Bone holding forceps

Abstract

The invention relates to bone holding forceps (1) having a first forceps rod (2) and a second forceps rod (3) which are connected to one another via a forceps hinge (4) and having a respective bone fixation element (15) which is associated with a distal end of the first forceps rod (2) or the second forceps rod (3) and which is mounted at the distal end by means of a fixation hinge (16). At least one jaw (17) is hingedly mounted at the bone fixation element (15) via a jaw hinge (18).

Description

Technical Field

[0001] The present invention relates to a bone holding forceps, which has a first forceps rod and a second forceps rod connected to each other via a forceps hinge and has at least one bone fixing element associated with the distal end of the first forceps rod or the second forceps rod, the bone fixing element being mounted at the distal end via a fixing hinge, wherein at least one forceps jaw is hingedly mounted on the bone fixing element via a jaw hinge. Background Art

[0002] In the medical field, imaging methods such as X-ray computed tomography (CT), magnetic resonance imaging (MRI magnetic resonance imaging), positron-electron tomography (PET) and ultrasound imaging are used for diagnostic purposes and are also used to guide the surgeon during surgery and to assist during surgical interventions with current information that can be provided in real time with high spatial and temporal resolution. For exact spatial orientation, navigation systems are also used, with which the patient's movements can also be detected and analyzed during surgery. These navigation systems include reference markers that need to be positioned on the patient, more precisely, preferably reversibly and releasably in a still stable, stationary connection, in order to avoid data drift. In addition to bone anchors that are invasively introduced into the bone, bone clamps are also suitable for this purpose, wherein the specific application situation influences the choice between bone anchors and bone clamps. Bone clamps are used in particular in spinal surgery, because sufficiently large and stable bones are available.

[0003] EP3247297B1 discloses a bone holding forceps for placement on a bone, which is composed of a first tong rod and a second tong rod that are connected in an articulated manner to each other. The position of one tong rod relative to the other tong rod can be determined by adjusting the position of a sliding shoe that is slidably mounted on the one tong rod relative to the one tong rod by means of a screw that is rotatably and non-displaceably mounted in the sliding shoe so that the sliding surface abuts against the other tong rod. US2009 / 0062869 A1 discloses a bone holding forceps, in which a pivoting tong rod is articulated on a rigid rod, in which a tension plate holder that carries a tension plate is mounted at the free ends of the pivoting tong rod and the rod. Summary of the invention

[0004] The object of the present invention is to provide a bone holding forceps which enables improved contact with the bone surface and which is gentler on the patient.

[0005] This object is achieved by a bone clamp having the features of claim 1. Advantageous embodiments of the invention with expedient developments are specified in the dependent claims.

[0006] Bone clamps of the type mentioned at the outset are unique in that the jaws can be brought into contact with the surface of the bone more easily by the synergistic effect of the jaw joint and the fixing joint, wherein this is particularly facilitated by the fact that the bone fixing element is composed of a first arm and a second arm, two jaws are present, and one of the jaws is articulatedly mounted on each of the arms via the jaw joint. The jaws can be pivoted independently, so that three pivot axes are provided taking into account the fixing joint and the two jaw joints, so that the jaws act like a kinematic multi-body chain and can achieve a further improved contact with the outer contour of the bone.

[0007] Also for reasons of symmetry, it is advantageous in this context if the fixed joint is arranged between the two arms.

[0008] It is also preferred that a groove is formed in the free end of the arm and is limited by two groove side plates, and the jaw is inserted into the groove, wherein a bearing seat is formed in the two groove side plates, and a hinge pin carrying the jaw is inserted into the bearing seat, so as to simply form the jaw hinge.

[0009] It is expedient if the clamping jaws are formed from a pin carrier having a through opening and a clamping plate arranged on the pin carrier, since in this way the functions of the clamping jaws can be separated and assigned to separate components.

[0010] In a preferred embodiment, in the bone fixation element, the fixing hinge is formed by a hinge through-hole for receiving the hinge axis, the hinge through-hole being traversed by a spring through-hole into which a spring is inserted, the spring being supported at the two jaws associated with the arm. This spring makes it possible to hold the two jaws in a neutral position in the bone fixation element, which is advantageous when the bone clamp can initially only be introduced to the bone through a tissue opening. This neutral position is maintained until contact with the bone has been achieved, wherein an equilibrium of the clamping forces between the jaws can be achieved at least partially.

[0011] In order to better hold the jaws on the bone surface, at least one spike is arranged on the jaw plate, preferably a plurality of spikes, wherein the spike is formed by two mutually intersecting blades which converge into a tip in an arrow-like manner toward the free end. This design reduces the force required for perforating the bone, since less bone material needs to be pushed out. It is also advantageous that it is less traumatic than, for example, a pyramid-shaped spike, so that the bone can heal more quickly after the bone holder is removed.

[0012] Theoretically, it is conceivable that the fixing element is associated with only one of the clamp rods, while the other clamp rod is fixed to the bone by friction or clamp means designed in another way. However, it is particularly preferred that two fixing elements according to the invention are present and the distal ends of the first clamp rod and the second clamp rod are each associated with one of the fixing elements.

[0013] It is also particularly preferred that a sleeve portion is formed in the proximal region of the first clamp rod, and an internal thread is formed on the inner side thereof, into which a clamp element having an external thread can be screwed so as to abut the proximal region of the second clamp rod with its free end. By means of this simple construction without the use of sliding shoes, the positions of the two clamp rods can be fixed in the clamping position. The clamping force achieved is thus maintained for a long time. It should also be noted that this safety mechanism design can be implemented in the proximal region independently of the measures at the distal ends of the two clamp rods, even though the advantages of clamping force safety have been shown, especially when the bone fixation element and the clamp claw of the present invention are used.

[0014] It is also advantageous if there is a preload spring acting between the first and second jaw levers, which loads the first and second jaw levers in a direction that closes the distal ends. This spring ensures a rest position of the two jaw levers in a closed configuration, which offers advantages when the tubular forceps are introduced into a patient.

[0015] If the free distal end of the jaw element is not threaded and is designed in a rounded manner, good contact between the jaw element and the proximal region of the second jaw shaft results, regardless of their position.

[0016] As intended, a reference marker can be coupled to the bone forceps, for which purpose jaw surfaces are conveniently formed on the outer side of the sleeve part, to which the reference marker is fixed. The sleeve part thus has a dual function, which again contributes to a simple construction of the bone forceps. In this case, the mounting of the reference marker can be simplified by forming an annular flange at the distal end of the sleeve part.

[0017] Without departing from the framework of the present invention, the features and feature combinations mentioned above in the description and the features and feature combinations mentioned below in the description of the figures and / or shown separately in the figures can be used not only in the respectively given combination, but also in other combinations or alone. Therefore, embodiments not explicitly shown or explained in the figures can also be regarded as being included and disclosed by the present invention, but emerge from the described embodiments and can be produced by individual feature combinations. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Further advantages, features and details of the invention are apparent from the claims, from the following description of preferred embodiments and with the aid of the drawings. In the drawings:

[0019] Figure 1 A side view of a bone holding forceps is shown, shown in a configuration suitable for introduction,

[0020] Figure 2 Shown from Figure 1 A stereoscopic view of a bone holding forceps in a configuration suitable for holding a bone segment,

[0021] Figure 3 The corresponding position of the bone forceps is shown Figure 2 , in a configuration secured for clamping with a jaw element,

[0022] Figure 4 Shown from Figure 3 Stereoscopic image of a bone holding forceps with reference markers,

[0023] Figure 5 An exploded view of the jaw section of the bone holding forceps with the bone fixation element is shown,

[0024] Figure 6 Shown from Figure 5 Details of VI,

[0025] Figure 7 Shown from Figure 6 Exploded view of the bone fixation element,

[0026] Figure 8 The bone fixation element is shown in the first pivot position of the jaws. Figure 6 ,

[0027] Fig. 9 The bone fixation element is shown in another pivot position of the jaws. Figure 6 ,

[0028] Fig.10 The bone fixation element is shown in yet another pivot position of the jaws, corresponding to Figure 6 ,

[0029] Fig.11 A perspective view showing the separation of the jaws,

[0030] Fig.12 Shown from Fig.11 A top view of the jaws.

[0031] Fig.13 A perspective view showing a bone clamp fixed to the cervical spine, with reference markers,

[0032] Fig.14 Shown from Fig.13 Details XIV,

[0033] Fig.15 A perspective view of a bone clamp fixed to the lumbar spine is shown, with reference markers, and

[0034] Fig.16 Shown from Fig.15 Details of XVI.

[0035] Fig.17 Shown from Figure 1 A stereoscopic view of a bone holding forceps with a screwed-in jaw element in a closed configuration,

[0036] Fig.18 Shown corresponding to Fig.17 without the jaw elements, in the open configuration, and

[0037] Fig.19 Shown from Fig.18 Exploded view of the bone holding forceps. DETAILED DESCRIPTION

[0038] exist Figure 1 , the bone forceps 1 is shown in a closed configuration, as is the case when the bone forceps 1 is initially placed through a tissue opening in a patient. The bone forceps 1 consists of a first forceps rod 2 and a second forceps rod 3, which are connected to one another by a forceps hinge 4. The forceps rods 2, 3 are formed to be rounded and complement each other in a cross section to form an approximately circular shape in an area defined for introduction into the patient's body. Along the main axis of the first forceps rod 2 and the second forceps rod 3, at least partially approximately cylindrical outer surfaces are present, wherein when the distal forceps area is opened by pressing the proximal ends of the two forceps rods together, the inner side of the second forceps rod 3 projects into the cylindrical inner opening of the first forceps rod 2. ( Fig.18 ) The sleeve portion of the first clamp rod 2 exceeds the length of the second clamp rod 3 in the proximal direction ( Figure 1 ).

[0039] A preload spring 5 is arranged between the first tongs lever 2 and the second tongs lever 3, which loads the first tongs lever 2 and the second tongs lever 3 in the direction of closing the distal end. In this case, in the embodiment shown, the preload spring 5 is associated with the proximal region of the two tongs levers 2, 3 and is designed as a compression spring.

[0040] At the proximal region of the first tongs shaft 2 there is a sleeve part 6, on the inner side of which an internal thread 7 is formed, into which a tongs element 8 with an external thread 9 can be screwed. The tongs element 8 can be screwed into the sleeve part 6 so that its free end abuts against the proximal region of the second tongs shaft 3. The free distal end of the tongs element 8 is not threaded and is designed in a rounded form.

[0041] By this structure, the bone clamp 1 is held in the Figure 1 In the closed configuration shown, this closed configuration is particularly suitable for introducing the bone clamp 1 into the patient's body because the tissue is protected. If the bone clamp 1 is already close to the bone, the two clamp rods 2, 3 can be adjusted against the force of the preload spring 5 ( Figure 2 ), wherein the desired configuration can be fixed by means of the clamp element 8 and the required clamping force can be introduced ( Figure 3 ).

[0042] If this has been achieved, the reference marker 10 can be coupled to the bone clamp 1, such as Figure 4 For this purpose, a jaw surface 11 is formed on the outer side of the sleeve part 6, to which the reference marker 10 is fastened. For this purpose, the sleeve part 6 can have an annular flange 12 as a stop, so that the position of the reference marker 10 relative to the bone holding forceps 1 can also be clearly determined.

[0043] It is particularly important that the reference marker 10 fixed relative to the bone retains its position over the long term, more specifically depending on whether the bone surface has a rounded contour or a flatter contour, as can be explained with respect to the spinous processes 13 of the vertebrae of the spinal column 14 ( Figures 13 to 16 ).

[0044] For this purpose, the bone clamp 1 has at least one bone fixation element 15 associated with the distal end of the first tongs rod 2 or the second tongs rod 3. In the embodiment shown, there are two bone fixation elements 15, wherein the distal ends of the first tongs rod 2 and the second tongs rod 3 are each associated with one of the bone fixation elements 15. The distal ends of the tongs rods 2, 3 are slightly larger in outer diameter than the proximally adjacent curve ( Figure 1 ).

[0045] The bone fixation element 15 is mounted at the distal end by means of a fixation hinge 16 ( Figure 5 ), wherein at least one jaw 17 is hingedly mounted on the bone fixation element 15 via a jaw hinge 18. Again in the embodiment shown, the bone fixation element 15 is composed of a first arm 19 and a second arm 20, so that there are two jaws 17, and at each of the arms 19, 20 one of the jaws 17 is hingedly mounted via a jaw hinge 18 ( Figure 7 ).

[0046] Figure 7 Here the construction of one of the bone fixation elements 15 is shown in detail. The fixing hinge 16 is arranged between the two arms 19, 20, and a groove 22 is formed in the free end of each arm 19, 20, which is bounded by two groove side plates 21, into which the jaws 17 are inserted. Figure 7It can be seen that bearing seats 23 are formed in the two groove side plates 21, into which bearing seats the hinge pins 24 carrying the jaws 17 are inserted. Planar portions are arranged at the distal ends of the first and second forceps rods 2 and 3, so as to provide a stop surface 34 for the bone fixation element 15 (more precisely on the groove side plates 21), wherein the jaws 27 are designed to be wider than the groove 22. The stop surface can extend at an angle ( Fig.19 ) to achieve greater deflection.

[0047] The clamp jaw 17 itself consists of a pin carrier 26 with a through opening 25 and a clamping plate 27 arranged on the pin carrier 26 .

[0048] In the bone fixation element 15, the fixing hinge 16 is formed by a hinge through hole 29 for receiving the hinge axis 28, which is traversed by a spring through hole 30, into which a spring 31 is inserted, which is supported at the two jaws 17 associated with the arms 19, 20, i.e. at the pin holder 26. This spring 31 enables the jaws 17 to be moved in a certain direction. Fig. 9 The orientation of the rest position is shown, the jaws 17 can be deflected from the rest position ( Figure 8 and 10 ), so that it can be close to the contour of the bone surface. If the jaws 17 lose contact with the bone surface again, the jaws 17 return to the rest position again due to the effect of the spring 31.

[0049] In addition, at least one spike 32 is arranged on the pliers 27, and in the embodiment shown, there are multiple spikes. The spike 32 itself consists of mutually intersecting blades 33, which converge into a tip in the shape of an arrow towards the free end. With this design, only a small force is required to perforate the bone, because only less bone material needs to be pushed out, which also helps healing because only a small area is involved. In addition, this shaping method prevents accidental "breaking (abzwicken)" of the bone structure (spinous process). The vertical extension of the blade 33 formed in the shape of an arrow is relatively large. This helps to stabilize relative to the bone. The number of blades 33 is not necessarily limited to two, for example, it can also be three blades at an angle of 120°.

[0050] The following will briefly explain the use of the bone clamp 1 of the present invention. A channel has been formed in the patient's body leading to the bone to which the bone clamp 1 is to be fixed. Figure 1 Starting from the configuration shown, the bone clamp 1 is introduced in the direction of the bone, wherein the patient's tissue is protected from the aggressive spikes 32 of the bone fixation element 15. The preload spring 5 and the spring 31 determine the Figure 1 The configuration shown in .

[0051] If the bone holding forceps 1 are already close to the bone, the proximal ends of the forceps rods 2, 3 can be pivoted toward each other to open the distal ends. This pivoting can be done manually or by screwing the forceps element 8 into the sleeve part 6 until the desired opening angle is reached. In this configuration, the bone fixation element 15 can be brought into contact with the bone contour by pivoting the forceps jaws 17 via the jaw hinge 18 and orienting the bone fixation element 15 via the fixing hinge 16. If this is done, the forceps force is increased by further twisting the forceps element 8 in the sleeve part 6.

[0052] The reference marker 10 can then be fastened to the outer jaw surface 11 of the sleeve part 6 using a tensioning ring.

[0053] After use, the reference marker 10 and the bone forceps 1 are similarly removed in the reverse order, wherein after the spikes 32 are removed from the bone, rapid wound healing is facilitated due to less trauma.

[0054] Reference numerals

[0055] 1 Bone forceps

[0056] 2 First clamp rod

[0057] 3 Second clamp lever

[0058] 4-Jaw Hinged Joint

[0059] 5 Preload spring

[0060] 6 Sleeve

[0061] 7 Internal thread

[0062] 8 Clamp elements

[0063] 9 External thread

[0064] 10 Reference markers

[0065] 11 Clamp surface

[0066] 12 Annular flange

[0067] 13 Pedicle

[0068] 14. Spine

[0069] 15 Bone fixation elements

[0070] 16 Fixing hinge

[0071] 17 Claw

[0072] 18-claw hinge

[0073] 19 First Arm

[0074] 20 Second Arm

[0075] 21 Grooved side panels

[0076] 22 grooves

[0077] 23 Support seat

[0078] 24 hinge pin

[0079] 25 Through opening

[0080] 26 Pin Bracket

[0081] 27 Clamp

[0082] 28 Articulated shaft

[0083] 29 hinged through hole

[0084] 30 Spring through hole

[0085] 31 Spring

[0086] 32 Spike

[0087] 33 Blade

[0088] 34 Stop surface

Claims

1. A bone holding forceps (1) comprising a first forceps rod (2) and a second forceps rod (3) connected to each other via a forceps hinge (4) and having at least one bone fixing element (15) associated with the distal end of the first forceps rod (2) or the second forceps rod (3), the bone fixing element being mounted at the distal end via a fixing hinge (16), characterized in that At least one jaw (17) is articulatedly mounted on the bone fixation element (15) via a jaw articulation (18).

2. The bone holding forceps (1) according to claim 1, characterized in that: The bone fixation element (15) is composed of a first arm (19) and a second arm (20), there are two jaws (17), and one of the jaws (17) is hingedly mounted at each of the arms (19, 20) via the jaw hinge (18).

3. The bone holding forceps (1) according to claim 2, characterized in that: The fixed hinge (16) is arranged between the two arms (19, 20).

4. The bone holding forceps (1) according to claim 2 or 3, characterized in that: A groove (22) defined by two groove side plates (21) is formed in the free ends of the arms (19, 20), into which groove the jaws (17) are inserted.

5. The bone holding forceps (1) according to claim 4, characterized in that: A support seat (23) is formed in the two groove side plates (21), and a hinge pin (24) carrying the clamp jaw (17) is inserted into the support seat.

6. The bone holding forceps (1) according to any one of claims 1 to 5, characterized in that: The clamp jaw (17) is composed of a pin holder (26) having a through opening and a clamp plate (27) arranged on the pin holder (26).

7. The bone holding forceps (1) according to any one of claims 1 to 6, wherein at least one flat portion is arranged at the distal end of the first forceps rod (2) and / or the second forceps rod (3) to provide a stop surface (34) for the associated bone fixing element (15).

8. The bone holding forceps (1) according to any one of claims 4 to 7, characterized in that The clamp plate (27) is designed to be wider than the groove (22) defined by two groove side plates (21).

9. The bone holding forceps (1) according to claim 7 or 8, characterized in that: The groove side plate (21) has two flat surfaces, which serve as stop surfaces (34) for the clamp plate (27).

10. The bone holding forceps (1) according to any one of claims 6 to 9, characterized in that In the bone fixation element (15), the fixing hinge (16) consists of a hinge through-hole (29) for receiving a hinge axis (28), which is traversed by a spring through-hole (30) into which a spring (31) is inserted, which is supported at two jaws (17) associated with the arms (19, 20).

11. The bone holding forceps (1) according to claims 6 to 9, characterized in that At least one spike (32) is arranged on the nipper (27).

12. The bone holding forceps (1) according to claim 11, characterized in that: There are a plurality of spikes (32), and the spikes (32) are composed of mutually intersecting blades (33) that converge into a tip in an arrow-like manner toward the free end.

13. The bone holding forceps (1) according to any one of claims 1 to 12, characterized in that There are two bone fixation elements (15), and the distal ends of the first forceps rod (2) and the second forceps rod (3) are each associated with one of the bone fixation elements (15).

14. The bone holding forceps (1) according to any one of claims 1 to 13, characterized in that A sleeve portion (6) is formed in the proximal region of the first pliers rod (2), on the inner side of which an internal thread (7) is formed, into which a pliers element (8) having an external thread (9) can be screwed so as to abut the proximal region of the second pliers rod (3) with its free end.

15. The bone holding forceps (1) according to claim 14, characterized in that: The free distal end of the clamp element (8) has no thread and is designed in a rounded or conical manner.

16. The bone holding forceps (1) according to any one of claims 1 to 15, characterized in that A reference marker (10) is coupled thereto.

17. The bone holding forceps (1) according to claim 16, characterized in that: A clamp surface (11) is formed on the outer side of the sleeve portion (6), and the reference marker (10) is fastened to the clamp surface.

18. The bone holding forceps (1) according to any one of claims 1 to 17, characterized in that There is a preload spring (5) acting between the first clamp lever (2) and the second clamp lever (3), which loads the first clamp lever (2) and the second clamp lever (3) in a direction to close the distal end.

19. The bone holding forceps (1) according to any one of claims 15 to 18, characterized in that Along the main axis of the first tongs rod (2) and the second tongs rod (3), at least partially they have an approximately cylindrical outer surface.

20. The bone holding forceps (1) according to any one of claims 14 to 19, characterized in that When the distal jaw region is opened by pressing the proximal ends of the two jaw rods together, the inner side of the second jaw rod (3) projects into the cylindrical inner opening of the first jaw rod (2).

21. The bone holding forceps (1) according to any one of claims 14 to 20, characterized in that When the bone clamp is in the open state, the clamp element (8) is mounted within the sleeve portion (6) on the proximal side of the first clamp rod (2) and is pressed radially outward by the axial displacement of the clamp element (8) above the clamp hinge (4) and in the proximal direction toward the distal side of the second clamp rod (3).

22. The bone holding forceps (1) according to any one of claims 1 to 21, characterized in that The sleeve portion (6) of the first clamp rod (2) exceeds the length of the second clamp rod (3) in the proximal direction.

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