DE29614922U1 - Surgical closure - Google Patents

Description

Surgical closure

The invention relates to a surgical closure for closing a trepanation hole made in a skull capsule.

Trepanation holes are drilled into the skull capsule of a patient to give the surgeon access to the surgical area. Such a procedure is required, for example, for an endoscopic procedure on the brain of a patient. If the procedure cannot be performed using microsurgical means, but a relatively large access to the surgical area must be created, several trepanation holes with a diameter of approximately 8 to 15 mm are usually drilled into the skull capsule, which are then connected to one another using craniotome cuts, so that a skull segment is defined, which can then be removed from the skull capsule. After the surgical procedure, the removed skull segment is reinserted into the remaining skull cap and fixed to it, for example, using wire loops, threads or metal micro-plates.

The object of the present invention is to provide a surgical closure with which a trepanation hole made in a skull capsule can be closed in a simple manner and with little expenditure of time.

This object is achieved according to the invention in a closure of the type mentioned at the outset in that the closure has a closure shaft that can be inserted into the trepanation bore and has at least one retaining device arranged on the outside.

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jump and a locking head to cover the trepanation hole.

Such a closure can be inserted directly into the trepanation hole, whereby a stable connection is achieved between the closure and the bone tissue of the skull capsule surrounding the trepanation hole by means of the retaining projection arranged on the outside of the closure shaft. At the same time, the closure head closes the access to the surgical area made possible via the trepanation hole.

The retaining projection creates a positive connection between the closure and the bone tissue surrounding the trepanation hole. In a particularly simple and inexpensive design of the surgical closure, the retaining projection is designed as a retaining rib running in the circumferential direction. This can, for example, be designed in a sawtooth shape with a lower side oriented at an angle to the longitudinal axis of the closure shaft and a top side oriented essentially transversely to the longitudinal axis, so that the surgical closure can be inserted into the trepanation hole with relatively little effort, but the closure is reliably prevented from coming loose by the shape of the retaining rib, which forms an undercut.

In order to give the surgeon the opportunity to release the closure from the trepanation hole for a further procedure, a preferred embodiment of the invention provides that the retaining projection is designed as an external thread. In this case, the closure can be screwed into the trepanation hole by

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The retaining projection designed with an external thread cuts a corresponding internal thread into the trepanation bore.

It is advantageous if the closure has a contact surface for the application of a surgical tool, for example in the form of a screwdriver, with the help of which a torque can be exerted on the surgical closure. The contact surface can, for example, be designed in the form of a diametrically running slot arranged on the outside of the closure head or in the form of an internal square.

It is advantageous if the closure head has a stop surface that protrudes beyond the outside of the closure shaft to limit the insertion movement of the closure into the trepanation hole. With such a design, when the closure is inserted into the trepanation hole, the stop surface of the closure head comes into contact with the bone tissue surrounding the trepanation hole. This prevents the closure from being accidentally inserted too deeply into the trepanation hole.

In many cases, it is intended that the closure should grow together with the bone tissue surrounding the trepanation hole. It is particularly advantageous if the closure shaft has at least one essentially radial through-opening, as this supports the growth of the closure with the bone tissue. For example, a large number of through-openings distributed around the circumference can be provided along the closure shaft.

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As mentioned at the beginning, in many cases it is necessary for a cranio-surgical procedure to remove a skull segment from the skull cap in order to give the surgeon access to the surgical area. For this purpose, not only are several trepanation holes made in the skull cap, but also craniotome cuts are made, which define the skull segment to be removed. If the removed skull segment is inserted into the remaining skull cap after the operation, the trepanation hole can also be closed in this case using the surgical closure according to the invention. At the same time, this means that the skull segment is also fixed to the remaining skull cap due to the mechanical tension of the closure with the bone tissue surrounding the trepanation hole.

In a particularly preferred embodiment of the surgical closure according to the invention, it is provided that the closure shaft has a region that is elastically deformable in the radial direction. Due to the elasticity of the closure shaft, the bone tissue surrounding the trepanation hole is subjected to a spring force acting in the radial direction. Such a design is particularly advantageous if a calotte segment removed from the skull cap is to be fixed to the remaining skull cap reliably and with little expenditure of time by means of the surgical closure. If such closures that are elastically deformable in the radial direction are inserted into all trepanation holes made in the skull cap for removing the calotte segment after the calotte segment has been inserted, the calotte segment is subjected to a radial force at all trepanation holes; this has the consequence that the calotte segment is so

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in the remaining skull cap so that an essentially uniformly wide gap is formed between the skull segment and the remaining skull cap along the entire circumference of the skull segment. Such positioning in turn has a positive effect on the fusion of the skull segment with the remaining skull cap.

The closure shaft can, for example, be designed in the shape of a sleeve. The outer diameter of the sleeve is adapted to the diameter of the trepanation hole selected by the surgeon. For example, it can be provided that the surgeon is provided with a set of closures whose shaft diameters correspond to the diameters of the trepan drills that are available to the surgeon for making the trepanation holes.

The elastic deformability of the closure shaft in the radial direction is achieved in a preferred embodiment in that the closure has at least one longitudinal slot extending from one end of the closure in the axial direction. Due to the longitudinal slot, the closure can be compressed in the radial direction, so that insertion into the trepanation hole is considerably simplified. With such a design, the retaining projection arranged on the outside of the closure shaft only cuts noticeably into the bone tissue surrounding the trepanation hole when the closure is released after its final positioning in the trepanation hole and then expands in the radial direction due to its elasticity.

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It is particularly advantageous if the retaining projection is arranged at the height of the longitudinal slot, because at the height of the longitudinal slot the closure is most deformable in the radial direction, so that with such an arrangement of the at least one retaining projection the closure can be compressed so far for insertion into the trepanation bore that the retaining projection does not come into contact with the wall of the trepanation bore at all.

A particularly stable fixation of the calotte segment removed from the skull capsule can be achieved by the closure having a receptacle at the height of the longitudinal slot as well as an expansion element that can be inserted into the receptacle to spread the closure shaft. In such an embodiment, after the calotte segment has been inserted, the closure shaft is inserted into the trepanation hole. The expansion element is then inserted into the receptacle; this results in the closure shaft also expanding in the radial direction, so that the bone tissue surrounding the trepanation hole and in particular the calotte segment reinserted into the skull capsule are subjected to a particularly large radial force. This results in a particularly secure fixation of the calotte segment to the remaining skull cap.

If the closure is to be removed from the trepanation hole for a further surgical procedure, it is advantageous if the expansion element can be releasably fixed in the holder. For example, it can be provided that the closure shaft has a through hole running in the axial direction into which the expansion element can be screwed. The expansion element can thus be removed again at any time.

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be released from the locking shaft so that the locking shaft can be pulled out of the trepanation bore.

Particularly in cases where a permanent connection of the closure with the bone tissue surrounding the trepanation hole is to be achieved, it is advantageous if the expansion element can be fixed in the receptacle by means of a locking connection. The closure shaft and the expansion element can thus be designed with a locking projection and a corresponding locking receptacle, which together form a snap closure with the help of which the expansion element can be secured against falling out of the connecting shaft.

In an advantageous embodiment, it is provided that the closure is made of a biocompatible material, for example a corresponding metal, for example of titanium or a biocompatible titanium compound.

In a particularly preferred embodiment of the surgical closure according to the invention, it is provided that the closure is made of a resorbable plastic. Such a design has the particular advantage that in postoperative computer tomography examinations, no image disturbances are caused by the surgical closure.

The following description of preferred embodiments of the invention serves to explain in more detail in conjunction with the drawing. They show:

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Figure 1: a schematic, perspective representation of a skull segment fixed to a remaining skull cap by means of a first embodiment of the surgical closure according to the invention;

Figure 2: a sectional view of the first embodiment of the surgical closure according to the invention along the line 2-2 in Figure 1;

Figure 3: a sectional view corresponding to Figure 2

after anchoring the surgical closure;

Figure 4: a sectional view of a second embodiment of the surgical closure according to the invention;

Figure 5: a sectional view of a third embodiment of the surgical closure according to the invention and

Figure 6: a sectional view of a fourth embodiment of the surgical closure according to the invention.

Figure 1 shows a skull capsule 10 from which a skull segment 12 was originally removed to allow a surgeon access to an operating area. The removal was carried out by making three trepanation holes 14, 15 and 16 in the skull capsule 10, which were then connected to one another using craniotome cuts 17, 18 and 19 so that the area defined by this

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Calotte segment 12 of the skull capsule 10 could be removed. Following the operation, the calotte segment 12 was reinserted into the remaining skull cap 20, as shown in Figure 1.

After insertion, the calotte segment 12 is fixed to the remaining skull cap 20 by inserting a surgical closure 22 into the trepanation holes 14, 15 and 16. The surgical closures 22 apply a radial force to the bone areas of the remaining skull cap 20 and the calotte segment 12 surrounding the trepanation holes 14, 15, 16, by means of which the calotte segment 12 is reliably fixed to the remaining skull cap 20, with the calotte segment 12 simultaneously assuming such a position within the skull capsule 10 that a cutting gap 24 is formed between the calotte segment 12 and the remaining skull cap 20, which has essentially the same width over the entire circumference of the calotte segment 12.

As can be seen in particular from Figures 2 and 3, the surgical closure 22 comprises a sleeve-shaped closure shaft 26 which can be inserted, for example, into the trepanation bore 14 and is integrally connected to a connecting head 30 which covers the edge of the trepanation bore and has a stop surface 28 aligned transversely to the longitudinal axis of the trepanation bore.

The connecting head and connecting shaft 30 or 26 have an axial through-bore 32 with an internal thread 33, and on the outside of the connecting shaft 26 there are retaining ribs 34 running in the circumferential direction, which

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form a positive connection with the bone tissue of the remaining skull cap 20 and the skull cap segment 12 surrounding the trepanation hole 14. Four longitudinal slots 35 are formed in the connecting head 30 and the connecting shaft 26, evenly distributed in the circumferential direction, which extend, starting from the top of the connecting head 30 in the axial direction, approximately over three quarters of the total length of the connecting shaft.

In addition to the connecting head 30 and the connecting shaft 26, the closure 22 comprises a substantially hollow-cylindrical expansion element 37, which has an external thread 38 corresponding to the internal thread 33 of the connecting shaft 26 and can be screwed into the through hole 32. In its proximal end region, an internal square 39 is formed in the front of the expansion element 37, so that the expansion element 37 can be screwed into the connecting shaft 26 using a socket wrench (not shown in the drawing), as shown in Figure 3.

The connecting head 30, like the connecting shaft 26, is elastically deformable in the radial direction due to the longitudinal slots 35. The connecting head and connecting shaft 30 or 26 can therefore be pressed together so far for insertion into the trepanation hole 14 that the retaining ribs 34 practically do not engage in the bone tissue surrounding the trepanation hole 14. In the pressed-together state, the connecting shaft 26 is inserted into the trepanation hole 14 until the stop surface 28 of the connecting head 30 comes to rest on the bone tissue surrounding the trepanation hole 14. The expansion element 37 is then screwed into the connecting head 30 and the connecting shaft 26; this has the result that

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these two parts of the closure 22 expand in the radial direction so that the retaining ribs 34 form a positive connection with the bone tissue of the remaining skull cap 20 and the skull cap segment 12 adjacent to the trepanation bore 14 and the skull cap segment 12 and the remaining skull cap 20 are subjected to a radial force.

Figure 4 shows an alternative design of a surgical closure 42 according to the invention with a closure head 43 and a closure shaft 44 which is integrally connected to it in the distal direction and into which a spreading element 45 can be screwed in the axial direction. The closure 42 differs from the closure 22 shown in Figures 1 to 3 in that only in the area of the closure shaft 44 are four longitudinal slots 46 which are evenly distributed over the circumference and which open into the distal end face 47 of the closure 42 facing away from the closure head 43. In addition, the closure shaft 44 of the closure 42 has an external thread 48 instead of retaining ribs running in the circumferential direction, so that the closure head and closure shaft 43 or 44 can be screwed into the trepanation bore. Such a design is particularly advantageous if it is intended to remove the closure 42 from the trepanation bore again, for example for a further surgical procedure.

A third and a fourth embodiment of the surgical closure according to the invention are shown in Figures 5 and 6. These differ from the closures 22 and 42 described above essentially in that neither longitudinal slots nor a spreading element are provided. Such closures are used in particular for inserting

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use when only a trepanation hole is to be closed, for example after an endoscopic procedure, without simultaneously fixing a skull segment removed from a skull capsule to a remaining skull cap. Its use is of course not limited to this area of application. In particular, when only a relatively small skull segment of the skull cap has been removed, the embodiments shown in Figures 5 and 6 can also be used to fix the skull segment.

Figure 5 shows a one-piece closure 52 with a closure head 53 and a closure shaft 54 that adjoins it in the distal direction. An internal square 56 is formed into the closure head 53 and a total of four axial bores 57 evenly distributed over its circumference, of which only two are visible in Figure 5. The closure shaft 54 is designed in the form of a sleeve that has radial bores 58 evenly distributed over its entire length. The closure shaft 54 has an external thread 59 so that the closure 52 can be screwed into a trepanation bore, whereby a socket wrench corresponding to the internal square 56 can be used to screw it in. The design of the closure 52 with the axial and radial bores 57 and 58 results in the closure 52 growing together with the bone tissue surrounding the trepanation bore in a relatively short time.

In Figure 6, a closure 62 is shown. This also comprises a closure head 63 and a closure shaft 64 connected in one piece to it, which can be inserted into a trepanation hole. In contrast to the

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Unlike the above-described locking shaft 54, the locking shaft 64 does not have an external thread but rather retaining ribs 65 running in the circumferential direction, which in cross section have the shape
of barbs. In this way, the closure 62 can be inserted into a trepanation hole with relatively little effort, and subsequent removal is
However, this is practically impossible due to the barb-shaped retaining ribs 65. Such a design of the surgical closure according to the invention
is used in particular when the trepanation hole is to be permanently closed after an endoscopic procedure.

Claims (15)

A 53 390 u 16 August 1996 - 14 - PROTECTION CLAIMS 1- Surgical closure for closing a trepanation hole made in a skull capsule, characterized in that the closure (22; 42; 52; 62) comprises a closure shaft (26; 44; 54; 64) which can be inserted into the trepanation hole (14) and has at least one retaining projection (34; 48; 59; 65) arranged on the outside, and a closure head (30; 43; 53; 63) for covering the trepanation hole (14). 2. Surgical closure according to claim 1, characterized in that the retaining projection is designed as a retaining rib (34; 65) running in the circumferential direction. 3. Surgical closure according to claim 1, characterized in that the retaining projection is designed as an external thread (48; 59). 4. Surgical closure according to claim 1, 2 or 3, characterized in that the closure head (30) forms a stop surface (28) projecting beyond the outside of the closure shaft (26) for limiting the introduction movement of the closure (22) into the trepanation bore (14). 5. Surgical closure according to one of the preceding claims, characterized in that the closure shaft (54) has a substantially radially extending through-opening (58). A 53 390 u 16 August 1996 - 15 - 6. Surgical closure according to one of the preceding claims, characterized in that the closure shaft (26; 44) has a region which is elastically deformable in the radial direction. 7. Surgical closure according to one of the preceding claims, characterized in that the closure shaft (26; 44; 54; 64) is designed in the shape of a sleeve. 8. Surgical closure according to one of the preceding claims, characterized in that the closure (22; 42) comprises a longitudinal slot (35; 46) extending in the axial direction from one end of the closure (22; 42). 9. Surgical closure according to claim 8, characterized in that the retaining projection (34; 48) is arranged at the level of the longitudinal slot (35; 46). 10. Surgical closure according to claim 8 or 9, characterized in that the closure (22) has a receptacle (32) at the level of the longitudinal slot (35) and a spreading element (37) insertable into the receptacle (32) for spreading the closure shaft (26). 11. Surgical closure according to claim 10, characterized in that the expansion element (37) can be releasably fixed in the receptacle (32). 12. Surgical closure according to claim 10, characterized in that the expansion element (37) can be fixed in the receptacle by means of a locking connection. A 53 390 u 16 August 1996 - 16 - 13. Surgical closure according to one of the preceding claims, characterized in that the closure is made of a biocompatible material. 14. Surgical closure according to claim 13, characterized in that the closure is made of titanium or a biocompatible titanium compound. 15. Surgical closure according to claim 13, characterized in that the closure is made of a resorbable plastic.