Cranial flap clamp

ES 2 245 692 T3

DESCRIPTION

Clamp for skull cap.

Clamp for skull cap and instrument to use it.

The present invention is directed to a skull cap stapling device that enables a bone cap to be attached to a skull according to the preamble of claim 1.

Craniotomies are surgical procedures carried out in the treatment of various brain problems, such as tumors, aneurysms, blood clots, head damage, abscesses, and the like. During a craniotomy procedure, access to the brain is achieved by creating a hole or opening in the bone that makes up the skull. The hole or "window" in the skull is usually carried out according to the following stages: identification of the part of the brain to which access is needed, drilling of several holes in the skull in proximity to the periphery of this area, insertion cutting tool into one of the holes and making cuts from one hole to another. It is possible, by removing the cut area of ​​the skull, generally called the bony flap or also "bony cap", thus having the desired access to the brain.

If all the holes that were drilled in the skull are joined by means of cuts, such that the cuts form a complete line that defines the “window”, then the bone cap can be removed simply. Alternatively, if the cuts form only a partial line of the window, the bone cap can be bent outward like a hinge so that it is no longer an obstacle. Although the size and shape of the bone cap will vary with the desired cranial access area and size, a typical bone cap would be generally rectangular in shape and approximately four centimeters by six centimeters in dimension.

Once the desired medical or surgical intervention on the brain has been carried out, the bony cap must be replaced and kept in a stable position to allow the skull to heal and heal. There are many methods available to fix the bone cap to the skull. A general method, for example, requires drilling pairs of holes in the respective peripheral areas of the skull and bone cap, passing or threading a wire through the holes, and twisting or tying the ends of the wire together to secure the edges of the bone. bone cap to the skull. Disadvantages of this method include the tedious nature and excessive time required to perform the procedure as well as the potential for damage when the holes are drilled too deep or damage from sharp ends of the wires. used for suturing.

Another method of fixation generally involves the use of osteosynthesis plates, which are secured through the spaces between the bone cap and the skull by means of screws. The disadvantages associated with the use of these plates and screws relate to the aesthetically undesirable appearance due to the protrusion formed by the plate and by the screws on the surface of the bone. Since there is minimal soft tissue in between, disposed between the skull bone and the skin, the unpleasant external appearance represents a particular problem. Another undesirable consequence due to the absence of soft tissue resides in the fact that the patient feels the plate and the screw to the touch simply by pressing on the scalp.

From US-A 6,068,631, LERCH, document on which the preamble of claim 1 is based, a cranial cap is known which has a second disk-shaped fixation element with four closed grooves extending in the direction radial, which begin at the central opening of the disc, only extend a very short distance and end away from the edge of the disc. The four slits only serve to ensure the adaptability of the central opening to a conical tensioning element that is passed through said opening. The four grooves only extend to the peripheral area of ​​the disc, the latter remaining relatively rigid and therefore cannot be easily removed after implantation.

From US-A 6,022,351, BREMER, another cranial cap is known with a second disc-shaped fixation element which does not have any indentations and therefore has essentially the same disadvantages. than the LERCH device, that is, it is difficult to remove after implantation.

The object of the invention is to create measures that make it possible to remedy said disadvantages. The invention solves the problems raised with the aid of a skull cap staple device having the features of claim 1.

In order to reduce the risk of brain trauma, the internal surfaces of the first and second staple members can be substantially smooth. The internal surfaces of the first and second staple members may be concave as the first and second staple members are in the first position and may be flattened in the second position.

In an exemplary embodiment, the extension member is a tube and the stop comprises a crimp or deformation in the tube. The extension member includes a head located at a distal end and the first staple member includes a hole for slidably receiving the extension member. The head contacts the edges of the hole to prevent the first staple member from sliding out of the extension member. The tube may also have an enlarged portion near the inner surface of the first staple member to prevent movement of said first staple member along the tube and away from the head. Lastly, the tube may be provided with an enlarged proximal portion to prevent the second staple member from sliding out of the tube.

If the stop is obtained by crimping, the aperture may have a substantially circular shape that is smaller than the crimp. The opening may include a flare to receive the stop so that the stop is received substantially within the flare.

In another exemplary embodiment, the extension member is a flat ribbon that may be integral with the first staple member and the opening of the second staple member has a rectangular shape. In this embodiment, the stopper comprises a twisted part of the tape. The second member

The staple ES 2 245 692 T3 may be provided with a recessed area surrounding the opening such that the abutment is received substantially within the recessed area. The recessed area has a width that increases from the center of the opening, a depth that increases from the center of the opening, and edges that form a cutting surface such that the stop can be formed by twisting and cutting the tape. .

Figure 1 represents a perspective view of an embodiment of a skull cap staple device according to the invention;

Figure 2 is a top view of the outer surface of a first staple member;

Figure 3 is a top view of the inner surface of a second staple member;

Figure 4 is a cross-sectional view of the skull cap staple of Figure 1, implanted between a skull and a bone cap prior to crimping and cutting of the extension member;

Figure 5 is a cross-sectional view of the skull cap clip of Figure 4 after crimping and cutting of the extension member;

Figure 6 is a perspective view of another embodiment of another skull cap clip in accordance with the present invention;

Figure 7 is a top view of the outer surface of a second staple member;

Figure 8 is a cross-sectional view taken along the line AA of Figure 7;

Figure 9 is a cross-sectional view taken along line BB of Figure 7;

Figure 10 is a perspective view of the second staple member of Figure 7 after twisting and cutting the extension member and Figure 11 is a cross-sectional view taken along line CC of Figure 10, showing the implanted skull cap clip.

As shown in Figures 1 through 4, one embodiment of a skull cap staple 10 in accordance with the present invention includes a first staple member 12, a second staple member 14, and an extension member 16. The Skull Cap Staple 10 may be made of any suitable biocompatible material, such as stainless steel, titanium, a titanium-based alloy, or a resorbable material. If the skull cap staple 10 is made of a metallic material, preferably the first and second staple members 12 and 14 as well as the extension member 16 are made of the same material to minimize possible galvanic corrosion. The first staple member 12 is disc-shaped with a concave inner surface 18 and a convex outer surface 20. The extension member 16 extends from the inner surface 18 of the first staple member 12. Although extension member 16 is illustrated as a tube, extension member 16 may have any similar structure as long as the structure and material allow for the crimping referred to below.

Extension member 16 may be integral with first staple member 12. Alternatively, extension member 16 may be threaded to first staple member 12 using any number of known ways. For example, the first staple member 12 may be provided with a hole 22 through which the extension member 16 is inserted. A head 24 is in contact with the edges of the hole 22 to prevent the first staple member 12 from sliding out of the extension member 16. The extension member 16 may be provided with an enlarged portion 26 in proximity to the inner surface. 18 of the first staple member 12 to prevent movement of the first staple member 12 along the extension 16 in a direction away from the head 24. The enlarged portion 26 can be created, for example, by crimping or mechanical deformation. Alternatively, a bushing or other similar component may be disposed on the extension member 16.

The second staple member 14 also has a disc shape with a concave inner surface 28 and a convex outer surface 30. The second staple member is provided with an opening 32 through the inner and outer surfaces 28 and 30 to receive into slidably forms extension member 16. Because opening 32 slidably receives extension member 16, opening 32 and extension member 16 preferably have complementary shapes. For example, if the extension member 16 is a tube, the opening 32 preferably has a substantially circular shape. In order to prevent the second staple member 14 from sliding out of the extension member 16, the extension member 16 may be provided with a flared proximal portion 34.

In use, skull cap clip 10 secures bone cap 36 to skull 38. Figure 4 shows skull cap clip 10 in a first position. At least a portion of the inner surface 18 of the first staple member 12 abuts against a lower surface 40 of bone cap 36 and a lower surface 42 of skull 38. At least a portion of the inner surface 28 of the second staple member 14 abuts against an upper surface 44 of the bone cap 36 and an upper surface 46 of the skull 38. A portion of the extension member 16 passes through a serrated space 48 between bone cap 36 and skull 38.

Figure 5 shows a skull cap staple 10 in a second position where the first and second staple members 12 and 14 are located more closely relative to each other than in the first position of Figure 4. This movement (which results from the movement of either of the staple members 12 and 14 or of both the first and second staple members 12 and 14) brings the inner surface 18 of the first staple member 12 against the lower surfaces 40 and 42 of bone cap 36 and skull 38 and inner surface 18 of second staple member 14 against upper surface 44 and 46 of bone cap 36 and skull 38. There are several possibilities that allow the skull cap clip 10 to be moved from the first position to the second position. For example, the extension member 16 can be pushed up while the second staple member 14 is pushed down.

In order to minimize the risk of brain trauma during implantation of the skull cap staple 10, the internal surfaces 18 and 28 of the first and second staple members 12 and 14 are devoid of teeth or similar surface characteristics. In other words, the internal surfaces 18 and 28 are substantially smooth. If the internal surfaces of the first and second staple members 12 and 14 are concave, then the movement from the first position to the second position ten3

ES 2 245 692 T3 will flatten the internal surfaces in such a way that a greater surface area will be in contact with the lower and upper surfaces of bone cap 26 and skull 38. In order to improve this effect, either or both of the first and second staple members may be provided with radial cuts. For example, Figure 3 shows that second staple member 14 has a plurality of radial cuts 50 extending radially from opening 32.

The mechanical deformation of the extension member 16 proximate the outer surface 30 of the second staple member 14 with the first and second staple members 12 and 14, in the second position, forms a stop 52 to secure the inner surface 18 of the first staple member 12 against lower surfaces 40 and 42 of bone cap 36 and skull 38 and inner surface 28 of second staple member 14 against upper surfaces 44 and 46 of bone cap 36 and skull 38. To secure the skull cap staple 10, mechanical deformation is achieved by crimping the extension member 16 close to the outer surface 30 of the second staple member 14. After crimping, the extension member 16 can be cut to remove any excess. extending substantially above the second staple member 14. The opening 32 of the second staple member 14 may include a flare 54 (see FIG. 3) to receive the stop 52. In an exemplary embodiment, stop 52 essentially enters flare 54 (FIG. 5).

Figures 6 to 11 show another embodiment of a side cap clip 110 in accordance with the present invention. The skull cap clip 110 includes a first clip member 112, a second clip member 114, and an extension member 116. Like the skull cap clip 10, the skull cap clip 110 can be made of any suitable biocompatible material, such as stainless steel, titanium, titanium-based alloy, or a resorbable material. If skull cap staple 110 is made of a metallic material, preferably the first and second staple members 112 and 114 and extension member 116 are made of the same material to minimize possible galvanic corrosion. The first staple member 112 is disc-shaped with an inner surface 118 and an outer surface 120. The extension member 116 extends from the inner surface 118 of the first staple member 112. Although the extension member 116 is shown as tape-shaped, the extension member 116 may have any similar structure as long as the structure and material allow it to be cut by twisting against a suitable surface, as explained below. .

As illustrated, extension member 116 is integral with first staple member 112. Alternatively, extension member 116 can be attached to first staple member 112 using any number of known ways. The second staple member 114 is disc-shaped with an inner surface 128 and an outer surface 130 and an opening 132 through the inner and outer surfaces 128, 130 to slidably receive the extension member 116. Because opening 132 slidably receives extension member 116, opening 132 and extension member 116 preferably have complementary shapes. For example, if the extension member 116 is a tape, then the opening 132 preferably has a substantially rectangular shape. In order to prevent the second staple member 114 from sliding out of the extension member 116, the extension member 116 may be provided with a flared proximal portion.

During use, skull cap staple 116 functions analogously to skull cap staple 10 and secures bone cap 36 to skull 38 bringing the first and second staple members 112 and 114 into a close shape relative to each other so that the inner surface 118 of the first staple member 112 is pushed against the lower surfaces 40 and 42 of the bone cap 36 and the skull 38 and the inner surface 128 of the second staple member 114 against the upper surfaces 44 and 46 of the bone cap 36 and skull 38. As best seen in Figures 10 and 11, the mechanical deformation of the extension member 116 in proximity of the outer surface 130 of the second staple member 114 with the first and second staple members 112 and 114 being in the second position, form a stop 152 to secure the inner surface 118 of the first staple member 112 against the lower surfaces 40 and 42 of the bone cap 36 and the skull 38 and the inner surface 128 of the second staple member 114 against the upper surfaces 44 and 46 of bone cap 36 and skull 38. The second staple member 114 may be provided with a fastening hole (s) 134 to receive a fastening element, such as a screw, for an additional mechanism to secure the second staple member 114 to the bone cap 36 and the skull 38 .

For attachment of the skull cap staples 110, mechanical deformation cuts the extension member 116. In particular, the extension member 116 is twisted in proximity to the outer surface 130 of the second staple member 114 with the first and second staple members 112 and 114 in the second position. A recessed area 154 surrounding the opening 132 has edges that form a cutting surface 156 for cutting the extension member 116 when it is reinforced to form a stop 152. A geometry for forming the cutting surface 156 is achieved if the recessed area 154 It has a width that increases from the center of the opening 132 and a depth that also increases from the center of the opening 132, as best seen in Figures 8 and 9. In an exemplary embodiment, stop 152 enters substantially within recessed area 154 to minimize the profile of skull cap staple 110 after implantation.