking means 41Perforation 42Socket 43First end face 44Second end face 45Incision 46Protrusion 48Flange 50Finger 52Free end of 50 54Contact area 60Protective sleeve X1first axis X2second axis

Claims

1. Aiming device (1) for forming a fastening of a prosthesis (8) to a bone fastening element (5) on a bone, comprising: - holding means (15) for positioning the prosthesis (8) in a first axis (X1), - a receptacle (20) that forms a guide opening (22), which is oriented along a second axis (X2) and penetrates the aiming device and is configured for receiving a protective sleeve, and - a locking means (40) which comprises at least one resiliently deflectable finger (50) which dan be deflected axially and / or radially with respect to the second axis (X2) and is configured for fixing the protective sleeve along the second axis (X2), - wherein the first axis (X1) and the second axis (X2) intersect, - wherein the at least one finger (50) protrudes into the guide opening (22), characterised in that the locking means (40) comprises a bush (42).

2. Aiming device (1) according to claim 1, characterised in that the bush (42) can be arranged in the receptacle (20).

3. Aiming device according to either of the preceding claims, characterised in that an annular space (26) is formed in the receptacle (20), and in that the at least one finger (50) can protrude into the annular space (26) in a freely movable manner.

4. Aiming device (1) according to claim 3, characterised in that a rinsing channel (30) leads into the annular space (26).

5. Aiming device (1) according to claim 4, characterised in that the rinsing channel (30) leads into the receptacle (30) in a direction oriented tangentially to the second axis (X2).

6. Aiming device (1) according to any of the preceding claims, characterised in that the locking means (40) is U-shaped in cross-section.

7. Aiming device (1) according to any of the preceding claims, characterised in that connecting means are provided, by which the locking means (40) can be held in the receptacle (20) so as to be arranged in a force-fitting, form-fitting and / or integrally locking manner.

8. Aiming device (1) according to any of the preceding claims, characterised in that the locking means (40) is made of a plastics material.

9. Aiming device (1) according to any of the preceding claims, characterised in that a plurality of free-standing fingers (50) is provided.

10. Aiming device (1) according to any of the preceding claims, characterised in that the free-standing fingers (50) are arranged in a peripherally symmetrical manner with respect to the second axis (X2).

11. Aiming device (1) according to any of the preceding claims, characterised in that the at least one finger (50) comprises a contact region (54) at a free end (52).

12. Aiming device (1) according to claim 11, characterised in that the contact region (54) of the at least one finger (50) is angled so as to lie in a planar manner on the protective sleeve.