MEDICAL DECOUPLING INSTRUMENT

Abstract

A medical decoupling instrument for decoupling a medical insertion instrument from a pedicle screw includes a shaft and a sleeve arranged around a portion of the shaft. The sleeve is configured for defined coupling to the medical insertion instrument. The shaft is rotatable relative to the sleeve, and the medical decoupling instrument is configured to bring the shaft and the sleeve autonomously and automatically into a defined starting position. A medical arrangement includes at least the medical decoupling instrument and a medical insertion instrument.

Claims

1. A medical decoupling instrument for decoupling a medical insertion instrument from a pedicle screw, comprising: a shaft and a sleeve which is arranged around a portion of the shaft, said sleeve-PO being configured for defined coupling to the medical insertion instrument, wherein the shaft is rotatable with respect to the sleeve, and wherein the medical decoupling instrument is configured to move the shaft and the sleeve self-actingly and automatically into a defined initial position.

2. The medical decoupling instrument according to claim 1, further comprising a spring which is arranged between a support surface, which is provided on the shaft, and the sleeve and is arranged to move the shaft and the sleeve into the defined initial position via its spring force.

3. The medical decoupling instrument according to claim 2, wherein the shaft has a peg-shaped projection at the portion around which the sleeve is arranged, the sleeve has a motion link, and the peg-shaped projection of the shaft is received in the motion link of the sleeve such that the motion link defines a range of rotation of the shaft with respect to the sleeve.

4. The medical decoupling instrument according to claim 3, wherein the motion link runs obliquely, i.e. extends both in a circumferential direction and an axial direction of the sleeve, such that a first end of the motion link is arranged closer to a distal end of the sleeve than a second end of the motion link.

5. The medical decoupling instrument according to claim 4, wherein in the defined the peg-shaped projection of the shaft is pressed against the first end of the motion link by the spring.

6. The medical decoupling instrument according to claim 4, wherein the motion link has a depression at its second end such that the peg-shaped projection of the shaft can be pressed into the depression via the spring.

7. The medical decoupling instrument according to claim 1, wherein the sleeve has peg-shaped projections for defined coupling to the medical insertion instrument.

8. The medical decoupling instrument (I) according to claim 1, wherein the shaft has a distal engagement portion that is cylindrically shaped with a non-circular cross-section.

9. The medical decoupling instrument according to claim 1, wherein a portion of the shaft has a push piece or an engagement mechanism that is configured to apply a push force radially outward.

10. A medical assembly comprising at least the medical decoupling instrument according to claim 1 and a medical insertion instrument.

11. The medical assembly according to claim 10, wherein the medical insertion instrument comprises V-shaped or U-shaped recesses, the sleeve of the medical decoupling instrument comprises peg-shaped projections, and the peg-shaped projections are provided to be received and held in the V-shaped or U-shaped recesses in a twist-proof manner.

12. The medical assembly according to claim 10, wherein the medical insertion instrument comprises coupling arms extending parallel in an axial direction and having latching structures at their distal ends, and the shaft of the medical decoupling instrument comprises a distal engagement portion which with rotation of the shaft spreads the coupling arms of the medical insertion instrument.

13. A medical decoupling instrument for decoupling a medical insertion instrument from a pedicle screw, the medical decoupling instrument comprising: a shaft having a support surface; a sleeve which is arranged around a portion of the shaft; and a spring which is arranged between the support surface of the shaft and the sleeve; wherein the sleeve has projections provided for defined coupling to the medical insertion instrument, the shaft is rotatable with respect to the sleeve, and the spring is provided to move the shaft and the sleeve self-actingly and automatically into a defined initial position.

14. The medical decoupling instrument according to claim 13, wherein the shaft has a peg-shaped projection at said portion of the shaft, the sleeve has a motion link, and the peg-shaped projection is received in the motion link such that the motion link defines a range of rotation of the shaft with respect to the sleeve.

15. The medical decoupling instrument according to claim 14, wherein the motion link runs obliquely, i.e. extends both in a circumferential direction and an axial direction of the sleeve, such that a first end of the motion link is arranged closer to a distal end of the sleeve than a second end of the motion link.

16. The medical decoupling instrument according to claim 15, wherein the peg-shaped projection of the shaft, in the defined initial position, is pressed against the first end of the motion link by the spring.

17. The medical decoupling instrument according to claim 15, wherein the motion link has a depression at its second end such that the peg-shaped projection is pressable into the depression via the spring.

18. The medical decoupling instrument according to claim 15, wherein the motion link allows a 90° rotation of the shaft with respect to the sleeve in a circumferential direction.

19. The medical decoupling instrument according to claim 13, wherein the shaft has a distal engagement portion that is cylindrically shaped with a non-circular cross-section.

20. The medical decoupling instrument according to claim 13, wherein a portion of the shaft has a push piece or an engagement mechanism that is configured to apply a push force radially outward.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0045] The invention is further explained below with the aid of figures. The following is shown:

[0046] FIG. 1 shows a sectional view of a decoupling instrument known from the prior art;

[0047] FIG. 2 shows an isometric detail view of a lower region of the decoupling instrument of FIG. 1;

[0048] FIG. 3 shows an isometric detail view of an upper region of the decoupling instrument of FIG. 1;

[0049] FIG. 4 shows an isometric view of the decoupling instrument of FIG. 1 inserted into an insertion instrument;

[0050] FIG. 5 shows an isometric view of the medical assembly according to the invention comprising the decoupling instrument according to the invention and an insertion instrument;

[0051] FIG. 6 shows an isometric view of the decoupling instrument according to the invention;

[0052] FIG. 7 shows a first isometric detail view of the decoupling instrument of FIG. 5; and

[0053] FIG. 8 shows a second isometric detail view of the decoupling instrument of FIG. 5.

DETAILED DESCRIPTION

[0054] The figures are merely schematic in nature and serve solely to aid understanding of the invention. Identical elements are marked with the same reference signs.

[0055] FIG. 5 shows a medical assembly 2, which comprises (among other things) a medical decoupling instrument 4 and a medical insertion instrument 6.

[0056] The insertion instrument 6 has a main body 8. This forms an upper receiving portion 10, among other things for the decoupling instrument 4. In the area of the upper receiving portion 10, the insertion instrument 6 has two V-shaped or U-shaped recesses 12 extending in the axial direction, which are designed to receive corresponding engagement structures provided on the decoupling instrument 4. In addition, the insertion instrument 6 has, in the region of the upper receiving portion 10, an internally (inner) threaded portion 14, which is designed to receive, in particular for screwing in, a different instrument (not shown) of the medical assembly 2. For example, the internally threaded portion 14 may house what is known as an insert pusher or insert presser, which serves to fix polyaxiality in the case of a polyaxial pedicle screw (by pressing on an ‘insert’).

[0057] Two diametrically opposite coupling arms 16 extending parallel in the axial direction follow the upper receiving portion 10 of the main body 8. At their distal ends, the coupling arms 16 have latching structures, in particular detents 18, which can basically be engaged with counter latching structures formed on a receiving sleeve/tulip of a polyaxial or monoaxial pedicle screw (not shown). The insertion instrument 6 further comprises a locking sleeve 20, which is arranged in a transition region 22 between the upper receiving portion 10 and the coupling arms 16 around the main body 8.

[0058] The insertion instrument 6 is basically designed to receive a pedicle screw, in particular a receiving sleeve/tulip of the pedicle screw, at its detents 18. In a first release position of the locking sleeve 20, the coupling arms 16 have a suitable elasticity/flexibility to receive the pedicle screw, in particular the counter latching structures of the pedicle screw, via their detents 18. By rotating the locking sleeve 20 from the first release position to a second locking position, the main body 8 is pulled axially upwards with respect to the locking sleeve 20. This fixes the coupling arms 16 by the locking sleeve 20 so that the pedicle screw is held firmly and securely by the insertion instrument 6.

[0059] If a surgeon/user wants to decouple the insertion instrument 6 from the pedicle screw after the pedicle screw has been screwed/anchored, he/she has to move the locking sleeve 20 from the second locking position to the first release position again (by twisting the locking sleeve 20). The surgeon/user also inserts the decoupling instrument 4 into the insertion instrument 6. With the aid of the decoupling instrument, the coupling arms 16 of the insertion instrument 6 can be spread/pressed radially outward, thus decoupling the pedicle screw from the insertion instrument 6.

[0060] The medical decoupling instrument 4 according to the invention is shown in more detail in FIG. 6, FIG. 7, and FIG. 8.

[0061] The decoupling instrument 4 basically has a shaft/rod 24, a sleeve 26, and a spring 28.

[0062] The shaft 24 has a proximal handle portion 30 at its proximal end. In the preferred example shown, the proximal handle portion 30 is oval-cylindrical in shape (cylindrical shape with an oval cross-section) and has a plurality of elongated recesses 32 extending in the axial direction and being evenly spaced/distributed in the circumferential direction, which serve to improve gripping of the shaft 24 by a user/surgeon.

[0063] A first cylindrical portion 34 with a round/circular cross-section follows the proximal handle portion 30 in the axial direction of the shaft 24. The first cylindrical portion 34 has a peg-shaped projection 36 extending radially outward.

[0064] The first cylindrical portion 34 is followed in the axial direction of the shaft 24 by a second cylindrical portion 38 with a round/circular cross-section. The second cylindrical portion 38 has a larger diameter than the first cylindrical portion 34. A push piece or engagement mechanism 40 is provided/arranged on the second cylindrical portion 38. The push piece 40 generates a compressive force radially outward and can thus press against the insertion instrument 6, so that unintentional slipping of the decoupling instrument 4 is prevented. Unintentional slipping of the decoupling instrument 4 can also be prevented by a different engagement mechanism.

[0065] The second cylindrical portion 38 is followed in the axial direction of the shaft 24 by a third cylindrical portion 42 with a preferably round/circular cross-section. The third cylindrical portion 42 has an equal or smaller diameter than the second cylindrical portion 38.

[0066] The third cylindrical portion 42 is followed in the axial direction of the shaft 24 by a distal engagement portion 43, which forms the distal end of the shaft 24. The distal engagement portion 43 is cylindrical with a non-circular cross-section.

[0067] The sleeve 26 of the decoupling instrument 4 is basically hollow cylindrical in shape and is arranged around the first cylindrical portion 34 of the shaft 24. The sleeve 26 has a motion link/elongated hole 44 in which the peg-shaped projection 36 provided on the shaft 24 is received or guided. The motion link 44 defines a range of rotation of the shaft 24 with respect to the sleeve 26. In particular, the motion link 44 of the sleeve 26 allows approximately 90° rotation of the shaft 24. The sleeve 26 has two peg-shaped projections 45 which are diametrically opposite each other and extend radially outward. The peg-shaped projections 45 of the sleeve 26 are provided to be received in the V-shaped or U-shaped recesses 12 of the insertion instrument 6, so that the sleeve 26 is/will be held in the insertion instrument 6 in a twist-proof manner.

[0068] The spring 28 is a coil spring or a compression spring and is disposed between a support surface 46 (for the spring 28), which is formed at a proximal end of the second cylindrical portion 38 of the shaft 24, and a contact surface 48 (for the spring 28), which is formed at a distal end of the sleeve 26.

[0069] The motion link 44 of the sleeve 26 extends obliquely, i.e., extends both in the circumferential direction and in the axial direction of the sleeve 26. This means that a first end 50 of the motion link 44 is arranged closer to a distal end of the sleeve 26 than a second end 52 of the motion link 44. The shape of the motion link 44, which is particularly apparent from FIG. 7 or FIG. 8, may also be present/formed in a mirrored manner (embodiment for left-handed users).

[0070] The spring 28 applies a compressive force to the sleeve 26 and pushes the sleeve 26 axially upward. As a result, the peg-shaped projection 36 of the shaft 24 is automatically or self-actingly pressed against the first end 50 of the motion link 44. When the peg-shaped projection 36 of the shaft 24 is at the first end 50 of the motion link/elongated hole 44, this represents a defined starting position/zero position/original position. In this defined starting position, the sleeve 26 and the shaft 24 are arranged with respect to each other such that when the peg-like projections 45 of the sleeve 26 are received in the V-shaped recesses 12 of the insertion instrument 6 and held in a twist-proof manner, the non-circular distal engagement portion 43 of the shaft 24 is arranged with respect to the coupling arms 16 of the insertion instrument 6 such that the coupling arms 16 are not spread. In other words, the shaft/rod 24 and the sleeve 26 of the decoupling instrument 4 are automatically oriented with respect to each other for inserting/positioning into the insertion instrument 6.

[0071] When the decoupling instrument 4 is inserted into the insertion instrument 6, the sleeve 26 (the peg-shaped projections 45 of the sleeve 26) is held in the V-shaped or U-shaped recesses 12 of the insertion instrument 6 in a twist-proof manner. A user/surgeon can now rotate the shaft 24 with respect to the sleeve 26 by turning the proximal handle portion 30 clockwise by about 90° until the peg-shaped projection 36 of the shaft 24 is located at the second end 52 of the motion link/elongated hole 44. In this position, the oval-shaped, distal engagement portion 43 of the shaft 24 spreads the coupling arms 16 of the insertion instrument 6 open, thereby decoupling the insertion instrument 6 from the pedicle screw.

[0072] As shown in particular in FIG. 8, the motion link/elongated hole 44 may have a depression/notch/trough 54 at its second end 52. However, it is also conceivable that the depression 54 is not provided. When the peg-shaped projection 36 of the shaft 24 slips or falls into or is received in the depression 54 at the second end 52 of the motion link 44, that is, in particular is pressed into the depression 54 by the spring 28, tactile feedback is provided to a user/surgeon indicating to the user/surgeon that the insertion instrument 6 is decoupled from the pedicle screw.

[0073] In this position, unintentional slipping of the decoupling instrument 4 is prevented by the push piece 40, which presses against the insertion instrument 6 from the inside, the depression 54 on the motion link 44, and the contact between the decoupling instrument 4 and the insertion instrument 6 at its distal end.

[0074] For decoupling the two instruments (decoupling instrument 4 and insertion instrument 6), the decoupling instrument 4 can be turned back 90° counterclockwise (supported by the spring force) so that the sleeve 26 is again in the zero position/starting position for the next application.