DE202004020209U1 - Aiming device for surgical drills and introduction of bone fixing means has aiming body comprising positioning device arranged at front surfaces which are insertable in hole on an implant - Google Patents

Abstract

The aiming device (35) has aiming body (1) comprising positioning device arranged at the front surfaces (6), which are insertable in a hole on an implant. The positioning device is built as circular elevation over the front surface. The aiming body is arranged at the rear end coaxial to central axle. The second fixing means has a flexible handhold. The aiming body with a central axle (2) is used for the introduction of locating holes and for centering the drill or to cover the front surface. The aiming body is detachably connected at the central axle with two respective holes on the implant at different positions.

Description

The The invention relates to a target device according to the preamble of the protection claim 1.

at Minimally invasive surgical procedures is to avoid Misplacement of the instrument a precise centering of the same required on the implant. Because of the small Insisions no optical control of the positioning of the instrument is possible become common Target device used. Such target devices are suitable for implantation of artificial Spinal discs, i. to the leadership of drills and / or for insertion of bone screws.

Out US-A 2004/0176843 ZUBOK a generic target device is known. This known target device is in particular for implantation an artificial one Intervertebral disc suitable and includes a center hole, in which a complementary one Centering pin can be inserted on the implant, and two guide holes, the for drilling the holes for the Fixation elements are suitable. The device can after positioning for the Creation of the first two holes to be rotated 180 °, leaving two second, symmetrically arranged holes can be drilled.

adversely in this known target device is that the target body with the guide holes not attachable to the implant so that the aiming device by the operator by means of a handle during the entire drilling process must be held by hand.

Here The invention aims to remedy this. The invention is the task based on creating a target device, which one on the implant in at least two different positions rotatable and releasably fastened target body includes.

The Invention solves the task with a target device, which features of claim 1.

• – die Drehung der Zielvorrichtung in eine zweite Zielposition erfolgt ohne vollständige Trennung vom Implantat, so dass die Fixierung in der zweiten Zielposition nicht zeitraubend ist;
• – eine hohe Positioniergenauigkeit der Zielvorrichtung erreichbar ist, so dass auch Kopfverriegelungsschrauben, die nur geringfügige Winkelabweichungen vertragen, einsetzbar sind; und
• – Einführen, Manipulation und Entfernen der Zielvorrichtung ist mit einem einzigen Instrument durchführbar.

The advantage achieved by the invention is to be seen essentially in the fact that thanks to the inventive target device:

• - The rotation of the target device in a second target position is carried out without complete separation from the implant, so that the fixation in the second target position is not time consuming;
• - A high positioning accuracy of the target device can be achieved, so that head locking screws that tolerate only minor angular deviations, can be used; and
• - Insertion, manipulation and removal of the target device can be carried out with a single instrument.

Further advantageous embodiments of the invention are characterized in the subclaims.

In a preferred embodiment includes the target body positioning device arranged on the end face of the aiming device, which are insertable into a bore on an implant. The advantages of this Design are essentially to be seen in that by a high positioning accuracy of the target device with respect to rotation can be reached around the central axis.

In a further embodiment includes the target body the target device a the central axis intersecting, rear End and coaxial to the central axis, arranged at the rear end, second fixative for releasable Attachment of a handle. The advantages of this design are in that after the positioning of the aiming device the handle can be removed, what the overview in situ as well as the freedom of movement for significantly improved the surgeon.

In a further embodiment is the centering of the target device with respect to the central axis axially fixed with the target body connected. The advantages of this embodiment can be seen in that thereby the target body is held axially. In addition, the target body by means of the centering element held by the implant at a defined distance, so that no unintentional axial movements of the target body are possible.

In a further embodiment have the guide holes the target device bore axes, which obliquely or skewed relative to the central axis run. The advantages of this design are essentially in that drilling and / or insertion of bone screws in Any direction in space is possible.

In a further embodiment are the fixation means of the target device as a thread or bayonet closure educated. The advantages of this embodiment are that This makes it easy to manufacture and use and universal usability allows becomes.

The Invention and developments of the invention will be in the following with reference to the partially schematic representations of several embodiments even closer explained.

It demonstrate:

1 a plan view of an embodiment of the inventive target device;

2 a longitudinal section through the in 1 illustrated embodiment;

3 a perspective view of the in the 1 and 2 illustrated embodiment of the inventive target device;

4 a perspective view of the in the 1 and 2 illustrated embodiment of the inventive target device attached to a introduced between two adjacent vertebral bodies intervertebral implant;

5 a lateral view of two adjacent vertebral bodies with an inserted intervertebral implant; and

6 a view from the ventral to the in 3 illustrated vertebral body with inserted intervertebral implant.

In the 1 to 3 are the essential components of the target device 35 shown. This includes a target body here 1 together with a centering element 8th and a handle 14 ( 2 ). The target body 1 is formed substantially cuboid, wherein on two opposite surfaces 17 ; 18 one survey each 19 protrude with the shape of a crooked pyramid. Furthermore, the target body comprises 1 one in a central and parallel between the surfaces 17 ; 18 lying median plane 9 extending central axis 2 , one the central axis 2 cutting rear end 12 and an axially opposite front end 20 with a suitable for engagement with a surgical implant, transverse to the central axis 2 arranged face 6 , The two guide holes suitable for centering a drill or for inserting a surgical implant 3 each have a bore axis 4 on, which skewed to the central axis 2 stand and have a distance from each other, which is greater than the diameter of the guide holes 3 is, so that the guide holes 3 in the target body 1 do not cut. Furthermore, the target device comprises 35 one the target body 1 coaxial or parallel to the central axis 2 penetrating cavity 15 and one in the cavity 15 coaxial rotatably mounted centering 8th with first fixatives 11 , The centering element 8th is designed as a screw whose thread 16 the first fixative 11 forms, and means of which the target device 35 on an intervertebral implant 28 ( 4 ; 5 ) is attachable. The screw head 21 is with an undercut 22 in the cavity 15 stored so that the target body 1 relative to the central axis 2 axially fixed, but rotatable about this with the centering element 8th connected is. This allows the target body 1 in at least two with respect to rotation about the central axis 2 different positions are rotated, wherein the first fixing means 11 at the centering element 8th only to be loosened during rotation, so that the target body 1 still loose with the intervertebral implant 28 connected is. Each of the guide holes 3 penetrates the target body 1 each one of the two surveys 19 forth and flows into the face 6 , The bore axes 4 the guide holes 3 close in longitudinal section ( 2 ) through the target body 1 consider an acute angle with the central axis 2 one.

Furthermore, the target body comprises 1 at the frontal area 6 arranged positioning 5 which are here as over the frontal area 6 projecting annular elevation 23 are formed, and in a defined position of the target body 1 relative to the intervertebral implant 28 into a hole 10 ( 5 ) on the intervertebral implant 28 are insertable. At the far end 12 includes the target body 1 to the central axis 2 coaxially arranged second fixation means 13 for releasably securing a handle 14 , These second fixatives 13 are here as internal thread 24 in the cavity 15 formed so that at its fixable end 30 a complementary external thread 31 having handle 14 detachable with the target body 1 is connectable.

In the 4 and 5 is as an intervertebral implant 28 one between two adjacent vertebral bodies 25 ; 26 introduced intervertebral implant 28 represented, which by means of four obliquely to the spine longitudinal axis in the vertebral bodies 25 ; 26 screw-in bone fixatives 27 on the vertebral bodies 25 ; 26 is fixed after the holes in the vertebral bodies 25 ; 26 by means of the target device according to the invention 35 were pre-drilled.

Operation method:

• a) Planung des chirurgischen Eingriffes:
• Zur Ermöglichung einer anterioren Fixation mittels der Knochenfixationsmittel 27 muss das Zwischenwirbelimplantat 28 durch einen direkten anterioren Eingriff eingeführt werden. Die Bandscheibe wird derart freigelegt, dass auf jeder Seite der Wirbelsäulenmittelachse ausreichend Platz ist, d.h. ungefähr die Hälfte der Breite des Zwischenwirbelimplantates 28, so dass keine Störung der angrenzenden Weichteile verursacht wird. Eine ausreichende Freilegung der Bandscheibe ist notwendig, damit nach dem Einführen des Zwischenwirbelimplantates 28 die gesamte anteriore Fixationsplatte 29 im Sichtbereich des Operateurs ist, so dass die Knochenfixationsmittel 27, welche hier als Knochenschrauben ausgebildet sind, in die Bohrungen am Zwischenwirbelimplantat 28 eingeführt und in den Knochen eingedreht werden können.
• b) Herausschneiden eines rechteckigen Fensters mit der Breite des Zwischenwirbelimplantates 28 aus den anterioren longitudinalen Ligamenten und dem annulus fibrosus;
• c) Präparieren der Deckplatte des unteren Wirbelkörpers 26 und der Grundplatte des oberen Wirbelkörpers 25;
• d) Distrahieren der zwei präparierten Wirbelkörper 25;26 mit einem geeigneten Distraktor;
• e) Einführen eines adäquaten Probeimplantates in den Zwischenwirbelraum;
• f) temporäres Entlasten des Distraktors, wobei die Höhe der Bandscheibe aufgrund des eingepressten Probeimplantates gehalten wird;
• g) Kontrollieren der Position des Probeimplantates mittels Röntgen;
• h) Auswahl des geeigneten Zwischenwirbelimplantates 28;
• i) Füllen des Zwischenwirbelimplantates 28 mit Knochenspänen bis diese aus den Perforationen des Zwischenwirbelimplantates 28 austreten, so dass ein optimaler Kontakt mit den Endplatten der angrenzenden Wirbelkörper 25,26 herstellbar ist;
• j) Einführen des Zwischenwirbelimplantates 28 unter wiederholter Distraktion des Wirbelsäulensegmentes mittels eines geeigneten Instrumentes;
• k) Entfernen des Instrumentes;
• l) Einführen und Ausrichten der Zielvorrichtung 35 mit montiertem Handgriff 14, bis die Positioniermittel 5 (3) in der definierten Bohrung 10 am Zwischenwirbelimplantat 28 einrasten;
• m) Befestigen der Zielvorrichtung 35, wobei der Zielkörper 1 mittels der Fixationsmittel 11 am Zwischenwirbelimplantat 28 befestigt wird;
• n) Entfernen des Handgriffes 14;
• o) Bohren der ersten zwei Bohrungen 10 am Zwischenwirbelimplantat 28, wobei der Bohrer durch die Führungsbohrungen 3 geführt wird;
• p) Montieren des Handgriffes 14;
• q) Lösen der Fixationsmittel 11 und Drehen der Zielvorrichtung 35 um die Zentralachse 2 um 180°, bis die Positioniermittel 5 (3) einrasten;
• r) Bohren der bezüglich der Mittelebene 9 (3) symmetrischen zweiten zwei Bohrungen 10 am Zwischenwirbelimplantat 28, wobei der Bohrer durch die Führungsbohrungen 3 geführt wird;
• s) Einführen der Knochenfixationsmittel 27 durch die Führungsbohrungen 3 der Zielvorrichtung 35 und Fixieren derselben, wobei die ersten zwei Knochenfixationsmittel 27 in der ersten Position der Zielvorrichtung 35 eingeführt und fixiert werden und nach Wiederholung des Schrittes q) die zweiten zwei Knochenfixationsmittel 27 in der zweiten Position der Zielvorrichtung 35 eingeführt und fixiert werden;
• t) Entfernen der Zielvorrichtung 35 vom Zwischenwirbelimplantat 28;
• u) Verifizierung der Plazierung des Zwischenwirbelimplantates 28 mittels Röntgen.

The following is based on the 4 - 6 the surgical method based on the implantation of an intervertebral implant 28 in the intervertebral space of two adjacent vertebral bodies 25 ; 26 described:

• a) Planning the surgical procedure:
• To enable anterior fixation by means of the bone fixative 27 needs the intervertebral implant 28 be introduced by a direct anterior procedure. The intervertebral disc is exposed such that there is sufficient space on each side of the spinal central axis, ie approximately half the width of the intervertebral implant 28 , so that no disturbance of the adjacent soft tissues is caused. Sufficient exposure of the disc is necessary so that after insertion of the intervertebral implant 28 the whole anterior fixation plate 29 in the field of vision of the surgeon, leaving the bone fixative 27 , which are designed here as bone screws, in the holes on the intervertebral implant 28 introduced and screwed into the bone.
• b) cutting out a rectangular window with the width of the intervertebral implant 28 from the anterior longitudinal ligaments and the annulus fibrosus;
• c) preparing the cover plate of the lower vertebral body 26 and the base plate of the upper vertebral body 25 ;
• d) distraction of the two prepared vertebral bodies 25 ; 26 with a suitable distractor;
• e) introducing an adequate trial implant into the disc space;
• f) temporarily relieving the distractor, whereby the height of the intervertebral disc is held due to the impressed trial implant;
• g) checking the position of the trial implant by X-ray;
• h) Selection of the appropriate intervertebral implant 28 ;
• i) filling the intervertebral implant 28 with bone chips until these from the perforations of the intervertebral implant 28 emerge, allowing optimal contact with the endplates of the adjacent vertebral bodies 25 . 26 can be produced;
• j) insertion of the intervertebral implant 28 under repeated distraction of the spine segment by means of a suitable instrument;
• k) removing the instrument;
• l) insertion and alignment of the target device 35 with mounted handle 14 until the positioning means 5 ( 3 ) in the defined hole 10 on the intervertebral implant 28 snap;
• m) attaching the aiming device 35 , where the target body 1 by means of the fixative 11 on the intervertebral implant 28 is attached;
• n) removing the handle 14 ;
• o) Drilling the first two holes 10 on the intervertebral implant 28 where the drill passes through the guide holes 3 to be led;
• p) mounting the handle 14 ;
• q) release the fixative 11 and rotating the aiming device 35 around the central axis 2 by 180 ° until the positioning means 5 ( 3 ) engage;
• r) drilling the relative to the median plane 9 ( 3 ) symmetrical second two holes 10 on the intervertebral implant 28 where the drill passes through the guide holes 3 to be led;
• s) Introduction of Bone Fixation Agents 27 through the guide holes 3 the target device 35 and fixing them, the first two bone fixatives 27 in the first position of the aiming device 35 introduced and fixed and after repeating step q) the second two bone fixatives 27 in the second position of the aiming device 35 introduced and fixed;
• t) removing the aiming device 35 from the intervertebral implant 28 ;
• u) Verification of the placement of the intervertebral implant 28 by X-ray.

Claims (7)

Target device ( 35 ) for surgical drills and for the positioning and insertion of bone fixatives ( 27 ) in an implant with A) a target body ( 1 ), which has a central axis ( 2 ), one transverse to the central axis ( 2 ) arranged end face ( 6 ) and at least two for centering a drill or introducing bone fixatives ( 27 ) suitable guide bores ( 3 ) each having a bore axis ( 4 ), wherein B) the target device ( 35 ) one the target body ( 1 ) coaxial or parallel to the central axis ( 2 ) penetrating cavity ( 15 ) and one in the cavity ( 15 ) coaxial rotatably mounted centering element ( 8th ) with fixatives ( 11 ), so that C) the target body ( 1 ) by means of the fixative ( 11 ) in at least two with respect to rotation about the central axis ( 2 ) different positions on an implant ( 7 ) is releasably attachable, characterized in that D) the target body ( 1 ) at the end face ( 6 ) Positioning means ( 5 ), which into a bore ( 10 ) on an implant ( 7 ) are insertable. Target device ( 35 ) according to claim 1, characterized in that the positioning means ( 5 ) than over the face ( 6 ) projecting annular elevations ( 23 ) are formed. Target device ( 35 ) according to claim 1 or 2, characterized in that the target body ( 1 ) the central axis ( 2 ) cutting, rear end ( 12 ) and to the central axis ( 2 ) coaxial, at the rear end ( 12 ), second fixation means ( 13 ) for releasably securing a handle ( 14 ). Target device ( 35 ) according to one of claims 1 to 3, characterized in that the centering element ( 8th ) with respect to the central axis ( 2 ) axially fixed with the target body ( 1 ) connected is. Target device ( 35 ) according to one of claims 1 to 3, characterized in that the guide bores ( 3 ) Bore axes ( 4 ), which relative to the central axis ( 2 ) obliquely. Target device ( 35 ) according to one of claims 1 to 5, characterized in that the bore axes ( 4 ) skewed to the central axis ( 2 ). Target device ( 35 ) according to one of claims 1 to 6, characterized in that the fixing means ( 11 ) as a thread ( 16 ) or bayonet closure are formed.