Surgical instrument

[0001] This application is a §371 National Phase of PCT/EP2013/067142, filed Aug. 16, 2013, which claims priority to German Patent Application No. 10 2012 107 521.2, filed Aug. 16, 2012.

[0002] The application relates to a surgical instrument according to the features and structures recited herein.

[0003] Surgical instruments for spacing apart tissue elements or spine elements are known, in which two contact elements are spread apart symmetrically to both sides from the center axis of the instrument via a scissors linkage. For example, EP 1 519 685 B1 discloses such an instrument.

[0004] The present disclosure provides a surgical instrument for spreading apart tissue, bones, or the like having an alternative design, which enables the surgical instrument to be constructed as very small in particular, in particular for minimally invasive surgery, without substantially impairing the stability at the same time.

[0005] The present application provides a surgical instrument having the features and structures recited herein.

[0006] Advantageous embodiments and refinements are specified in the further features and structures recited herein.

[0007] The surgical instrument has a working end, which has a first and a second contact element for spreading apart tissue, bone, or the like, is distinguished in that the instrument has a stationary base part and a sliding part arranged so it is longitudinally displaceable thereon, wherein the first contact element is arranged integrally on the distal end of the base part, wherein the second contact element is connected via a first arm to the base part and the sliding part and via a second arm to the base part, wherein the first arm is arranged via a first pivot axis on the second contact element, via a second pivot axis on the base part, and via a third pivot axis on the sliding part, and the second arm is arranged via a fourth pivot axis on the second contact element and via a fifth pivot axis on the first contact element of the base part, and wherein the fourth pivot axis is arranged distal from the first pivot axis and the fifth pivot axis is arranged distal from the second pivot axis. It is thus ensured that the arms do not intersect, but rather are arranged adjacent to one another in every position of the second contact element in relation to the first contact element. The first arm acts in particular like a type of rocker or a pivot lever. In particular an alignment of the second contact element in relation to the first contact element is enabled by the first arm, in particular in a stable manner, so that surgical instruments having small dimensions but a high level of effectiveness are possible. In particular, the instrument is distinguished in that the first contact element is arranged integrally on the distal end of the base part and therefore is not moved during the alignment, while only the second contact element is displaced in relation to the base part during the alignment and spreading only occurs in one direction proceeding from the instrument axis of the surgical instrument.

[0008] According to one advantageous refinement, the first arm penetrates the base part in a recess in which the second pivot axis is arranged, whereby a more compact structure of the surgical instrument is enabled.

[0009] According to one particularly advantageous embodiment, a first straight line which extends perpendicularly through the first pivot axis and perpendicularly through the second pivot axis, intersects a second straight line, which extends perpendicularly through the second pivot axis and perpendicularly through the third pivot axis, in a point, wherein the first and the second straight lines in particular enclose an angle between 90° and 180°. Particularly favorable lever ratios thus result.

[0010] One advantageous refinement provides that in a first position of the second contact element, a third straight line intersects both the first pivot axis and also the second pivot axis and the fourth pivot axis perpendicularly and a fourth straight line intersects both the third pivot axis and also the fifth pivot axis perpendicularly and in particular the third straight line and the fourth straight line are arranged in parallel to one another at a spacing A.

[0011] One particularly preferred embodiment, provides that the second contact element is displaceable from a first position into a second position, wherein the second contact element is arranged essentially parallel to the first contact element both in the first position and also in the second position. The second contact element is advantageously arranged parallel to the first contact element at least in the first position. In particular, the second contact element is arranged parallel to the first contact element in all positions in relation to the first contact element. Due to the parallel opening, almost no forces act in the direction of the position of the surgical element, so that the surgical element is not displaced during the movement of the working end, which enables more reliable operation.

[0012] According to one preferred embodiment, it is provided that the ratio of the spacing between the first pivot axis and the second pivot axis to the spacing between the second pivot axis and the third pivot axis is in the range of 1:2 to 1:5, advantageously in the range of 1:3 to 1:4.

[0013] The second contact element is preferably arranged in a recess of the base element in the first position, whereby a more compact structure of the instrument is enabled.

[0014] The sliding part is advantageously arranged in the base part, wherein preferably the distal end of the sliding part is accessible through a recess of the base part. On the one hand, the compact structure of the instrument is thus promoted, on the other hand, the recess enables simplified cleaning of the instrument.

[0015] According to one advantageous embodiment, the base part is at least sectionally implemented as a tube, in which the sliding part, which is at least sectionally implemented as a rod, is arranged, which further promotes the compact structure of the instrument.

[0016] The surgical element is particularly preferably implemented as a tube shaft instrument.

[0025] FIGS. 1 to 7 show various views of a surgical instrument 10, wherein all reference signs are not specified in all figures for better comprehensibility.

[0026] The surgical instrument 10 has a stationary base part 20, which is implemented in particular at least sectionally as a tube, and a sliding part 30 arranged so it is longitudinally displaceable thereon, which is in particular arranged at least sectionally as a rod and in particular is arranged so it is longitudinally displaceable coaxially in the base part 20. The stationary base part 20 is preferably detachably connected to a first handle part 24, while the second sliding part 30 is also preferably detachably connected to a second handle part 34. By pivoting the two handle parts 24, 34 in relation to one another, the longitudinal displacement of the sliding part 30 in relation to the base part 20 is achieved. In particular, the surgical instrument 10 is implemented in this case as a tube shaft instrument.

[0027] A first contact element 22 is integrally arranged on the distal end of the base part 20. The distal end of the sliding part 30 is connected to a second contact element 32 via a first arm 40a. The second contact element 32 is furthermore connected to the base part 20, in particular the first contact element 22 of the base part 20, via a second arm 40b. The first arm 40a is connected so it is rotatably mounted on the second contact element 32 via a first pivot axis 41, while the second contact element 32 is connected so it is rotatably mounted to the distal end of the sliding part 30 via a third pivot axis 43. The first arm 40a is furthermore arranged so it is pivotably mounted via a second pivot axis 42 on the base part 20. The second arm 40b is arranged so it is rotatably mounted via a fourth pivot axis 44 on the second contact element 32, while the second arm 40b is arranged so it is rotatably mounted on the base part 20 via a fifth pivot axis 45. The pivot axes 41, 42, 43, 44, 45 are each arranged in parallel to one another and extend in particular perpendicularly to the longitudinal axis of the surgical instrument 10, in particular to the longitudinal axis of the tubular base part 20 or the rod-shaped sliding part 30. In the illustrations of FIGS. 5, 6, and 7, the pivot axes 41, 42, 43, 44, and 45 extend perpendicularly to the plane of the paper.

[0028] The fourth pivot axis 44 is arranged distal from the first pivot axis 41, while the fifth pivot axis 45 is arranged distal from the second pivot axis 42. The two arms 40a, 40b thus lie adjacent to one another and do not intersect.

[0029] The second pivot axis 42 forms the rotational axis, about which the first arm 40a is rotated in relation to the base part 20 upon longitudinal displacement of the sliding part 30.

[0030] The first pivot axis 41 and the second pivot axis 42 lie on a first straight line g1, while the third pivot axis 43 and the second pivot axis 42 lie on a second straight line g2. In this case, the first straight line g1 intersects the first pivot axis 41 and the second pivot axis 42 perpendicularly, while the second straight line g2 intersects the third pivot axis 43 and the second pivot axis 42 perpendicularly. In one embodiment, the first straight line g1 and the second straight line g2 are not coincident, but rather they intersect at a point, specifically in particular at the second pivot axis 42, and enclose an angle α therein, which is in particular between 90° and 180°, for example, between 120° and 135°, in particular 121.33° or 133.03°.

[0031] The first pivot axis 41, the second pivot axis 42, and the third pivot axis 43 are all arranged on the first arm 40a and are fixed in relation to one another. The angle α is therefore not variable for a given instrument 10.

[0032] If the sliding part 30 is displaced in the distal direction in the base part 20, the arm 40a pivots about the second pivot axis 42, wherein the first pivot axis 41 is moved away from the base part 20 and the second contact element 32 also moves in this case. As shown in FIGS. 1 to 6, the second contact element 32 is finally located in an aligned second position, in which it is arranged parallel to the first contact element 22. If the sliding part 30 is drawn in the proximal direction, the arm 40a pivots back about the second pivot axis 42 and moves the first contact element 22 into a first position (cf. FIG. 7), in which it presses against the base part 20 and in particular comes to rest in a recess 26 of the base part 20. The first position is in particular the closed position of the instrument 10. The second contact element 32 is also arranged parallel to the first contact element 22 in this first position and in particular in all intermediate positions. The second contact element 32 is dimensioned in particular such that it does not substantially enlarge the external dimensions of the base part 20 when it is in contact with the base part 20, in particular in the recess 26.

[0033] As is recognizable in FIG. 7, the first pivot axis 41, the second pivot axis 42, and the fourth pivot axis 44 lie in one plane in the first position of the second contact element 32 or, in other words, a third straight line g3 intersects both the first pivot axis 41 and also the second event axis 42 and the fourth pivot axis 44 perpendicularly. In particular, the third straight line g3 lies parallel to a fourth straight line g4, which perpendicularly intersects the third pivot axis 43 and the fifth pivot axis 45, in the first position of the second contact element 32. In this case, the third straight line g3 and the fourth straight line g4 have a spacing A to one another, which, in the case of an external diameter D of the instrument 10, can be between 20% and 60%, in particular approximately 30% to 50%, of the external diameter D.

[0034] During the movement of the second contact element 32 in relation to the first contact element 22 and the base part 20, the second arm 40b is pivoted about the fifth pivot axis 45. The second arm 40b is essentially used to support the distal end of the second contact element 32 in relation to the base part 20, in particular the first contact element 22 of the base part 20.

[0035] The second part 40b can be implemented as curved and in particular can be part of an external circumference of a circle having a radius r.

[0036] The distal end of the sliding part 30 can be arranged inside the base part 20. It is preferably externally accessible through a recess 28, to enable better cleaning.

[0037] The first arm 40a penetrates the base part 20 in a recess in which the second pivot axis 42 is arranged, in particular in this manner to enable the arrangement of the first pivot axis 41 and the third pivot axis 43 essentially on two different sides of the second pivot axis 42.

[0038] The first pivot axis 41 and the fourth pivot axis 44, which are both arranged on the second contact element 32, have a spacing a. The first pivot axis 41 and the second pivot axis 42, which are both arranged on the first arm 40a, have a spacing b. The second pivot axis 42 and the fifth pivot axis 4, which are both arranged on the base part 20, have a spacing d. The fourth pivot axis 44 and the fifth pivot axis 45, which are both arranged on the second arm 40b, have a spacing e. The second pivot axis 42 and the third pivot axis 43, which are both arranged on the first arm 40a, have a spacing c to one another. The ratio of c:b is in the range of 1:2 to 1:5, in particular in the range of 1:3 to 1:4.

• [0039] 10 instrument
• [0040] 20 base part
• [0041] 22 first contact element
• [0042] 24 first handle part
• [0043] 26 recess
• [0044] 28 recess
• [0045] 30 sliding part
• [0046] 32 second contact element
• [0047] 34 second handle part
• [0048] 40a first arm
• [0049] 40b second arm
• [0050] 41 first pivot axis
• [0051] 42 second pivot axis
• [0052] 43 third pivot axis
• [0053] 44 fourth pivot axis
• [0054] 45 fifth pivot axis
• [0055] g1 first straight line
• [0056] g2 second straight line
• [0057] g3 third straight line
• [0058] g4 fourth straight line
• [0059] α angle
• [0060] a spacing
• [0061] b spacing
• [0062] c spacing
• [0063] d spacing
• [0064] e spacing
• [0065] A spacing
• [0066] D diameter
• [0067] r radius