DE202011102890U1 - Instrument for introducing and repositioning a spinal rod in a posterior screw-rod implant - Google Patents

Abstract

Instrument for inserting and repositioning a spinal rod in a dorsal screw-rod implant, characterized in that it has two clamping jaws, one clamping jaw 2 being fixedly attached to the front handle 5 of the instrument and the second clamping jaw 1 movable via one on the front handle 5 spring-mounted lever mechanism 6, is attached to the lower end of the instrument via a fastening 9 of the clamping jaws 1 and 2, with a thread 10 in the front handle 5 of the instrument through which an insertion mechanism consisting of the spinal rod insertion elements 8 is movable with the rear Handle 7 of the instrument is connected.

Description

Technical description:

The present invention is from the field of spinal fixation systems. Specifically, it is an instrument for introducing and repositioning a spinal rod into a posterior screw-rod implant.

Dorsal screw-rod implant systems are used in medicine for the fixation of the spine in various indications (for example, degenerative disc disease, spondylolisthesis, trauma, spinal stenosis, deformations, curvatures, tumor, pseudarthrosis). Such systems usually consist of a spinal fixation element (pedicle screw or hook with U-shaped, fork-like spine rod retainer, wires, etc.) and a relatively stable spine rod, which is firmly connected to the adjacent vertebrae via the respective spinal fixation elements. The spinal rods either already have a prefabricated contour or are adjusted during surgery according to the individual curvature of the spine of the patient, so that the spinal column fixes the spine after implantation in the desired shape until the healing has occurred or the vertebrae permanently reaches the desired position have, or for a longer period of time.

Spinal fixation elements can be attached to all sections of the spine. As each section of the spine varies in shape and size, a large number of spinal fixation elements have been developed to facilitate connection of a particular spine bone section to the spine post. These spinal fixation elements include, for example, the pedicle screws. These usually consist of two sections: a lower threaded or hooked part for attachment in or on the bone and an upper U-shaped, fork-like designed, upwardly open head portion, which serves to receive the spine according to the curvature of the patient's spinal column fixation. In this case, the spinal fixation rod is inserted into the U-shaped, fork-like designed head part and this then closed by means of a set screw from above and thus fixed. Other spinal fixation elements include hooks and other types of bone screws.

While the presently used dorsal screw rod implants have been found to be effective, there are still great difficulties with the instruments used to insert and reposition the spine fixation rod.

Typically, one or more instruments are used to insert and reposition a spinal rod into a dorsal screw-rod implant. As far as several instruments are used, an instrument is used to fix the U-shaped, fork-like designed head of the spinal fixation element during insertion of the spinal rod and another instrument is used to introduce the spinal rod in the U-shaped, forked designed head. Insofar as only one instrument is used, which at the same time serves to fixate the spinal fixation element and apply force to insert the spinal rod, it is placed over the opening of the U-shaped, fork-shaped head of the spinal fixation element to insert the spinal rod.

A disadvantage of the previous instruments for introducing and repositioning a spinal rod in a dorsal screw-rod implant is in particular that the introduction and repositioning with the currently available instruments unnecessarily prolongs the operating time. The reason for this is the use of several instruments in the variety of operations required for this, or in the use of an instrument in which the functions of fixing the spine fixation element and the force application are introduced for the introduction of the spinal rod, in the typical for these instruments cumbersome to be operated mechanism to overcome the difficulty of aligning the stable spine rod as desired despite the solid deformed spine that can only be manipulated under great force and to introduce it into the U-shaped, fork-like receptacle of the spinal fixation elements.

Moreover, in any case, the use of multiple spinal rod insertion and repositioning instruments requires more than one surgeon to perform the surgery as it no longer has a free hand to accommodate the other instruments required to perform a dorsal screw-rod implant placement.

Insofar as only one instrument is used, which combines the introduction and fixation function in any case exists in the existing instruments, the problem that the introduction of the instrument on the feminine or masculine recording of the spine fixation element introduction is difficult for clarity.

Moreover, there is a problem with the existing instruments that the error rate when screwing the set screw is very high. In view of the high amount of force which the surgeon must simultaneously apply in inserting and holding the spinal rod in the U-shaped, forked spine fixation element, it often causes tilting and slipping on insertion of the set screw.

In addition, the additional instruments required for fixation and insertion make the surgical wound and the damage to the healthy tissue larger than would be absolutely necessary.

The object of the invention is to provide a tool for introducing and repositioning a spinal rod in a dorsal screw-rod implant, which reduces the time required for insertion and repositioning of the spinal rod, facilitates the introduction and repositioning as a whole (in particular With regard to the mechanism of the instrument and the clarity during the implantation), which reduces the number of surgeons required in the OR, prevents slippage and tilting of the set screw during insertion and reduces the number of additional instruments required for fixation, as well as those resulting from the insertion and repositioning To reduce damage to the healthy tissue of the patient to the lowest required level.

This problem is solved with the features listed in the protection claim 1.

• – dass sich die Operationszeit angesichts der Kombination von 3 verschiedenen Instrumenten-Funktionen, nämlich 1. der Fixierungsfunktion hinsichtlich des Wirbelsäulenfixationselements, 2. der Einführungsfunktion des Wirbeisäulenstabs sowie 3. der Repositionierungsfunktion des dorsalen Schrauben-Stab-Implantats und daneben zusätzlich der Aufnahme des Setzschraubendrehers im Instrumenteninnern, erheblich verkürzt,
• – dass sich wegen der vorgenannten Kombination auch die durch die Einführung und Repositionierung entstehenden Schäden am gesunden Gewebe des Patienten auf ein geringes Maß reduzieren,
• – dass durch die Aufnahme für den Setzschraubendreher im Innern des Instruments die Positionierung und Einbringung der Setzschraube problemlos möglich ist, d. h. insbesondere ohne ein Verkanten der Setzschraube,
• – dass das Instrument durch die vorgenannte Funktionskombination eine ausreichende Übersichtlichkeit und leichte Handhabbarkeit zur Einführung und Repositionierung des Wirbelsäulenstabs bietet.

With the instrument for introducing and repositioning a spinal rod in a dorsal screw-rod implant is achieved

• That the operation time in view of the combination of 3 different instrument functions, namely 1. the fixation function with respect to the spinal fixation element, 2. the introduction function of the Wirbeisäulenstabs and 3. the repositioning function of the dorsal screw-rod implant and in addition to the addition of the set screwdriver in Instrument inside, considerably shortened,
• That due to the aforementioned combination, the damage to the healthy tissue of the patient resulting from the introduction and repositioning is reduced to a small degree,
• That the positioning and insertion of the set screw is easily possible by the inclusion of the set screwdriver inside the instrument, ie in particular without tilting the set screw,
• - That the instrument by the aforementioned combination of functions provides sufficient clarity and ease of handling for the introduction and repositioning of the spinal rod.

In this case, the spinal rod insertion elements located inside the instrument are first turned back over the rear grip piece so that a clearance for the rod is created at the lower end of the instrument ( 1 - 2 ). Then the lever mechanism on the front handle of the instrument is actuated by pulling the front handle against the lever mechanism ( 3 ), so that the movable jaw of the instrument together with the immovable jaw of the instrument, which is attached via a mounting at the lower end of the instrument ( 4 ), the U-shaped upwardly open clevis of the dorsal screw-rod implant can take on this purpose intended feminine or masculine recording with his masculine or feminine recording in attack. For this purpose, the instrument with the actuated lever mechanism is placed on the rod already pre-fixed to the spinal column via two adjacent spinal fixation elements at the location of the vertebral fixation element to be attached. By releasing the lever mechanism, the instrument is locked ( 3 ). Then the repositioning can be done by screwing the spine rod insertion elements over the back handle of the instrument ( 5 ). In this case, the rotation is exerted until the spinal rod insertion elements have pressed the spine rod into the desired position and thus manipulated the spinal column accordingly. Then the set screwdriver is inserted into the opening of the instrument together with the set screw axially aligned exactly to the saw thread in the U-shaped clevis of the spinal fixation element ( 6 ). Finally, the lever mechanism on the front handle is actuated again and the instrument is released from the spinal fixation element.

An embodiment of the invention will be described with reference to 1 to 6 explained.

These show:

1 : the instrument with released lever mechanism and closed jaws in side view.

2 : the instrument with backscrewed spinal rod insertion elements in cross section.

3 : the instrument with operated lever mechanism and opened jaws in the side view.

4 : the engagement of the U-shaped fork head through the jaws of the instrument in cross section.

5 Figure 4 shows the instrument with closed jaws and lowered spine rod insertion elements on the spinal fixation member in cross section.

6 : the instrument with inserted set screwdriver in cross section.

In the figures are the movable jaw 1 , the immovable jaw 2 , an exemplary embodiment of the recordings of the jaws in the form of a feminine recording, 3 , the front handle 4 , the front handle 5 spring-mounted lever mechanism mounted 6 , the rear handle 7 , the spinal rod insertion elements 8th , fixing the jaws 9 , the thread in the front grip 10 , the cavity in the instrument for the set screwdriver 11 and an exemplary embodiment of a spinal fixation element 12 , An exemplary embodiment of the recording of the spinal fixation element 13 in the form of a masculine image, the spinal fixation rod 14 and an exemplary embodiment of the set screwdriver 15 shown

• – dass das Instrument 3 verschiedene Instrumentenfunktionen nebst der erleichterten Aufnahme des Setzschraubendrehers in sich vereint, wodurch die Operationszeit verkürzt wird, die Schädigungen des gesunden Gewebes auf ein Minimum verringert werden und das Instrument dennoch die notwendige Übersichtlichkeit aufweist,
• – dass der Chirurg durch die optimale Verbindung von maskulinem Aufnahmeteil des Instruments und femininer Aufnahme des Wirbelsäulenfixationselements sowie durch die an die Kontur des Stabs angepasste untere Kontur der Wirbelsäulenstabeinführungselemente eine bessere Kraftaufbringung leisten kann und dennoch sichergestellt ist, dass ein Abrutschen des Instruments vom Wirbelsäulenfixationselement ausgeschlossen ist,
• – dass eine knochenschonende und exakte Manipulation der Wirbelsäule möglich ist, da die Kraftaufbringung im Wesentlichen nur aus einer Richtung erfolgt,
• – dass ein Verklemmen/Verkanten der Setzschraube bei deren Einbringen verhindert wird,
• – dass der OP-Ablauf vereinfacht wird und die Übersichtlichkeit des Systems erhöht wird,
• – dass die Anzahl der für eine OP erforderlichen Chirurgen reduziert werden kann und damit kostengünstiger operiert werden kann.
• – dass ein Lösen des Instruments von dem Wirbelsäulenfixationselement nach durchgeführter Implantation leicht möglich ist, durch die Eingriffselemente im hinteren Ende der beweglichen Klemmbacke,

Advantages of the instrument for insertion and repositioning of a dorsal screw-rod implant are,

• - that the instrument 3 unites various instrument functions in addition to facilitating the insertion of the set screwdriver, thereby shortening the operation time, minimizing the damage to the healthy tissue and yet providing the instrument with the necessary clarity;
• - That the surgeon through the optimal connection of masculine receiving part of the instrument and feminine recording of the spine fixation element and adapted to the contour of the rod lower contour of the spine rod insertion elements can provide a better force application and yet ensures that slipping of the instrument is excluded from the spinal fixation element .
• That a bone-sparing and exact manipulation of the spinal column is possible, since the force application essentially takes place only from one direction,
• - That jamming / tilting of the set screw is prevented during their introduction,
• - that the surgical procedure is simplified and the clarity of the system is increased,
• - That the number of surgeons required for an operation can be reduced and thus operated more cheaply.
• That a release of the instrument from the spinal fixation element after implantation performed is easily possible, by the engagement elements in the rear end of the movable jaw,

Claims (6)

Instrument for introducing and repositioning a spinal rod in a dorsal screw-rod implant, characterized in that it has two jaws, wherein the one jaw 2 firmly on the front grip 5 of the instrument is attached and the second jaw 1 movable over one on the front grip 5 spring-mounted mounted lever mechanism 6 , about a fortification 9 the jaws 1 and 2 attached to the lower end of the instrument, with the front handle 5 of the instrument a thread 10 through which an insertion mechanism consisting of the spine rod insertion elements 8th movable with the rear handle 7 the instrument is connected. Instrument according to claim 1, characterized in that at the distal end of the movable jaw 1 the front handle 4 of the instrument is attached. Instrument according to claim 1, characterized in that the spine rod insertion elements 8th consist of two forks, which have at the bottom of a concave curve for receiving the rod. Instrument according to claim 1, characterized in that the insertion mechanism consists of the spine rod insertion elements 8th in one from the rear handle 7 to the jaws 1 and 2 continuous cylindrical cavity 11 for recording other instruments, such as the set screwdriver 15 , Has. Instrument according to claim 1, characterized in that the clamping jaws 1 and 2 have on the inside a masculine or feminine receptacle for engaging a spinal fixation element. Instrument according to claim 1, characterized in that the rear handle 7 a first cylindrical section which has cutouts or perforations for better engagement is provided and has a second upper spherical rounded portion.

Images