AU2017100686A4

AU2017100686A4 - An auricular prosthetic implant for the attachment of a prosthetic ear and a method for the patient specific customisation, manufacture and placement thereof

Info

Publication number: AU2017100686A4
Application number: AU2017100686A
Authority: AU
Inventors: George Dimitroulis
Original assignee: Tmj Orthopaedics Pty Ltd
Current assignee: Tmj Orthopaedics Pty Ltd
Priority date: 2017-03-31
Filing date: 2017-06-09
Publication date: 2017-07-13
Anticipated expiration: 2025-06-09
Also published as: AU2018201770A1; AU2017100686B4

Abstract

Abstract There is provided a method for the patient specific customisation and placement of an auricular prosthetic implant, the method comprising: obtaining skull geometry of a patient; generating a digital model of an auricular prosthetic implant wherein the prosthetic implant comprises: a baseplate comprising a plurality of microfixation apertures; and a plurality of transdermal abutments extending perpendicularly from one side of the baseplate; virtual 3D modelling for generating a patient specific digital model, the modelling comprising: conforming contouring of the baseplate according to local bone geometry obtained from the skull geometry and in opposite ear reference; optimising the location of the abutments with respect to the baseplate using an opposite ear reference; manufacturing the auricular prosthetic implant utilising the patient specific digital model; placing the patient under anaesthetic; making an incision in the skin of the patient to expose the underlying skull bone of the patient; placing the baseplate on the exposed underlying skull bone; fixing the baseplate to the underlying skull bone by driving a plurality of microfixation screws through chosen ones of the apertures, closing the skin to cover the baseplate whilst leaving the abutments protruding transdermally; and fastening a prosthetic ear to the abutments. Finimr A

Description

An auricular prosthetic implant for the attachment of a prosthetic ear and a method for the patient specific customisation, manufacture and 2017100686 09 Jun2017 placement thereof

Field of the Invention [1] This invention relates generally to facial prosthetics. More particularly, this invention relates to a method for the patient specific customisation and placement of an auricular prosthetic implant for the attachment of a prosthetic ear.

Background of the Invention [2] The pinna describes the skin and cartilage appendage that protrudes from the side of the skull that makes up the external ear.

[3] Trauma, disease and developmental deformities may result in missing or the loss of part or all the pinna or external ear. Missing external ears can be problematic not only from a functional aspect where the patient cannot locate the source or direction of sounds, but also limits the patient's ability to wear eyeglasses. There is also an aesthetic and psychological stigma to a missing external ear which patient's become very conscious of, and may lead to social seclusion and depression.

[4] The holy grail for external ear reconstruction is bioengineering of skin and cartilage stem cells which are grown in the laboratory on polymer scaffold that resembles an ear shape before being attached to the patient's scalp with microvascular techniques. Unfortunately, the technology is still very much limited to the laboratory with no timeline or assurance that it will ever become a clinical practicality.

[5] Another complex reconstructive option for missing external ears is transplanting the patient's rib cartilage with forearm skin as a multi stage surgical procedure with the crudely sculptured ear attached to the side of the head using microvascular techniques. The aesthetics are poor and the surgery lengthy, complex and at high risk of failure.

[6] Currently, facial prosthetic laboratories around the world are able to build life-like external ears made predominately of silicon rubber that is attached to 2 or 3 osseointegrated screw implants that are surgically drilled into the side of the skull.

[7] However, because the skull thickness is very thin, the screws are extremely short and the placement of the screws is often reliant on guess work.

[8] As such, the current techniques involve a first surgical process wherein titanium screws are inserted into the skull for 3 to 6 months to osseointegrate before a second surgery is used to expose the osseointegrated screws to attach transdermal healing abutments thereto. 1 [9] As such, not only does such a prior art technique required two surgical processes, the construction of the artificial ear can only commence once the transdermal abutments are in place and so the patient has to wait a yet further 2-3 weeks before the final prosthetic ear is ready to attach to the implants. 2017100686 09 Jun2017 [10] It would be ideal to be able to have an auricular prosthetic implant that allows for the connection of the prosthetic external ear at the time of placement of the implant in a single surgical process.

[11] The present invention seeks to provide an auricular prosthetic implant and a method for the patient specific customisation, manufacture and placement thereof, which will overcome or substantially ameliorate at least some of the deficiencies of the prior art, or to at least provide an alternative.

[12] It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country.

Summary of the Disclosure [13] There is provided an auricular prosthetic implant for the attachment of a prosthetic ear and a method for the patient specific customisation, manufacture and placement thereof that requires only a single surgical process and furthermore allows for the design of the prosthetic ear prior surgery allowing for the attachment thereof substantially at the time of surgery, such as before the patient wakes from anaesthetic.

[14] Specifically, the present auricular prosthetic implant utilises a patient-specific baseplate that is manufactured according to the patient specific skull geometry and wherein the baseplate is perforated and comprises transdermal abutments extending therefrom.

[15] As such, the baseplate may be placed and simultaneously fastened to the skull utilising a plurality of micro fixation screws in chosen locations.

[16] Also, the present method allows for the design of the prosthetic ear utilising a patient specific skull mould so as to allow for the fastening thereof substantially at the time of surgery such as prior the patient waking from an anaesthetic, and negates the need for the revision surgery of the prior art arrangements.

[17] The auricular prosthetic implant provided herein in accordance with a preferred embodiment is made of a perforated titanium baseplate that supports 3 strategically placed transdermal titanium abutments. 2 [18] Each cylindrical abutment contains an inner screw thread to which a bar framework for anchoring the prosthetic ear is attached via microscrews. 2017100686 09 Jun2017 [19] The titanium baseplate may be kidney shaped and is further perforated throughout with dozens of evenly placed microfixation screw holes.

[20] The auricular prosthetic implant may be moulded to the patient's skull using the patient's 3D formatted CT scans.

[21] The position of the 3 perpendicular abutments arising from the baseplate is determined by the position and shape of the normal ear on the opposite side which is digitally scanned, reflected and transposed to the missing side. The auricular prosthetic implant may be digitally positioned against the side of the skull using the opposite ear as a reference to establish the precise symmetry and location of where the prosthetic ear should be placed, which guides the accurate placement of the ear implant. Once the auricular prosthetic implant is properly positioned, the baseplate may be digitally contoured to the skull bone so that it lies flush with the bone.

[22] The auricular prosthetic implant may then 3-D printed in medical grade titanium and the abutments are polished but the baseplate remains with a rough surface to allow for osseointegration with the underlying bone and attachment of the overlying soft tissues.

[23] Before the surgery, a 3-D printed biomodel may be made of the patient's skull with a replica of the auricular prosthetic implant attached so the Prosthetist can use it to construct the silicon rubber ear prosthetic implant which is ready to attach to the ear implant at the same surgery.

[24] To install the auricular prosthetic implant, the patient is placed under general anaesthesia. A semicircular incision is made around the ear hole and the underling skull bone is exposed.

[25] The auricular prosthetic implant is carefully positioned directly to the skull bone according to the bony contours. The prosthetic implant is secured directly to the skull bone with 6-10 titanium microscrews that fit through the holes in the baseplate. The surrounding skin is then used to completely cover the base plate of the prosthetic implant with only the 3 polished transdermal abutments left protruding through the skin incision after the incision is closed with interrupted sutures.

[26] A titanium bar superstructure is then screwed onto the 3 protruding ear abutments and finally the prosthetic silicon rubber ear is attached to the bar at the same surgery. The patient wakes up from their general anaesthetic with their new prosthetic ear.

[27] Using 3-D print technology as well as Computer aided design and manufacture (CAD-CAM), the prosthetic implant eliminates the guesswork as far as proper positioning of the new ear is concerned. 3 [28] Furthermore, this prosthetic implant makes it possible for the prosthetist to build the silicon rubber ear prosthetic implant before surgery so that the ear can be attached at the time of surgery which eliminates the current 3 stage process of 2 surgical procedures and a 3rd step of impressions for manufacture of bar and prosthetic ear. Ultimately, CAD CAM technology involving 3D printing will allow an all in one procedure where the titanium implant, titanium bar superstructure and the prosthetic ear are attached all at the same operation. 2017100686 09 Jun2017 [29] Other aspects of the invention are also disclosed.

Brief Description of the Drawings [30] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which: [31] Figure 1 shows a method for the patient specific customisation and manufacture of an auricular prosthetic implant in accordance with an embodiment; [32] Figure 2 shows a method for the placement of the prosthetic implant in accordance with an embodiment; [33] Figure 3 shows a top plan view of the prosthetic implant in accordance with an embodiment; [34] Figure 4 shows a lengthwise side elevation view of the prosthetic implant in accordance with an embodiment; [35] Figure 5 shows a side on elevation view of the prosthetic implant in accordance with an embodiment; [36] Figure 6 shows a cross-sectional elevation view of an abutment of the prosthetic implant in accordance with an embodiment; [37] Figure 7 shows a top plan view of the abutment in accordance with an embodiment; [38] Figure 8 shows a bar superstructure structure for bolting to the abutments of the prosthetic implant in accordance with an embodiment; [39] Figure 9 shows a side on elevation view of the bar superstructure in accordance with an embodiment; [40] Figure 11 shows the prosthetic and bar superstructure in situ; and [41] Figure 12 shows an ear prosthetic fastened to the bar superstructure in situ.

Description of Embodiments [42] Turning to figure 1, there is shown a method for the customisation of a prosthetic implant 21.

[43] Figure 3-5 show an exemplary embodiment of the prosthetic implant 21. 4 [44] As can be seen from these figures, the prosthetic implant 21 comprises a generally kidney shaped baseplate 22 suitably shaped for accommodating an adjacent ear canal once placed. 2017100686 09 Jun2017 [45] The baseplate 22 comprises many apertures 23, suited for the placement of microfixation screws to fixate the baseplate 22 to the skull wherein the availability of apertures 23 allow choice in the location placement of the microfixation screws. Ideally, between approximately 6-10 microfixation screws are utilised to secure the baseplate 22 to the skull adjacent the ear canal.

[46] As is best shown in figure 4 -5, the prosthetic implant 21 comprises transdermal abutments 24. In a preferred embodiment shown, the prosthetic implant 21 comprises three transdermal abutments.

[47] As will be described in further detail below, the abutments 24 are utilised for securing a titanium bar superstructure 27 to the abutments 24 so that a silicon rubber prosthetic ear 28 can be attached to the bar 27. An exemplary bar superstructure 27 is shown in figures 8 -10.

[48] Returning to figure 1, the method comprises obtaining 3D skull geometry of the patient via CAT scan 2.

[49] Thereafter, a digital model is generated 3 of the prosthetic implant 21, the model including the baseplate 22 and the transdermal abutments 24.

[50] Then, through a virtual 3D modelling process 9, the digital model of the prosthetic implant 21 is customised for the patient.

[51] Specifically, having reference to the opposite ear 5 (if available) the placement of the abutments 24 are digitally adjusted 6 with reference to the baseplate 22.

[52] Furthermore, the contouring of the baseplate 22 is digitally adjusted 7 having reference to the local bone geometry 8 obtained with reference to the opposite ear reference 5.

[53] The patient specific digital model of the prosthetic implant 21 is then 3D printed 10 in medical grade titanium.

[54] The printed prosthetic 21 is then finished 11 wherein the abutments 24 may be polished and the baseplate 22, especially the underside of the base plate 22, may be left roughened or further roughened to enhance Osseo integration.

[55] Thereafter, the patient's skull may be 3D printed 12 so as to allow a Prosthetist to model a silicon rubber prosthetic ear 12.

[56] Turning now to figure 2, there is shown the method 4 of the placement of the 3D printed patient specific prosthetic 21.

[57] The patient is placed under general anaesthesia 14 whereafter a generally semicircular incision 15 is made to expose the underlying skull bone adjacent the ear canal. 5 [58] The 3D printed patient specific prosthetic implant 21 is then placed 16 on the exposed underlying skull bone and located by matching the contouring of the baseplate 22 to the underlying geometry. 2017100686 09 Jun2017 [59] Thereafter, between approximately 6-10 microscrews are inserted through the apertures 23 of the baseplate so as to fix the prosthetic 21 to the underlying skull bone.

[60] The skin is thereafter closed 18 so as to cover the baseplate 22 while leaving the abutments 24 exposed.

[61] The titanium bar superstructure 27, having apertures 28 corresponding in location to the respective location of the abutments 24, is then bolted 19 onto the abutments 24.

[62] The modelled silicon rubber prosthetic ear is then attached 20 to the bar superstructure 27.

[63] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that specific details are not required in order to practice the invention. Thus, the foregoing descriptions of specific embodiments of the invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed; obviously, many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, they thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the following claims and their equivalents define the scope of the invention. 6

Claims

Claims

1. A method for the patient specific customisation and placement of an auricular prosthetic implant, the method comprising: obtaining skull geometry of a patient; generating a digital model of an auricular prosthetic implant wherein the prosthetic implant comprises: a baseplate comprising a plurality of microfixation apertures; and a plurality of transdermal abutments extending perpendicularly from one side of the baseplate; virtual 3D modelling for generating a patient specific digital model, the modelling comprising: conforming contouring of the baseplate according to local bone geometry obtained from the skull geometry and in opposite ear reference; optimising the location of the abutments with respect to the baseplate using an opposite ear reference; manufacturing the auricular prosthetic implant utilising the patient specific digital model; placing the patient under anaesthetic; making an incision in the skin of the patient to expose the underlying skull bone of the patient; placing the baseplate on the exposed underlying skull bone; fixing the baseplate to the underlying skull bone by driving a plurality of microfixation screws through chosen ones of the apertures, closing the skin to cover the baseplate whilst leaving the abutments protruding transdermally; fastening a prosthetic ear to the abutments.
2. A method as claimed in claim 1, wherein fastening a prosthetic ear to the abutments comprises bolting a bar superstructure to the abutments, the prosthetic ear being fastened to the bar superstructure.
3. A method as claimed in claim 1, further comprising generating a 3D print of the skull geometry of the patient and physically moulding the prosthetic ear with reference to the 3D print.
4. An auricular prosthetic implant comprising: a baseplate comprising a plurality of microfixation apertures; and a plurality of transdermal abutments extending perpendicularly from one side of the baseplate, wherein the locations of the transdermal abutments with respect to the baseplate are optimised utilising patient specific geometry.
5. An auricular prosthetic implant as claimed in claim 4, wherein the locations of the transdermal abutments with respect to the baseplate are further optimised using an opposite ear reference.