DE102012104390B4 - Implant alignment / aiming device for alignment and / or positioning of an acetabulum implant during implantation - Google Patents

Abstract

Disclosed is an implant alignment / aiming device for aligning and / or positioning an acetabulum implant during the implanting process. It has two pointers for visualizing the anteversion and inclination of the implant, as well as a mount for direct or indirect coupling of the implant alignment / aiming device with the implant in a predefined relative position. Further, it has a first circular segment-shaped pointer sheet, along the arc portion of the first pointer is adjustably mounted to indicate its circumferential position on the arc portion of the first pointer sheet and a second, circular segment-shaped pointer blade, which is arranged with its flat side tangent to the arc portion of the first pointer sheet to together with the first pointer mitzuwandern and along the arc portion of the second pointer is adjustably mounted to indicate the circumferential position of the arc portion of the second pointer sheet.

Description

The present invention relates to an implant alignment / aiming device for aligning and / or positioning an implant, for example an acetabulum during the implantation process, and more particularly to an implant alignment / aiming device having the features according to the preamble of claim 1.

Background of the invention

• – Die Hüftgelenkpfanne sollte eine seitwärts gerichtete Neigung bezüglich der Körperlängsachse (Inklination) von ca. 45° +/– 5° aufweisen,
• – Die Hüftgelenkpfanne sollte eine bauchwärts gerichtete Neigung bezüglich der Körperlängsachse (Anteversion) von ca. 15° +/– 5° aufweisen.

When inserting a (bone) implant in the human / animal body, in particular an artificial acetabulum acetabulum is their correct orientation relative to the body longitudinal axis, ie in the sideways and bellyward for their later functioning and durability of great importance. In the human body, there are general guidelines for the orientation of an acetabular cup, which are defined as follows:

• - The acetabulum should have a lateral inclination with respect to the body's longitudinal axis (inclination) of approximately 45 ° +/- 5 °,
• - The acetabular cup should have a downward inclination with respect to the body's longitudinal axis (anteversion) of approx. 15 ° +/- 5 °.

The implantation of an acetabulum is usually carried out by means of a so-called handle bar, which is detachably connected centrally at its distal end to the acetabular cup and at its proximal end a striking plate, which can be opened with a suitable impact tool to the acetabulum in the acetabulum collect. Since the handle bar, which protrudes from the patient's body during the implantation, is held centrally on the acetabulum, this can serve as a visual pointing device for the alignment of the acetabular cup.

However, as indicated above, the acetabulum must be aligned within a very narrow range of angular tolerance that can be achieved without external reference points, i. H. only on the basis of the orientation of the handle bar anywhere in the room is not or only randomly visually assessable. Therefore, there are so-called target devices in the form of mechanical direction finding, which can be plugged or clipped on the handle bar and each equipped with two hands, of which the one with the correct orientation of the handle bar (and thus the temporally fixed thereto acetabulum) extends vertically and the Align others parallel to a line on the operating table that corresponds to the patient's body longitudinal axis. In the simplest case, this line is a straight longitudinal edge of the operating table itself.

State of the art

For manual / visual orientation nowadays target devices are in use, which are not adjustable at all or only with regard to one of the aforementioned angles. With patient-specific divergent Pfannenpositionen thus manual / visual orientation is difficult, if not impossible at all, because the angle can not be corrected on the target device. Ie. the known target devices are not provided due to the lack of or only limited adjustability of the projecting angle in order to respond to deviating pan positions.

Acetabular cups are implanted on the right and left sides of the acetabulum. Depending on the type of patient (fat / lean), the implantations are performed in the patient's back or side position. Today targeting devices are therefore used specifically for the back and the lateral position as well as for the left and right side of the patient, which must therefore be kept at the surgical site. This is not only costly and expensive but also forms a potential source of error, since in the large number of necessarily stocked target devices can quickly occur a confusion that, if any, may be noticed too late.

The DE 202 00 990 U1 For example, a target surgical gage discloses a first display element that includes a first display device that is transverse to a plane of the drawing and a second display element that provides a second display direction. Only the second display device has a pointer sheet along the curved portion of a pointer is mounted adjustable. This target theory makes it possible to adapt exactly one angle, namely the anteversion angle, to a given operative situation. The inclination angle is not adjustable.

The EP 2 294 980 A1 discloses an implant alignment device having a protractor with a single pointer blade, and a pointer. The pointer and the pointer blade can be continuously pivoted against each other and so indicate an angle α

Brief description of the invention

In view of this current situation, there is a need for a universal target device that can individually respond to a variety of different implant constraints. It is therefore the object of the present invention to provide such a universal target device of this type.

This object is achieved by a target device with the features of claim 1. Advantageous embodiments and / or developments of the invention are the subject of the dependent claims.

Basically, the implant alignment / aiming device according to the invention has a first, preferably circular segmented pointer leaf or a pointer leaf with a circular segment-shaped display (scale), along the circumference of which a first pointer is adjustably mounted about its circumferential position along the display of the first pointer leaf and a second, preferably circular segment-shaped pointer leaf or a pointer blade with a circular segment-shaped display (scale), which is arranged with its flat side tangent to the arc portion / display of the first pointer sheet to mitzuwandern together with the first pointer and along the circumference of a second pointer is adjustably mounted to indicate its circumferential position along the display of the second pointer sheet.

The target device according to the invention therefore has two individually adjustable hands whose pivot axis are perpendicular to each other with corresponding pointer hands, of which one (second) pointer leaf together with associated (second) pointer together with the (first) pointer of the other (first) pointer leaf is pivoted , In this way, on the one hand, the anteversion as well as the inclination can be adjusted individually and also read off.

Preferably, the second pointer blade and (independently thereof) the second pointer are each rotatably mounted about the longitudinal axis of the first pointer. Thus, no separate storage of the second pointer sheet and the second pointer is required, but the first pointer already serves as a hub of the second pointer sheet and the second pointer. This simplifies the mechanics of the device.

As already described above, it is in principle possible by the two relatively movable hands (second hand blade is movable together with the first pointer) to adjust the anteversion and the inclination individually and thus to increase the applicability of a target device. According to another, possibly independent aspect of the invention, it may also be provided that the rotatable about the first pointer mounted second pointer blade has two predefined, 180 ° angularly spaced rotational positions about the longitudinal axis of the first pointer, in which the second pointer blade selectively locked is. By this possibility of rotation of the second pointer sheet to the (first) pointer of the first pointer sheet is basically the ability to use the target device according to the invention for the patient backrest as well as the patient page position and thus to expand the capabilities.

It is advantageous in this case if the first pointer in the first rotational position of the second pointer sheet shows the inclination and the second pointer indicates the anteversion for a patient page position, whereas the first pointer in the second rotational position of the second pointer sheet the anteversion and the second pointer the inclination for a Patient back position indicates. The operator must therefore, depending on the patient's position, only rotate the second pointer leaf relative to the first pointer blade (around the first pointer) in order to use different display scales on the respective pointer blades as a function of the patient's situation.

Accordingly, the first pointer blade preferably has two detent units (corresponding to two indicator scale units) spaced circumferentially of its arcuate portion (display), each consisting of a number of different detent circumferential positions, one of which is a first rotational position detent unit of the second pointer blade (patient side position) is provided and the other latching unit for the second rotational position of the second pointer sheet (patient backsheet) is provided for use. That is, the two locking units (display scale units) on the first pointer blade are arranged along its arcuate portion such that the target apparatus upon "switching" (180 ° rotation of the second pointer blade around the first pointer), for example, from the supine position to the lateral position inevitably align the two hands so that they always correctly indicate the inclination and the anteversion.

In order to prevent a surgeon from making mistakes when handling the target device according to the invention, for example by using the wrong display scale unit (latching unit), it is advantageous to provide a locking mechanism which permits the use of one latching unit in the second rotary position of the second pointer blade and the other latching unit blocked in the first rotational position of the second pointer sheet. For example, such a locking mechanism may each be a rider or a cam for each predefined rotational position of the second pointer sheet, which cooperate with a backdrop on the first pointer blade depending on the rotational position of the second pointer blade such that the first pointer is provided only in those intended for that rotational position Snap unit can engage the first pointer leaf.

According to a further, optionally independent aspect of the present invention, the second pointer blade has four locking units spaced apart in the circumferential direction of its curved portion (display), each consisting of a number of different detent circumferential positions, of which two detents are provided for the first rotational position of the second pointer blade for use and two other detent units are provided for the second rotational position of the second pointer blade for use. Preferably, the two locking units of each rotational position are representative of the left and right side of the patient, ie they are selected depending on whether the left or right patient hip is to be operated on.

figure description

The invention will be explained in more detail below with reference to a preferred embodiment with reference to the accompanying figures.

Show it:

1 the perspective view of a universal target device according to a preferred embodiment of the invention, set for an operation of the right hip joint in patient lateral position,

2 the side view of the universal target device according to the 1 set for a patient side surgery,

3 the perspective view of a first pointer sheet of the universal target device according to the 1 , for adjustment for a patient's back,

4 the perspective view of the first pointer sheet of the universal target device according to the 1 , for setting for a patient page situation,

5 the upper perspective view of a second pointer sheet of the universal target device according to the invention and

6 the lower perspective view of a sliding / latching shoe for mounting on the underside of the second pointer sheet as well as for the sliding / latching engagement with the first pointer sheet at selectable detent positions (notches).

A universal aiming device for free (independent) adjustment of inclination and anteversion of a right and left hip acetabulum implant in both patient's back and patient's lateral position according to a preferred embodiment of the present invention is disclosed in U.S. Pat 1 and 2 shown in the assembled state.

Consequently, the target device according to the invention essentially consists of a first pointer blade or base 1 at which a first pointer 2 pivotable (in the direction of arrow A according to the 2 ) about a central pivot pin 4 is stored, a second pointer sheet 6 that on the first hand 2 rotatable (in the direction of arrow C according to the 2 ) is held around this and on which also a second pointer 8th individually pivotable around the first pointer 2 is stored and a holder 10 , which on the first hand pointer 1 is mounted for temporary fixation of the target device according to the invention in a predetermined relative position (inevitably predetermined by the holder) on the acetabulum implant or on a commonly known from the prior art grip rod (not shown) for implantation of the acetabulum implant in an acetabulum.

According to the 1 is the holder 10 in the form of a spring clip formed with two elastic clamping legs 12 , which are formed for the intervening - recording of a rod, preferably round rod. In that regard, the holder forms 10 in cross-section a U-shape with one of the two clamping legs 12 integrally connecting crosspiece 14 on which the spring clip 10 with the first hand 1 connected (screwed) is.

The first pointer sheet 1 according to the 3 and 4 consists of a preferably rectangular base portion 16 , on which are two semicircular plates 18 upright and material in one piece connect, in a parallel distance to form a gap at the base section 16 are held. On the outer circumference of each plate 18 are several notches 20 . 22 cut, which detent circumferential positions for the first pointer 2 and thus for the first pointer rotatably mounted second pointer plate 6 predefine.

Like from the 3 and 4 can be seen form the detent circumferential positions (notches) 20 . 22 two circumferentially spaced locking units (scale units) 20 . 22 each consisting of three notches, the two locking units 20 . 22 are relevant for the patient page situation or the patient back. In concrete shows the 3 that half-circle plate 18 on the the notches of a catch unit 22 which are used for the patient's back, while the 4 the other half-circle plate 18 shows on the notches of the other detent unit 20 are marked, which are used for the patient page situation.

In the theoretical center of the two semicircular plates 18 is a common through-hole 24 educated. In addition, at least one of the two Habkreisplatten points 18 , in this case, the semicircular plate according to the 4 , one from the central through-hole 24 to the outer periphery of the semicircular plate 18 continuous longitudinal slot 26 on to an access slot to the central through-hole 24 this a semicircular plate 18 to accomplish. Finally, both have half-circular plates 18 on their respective facing side surface a milled 28 to slightly increase the gap, resulting in each case a material edge 30 at the respective inner side surface of the semicircular plates 18 forms, extending between the two on both semicircular plates 18 formed (notched), circumferentially spaced locking units 20 . 22 extend in a straight line.

At this point it should be noted that the rectangular base section 16 on two opposite side surfaces in each case a threaded bore 32 is formed, where the spring clip 10 screwed on, like this in the 1 and 2 is hinted at.

The second pointer sheet 6 according to the 5 consists of a preferably provided with recesses for weight reduction circular segment plate having a central through hole 34 and a plurality of (exactly four) locking units (scale units) 36 . 38 . 40 . 42 at the arc circumference of the circular segment plate 6 spaced apart from each other. Each catch unit 36 . 38 . 40 . 42 In the present case, this includes three detent circumferential positions, each of which has through holes along the arc circumference of the circular segment plate 6 be formed. Finally, in the area of the central through-hole 34 still (two) further mounting holes 44 formed, in which one of the according to the 5 lower flat side of the circular segment plate 6 to be mounted sliding shoe 46 according to the 6 is fixed.

This shoe 46 has a flat mounting side 48 with a sleeve-shaped centering base 50 entering the center through hole 34 of the second pointer sheet 6 is inserted as well as a concave-barrel-shaped curved sliding side 52 for sliding contact with the outer peripheral edge sides of the two semicircular plates 18 of the first pointer sheet 1 (for sliding in the direction of arrow A according to the 6 ) are provided. On this sliding side 52 is a catch 54 formed transversely to the intended sliding direction A, with the marginal notches 20 . 22 the two semicircular plates 18 can be brought into latching engagement. Finally, on the sliding side 52 two protruding riders or cams 56 provided, the cam width are dimensioned so that they are exactly between the two semicircular plates 18 in the area of the recesses (with extended gap) 28 but do not fit in the area outside the cutouts 28 , These two cams are in the direction of sliding A according to the 6 before and after the catch 54 placed at about the same distance from this.

The first pointer 2 according to the 1 and 2 has the pivot pin 4 , from the axial center portion of a dipstick 2a perpendicular to this projecting, between the two half-circular plates 18 schwenkar is guided. This dipstick 2a has at least partially a round profile and thus also serves as a hub for the second hand pointer 6 and the second pointer 8th , In concrete terms, the second hand is the hand 6 , in particular the sliding shoe 46 at its central sleeve socket 50 at the first hand 2 (dipstick 2a ) rotatably mounted, wherein the sleeve base 50 slightly the top of the circular segment plate 6 (according to the 5 ) surmounted. Subsequently, the second pointer 8th at the first hand 2 (dipstick 2a ) and is thereby through the sleeve socket 50 slightly from the top of the circular segment plate 6 spaced apart in parallel. Above the second pointer 8th is a spiral spring 58 around the first pointer 2 arranged around, located at a central heel ring 60 axially supported and the second pointer 8th against the upper end side of the sleeve base 50 and thus the sliding shoe 46 against the arcuate edge side of the two semicircular plates 18 of the first pointer sheet 1 biases.

Finally it should be mentioned that on the second hand 8th a latching hook or fingers 62 is formed, taking advantage of the inherent elasticity of the second pointer 8th in the through holes 36 - 42 the circular segment plate 6 can intervene.

The function of the universal target device according to the invention is described below with reference to 1 and 2 described in more detail:
In order to set the target device individually for a hip operation in patient lateral position or patient back position, the sliding shoe must first be used 46 against the biasing force of the coil spring 58 from the margin of the two semicircular plates 18 be lifted in the direction of arrow B until the two cams 56 from the gap between the semicircular plates 18 come. Now the shoe can 46 together with the circular segment plate fixed thereto 6 and the second pointer 8th around the first pointer 2 be turned in one of its two rotary positions. Subsequently, the sliding shoe 46 released again and the two cams 56 reach into the gap between the two semicircular plates 18 on to block further rotation.

Depending on the selected rotational position, one of the two cams is triggered 56 when pivoting the first pointer 2 in the area outside the milling / milling 28 a riding of the shoe 46 of the cam concerned 56 on the margin of the two semicircular plates 18 so that the latch 54 is forcibly spaced from the sheet edge. The two cams 56 thus prevent depending on the rotational position of the shoe 46 that the latch 54 into the notches of the wrong detent unit for this rotational position 20 . 22 can engage.

The one half circle plate 18 is therefore characterized by "lateral position" and the other semicircular plate 18 carries the name "supine". The notches of a catch unit 20 are labeled "inclination" on the "side-plies" plate, whereas the notches of the other detent unit 22 on the "supine" plate are labeled "anteversion".

If the surgeon therefore wishes to perform a hip operation, for example in the patient's lateral position, the sliding shoe will become 46 with circular segment plate 6 and second hand 8th turned so that the cam in question 56 the sliding shoe 46 above the detent unit "Anteversion" according to the 3 raises (locking engagement not possible) and only a snap with the notches of the detent unit "inclination" according to the 4 allows. Now is the correct rotational position of the second pointer sheet 6 with respect to the first pointer sheet 1 found for a patient site situation. Subsequently, the second pointer 8th in one of the two locking units 40 . 42 depending on whether the left or right hip is to be operated on.

There are several detent positions (notches, through-holes) available within the selected detent units, via which patient-specific deviations from the standard for anteversion and inclination (in 5 ° increments) can be set. As a result, the first pointer becomes 2 complete with second display sheet 6 into the correct notch of the "lateral position" latch unit 22 engaged. Then the second pointer will appear 8th into the correct through hole of one of the "side-lay" locking units 40 . 42 engaged. This completes the setting of the target device. Finally, the target device is clipped to a well-known handle bar, at the distal end of which an acetabular cup is temporarily mounted.

To clean the target device, the first pointer 2 down to the area of the passage slot 26 be pivoted so that the entire first pointer 2 including the second pointer sheet mounted thereon 6 and second pointer 8th through this slot 26 from the first hand 1 can be removed.

Claims (15)

Implant alignment / aiming device for aligning and / or positioning an acetabulum implant during implantation, with two pointers ( 2 . 8th ) for visualizing the anteversion and inclination of the implant and a holder ( 10 ) for direct or indirect coupling of the implant alignment / aiming device with the implant in a predefined relative position, characterized by a first, preferably circle segment-shaped, pointer blade ( 1 ), along the arc portion of the first pointer ( 2 ) is adjustably mounted to its circumferential position at the arc portion of the first pointer sheet ( 1 ) and a second, preferably circular segment-shaped pointer blade ( 6 ), which with its flat side tangent to the arc section of the first pointer blade ( 1 ) is arranged together with the first pointer ( 2 ) and along the arc section of the second pointer ( 8th ) is adjustably mounted around its circumferential position on the arc portion of the second pointer blade ( 6 ). Implant alignment / aiming device according to claim 1, characterized in that the second pointer blade ( 6 ) together with the second pointer ( 8th ) about the longitudinal axis of the first pointer ( 2 ) is rotatable. Implant alignment / aiming device according to claim 2, characterized in that the second pointer blade ( 6 ) two predefined, 180 ° spaced rotational positions about the longitudinal axis of the first pointer ( 2 ), in which the second hand ( 6 ) is optionally latched. Implant alignment / aiming device according to claim 3, characterized in that the first pointer ( 2 ) in the first rotational position of the second pointer sheet ( 6 ) the inclination and the second hand ( 8th ) indicates the anteversion for a patient site, whereas the first pointer ( 2 ) in the second rotational position of the second pointer sheet ( 6 ) the anteversion and the second pointer ( 8th ) indicates the inclination for a patient's back. Implant alignment / aiming device according to claim 4, characterized in that the first pointer blade ( 1 ) spaced in the circumferential direction of its bow portion locking units ( 20 . 22 ), each consisting of a number of different detent circumferential positions, of which the one detent unit ( 22 ) for the first rotational position of the second pointer sheet ( 6 ) is provided for use and the other locking unit ( 20 ) for the second rotational position of the second pointer sheet ( 6 ) is intended for use. Implant alignment / aiming device according to claim 5, characterized by a locking mechanism ( 56 ), the use of a detent unit ( 22 ) in the second Rotational position of the second pointer sheet ( 6 ) and the other deterrent unit ( 20 ) in the first rotational position of the second pointer sheet ( 6 ) blocked. Implant alignment / aiming device according to one of claims 4 to 6, characterized in that the second pointer blade ( 6 ) four spaced in the circumferential direction of its arc section locking units ( 36 - 42 ), each consisting of a number of different detent circumferential positions, of which two detent units ( 40 . 42 ) for the first rotational position of the second pointer sheet ( 6 ) are provided for use and two other locking units ( 36 . 38 ) for the second rotational position of the second pointer sheet ( 6 ) are intended for use. Implant alignment / aiming device according to claim 7, characterized in that the two locking units ( 36 . 38 ; 40 . 42 ) each rotational position of the second pointer sheet ( 6 ) represent the left and right sides of the patient's hip. Implant alignment / aiming device according to one of the preceding claims, characterized by a pivot pin ( 4 ) rotatably in the center of the first pointer sheet (FIG. 1 ) is mounted with respect to its circle segment and the first pointer ( 2 ), which at the same time a pivot pin for the second pointer ( 8th ) and preferably for the second pointer sheet ( 6 ). Implant alignment / aiming device according to claim 9, characterized in that at the first pointer ( 2 ) middle section side an axial stop shoulder ( 60 ) is formed, on which a spiral spring ( 58 ) supporting the second pointer sheet ( 6 ) against the arc circumference of the first pointer sheet ( 1 ) presses. Implant alignment / aiming device according to claim 10, in conjunction with claim 5, characterized in that at the arc circumference of the first pointer blade ( 1 ) are formed a number of circumferentially spaced notches, which the locking units ( 20 . 22 ) of the first pointer sheet ( 1 ) and at the first pointer sheet ( 1 ) facing flat bottom of the second pointer sheet ( 6 ) a sliding shoe ( 46 ) is formed or fixed with at least one preferably wedge-shaped detent ( 54 ), with the notches in the first hand ( 1 ) by the biasing force of the coil spring ( 58 ) can be brought into selected latching engagement. Implant alignment / aiming device according to claim 11 in conjunction with claim 6, characterized in that on the sliding shoe ( 46 ) of the second pointer sheet ( 6 ) to the arc circumference of the first pointer sheet ( 1 ) projecting cam ( 52 ), which, depending on the rotational position of the second pointer sheet ( 6 ) at a predetermined pivot position of the first pointer ( 2 ) each with a backdrop ( 30 ) on the first hand ( 1 ) comes into sliding contact with the second hand ( 6 ) against the biasing force of the coil spring ( 58 ) of the arc circumference of the first pointer sheet ( 1 ) and so a latching engagement of the detent ( 54 ) in a notch. Implant alignment / aiming device according to one of claims 9 to 12, characterized in that the first pointer blade ( 1 ) of two parallel spaced and one longitudinal side interconnected plates ( 18 ), which form a gap between them, which from the pivot pin ( 4 ) and in which the first pointer ( 2 ) is pivotally received. Implant alignment / aiming device according to claim 13, characterized in that on the one longitudinal side of the first pointer blade ( 1 ), on which the two plates ( 18 ) are connected together, the holder ( 10 ) is preferably arranged in the form of a spring clip. Implant alignment / aiming device according to claim 13 in conjunction with claim 12, characterized in that the link ( 30 ) between and on the two plates ( 18 ) and the cam ( 56 ) between the two plates ( 18 ) is guided in a sliding manner.

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