Device for restoring the integrity of the cranial bones, particularly of the non-resorbable type

Abstract

The present invention concerns a device (1) for restoring the integrity of the cranial bones, particularly of the non-resorbable type, comprising a plate body (3) in turn comprising a central body (5) and at least one peripheral portion (71), wherein said at least one peripheral portion (71) comprises fastening means (72) for fastening the device itself to the cranial bone (100), and wherein said cranial fixation device (1) comprises, at said central body (5), at least one insertion portion (50) protruding in a direction substantially orthogonal to said plate body (3) and which is configured to be inserted within a hole (102), drilled in the skull (100) of a patient, wherein said insertion portion (50) comprises a trabecular structure (51), suitable for stimulating bone regrowth and osseointegration of the device itself.

Description

[0001] DEVICE FOR RESTORING THE INTEGRITY OF THE CRANIAL BONES, PARTICULARLY OF THE NON-RESORBABLE TYPE

[0002] FIELD OF THE INVENTION

[0003] The present invention concerns an innovative device for restoring the integrity of the cranial bones, of the non-resorbable type, particularly for plugging cranial gaps or holes made necessary in case of decompressive craniotomy or in case of other interventions in which the use of the craniotome itself has led to the formation of a hole.

[0004] The device according to the invention allows the particularly effective restoration of the integrity of the cranial box, by virtue also of the osseointegration that is favoured by the device according to the invention.

[0005] BACKGROUND

[0006] As is known, in craniotomy neurosurgical interventions, also known as cranioresections, a more or less large portion of the cranial bones, defined as the bone flap, is removed. This operation takes place by using a craniotome, that is, a saw surgical instrument. Often, however, access to the cranial box with the craniotome requires the prior creation of holes made in the skull, which are made by drilling. A drawback of this procedure consists in that the repositioning of the bone flap in the operculum does not allow the holes made necessary for using the craniotome to be covered. In addition, there are multiple surgical situations in which it is necessary to proceed with cranial drilling such as in the case of decompressive craniotomy. In fact, decompressive craniotomy is implemented in the case of intracranial haematoma (for example epidural haematoma, subdural, intracerebral, subarachnoid haematoma) in order to allow the reduction of intracranial pressure if the latter does not respond to pharmacological therapy, or, in emergency cases, draining body fluids in such a way that they do not compress brain tissues.

[0007] The procedure of reconstruction of the damaged cranial bones, either following trauma, or following interventions such as the one described above, is called cranioplasty. The flap that is used to restore the skull contour may be an autologous bone graft originally removed from the patient, or a prosthesis realisable in a wide range of biomaterials, including polymethylmethacrylate (PMMA), polyetheretherketone (PEEK), hydroxyapatite, titanium alloy, etc., held in place by titanium alloy fasteners and screws.

[0008] Currently, different types of devices used to restore the skull contour are known, which vary, as mentioned, in addition to the material, also in size, shape and structure.

[0009] Such cranial fixation devices of known type are not free from drawbacks among which it should be mentioned that they are often not suitable for effectively and completely reconstructing the cranial box, in particular in the event that the patient has undergone cranial drilling.

[0010] Another drawback of such devices of known type consists in the fact that they often do not have a precise reduction, a stable fixation, and undergo early mobilization.

[0011] A further drawback of the devices of known type, in particular those using bioresorbable materials, consists in the fact that they often lead to a bone regeneration that is not perfectly predictable and controllable, such as to hinder a possible future access to the surgical area of interest.

[0012] SUMMARY OF THE INVENTION

[0013] In light of the above, the task of the present invention is to realise a device for restoring the integrity of the cranial bones, particularly of the non-resorbable type, which overcomes the limits of the prior art allowing to guarantee a stable holding of the cranial fixation and an effective restoration of the integrity of the cranial box.

[0014] Within the scope of this task, it is an object of the present invention to realise a device for restoring the integrity of the cranial bones that allows to obtain a precise and stable reduction of the skull fracture.

[0015] Another object of the present invention is to prevent early mobilization, and to favour predictable and controllable bone regeneration.

[0016] A further object of the invention consists in realising a device for restoring the integrity of the cranial bones which is capable of giving the widest guarantees of reliability and safety in use.

[0017] Yet another object of the invention consists in realising a device for restoring the integrity of the cranial bones that is overall economically competitive when compared to the prior art.

[0018] The above task, as well as the purposes mentioned and others that will better appear later, are achieved by a device for restoring the integrity of the cranial bones, particularly of the non-resorbable type, according to claim 1.

[0019] Other features are provided in the dependent claims.

[0020] LIST OF FIGURES

[0021] Further characteristics and advantages will become more apparent from the exemplary but non-limiting description of a preferred embodiment of the present invention, illustrated with the aid of the accompanying drawings in which: figure 1 is a schematic perspective view of an embodiment of a device for restoring the integrity of the cranial bones according to the invention, applicable for the reduction of a skull fracture also having a drilling hole; figure 2 is a perspective view of the device according to the invention; figure 3 is a side elevational view of the device according to the invention; figure 3a schematically illustrates some geometric characteristics of the device according to the invention; figures 4 and 5 are plan views, from above and from below respectively, of the device according to the invention.

[0022] DETAILED DESCRIPTION OF THE INVENTION

[0023] With particular reference to the figures, the device for restoring the integrity of the cranial bones, particularly of the non-resorbable type, globally indicated with reference numeral 1, comprises a plate body 3, in turn comprising a central body 5 and at least one peripheral portion 71, wherein said at least one peripheral portion 71 comprises fastening means 72 for fastening the device itself to the cranial bone 100. This device for restoring the integrity of the cranial bones 1 further comprises, at the central body 5, at least one insertion portion 50 protruding in a direction substantially orthogonal to the plate body 3 and which is configured to be inserted within a hole 102 drilled in the skull 100 of a patient. This insertion portion 50 in turn comprises a trabecular structure 51.

[0024] The trabecular structure 51 is suitable for stimulating bone regrowth, thereby leading the device for restoring the integrity of the cranial bones 1 to osseointegrate directly with the patient's bone tissue, surrounding the hole 102, thus eliminating the risk of mobilization of the prosthesis, as instead happens in the case of cranial fixation devices of known art.

[0025] Preferably, the insertion portion 50 has a substantially truncated cone shape, where it is possible to identify a major base B 1 at the plate body 3, and a minor base B2, furthest from the plate body 3.

[0026] Preferably, the insertion portion 50 of the device 1 is sized so as to be insertable by interference within the hole 102 present in the patient's skull 100.

[0027] The sizing of the insertion portion 50 is such that the same can be inserted by interference within the hole 102 made in the patient and results in a compression of this insertion portion 50 of the device 1 with the bone tissue present at the walls surrounding the hole 102, the surgical area of the patient. This compression ensures a constant mechanical load on this surrounding bone tissue, ensuring on the one hand the holding of the device 1 in place, and on the other hand inducing and favouring bone remodelling of the surgically treated part, thus leading to a better osseointegration of the device 1 itself.

[0028] Preferably, the major base B 1 of the insertion portion 50 has a diameter greater than the diameter of the hole 102 by a value between 0.40 and 0.05 mm, preferably between 0.30 and 0.10 mm, more preferably substantially equal to 0.20 mm. The diameter of the major base Bl of the insertion portion 50 therefore advantageously has nominal sizes equal to those of the gap increased by 0.05 mm, preferably by 0.10 mm and even more preferably by 0.20 mm, thus ensuring interference with the hole 102 present on the skull 100 and at the same time facilitating insertion of the device 1 into its seat.

[0029] Preferably, the major base B 1 has a diameter between 3 and 50 mm, preferably between 6 and 40 mm, more preferably between 9 and 25 mm.

[0030] Preferably, the lateral surface of the insertion portion 50 is inclined with respect to a direction orthogonal to the plate body 3 by an angle A between 1° and 10°, preferably between 3° and 7°, more preferably equal to 5°.

[0031] This inclination favours the insertion of the device 1 , in particular of its insertion portion 50, into the hole 102 of the patient's skull 100, while maintaining a constant mechanical load on the bone tissue surrounding the surgical area, given by the interfering sizes of the insertion portion 50 with the hole 102.

[0032] Preferably, the insertion portion 50 has a plurality of support walls 53 to which the trabecular structure 51 is attached.

[0033] Preferably, said support walls 53 are developed in a substantially orthogonal direction with respect to the plate body 3.

[0034] Advantageously, as illustrated in particular in figure 5, the device 1 according to the invention comprises a plurality of support walls 53 that are developed orthogonally with respect to the plate body 3 and along a respective plurality of radial directions. In this way, the trabecular structure 51 is subdivided into a plurality of trabecular sub-structures each having a shape of a circular sector. In other words, the support walls 53 can be arranged at the central body 5 along radii angularly separated from each other, and the trabecular sub-structures of the trabecular structure 51 can be delimited and supported between pairs of support walls 53.

[0035] Preferably, the at least one peripheral portion 71 comprises a plurality of radii 7, which preferably extend from the central body 5 along respective radial directions.

[0036] Preferably, each radius 7 comprises, at its peripheral end, the aforementioned fastening means 72 configured for fastening the device 1 to the patient's skull 100. The fact of providing the radii 7, allows the device 1 according to the invention to have a high flexibility and adaptability to the curvatures of the patient's skull 100, thus ensuring the fastening to the patient's skull 100 in any position.

[0037] Preferably, the fastening means 72 of the at least one peripheral portion 71 comprise a plurality of holes 73, preferably obtained at the peripheral end of each radius 7, where each hole 73 is advantageously configured to accommodate a respective screw 74.

[0038] Preferably, the device 1 comprises a number of radii 7 equal to the number of support walls 53. More preferably, the radii 7 and the support walls 53 are developed along radial directions coinciding with each other, as illustrated in particular in figure 5. This guarantees a particular compactness and mechanical resistance to the device 1 itself.

[0039] Preferably, the plate body 3 is configured to be placed straddling a fracture 101 of the skull 100 of a patient, at a hole 102 drilled in the skull 100 itself. As illustrated in figure 1, in fact, the device 1 according to the invention can be attached to the skull 100 of a patient, so that the insertion portion 50, comprising the trabecular structure 51, is inserted into the hole 102, also present straddling the fracture 101, while the peripheral portions 71 of the device 1 lie on both sides of the fracture 101. In this way, the device 1 allows both to reduce the fracture 101 and to plug, by osseointegration, the hole 102 drilled in the skull 100.

[0040] Preferably, the plate body 3 is made of titanium material.

[0041] More preferably, the plate body 3 is made of titanium alloys.

[0042] Preferably, the trabecular structure 50 has sizes of the trabeculae and intratrabecular cavities that are comparable to those of the cancellous bone of the bone tissue surrounding the surgical area of the patient's skull 100, so as to favour bone integration thereof.

[0043] Preferably, the trabecular structure 50 is made of titanium or an alloy thereof.

[0044] Preferably, the plate body 3 is made of titanium or an alloy thereof.

[0045] Preferably also the support walls 53 of the trabecular structure 50 are made of titanium or an alloy thereof.

[0046] More preferably the entire device 1 according to the invention is made of titanium or an alloy thereof.

[0047] In fact, titanium and alloys thereof have an elastic modulus very similar to that of natural trabecular bone, favouring its regrowth in contact with the trabecular structure 50.

[0048] Advantageously, the plate body 3 has a thickness of a value between 0.10 and 0.50 mm, preferably between 0.20 and 0.40 mm, more preferably substantially equal to 0.30 mm, to have an optimal aesthetic impact. The operation of the device according to the invention, particularly of the non- resorbable type, is clear and evident from what has been described.

[0049] In practice, it has been found that the device according to the present invention fulfils the task as well as the intended purposes as it allows to plug a hole drilled in the skull of a patient, as well as to reduce a fracture present in the skull of a patient, favouring a predictable and controllable bone regeneration according to the expectations of the intervention.

[0050] Another advantage of the device according to the invention consists in that it does not hinder access to the incised area in the patient for any future removal of the device itself, as occurs instead in bioresorbable devices, which fuse uncontrollably with the surrounding bone tissue.

[0051] A further advantage of the device according to the invention consists in its easy insertion in the surgical area of the patient, while maintaining a constant mechanical load with the surrounding bone tissue.

[0052] The device for restoring the integrity of the cranial bones, particularly of the non- resorbable type, thus conceived is susceptible to numerous modifications and variants all falling within the scope of the inventive concept.

[0053] Furthermore, all the details can be replaced by other technically equivalent elements.

[0054] In practice, any materials can be used according to requirements, as long as they are compatible with the specific use, the dimensions and the contingent shapes.

Claims

CLAIMS1. Device for restoring the integrity of the cranial bones (1), particularly of the non- resorbable type, comprising a plate body (3) in turn comprising a central body (5) and at least one peripheral portion (71), said at least one peripheral portion (71) comprising fastening means (72) for fastening the device itself to the cranial bone (100), wherein said cranial fixation device (1) comprises, at said central body (5), at least one insertion portion (50) protruding in a direction substantially orthogonal to said plate body (3) and which is configured to be inserted within a hole (102), drilled in the skull (100) of a patient, said insertion portion (50) being configured to be inserted by interference within said hole (102) present in said skull (100), and comprising a trabecular structure (51), suitable for stimulating bone regrowth and osseointegration of the device itself, wherein said insertion portion (50) has a substantially truncated cone shape, wherein the major base (Bl) is that at said plate body (3) and the minor base (B2) is that furthest from said plate body (3), and wherein said at least one peripheral portion (71) comprises a plurality of radii (7) extending from said central body (5) along respective radial directions.

2. Device (1) according to the preceding claim, wherein said insertion portion (50) has a plurality of support walls (53) to which said trabecular structure (51) is attached.

3. Device (1) according to one or more of the preceding claims, wherein said support walls (53) are developed orthogonally with respect to said plate body (3) and along a respective plurality of radial directions, said trabecular structure (51) being subdivided into a plurality of trabecular sub-structures each having the shape of a circular sector included between a pair of said support walls (53), respectively.

4. Device (1) according to one or more of the preceding claims, wherein said major base (Bl) of said insertion portion (50) has a diameter greater than the diameter of said hole (102) by a value between 0.40 and 0.05 mm, preferably between 0.30 and 0.10 mm, more preferably substantially equal to 0.20 mm.

5. Device (1) according to one or more of the preceding claims, wherein said major base (B 1) of said insertion portion (50) has a diameter between 3 and 50 mm, preferably between 6 and 40 mm, more preferably between 9 and 25 mm.

6. Device ( 1 ), according to the preceding claim, wherein the lateral surface of said insertion portion (50) is inclined with respect to a direction orthogonal to said plate body (3) by an angle (A) between 1° and 10°, preferably between 3° and 7°, more preferably equal to 5°.

7. Device (1) according to one or more of the preceding claims, wherein said fixationmeans (72) of said at least one peripheral portion (71) comprise a plurality of holes (73), each of said holes (73) being configured to accommodate a respective screw (74).

8. Device (1) according to one or more of the preceding claims, wherein said plate body (3) is configured to be placed at a hole (102) obtained in the skull (100) of a patient, straddling a fracture (101) present in said skull (100).

9. Device (1) according to one or more of the preceding claims, wherein said plate body (3) has a thickness of a value between 0.10 and 0.50 mm, preferably between 0.20 and 0.40 mm, more preferably substantially equal to 0.30 mm.

10. Device (1) according to one or more of the preceding claims, wherein said plate body (3) and / or said trabecular structure (50) are made of titanium or an alloy thereof.

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