Cranioplasty prostheses and their components

Abstract

The cranioplasty attachment device may have a body defined from a sheet material and may include a first connecting end having at least a first connecting hole configured to couple with a fastener to secure the attachment device to a bone flap or prosthesis covering at least a portion of the opening in the skull. The second connecting end has at least one second connecting hole configured to couple with a fastener to secure the attachment device to the skull adjacent the opening in the skull. The frame portion extends from the first connecting end. The coil portion is between the frame portion and the second connecting end, and the coil portion may have struts configured to bend and webs between the struts configured to bend. The frame portion is configured to be positioned over a periphery of the opening in the skull to inhibit inward movement. The coil portion allows for out-of-plane deformation of the attachment device for outward movement of the first connecting end from a neutral plane with the second connecting end.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. patent application Ser. No. 63 / 271,432, filed on October 25, 2021, and incorporates the contents of that U.S. patent application by reference. [Technical field]

[0002] This application relates to implants, attachment devices, fixation plates, plating systems, and / or prostheses for use in surgical procedures such as craniotomy, craniectomy, and / or cranioplasty. [Background technology]

[0003] Some neurosurgical procedures involve the temporary or permanent removal of bone flaps from the skull for various reasons. For example, a craniotomy is a procedure in which a bone flap is temporarily removed to access parts of the brain, blood vessels, or similar soft tissues within the skull. In a craniotomy, the bone flap is replaced at the end of the procedure before the skin is closed. A craniectomy is a procedure in which a bone flap is permanently removed from the remainder of the skull. This procedure can be performed to reduce intracranial pressure (decompressive craniectomy) because the skull itself is fractured beyond repair or infected and needs to be removed to heal the infection. In a craniectomy, if the skin is closed without the bone flap in place, areas of the brain are left unprotected. A cranioplasty is the reinsertion of a bone flap or equivalent prosthesis to cover an opening in the skull.

[0004] Cranioplasty is often performed several weeks after craniectomy, after the intracranial pressure has returned to an acceptable level or after the infection has subsided. In some cases, a custom-made cranial prosthesis is used for cranioplasty after craniectomy. Because it is difficult to predict the geometric parameters of the bone flaps before surgery, the skull opening may remain uncovered for a long period of time, leaving parts of the brain within the skull structurally unprotected. In the case of decompressive craniectomy, a period of bone flap removal is often required so that the intracranial pressure can be reduced.

[0005] Therefore, patients waiting for cranioplasty may be at high risk of injury and must often wait in a hospital or similarly controlled environment. One thing that can happen is that sinking flap syndrome can develop, with potentially serious complications including paralysis and coma. In addition, postoperative procedures may be required to attach the cranial prosthesis or bone flap, adding expense and additional hospital time.

[0006] Dynamic systems have been developed to allow bone flaps to move and expand the intracranial volume, thereby enabling a "decompressive craniotomy." Dynamic systems typically may include telescopic or spring-loaded expansion. However, such systems are bulky and may offer unnecessary resistance to bone flap or prosthesis movement, resulting in insufficient decompression. Additionally, dynamic systems, being bulky in nature, may be unsightly as they may create a protuberance on the head. Summary of the Invention

[0007] In a first aspect, there is provided an attachment device for cranioplasty, comprising: a body defined from a sheet material, the body including: a first connecting end having at least a first connecting hole configured to couple with a fastener to secure the attachment device to a bone flap or prosthesis covering at least a portion of an opening in a skull; a second connecting end having at least a second connecting hole configured to couple with a fastener to secure the attachment device to the skull adjacent the opening in the skull; a frame portion extending from the first connecting end; and a coil portion between the frame portion and the second connecting end, the coil portion having struts configured for bending deformation and webs between the struts configured for torsional deformation; wherein the frame portion is configured to rest on a periphery of the opening in the skull to inhibit inward movement, and the coil portion allows out-of-plane deformation of the attachment device for movement outward from a neutral plane between the first connecting end and the second connecting end.

[0008] Further according to the first aspect, for example, the body extends longitudinally from a first connecting end to a second connecting end, and at least some of the struts extend at least partially longitudinally.

[0009] Further according to the first aspect, for example, at least a portion of the web extends at least partially widthwise.

[0010] Further according to the first aspect, for example, the second connecting end has a pair of second connecting holes.

[0011] Further according to the first aspect, for example, the coil portion has a first set of coils and a second set of coils, the first set of coils and the second set of coils connected to respective ones of the second connecting holes and meeting at the frame portion.

[0012] Further according to the first aspect, for example, the second connection hole forms a rotational joint with a fastener configured to secure the second connection end to the skull, the rotational joint allowing longitudinal expansion of the attachment device.

[0013] Further according to the first aspect, for example, a portion of the coil portion is on one side of a line passing through the second connecting hole, and the first connecting end is on the other side of the line.

[0014] Further according to the first aspect, for example, the portion extends towards the line.

[0015] Further according to the first aspect, for example, the frame portion has a closed frame between the first connecting end and the coil portion.

[0016] Further according to the first aspect, for example, the entire contour edge of the body is arched.

[0017] Further according to the first aspect, for example, the first connecting end has a pair of first connecting holes.

[0018] Further according to the first aspect, for example, the frame portion has struts extending longitudinally from the coil portion.

[0019] Further according to the first aspect, for example, the attachment device has an axis of symmetry extending longitudinally.

[0020] According to a second aspect, there is provided a cranioplasty prosthesis comprising: a pair of attachment devices as described above; and a prosthetic blade having a body defined from a sheet material, the body including: a first connecting end configured to be secured to a first location on the skull by one of the attachment devices; a second connecting end configured to be secured to a second location on the skull by the other of the attachment devices, the first and second locations being separated by an opening in the skull; and an elongated plate portion between the first and second connecting ends, the elongated plate portion having a major surface facing towards the opening in the skull; and the sheet material is a rigid biocompatible material capable of out-of-plane deformability.

[0021] Further according to the second aspect, for example, the body has a hole.

[0022] Further according to the second aspect, for example, the body is elongated.

[0023] Further according to the second embodiment, for example, the attachment device and the prosthesis blade are one integral part.

[0024] According to a third aspect, there is provided a prosthetic blade for covering an opening in a skull in cranioplasty, the prosthetic blade comprising: a body defined from a sheet material, the body including: a first connecting end configured to be fixed to a first location on the skull; a second connecting end configured to be fixed to a second location on the skull, the first and second locations being separated by an opening in the skull; and an elongated plate portion between the first and second connecting ends, the elongated plate portion having a major surface facing towards the opening in the skull; wherein the sheet material is a rigid biocompatible material capable of out-of-plane deformability.

[0025] Further according to the third aspect, for example, the body has a hole.

[0026] According to yet a third aspect, for example, the body is elongated. [Brief description of the drawings]

[0027] Reference is now made to the attached drawings. [Figure 1] FIG. 1 is a perspective view of a cranioplasty prosthesis relative to an opening in a skull, according to one embodiment of the present disclosure. [Diagram 2] FIG. 2 is an enlarged view of the end of the cranioplasty prosthesis of FIG. [Diagram 3] FIG. 3 is a perspective view of the cranioplasty prosthesis of FIG. [Figure 4] FIG. 4 is a plan view of a series of prosthetic blades relative to an opening in a skull according to another embodiment of the present disclosure. [Diagram 5] FIG. 5 is a plan view of an attachment device according to another embodiment of the present disclosure. [Figure 6] FIG. 6 is a perspective view showing the out-of-plane deformation and neutral position of the attachment device of FIG. [Figure 7] FIG. 7 is an elevational view of the attachment device of FIG. 5 in an out-of-plane deformation. [Figure 8] FIG. 8 is a series of plan views showing possible configurations of the attachment device of the present disclosure. [Figure 9] FIG. 9 is a graph showing the displacement versus force relationship of the attachment device of FIG. 5 compared to an attachment device that operates according to Hooke's Law. [Figure 10] FIG. 10 is a plan view of an attachment device according to one variation of the present disclosure. Detailed Description

[0028] Referring to the figures, and more particularly to FIG. 1, a cranioplasty prosthesis in accordance with the present disclosure is illustrated at 10. The cranioplasty prosthesis 10 is shown across an opening S1 in the skull S. The opening S1 may result from, for example, a craniectomy. For simplicity, a single cranioplasty prosthesis 10 is shown, thus only partially covering the opening S1 in the skull S, however, multiple cranioplasty prostheses 10 can be used side-by-side in a manner similar to the embodiment shown in FIG.

[0029] Cranioplasty prosthesis 10 is of a type that is used to temporarily or permanently cover an opening S1 following, for example, a craniectomy or craniotomy procedure. The expression "cranioplasty" is used to refer to prosthesis 10 in that prosthesis 10 serves to cover opening S1 in skull S. Although the use of cranioplasty prosthesis 10 has been described in the context of a craniotomy, craniectomy, or cranioplasty, it may be used in other situations as well.

[0030] The cranioplasty prosthesis 10 is shown with a pair of attachment devices 20 at opposite ends of a prosthesis blade 30 according to one variation of the present disclosure. The attachment device 20 may be deformable to allow adjustment of the prosthesis blade 30 relative to the skull S, while the prosthesis blade 30 defines a structural portion of the cranioplasty prosthesis 10 that serves as a temporary or permanent skull shell portion to cover the opening S1. The prosthesis blade 30 may be made of a formable material, such as a metal plate, so that the prosthesis blade 30 can be molded to a predetermined curvature that is continuous with the surrounding skull surface while providing adequate impact resistance to protect the brain. In the embodiment shown in Figures 1 to 3, the attachment device 20 and the prosthesis blade 30 are one integral structure. For example, the attachment device 20 and the prosthesis blade 30 may be made of a single sheet of material that can be cut by any suitable method, such as laser cutting, CNC machining, casting, etc. It is also possible to mechanically attach the attachment device 20 to the prosthesis blade 30 so as to have three components that are separable from one another. For example, the attachment device 20 may be fixed to the prosthesis blade by screws, welding, gluing, etc. The attachment device 20 can also be used as a fixation for bone flaps, i.e. together with the prosthesis blade 30.

[0031] According to one variation of the present disclosure, the cranioplasty prosthesis 10 may have only one of the attachment devices 20 (single or multiple), i.e., one end of the prosthesis blade 30, with the other end directly fixed to the skull. According to another variation, the prosthesis blade 30 may be used without the attachment device 20, but with other fixation means, such as screws, to fix the prosthesis blade 30 to the skull S. Such a prosthesis blade 30 may not be able to allow dynamic adjustment of shape at the coverage of the opening S1, for example, to address intracranial pressure concerns, but may nevertheless form a prosthetic flap that provides adequate structural integrity. Furthermore, the prosthesis blade 30 may be molded to a predetermined shape to conform to the surrounding external cranial surface, while also providing some pressure relief due to its thinness compared to bone flaps.

[0032] To illustrate that the attachment device 20 can be fixed to the bone of the skull by means of a screw F, a close-up view is shown in FIG. 2. Other fixing means are also conceivable, such as bolts, sutures, adhesives, etc. With reference to FIG. 3, it is observed that the cranioplasty prosthesis 10 has a planar body extending in length L compared to width W, the thickness of the planar body being substantially thinner (e.g., at least 10 times thinner) than the width W. The planar body can be made of a biocompatible material or a combination of materials such as metals or polymers. For example, titanium is well suited to be used to define the cranioplasty prosthesis 10, as is titanium in sheet form. This material is a hard material, but due to its limited thickness, it can exhibit some flexibility. Thus, the cranioplasty prosthesis 10 can have portions that can be deformed out of plane (e.g., when the cranioplasty prosthesis 10 is made from a sheet). The deformation can be within the range of elastic deformation or can reach plastic deformation. This can be observed, for example, in FIG. 3, which shows the prosthesis blade 30 curved to conform to the shape of the surrounding external cranial surface. Due to the use of rigid materials and a width and length that are substantially greater than the thickness, in-plane deformation, i.e., deformation while the cranioplasty prosthesis 10 remains planar, may not be possible. More specifically, the cranioplasty prosthesis 10 does not deform while remaining in the LW plane (FIG. 6). The shape of the cranioplasty prosthesis 10 allows it to resist any buckling.

[0033] The out-of-plane deformation of the prosthetic blade 30, embodied by a curve in FIG. 2, allows the user to manually define the shape of the prosthetic blade 30, for example, to mimic the shape of the bone flap to be removed. In one variation, this shape can be obtained by applying the prosthetic blade 30 to the target site of the skull S prior to the craniectomy. An instrument can optionally be used to shape the blade 30. For example, a measuring instrument can be used to mimic the shape of the skull to obtain the dimensions of the physical shape. As shown in FIG. 4, blades 30 of different lengths can be arranged side-by-side to customize the shape of a flap composed of multiple blades 30. The elongated nature of the blade 30, whether or not it is part of the cranioplasty prosthesis 10, can facilitate the insertion of the blade 30 through a small incision, for example, by endoscopic manipulation. If multiple blades are used, a single incision dimensioned based on the width of a single blade 30 can be used for the insertion of all blades 30. Additionally, the rounded ends of the blades 30, while optional, are free of corners and therefore reduce the risk of catching the surrounding soft tissue when sliding the blades 30 into place, for example, by a pushing motion on the rear end of the blades 30 or the cranioplasty prosthesis 10. In addition to the semicircular end shape shown, other tip shapes are contemplated for the blades 30.

[0034] With reference to FIG. 5, an exemplary embodiment of the attachment device 20 is provided. As explained above, the attachment device 20 may or may not be part of the cranioplasty prosthesis 10. For example, the attachment device 20 may be used alone to join the skull to a bone flap, to a prosthesis shell, or to a prosthesis different from the prosthesis blade 30. The attachment device 20 is designed to allow relative and constrained movement between the bone flap, prosthesis shell, or prosthesis covering the opening S and the skull surface surrounding the opening S. This movement can be described as being mostly out of plane, with bidirectional residual movement of length L.

[0035] The attachment device 20 of FIG. 5 is shown having a planar body and can be made of a unitary construction from a sheet of material. For example, the attachment device 20 of FIG. 5 can be made of a single sheet of material that can be cut in any suitable manner, such as laser cutting, CNC machining, casting, etc. For reference, the attachment device 20 can be located in a plane defined by a length L and a width W in a neutral position. The neutral position can be the original state of the attachment device 20. The plane defined by the length L and width W can be planar, but can also be curved, i.e., a curved surface.

[0036] The attachment device 20 has a first connecting end 21 and a second connecting end 22. The first connecting end 21 is defined by a pair of holes 21A configured to receive a fastener, such as the screw F of FIG. 2. The holes 21A may be fewer or more and may have other fastening members, such as spikes, tacks, nails, adhesives, etc. Similarly, the second connecting end 22 has a pair (or more, or less) of holes 22A for receiving a fastener, such as the screw F of FIG. 2. In one embodiment, the holes 21A are aligned with one another along the width W. Similarly, in one embodiment, the holes 22A are aligned with one another along the width W. Other arrangements are contemplated. In one variation, the holes 21A and / or holes 22A have the illustrated circular shape (e.g., straight holes, countersunk holes, countersunk holes). A complementary fastener such as a screw F (FIG. 2) or the like (pin, bolt, etc.) is received in holes 21A and / or 22A, thereby defining a rotational joint, provided that the fastener is not attached too tightly. The rotational joint may thus permit rotational movement about a rotational axis H1 generally parallel to height H, as described below and indicated at R.

[0037] The first connecting end 21 and the second connecting end 22 are interconnected by a coil portion 23, for example formed of multiple coils, and a frame portion 24. The coil portion 23 may also be referred to as a switchback mechanism with multiple switchbacks. In use, the attachment device 20 has the first connecting end 22 fixed to the skull S adjacent to the opening S1 in the skull. The second connecting end 21 can be connected to a bone flap or prosthesis, for example a prosthesis blade 30, that covers the opening S1 in the skull. The reverse arrangement is also possible. Thus, although the second connecting end 22 is shown as having a hole for screwing to a part, the second connecting end 22 may be integrally joined to the blade portion 30 as shown in FIG. 1.

[0038] The coil portion 23 is responsible for allowing out-of-plane movement of the second connecting end 22 relative to the first connecting end 21, and FIG. 6 shows the attachment device 20' after undergoing out-of-plane deformation compared to the attachment device 20 in a neutral position (also referred to herein as the original state). The coil portion 23 is configured to constrain the movement of the first connecting end 21 such that the first connecting end 21 actually overlaps at the height H in the manner shown in FIGS. 6 and 7. The revolute joints at the ends 22 may contribute to this pseudo overlap. In other words, the coil portion 23 is arranged to restrict the movement of the first connecting end 21 along the height H. The first connecting end 21 can also move along the length L, but the variation in distance along the length L when projected onto the neutral plane (i.e., the original state) is substantially smaller than the variation in distance along the height H. The frame portion 24 on the other end is between the first connecting end 21 and the coil portion 23. The frame portion 24 is a rigid portion (i.e., no in-plane deformation) that can be optionally placed on the kerf (the gap between the skull and the skin flap) to enforce the unidirectional deformation characteristic of the attachment device 20, i.e., movement upward from a neutral state, as described below. Thus, the movement of the first connecting end 21 in the width W direction is limited or negligible due to the physical constraints imposed by the frame portion 24. As can be observed, the coil portion 23 is connected to the frame portion 24, which allows various types of deformation of the coil portion 23, but in one variation, the frame portion 24 can only deform in bending. Although this movement is described as the movement of the first connecting end 21, a similar motion may also be applied to the first connecting end 21 as viewed from the second connecting end 22. In use, in one embodiment, the second connecting end 22 leads when sliding into the incision. Although not necessarily, the flared shape from the tip to the trailing hole 22A and the trailing location of the hole 22A relative to the tip of the coil portion 23 in the direction -L helps to limit movement in H and keep the attachment device 20 planar and moving along the surface of the skull. The flared shape from the tip to the trailing hole 22A can be described as arcuate, or, if present, may have other shapes.

[0039] The coil portion 23 and the frame portion 24 have various components that constrain the movement of the ends 21 and 22 relative to each other. The coil portion 23 has struts 23A that extend at least partially along the length L. The struts 23A can be interconnected by webs 23B. The webs 23B can be shorter than the struts 23A and can be located at the ends of the struts 23A. For example, the webs 23B can cross the struts 23A and extend at least partially along the width W. Thus, when one of the ends 21 and 22 is subjected to a force as shown in FIG. 6, the webs 23B deform by leveraging the struts 23A and allow the struts 23A to move out of plane. The webs 23B deform to function as a rotational joint (along W). Although struts 23A and webs 23B are described as being of different characteristics, coil portion 23 may have curved portions that function as struts 23A and webs 23B, with webs 23B at the junctions with other struts 23A to which the curved portions are connected. Again, struts 23A and webs 23B may all be made of a single sheet of material. In one variation, when out-of-plane movement occurs relative to strut 23A, web 23B is said to exhibit twisting. In parallel with the twisting of web 23B, strut 23A may exhibit bending in the out-of-plane movement. In one variation, such twisting may be elastic (but may also be plastic). When subjected to deformation, attachment device 20 may be defined as a compliant mechanism, i.e., a flexible body that undergoes elastic deformation. Moreover, due to its construction, attachment device 20 can be said to be unidirectional in that upon displacement from the original state (shown in lighter shades in FIG. 6), attachment device 20 can only move in one direction from the original state (neutral plane), i.e., toward the deformed state shown in FIG. 6. In the original state, attachment device 20 cannot move in any other direction due to forces or pressures during normal use. Stated another way, attachment device 20 cannot deform from the neutral plane / original state to a negative H.This is because the frame portion 24 of the attachment device 20 is essentially lateral to and above the calf between the skull and the flap, and such attachment device 20 prevents the bone flap from moving inwards, i.e., from collapsing. The frame portion 24 is shown as having a strut 24A, to which a coil portion 23 is connected at a first end. The coil portion 23 can be said to be split into two sets of coils from the strut 24A of the frame portion 24. In one variant, the strut 24A extends along L. Other arrangements are possible, such as paired struts 24A. The frame portion 24 may further include a frame member 24B at the end of which the connection hole 21A of the first connection end 21 is located. Thus, in contrast to the coil portion 23, the absence of a coil portion limits the deformation of the frame portion 24. This can be observed, for example, in Figs. 6 and 7.

[0040] Moreover, as can be seen from FIG. 6, the optional rotation joint of the end 22 (with a fastener like F (FIG. 2)) allows the rotation of the first coil part in the direction R, i.e., around the axis H1, as the attachment device 20 moves outward from the neutral plane. This is considered possible due to the fact that the coupling holes 22A are each connected to each coil of the coil part 23, referred to as the set. This rotation contributes to the expansion of the attachment device 20 along the direction L, which contributes to the footprint of the attachment device 20 in the deformed state approaching the footprint in the neutral state. It can also be seen that the coil part 23 has a part in the opposite direction to the coupling end 21 with respect to the line L1 passing through the coupling hole 22A. This allows a larger range of movement of the first coupling end 21 relative to the second coupling end 22.

[0041] In one variation, the second connecting end 22, i.e., the second connecting end 22 featuring a rotational joint, rests on the skull while the first connecting end is connected to the flap or blade 30. The first connecting end 21 has a single member interconnecting the holes 21A so that no substantial rotation occurs at the holes 21A.

[0042] Due to the combination of different motions, i.e. rotation, twisting, bending, and deformations occurring within the elastic deformation range, the displacement vs. force plot may exhibit non-linear behavior (as opposed to a spring-loaded system that follows Hooke's Law), resulting in a large ratio of displacement to force. This may be useful in reducing intracranial pressure. To illustrate this, an example graph is shown in Figure 9.

[0043] Referring to FIG. 10, another embodiment of the attachment device 20 is shown, with like reference numbers representing like elements for all embodiments shown herein. The attachment device 20 may include a closed frame 24D as part of the frame portion 24. The closed frame 24 is a rigid portion (i.e., no in-plane deformation) that can be optionally placed over the kerf to enforce the unidirectional deformation characteristics of the attachment device 20. The presence of the third hole 21A can also contribute to, for example, firmly fixing the first connecting end 21 to the bone flap. The presence of the anchor hole 24D at the junction of the coil portion 23 and the frame portion 24 or in the frame portion 24 can prevent rotation about H1, and its presence can give the attachment device 20 the possibility of being used as described above or as a fixed anchor. The frame portion 24 interconnects the two halves of the coil portion 23 (e.g., via the struts 24A and / or the holes 24D), thus preventing bending, twisting, and rotation. The two halves may be dissimilar and may be considered as two sets of coils, i.e., a first set of coils and a second set of coils, which are connected and merge into respective ones of the second connecting holes 22A.

[0044] 5, attachment device 20 may have one or more axes of symmetry, with one such axis of symmetry being substantially parallel to length L. By being coupled on either side of an axis of symmetry or otherwise coupled on either side of a central axis parallel to length L, attachment device 20 is generally prevented from twisting along length L.

[0045] FIG. 8 illustrates various attachment device shapes that can be used to achieve such out-of-plane deformation. All of the embodiments of FIG. 8 can be made from sheet material and all of these views are plan views. The shapes of FIG. 8 have a set of struts 23A and webs 23B in a coil portion 23 and a frame portion 24 that is disposed over the kerf. Additionally, although not required, all of the attachment device shapes have an axis of symmetry parallel to the length L direction. In all of the attachment devices of FIG. 8, the interlocking features, such as holes, are on opposite sides of a central axis that is parallel to the length L direction. The central axis may coincide with the axis of symmetry.

[0046] The proposed thickness of the attachment device 20 can vary between 0.4 mm and 0.6 mm, inclusive. It is also possible to make it thicker or thinner. This limited thickness is used to obtain a suitable aesthetic result. Inclusive, the width can be 25 mm ± 2 mm, and the length between 20 mm and 35 mm. These dimensions can vary depending on the dynamic displacement required, but these dimensions are shown only as an example. The material used is, for example, titanium grade 23 (TiAl6V4 ELI). This material can be used because of its ability to withstand large deformations before plastic deformation. Titanium grade 23 was selected considering its malleability and the possibility of manufacturing in sheet form, making it well suited for use in the attachment device 20 and the prosthetic blade 30.

[0047] The attachment device 20 is well suited to fix the prosthesis or bone flap to the skull and allow dynamic unidirectional movement, i.e., movement essentially limited to the displacement of the connecting end 21 or the connecting end 22 from the neutral plane in the height H direction and possibly back toward the neutral plane. Thus, the attachment device 20 allows the displacement of the bone flap or prosthesis in response to intracranial pressure. As a result, the increase in cerebral volume may inhibit damage due to intracranial hypertension. In the neutral position, the attachment device 20 provides maximum shear resistance, thereby preventing inward movement of the bone flap or prosthesis. The flared shape from the tip to the hole 22A may also contribute to preventing inward movement. The attachment device 20 may be made of any suitable material that is semi-flexible, biocompatible and / or biodegradable, such as metal and plastic.

[0048] The attachment device 20 may be used in a hybrid manner, for example by being used as part of the cranioplasty prosthesis 10, or to connect a bone flap to the remainder of the skull. For example, in the latter scenario, while not as optimal as the cranioplasty prosthesis 10 in addressing intracranial pressure issues (because the prosthesis blades 30 are substantially thinner than the bone flaps), the presence of the attachment device 20 may also allow for some form of reduced pressure.

[0049] 1 to 4, the prosthetic blade 30 is shown as having an elongated body between a first connecting end 31 and a second connecting end 32. The elongated body is a planar body and may be made in one piece from a sheet material manufactured using, for example, laser cutting, CNC machining, casting, etc. For reference, the prosthetic blade 30 may be located in a plane defined by a length L and a width W in a neutral position. The neutral position may be the original state of the prosthetic blade 30. The plane defined by the length L and the width W may be a plane, but may also be curved, i.e., a curved surface. The main surfaces of the prosthetic blade 30, i.e., the main surfaces that have the brain in use and the main surfaces that face away from the skull, extend in the length L and width W directions. The thickness of the prosthetic blade 30 may be substantially less than the length and width of the main surfaces, such that the prosthetic blade 30 is deformable out of plane from its natural state within an elastic deformation range and, optionally, a plastic deformation range.

[0050] To avoid damaging the surrounding tissue, the first and second connecting ends 31, 32 may have a rounded or similar arch shape, although other shapes are possible. In the illustrated embodiment, the overall shape of the prosthetic blade 30 can be described as oval. As shown in Figs. 1 to 3, the prosthetic blade 30 may have an attachment device 20 integrated therewith or mechanically connected thereto, such as by a fastener. As observed in the variant of Fig. 4, holes 31A and 32A can be defined in the first and second connecting ends 31, 32, respectively, for fixing the prosthetic blade 30 directly to the skull by a fastener (e.g., screw F in Fig. 2) or to an attachment device 20 or other attachment means. The prosthetic blade 30 may be used alone, for example in scenarios that do not require expansion to counter elevated intracranial pressure.

[0051] A number of holes 33 can be provided in the main surface of the prosthetic blade 30 to reduce its weight, increase its flexibility, and / or allow scanning through the prosthetic blade 30, for example, if a radiopaque material is used in the prosthetic blade 30. The holes 33 can also serve to attach devices to the blade 30, such as fillers, monitoring devices or sensors, drains, etc. As observed in FIG. 4, various lengths and widths of the prosthetic blade 30 are possible. Thus, during surgery, the surgeon can utilize multiple blades of different sizes, as shown in FIG. 4, to customize and cover the opening S1. The blades 30 are used in a side-by-side arrangement, although other patterns are possible, such as overlapping. In FIG. 4, it is observed that the prosthetic blade 30 does not extend onto the skull S, meaning that the attachment device 20 or equivalent can be used. However, the prosthetic blade 30 may extend to overlap the surface of the skull S such that the blade 30 is fixed directly to the skull S.

[0052] In FIG. 1, it is observed that the prosthesis blade 30 is placed on the upper surface of the skull S. Moreover, the prosthesis blade 30 can be thinner than the thickness of the removed bone flap due to the use of a sheet material or an equivalent thin material. As a result, a gap can be provided between the main surface of the prosthesis blade 30 facing the brain and the soft tissue inside the skull S. This can result in an increase in the intracranial volume and can contribute to a decrease in intracranial pressure. Thus, in some cases, it may be necessary to use an attachment device 20 or equivalent that allows dynamic deformation based on local pressure, but in other cases, the use of the prosthesis blade 30 is sufficient to increase the cranial volume and reduce the intracranial pressure. The elongated shape of the prosthesis blade 30 can facilitate its insertion under the skin, for example through a 2 cm to 3 cm incision, with or without the assistance of an endoscope.

[0053] The attachment device 20 can be used to treat several pathologies resulting from trauma, subdural hematoma, subarachnoid hemorrhage, intracerebral hemorrhage, cerebral venous thrombosis, meningitis, empyema, osteomyelitis, hydrocephalus, tumors, or similar intracranial diseases. Using the cranioplasty prosthesis 10, attachment device 20, and / or prosthesis blade 30 of the present disclosure, it is possible to treat intracranial hypertension in a single operation. Doing so may significantly reduce the risk of complications and shorten the patient's recovery time. Furthermore, a single procedure may avoid post-operative complications. The cranioplasty prosthesis 10 is a universal, dynamic bone flap prosthesis that can be implanted at the time of craniotomy or craniectomy. The cranioplasty prosthesis 10 not only forms an effective protection against impacts and results in a reduction in intracranial pressure, but also reduces the surgical costs associated with the use of the cranioplasty prosthesis 10.

[0054] The attachment device 20 may generally be described as having a body defined from a sheet material, the body including: a first connecting end having at least a first connecting hole configured to couple with a fastener to secure the attachment device to a bone flap or prosthesis covering at least a portion of the skull opening; a second connecting end having at least a second connecting hole configured to couple with a fastener to secure the attachment device to the skull adjacent the skull opening; a frame portion extending from the first connecting end; and a coil portion between the frame portion and the second connecting end, the coil portion having struts configured for bending deformation and webs between the struts configured for torsional deformation; the frame portion configured to be positioned over a periphery of the skull opening to inhibit inward movement, and the coil portion allowing out-of-plane deformation of the attachment device for movement outward from a neutral plane between the first connecting end and the second connecting end. In one embodiment, it can be described as a pair of coils, each of which is connected to the bone by a screw or similar fastener to form a rotational joint, and a frame portion that joins the pair of coils and connects them to the blade or flap.

[0055] The prosthetic blade 30 can be described as being used to cover an opening in the skull in cranioplasty and has a body defined from a sheet material, the body including: a first connecting end configured to be secured to a first location on the skull; a second connecting end configured to be secured to a second location on the skull, the first and second locations being separated by an opening in the skull; and an elongated plate portion between the first and second connecting ends, the elongated plate portion having a major surface that faces toward the opening in the skull. The sheet material is a rigid biocompatible material that is out-of-plane deformable. The above description is for illustrative purposes only, and one of ordinary skill in the art will recognize that changes can be made to the described embodiments without departing from the scope of the disclosed invention. Still other modifications that fall within the scope of the invention will be apparent to those of ordinary skill in the art upon review of this disclosure, and such modifications are intended to be included within the scope of the appended claims.

Claims

Claim 1 An attachment device for cranialplasty, comprising: a body defined by a sheet material, the body comprising: a first connection end having at least a first connection hole configured to couple with a fastener for fixing the attachment device to a bone flap or prosthesis covering at least a part of an opening in the skull; a second connection end having at least a second connection hole configured to couple with a fastener for fixing the attachment device to the skull adjacent to the opening in the skull; a frame portion extending from the first connection end; a coil portion between the frame portion and the second connection end, the coil portion having struts configured to bend and webs between the struts configured to twist; the frame portion is configured to be disposed on a peripheral edge of the opening in the skull to prevent inward movement; the coil portion enables out-of-plane deformation of the attachment device for outward movement of the first connection end from a neutral plane with the second connection end, the attachment device. Claim 2 The body extends in a length direction from the first connection end to the second connection end, and at least a part of the struts extends at least partially in the length direction, the attachment device according to claim 1. Claim 3 At least some of the webs extend at least partially in a width direction, the attachment device according to claim 2. Claim 4 The second connection end has a pair of the second connection holes, the attachment device according to any one of claims 1 to 3. Claim 5 The coil portion has a first set of coils and a second set of coils, the first set of coils and the second set of coils are each connected to the second connection hole and merge at the frame portion, the attachment device according to claim 4. Claim 6 The second connection hole forms a rotary joint having a fastener configured to fix the second connection end to the skull, the rotary joint enabling extension in the length direction of the attachment device, the attachment device according to claim 5. Claim 7 A part of the coil portion is on one side of a line passing through the second connecting hole, and the first connecting end is on the other side of the line. The attachment device according to any one of claims 4 to 6.

8. The attachment device according to claim 7, wherein the part spreads toward the line.

9. The attachment device according to any one of claims 1 to 8, wherein the frame portion has a closed frame between the first connecting end and the coil portion.

10. The attachment device according to any one of claims 1 to 9, wherein the entire contour edge of the main body is arched.

11. The attachment device according to any one of claims 1 to 10, wherein the first connecting end has a pair of the first connecting holes.

12. The attachment device according to any one of claims 1 to 11, wherein the frame portion has struts extending in the longitudinal direction from the coil portion.

13. The attachment device according to any one of claims 1 to 12, wherein the attachment device has a longitudinal axis of symmetry.

14. A prosthesis for cranioform surgery, comprising: A pair of the attachment devices according to any one of claims 1 to 13; and A prosthesis blade having a main body defined by a sheet material, wherein the main body: A first connecting end configured to be fixed to a first position of the skull by one of the attachment devices; A second connecting end configured to be fixed to a second position of the skull by the other of the attachment devices, wherein the first position and the second position are separated by an opening in the skull. The second connecting end; An elongated plate portion between the first connecting end and the second connecting end, the elongated plate portion having a main surface facing the opening in the skull. An elongated plate portion; and The sheet material is a rigid biocompatible material deformable out of plane. A prosthesis for cranioform surgery.

15. The prosthesis for cranioform surgery according to claim 14, wherein the main body has holes.

16. The prosthesis for cranioform surgery according to claim 14 or claim 15, wherein the main body is elongated.

17. The prosthesis for cranioplasty according to any one of claims 14 to 16, wherein the attachment device and the prosthesis blade are integral parts.

18. A prosthesis blade for covering an opening in the skull in cranioplasty, comprising: A body defined by a sheet material, the body comprising: A first connecting end configured to be fixed to a first position of the skull; A second connecting end configured to be fixed to a second position of the skull, the first position and the second position being separated by the opening in the skull; An elongated plate portion between the first connecting end and the second connecting end, the elongated plate portion having a main surface facing the opening in the skull; The prosthesis blade, wherein the sheet material is a rigid biocompatible material deformable out of plane.

19. The prosthesis blade according to claim 18, wherein the body has holes.

20. The prosthesis blade according to claim 18 or claim 19, wherein the body is elongated.

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