Synthetic acetabular lip and method for making it

Abstract

Described is a method for making a synthetic acetabular lip comprising the following steps: forming a semi-finished product (300) extending longitudinally from a first to a second end (300a, 300b) and having a transversal cross-section shaped to match a corresponding cross-section of a human acetabular lip (L); obtaining a reference measurement; cutting the semi-finished product (300) along a direction perpendicular to a main direction of extension (X) of the semi-finished product (300), to obtain a synthetic acetabular lip with a length equal to the reference measurement.

Description

[0001] DESCRIPTION

[0002] SYNTHETIC ACETABULAR LIP AND METHOD FOR MAKING IT

[0003] Technical field

[0004] This invention relates to a method for making a synthetic acetabular lip, a synthetic acetabular lip and a semi-finished product for making a synthetic acetabular lip.

[0005] Background art

[0006] The acetabular lip is a ring made of fibro-cartilage positioned around the acetabulum defining a housing in which the head of the femur is inserted.

[0007] The acetabular lip is essential for the normal function of the hip joint, it helps to keep the head of the femur inside the acetabulum as it functions as a seal providing stability to the hip joint.

[0008] As is known, the acetabular lip helps seal the hip joint thus correctly maintaining the fluid pressure inside the joint and providing nutrition to the surrounding articular cartilage.

[0009] Without an intact seal, that is to say, if the acetabular lip is damaged, the risk of early degenerative arthrosis increases.

[0010] More in detail, a damaged acetabular lip can cause a movement of the center of rotation of the hip, that is to say, of the femoral head. Such a change increases the impact and load on the joint. In this situation, since the acetabular lip is damaged and the femoral head is off centre, the repetitive movement of the hip can create further lesions to the acetabular lip and to the hip joint that, over time, can lead to arthrosis.

[0011] In order to understand whether a patient’s acetabular lip is damaged and determine the extent of the damage, the patient is first subjected to an MRI accompanied by a visit where, by manipulating, the hip function is inferred. If the MRI and the visit show that the situation is serious, the patient will undergo arthroscopy surgery in which a previously prepared tendon is implanted. However, it is currently particularly difficult to understand the extent of damage to the acetabular lip with the magnetic resonance imaging and / or the manipulation. For this reason, it is difficult to understand whether it is possible to “repair” the existing acetabular lip or it is necessary to replace it. In this situation, to date, the patient having the damaged acetabular lip must undergo two separate operations.

[0012] The first arthroscopy operation is aimed at checking the state of the acetabular lip by using video cameras and measuring instruments. This procedure determines whether it is sufficient to clean and suture the acetabular lip or whether a new acetabular lip must be implanted. In the latter case, the patient must undergo second arthroscopy surgery to replace the acetabular lip.

[0013] The fact that the patient has to undergo two surgeries (one to decide whether or not to implant a new acetabular lip and one to actually implant it), even though in arthroscopy, makes the process of diagnosing and replacing the acetabular lip invasive and complex.

[0014] Currently, if it is considered that a new acetabular lip must be implanted, use is made of allograft techniques (wherein the new acetabular lip is taken from a donor) or autograft techniques (that is to say, a tendon of the patient is taken and implanted to form the acetabular lip).

[0015] These techniques have a first drawback linked to the shape of the acetabular lip to be implanted which might not guarantee an efficient sealing effect of the joint with consequent alteration of its functionality.

[0016] A second drawback is due to the prior art methods for making, manipulating and preparing synthetic acetabular lips to be implanted which lead to a further increase in surgical times. An example of a method for making a synthetic acetabular lip is shown, for example, in patent document WO2022 / 098774A1 .

[0017] Another drawback, in the case of the autograft technique, is due to the possibility that further incision of the patient’s skin is necessary to withdraw a tendon of the fascia lata or a quadriceps tendon or other tendon. Other examples of a method for making a synthetic acetabular lip are provided in patent documents US2013245780A1 , US2016310282A1 and US2015066151 A1.

[0018] Patent document US2013245780A1 relates to the manufacture of a semifinished product for labrum with the possibility of adaptation in-situ. However, that document does not provide any indication of how to adapt the measurement of the artificial lip to replace a portion of the lip.

[0019] Patent document US2016310282A1 mainly concerns knee prostheses, and the production of custom-made prostheses; however, the procedure to obtain the adaptation to the specific patient is complex and involves drawing on a stock of prosthesis measurements and sizes.

[0020] Patent document US2015066151 A1 describes an implant for replacing cartilage and a single lip portion: but the implant is rigid and made of a multi-material, including a bone component.

[0021] The technical purpose of the invention is therefore to provide a method for making a synthetic acetabular lip and a semi-finished product for making a synthetic acetabular lip which are able to overcome the drawbacks of the prior art.

[0022] Aim of the invention

[0023] The aim of the invention is to provide a method for making a synthetic acetabular lip which is fast, precise and practical.

[0024] A further aim of the invention is to provide a method for making a synthetic acetabular lip which makes the arthroscopy operation less invasive for the patient.

[0025] A further aim of the invention is to provide a semi-finished product for making a synthetic acetabular lip from which it is possible to obtain a synthetic acetabular lip which can be easily adapted to the patient.

[0026] The technical purpose indicated and the aims specified are substantially achieved by a method for making a synthetic acetabular lip and a semifinished product for making a synthetic acetabular lip comprising the technical features described in one or more of the appended claims. The dependent claims correspond to possible embodiments of the invention.

[0027] In particular, the technical purpose indicated and the aims specified are achieved by a method for making a synthetic acetabular lip. The method comprises a step of forming a semi-finished product extending longitudinally from a first to a second end (and having a transversal crosssection (constant or variable) shaped to match a corresponding crosssection of a human acetabular lip.

[0028] In accordance with an embodiment of the invention, the forming step is performed by means of process for removal of material, manual shaping or extrusion processing.

[0029] Alternatively, the forming step is performed by means of a 3D printing process, that is to say, by means of an additive manufacturing process.

[0030] Alternatively, the forming step comprises a step of preparing at least one mould which is open at the top.

[0031] According to an embodiment, the mould may be made Teflon.

[0032] For example, the mould has an elongate and rectilinear shape.

[0033] For example, the mould has a substantially rectangular shape. In this situation, a length of the mould is between 2mm and 220mm, preferably equal to 110mm, whilst a width of the mould is between 4 mm and 24mm, preferably equal to 14mm.

[0034] A seat extended longitudinally from a first to a second end is made on the mould, starting from a top surface.

[0035] The seat extends between the first and the second end, for example, by a length of between 5mm and 400mm, approximately equal to 100mm.

[0036] In other words, the top surface of the mould is “excavated” to make the seat.

[0037] In particular, the seat is made by means of a processing by removal of material. Preferably, the seat is made by milling. In this situation, the seat is made starting from the top surface of the mould towards the inside of the latter. The seat has a transversal cross-section shaped to match a corresponding cross-section of a human acetabular lip.

[0038] In other words, the seat follows or imitates, in transversal cross-section, the cross-section of a human acetabular lip.

[0039] According to the embodiment illustrated, in a transversal cross-section, the seat has a first rectilinear stretch and a second rectilinear stretch defining with the first rectilinear stretch a right angle.

[0040] The seat also has a third rectilinear stretch forming with the second rectilinear stretch a substantially right angle.

[0041] The term “substantially right angle” means that the third rectilinear stretch defines with the second rectilinear stretch an angle of between 80° and 95°.

[0042] The third rectilinear stretch extends substantially parallel to the first rectilinear stretch on the same side as the first rectilinear stretch.

[0043] The seat also has a fourth curved stretch, preferably defining an arc of a circle, joining the first rectilinear stretch to the third rectilinear stretch.

[0044] Alternatively, the seat could have, in a transversal cross-section, other shapes comprising at least one rectilinear stretch and at least one curved, concave or convex stretch.

[0045] The forming step comprises a step of filling the seat with a filling material.

[0046] The filling step may be performed, for example, by casting the filling material in the seat.

[0047] According to an aspect of the invention, the filler material is a silicone, for example a silicone of the VK100 type. It is important that the material used is flexible.

[0048] As an alternative to silicone, it is possible to use thermoplastic polymers which, however, result in a particularly rigid synthetic acetabular lip.

[0049] In general, the filling material is a biocompatible material.

[0050] Thus, the fact that the semi-finished product is made with excessive dimensions and then cut transversely allows the prosthesis to be adapted effectively and quickly, with an operation in a single step, without the need to generate a custom-made prosthesis.

[0051] The fact that the semi-finished product is made of flexible material (for example silicone) is advantageous because it facilitates adaptation of the synthetic lip to the implant seat. This contributes to making the solution particularly quick and convenient to use and is immediately available to the surgeon, as it is a “shelf-ready” solution; compared with the custom-made solutions there is no need for processing prior to manufacturing.

[0052] The method according to the invention is particularly convenient, because it allows the surgical operation to be performed in a single step, thanks to the flexibility of the material of the semi-finished product.

[0053] After the step of filling the seat, so that the filling material is level (or flush) with the top surface of the mould, it is levelled in such a way as to remove the excess material and form a smooth and flat upper surface (and coplanar with the top surface of the mould).

[0054] In other words, once the seat is filled, in order to remove the excess filling material, an action for levelling or flattening the filling material is performed in such a way as to define a smooth upper surface.

[0055] By way of a non-limiting example, the levelling sub-step may be performed using a trowel or a blade.

[0056] During the filling step, it is possible that part of the filling material escapes from the seat, depositing itself on the top surface of the mould. In this situation, in order to prevent the filling material deposited there from hardening, thus resulting in a synthetic acetabular lip having a burr, the method comprises a removal step wherein any filling material deposited on the top surface of the mould is removed.

[0057] By way of a non-limiting example, the removing step may be performed using a trowel, a blade or a scraper.

[0058] The removing step may be performed after the levelling step.

[0059] According to the preferred embodiment, the removing step occurs at the same time as the levelling step in which the filler material is levelled to form the smooth upper surface in the same plane as the top surface of the mould. In this situation, when the filling material in the seat is subjected to the levelling action, the filling material escaped from it and deposited on the top surface of the mould is removed.

[0060] For example, if the levelling occurs using a blade or a trowel, the latter is placed in contact with the top surface of the mould and moved from the first towards the second end of the seat (or vice versa) in such a way as to slide against the top surface of the mould. In this situation, whilst the material inside the seat is levelled, the material deposited outside it is removed.

[0061] In this way, the top surface of the mould is free of filling material and the seat is correctly filled.

[0062] The forming step then comprises a step of hardening the filling material in the seat in such a way as to obtain a semi-finished product having a transversal cross-section which follows the cross-section of a human acetabular lip.

[0063] According to an aspect of the invention, the hardening step may be performed at ambient temperature or by positioning the mould filled with filling material in a drying device in which the filling material is heated until it hardens.

[0064] Subsequently, there is a step of extracting the semi-finished product from the mould.

[0065] In this situation, a semi-finished product is obtained having a transversal cross-section which follows the cross-section of a human acetabular lip.

[0066] Preferably, the semi-finished product obtained has a length greater than the length of a normal human acetabular lip.

[0067] Preferably, the semi-finished product has a length of between 5 mm and 400mm, approximately equal to 100 mm. The semi-finished product also has a height of between 1 mm and 50 mm, for example equal to approximately 6 mm, and a width of between 0.1 and 50 mm, for example equal to approximately 6 mm.

[0068] After the forming step, regardless of the way it is performed (using the mould, 3D printing, extrusion and the like), the method comprises a step of obtaining a reference measurement and a step of cutting the semi-finished product along a direction perpendicular to a main direction of extension of the semi-finished product to obtain a synthetic acetabular lip with length equal to the reference measurement.

[0069] In other words, on the basis of the reference measurement, the semifinished product obtained is cut in such a way as to obtain a synthetic acetabular lip with desired length.

[0070] According to the preferred embodiment, the obtaining step is performed by acquiring a measurement data representing a length of a damaged portion of an acetabular lip of a patient.

[0071] In this situation, the reference measurement represents a length of a damaged portion of an acetabular lip of a patient. In this situation, the semi-finished product is cut by a length equal to the reference measurement in such a way that the piece of semi-finished product obtained in this way can be used to replace the damaged portion of the acetabular lip of the patient.

[0072] Advantageously, the method according to the invention allows semifinished products to be made from which it is possible to obtain (simply by cutting) synthetic acetabular lips with different lengths depending on the length of the damaged portion (and therefore to be replaced) of the patient being treated.

[0073] Advantageously, once the length of the synthetic acetabular lip necessary for the patient has been determined, the semi-finished product already available must only be cut in such a way as to obtain a piece of that length.

[0074] According to an embodiment of the method, it is possible to simultaneously make four semi-finished products. In this situation, the preparing step comprises a sub-step of preparing a first mould open at the top on which is made a seat extending longitudinally from a first to a second end. The seat has a transversal cross-section shaped to match a corresponding cross-section of a human acetabular lip.

[0075] The preparing sub-step also comprises a sub-step of preparing a second mould which is substantially identical to the first mould and a third mould, open at the top, on which two seats symmetrical to each other are made. The seats extend longitudinally from a first to a second end and have a transversal cross-section shaped to match a corresponding cross-section of a human acetabular lip.

[0076] The seats of the third mould are identical in terms of dimensions and shape of the transversal cross-section to the seats of the first and second mould.

[0077] The seats of the first, second and third moulds are made from consecutive surfaces of the respective moulds, in particular from respective top surfaces and from respective side surfaces perpendicular to the corresponding top surfaces.

[0078] The preparing step also comprises a sub-step of preparing a pair of containing elements, for example a pair of bars having the shape of a parallelepiped.

[0079] Subsequently, the preparing step comprises a sub-step of moving alongside each other the first, second and third mould in such a way that the third mould is interposed between the first and the second mould and a sub-step of moving one of the containing elements alongside the first mould and the other of the containing elements alongside the second mould.

[0080] During the moving alongside each other, the moulds are placed alongside each other in such a way that the seats are delimited laterally by a continuous side wall of the adjacent mould or of the containing element.

[0081] In other words, the seat of the first mould is delimited laterally by one of the containing elements. One of the two seats of the third mould is delimited laterally by the continuous side wall (that is to say, by the side wall opposite to the side wall where the seat of the first mould is made) of the first mould whilst the other seat of the third mould is delimited laterally by the continuous side wall (that is to say, by the side wall opposite to the side wall where the seat of the second mould is made) of the second mould. The seat of the second mould is delimited laterally by the other of the containing elements.

[0082] After the moving alongside, the preparing step comprises the sub-step of connecting the containment elements and the moulds in such a way as to create a single body.

[0083] In this way, by filling the seats with the filling material and proceeding as described above (that is, levelling the filling material and extracting the semi-finished products), four semi-finished products are obtained.

[0084] The technical purpose indicated and the aims specified are also achieved by a semi-finished product for making a synthetic acetabular lip. The semifinished product extends longitudinally between a first and a second end and has a transversal cross-section shaped to match a corresponding cross-section of a human acetabular lip.

[0085] The transversal cross-section comprises at least one rectilinear stretch and at least one curved stretch.

[0086] According to a possible embodiment, the semi-finished product comprises a first rectilinear stretch and a second rectilinear stretch defining a right angle with the first rectilinear stretch.

[0087] According to this embodiment, the semi-finished product comprises a third rectilinear stretch forming with the second rectilinear stretch a substantially right angle.

[0088] The term “substantially right angle” means that the third rectilinear stretch defines with the second rectilinear stretch an angle of between 80° and 95°.

[0089] The third rectilinear stretch extends substantially parallel to the first rectilinear stretch on the same side as the first rectilinear stretch.

[0090] Again according to the above-mentioned embodiment, the semi-finished product also comprises a fourth curved stretch, preferably defining an arc of a circle, joining the first rectilinear stretch to the third rectilinear stretch. The semi-finished product is made of biocompatible material, preferably silicone.

[0091] The semi-finished product has a length equal to, preferably greater than, the length of a human acetabular lip.

[0092] The semi-finished product has a length, measured between the first and the second end, of between 5 mm and 400 mm.

[0093] In this situation, depending on the extension of the damaged portion (and therefore to be replaced) of the acetabular lip of a patient, it is possible to obtain from the semi-finished product a piece of synthetic acetabular lip equal to the length necessary for replacement.

[0094] In this way, whilst the patient undergoes arthroscopy surgery in which the health of the acetabular lip is checked, it is possible, if necessary, to directly replace the damaged part simply by cutting the semi-finished product already available to the surgeon to measurement of the damaged part to be replaced.

[0095] Further features and advantages of the invention are more apparent in the non-limiting description which follows of a method for making a synthetic acetabular lip and a semi-finished product for making a synthetic acetabular lip.

[0096] Brief description of the drawings

[0097] The description is set out below with reference to the accompanying drawings which are provided solely for purposes of illustration without restricting the scope of the invention and in which:

[0098] Figure 1 is a perspective view of a hip of a patient showing an acetabular lip;

[0099] Figure 2 is a perspective view of the hip of Figure 1 in which a portion of the damaged acetabular lip is removed;

[0100] Figure 3 is a cross-section of the zone in which the damaged portion of the acetabular lip has been removed; Figure 4 is a perspective view of a semi-finished product for making a synthetic acetabular lip and a mould from which said semifinished product is made;

[0101] Figure 5 is a perspective view of a kit for simultaneously making four semi-finished products for making respective synthetic acetabular lips;

[0102] Figures 6A-6D show transversal cross-sections of the semi-finished product according to different embodiments.

[0103] Detailed description of preferred embodiments of the invention

[0104] The invention relates to a method for making a synthetic acetabular lip.

[0105] The method comprises a step of forming a semi-finished product 300 extending longitudinally from a first to a second end 300a, 300b.

[0106] The semi-finished product 300 has a transversal cross-section shaped to match a corresponding cross-section of a human acetabular lip “L”.

[0107] After the step of forming the semi-finished product 300, the method comprises a step of obtaining a reference measurement.

[0108] According to the preferred embodiment, the obtaining step comprises a sub-step of acquiring a measurement data representing a length of a damaged portion “P” (Figure 2) of an acetabular lip “L” of a patient.

[0109] Following the obtaining step, the method comprises a step of cutting the semi-finished product 300 along a direction perpendicular to a main direction of extension “X” of the semi-finished product 300 to obtain a synthetic acetabular lip with a length equal to the reference measurement. In this situation, on the basis of the length of the damaged portion “P” of an acetabular lip “L” of a patient, it is possible to cut from the semi-finished product 300 a corresponding portion in such a way that it can be used to replace the damaged portion “P”.

[0110] Advantageously, the semi-finished product 300 may be cut to the desired length in such a way as to obtain a synthetic acetabular lip of the necessary length.

[0111] According to a possible embodiment, the forming step is performed by means of a 3D printing process.

[0112] Alternatively, the forming step is carried out by means of a moulding process wherein material is cast in a mould to obtain the semi-finished product 300 following a human acetabular lip “L”, as described below.

[0113] In this situation, the step of forming the semi-finished product 300 comprises a step of preparing at least one mould 100 open at the top. According to the preferred embodiment, the mould 100 is made of Teflon. The mould 100 has an elongate and rectilinear shape.

[0114] The mould 100 has, for example, a substantially rectangular shape. In this situation, the length of the mould 100 is between 20mm and 220 mm, preferably equal to 110 mm, whilst the width is between 4 mm and 24 mm, preferably equal to 14 mm.

[0115] As shown in Figure 4, a seat 200 is made on the mould 100, starting from a top surface 100a, extending longitudinally from a first to a second end 200a, 200b.

[0116] According to a possible embodiment, the preparing step comprises a substep of making the seat 200 by means of a processing for removal of material, preferably by milling.

[0117] As shown in Figure 4, the seat 200 has a transversal cross-section shaped to match a corresponding cross-section of a human acetabular lip “L”.

[0118] In fact, as shown in Figure 3, the human acetabular lip “L” has, in crosssection, a shape following the seat 200 of the mould 100.

[0119] According to the embodiment illustrated, the seat 200 has a first rectilinear stretch “A” and a second rectilinear stretch “B” defining a right angle with the first rectilinear stretch “A”.

[0120] The seat 200 also has a third rectilinear stretch “C” forming with the second rectilinear stretch “B” a substantially right angle. The third rectilinear stretch “C” extends substantially parallel to the first rectilinear stretch “A” on the same side as the first rectilinear stretch “A” itself.

[0121] The seat 200 also has a fourth curved stretch “D”, preferably defining an arc of a circle, joining the first rectilinear stretch “A” to the third rectilinear stretch “C”.

[0122] Alternatively, the seat 200 may have a transversal cross-section having at least one rectilinear stretch and at least one curved, concave or convex stretch.

[0123] For example, Figures 6A-6D show transversal cross-sections of the semifinished product 300 matching the shape of the transversal cross-section of a corresponding seat 200.

[0124] In accordance with the embodiment illustrated, the forming step comprises a step of filling the seat 200 with a filling material, for example a biocompatible material.

[0125] According to an embodiment, the filler material is silicone, for example of the VK100 type.

[0126] At the end of the filling step, the seat 200 is filled with the filling material.

[0127] At the end of the filling step, the filling material dispensed in the filling step may be too much and create a sort of camber or overflowing from the seat 200.

[0128] However, in order to obtain a precise synthetic acetabular lip without processing burrs, it is best that, once the seat 200 is filled, the filling material defines a smooth upper surface coplanar with the top surface 100a of the mould 100. In this situation, the method comprises a step of levelling the filling material to form a smooth upper surface coplanar with the top surface 100a of the mould 100.

[0129] The levelling step may be performed, for example, by sliding a trowel in contact with the top surface 100a of the mould 100. In this situation, the trowel pulls the excess filling material with it, eliminating the camber to obtain a smooth and uniform surface.

[0130] In accordance with the embodiment illustrated, in which the formation of the semi-finished product 300 is performed by moulding with the mould 100, the method also comprises a removing step in which any filling material deposited on the top surface 100a of the mould 100 is removed.

[0131] According to the preferred embodiment, the removing step is simultaneous with the levelling step. In this situation, for example, when the trowel is made to slide in contact with the top surface 100a of the mould 100, it also pulls with it the filling material deposited on the top surface 100a of the mould 100, thus eliminating it.

[0132] Subsequently, the method comprises a step of hardening the filling material in the seat 200 in such a way as to obtain a semi-finished product 300 having a transversal cross section which follows the cross-section of a human acetabular lip “L” (Figure 4).

[0133] The method then comprises a step of extracting the semi-finished product 300 from the mould 200. The mould 200 may be re-used for making other semi-finished products 300.

[0134] According to an embodiment of the method (Figure 5), wherein the forming step is performed using moulds 100, it is possible to simultaneously make four semi-finished products 300. In this situation, the preparing step comprises a sub-step of preparing a first mould 400 open at the top on which a seat 200 is made extending longitudinally from a first to a second end 200a, 200b. The seat 200 has a transversal cross-section shaped to match a corresponding cross-section of a human acetabular lip “L”.

[0135] The preparing step also comprises a sub-step of preparing a second mould 500 substantially identical to the first mould 400 and a third mould 600 open at the top, on which two seats 200 symmetrical to each other are made. The seats 200 extend longitudinally from a first to a second end 200a, 200 and have a transversal cross-section shaped to match a corresponding cross-section of a human acetabular lip.

[0136] The seats 200 of the third mould 600 are identical in terms of dimensions and shape of the transversal cross-section to the seats 200 of the first and second mould 400, 500.

[0137] The seats 200 of the first, second and third moulds 400, 500, 600 are made starting from consecutive surfaces of the respective moulds 400, 500, 600, in particular from respective top surfaces 400a, 500a, 600a and from respective side surfaces perpendicular to the corresponding top surfaces 400a, 500a, 600a.

[0138] The preparing step also comprises a sub-step of preparing a pair of containment elements 700, for example a pair of bars having the shape of a parallelepiped.

[0139] Preferably, the first, second and third moulds 400, 500, 600 and the containing elements 700 are made of Teflon.

[0140] The preparing step comprises a sub-step of moving alongside each other the first, second and third moulds 400, 500, 600 in such a way that the third mould 600 is interposed between the first and the second moulds 400, 500 and a sub-step of moving one of the containing elements 700 alongside the first mould 400 and the other of the containing elements 700 alongside the second mould 500.

[0141] During the moving alongside each other, the moulds 400, 500, 600 are placed alongside each other in such a way that the seats 200 are delimited laterally by a continuous side wall of the adjacent mould or of the containing element 700.

[0142] In other words, as shown in Figure 5, the seat 200 of the first mould 400 is delimited laterally by one of the containing elements 700. One of the two seats 200 of the third mould 600 is delimited laterally by the continuous side wall (that is to say, by the side wall opposite to the side wall where the seat 200 of the first mould 400 is made) of the first mould 400 whilst the other seat 200 of the third mould 600 is delimited laterally by the continuous side wall (that is to say, by the side wall opposite to the side wall where the seat 200 of the second mould 500 is made) of the second mould 500. The seat 200 of the second mould 500 is delimited laterally by the other of the containing elements 700.

[0143] After the moving alongside, the preparing step comprises the sub-step of connecting the containment elements 700 and the moulds 400, 500, 600 in such a way as to create a single body.

[0144] In this situation, by filling the seats 200 with the filling material, levelling, drying and extraction, four semi-finished products 300 are obtained. This invention also relates to a semi-finished product 300 for making a synthetic acetabular lip extending longitudinally between a first and a second end 300a, 300b. The semi-finished product 300 has a transversal cross-section shaped to match a corresponding cross-section of a human acetabular lip “L” and comprising at least one rectilinear stretch and at least one curved stretch.

[0145] According to the embodiment illustrated in Figure 4, by way of a nonlimiting example, the semi-finished product 300 comprises in cross-section a first rectilinear stretch A’ and a second rectilinear stretch B’ defining a right angle with the first rectilinear stretch A’.

[0146] The semi-finished product 300 also comprises a third rectilinear stretch C’ defining with the second rectilinear stretch B’ a substantially right angle. The third rectilinear stretch C’ extends substantially parallel to the first rectilinear stretch A’ on the same side as the first rectilinear stretch A’. The semi-finished product 300 also has a fourth curved stretch D’, preferably defining an arc of a circle, joining the first rectilinear stretch A’ to the third rectilinear stretch B’.

[0147] Alternatively, the semi-finished product 300 may have, in a transversal cross-section, a shape according to those shown in Figures 6A-6D.

[0148] Preferably, the semi-finished product 300 has a length, measured between the first and the second ends 300a, 300b, of between 5 and 400 mm, for example equal to approximately 100 mm.

[0149] Preferably, the semifinished product 300 has a height of between 0.1 and 50 mm, for example equal to approximately 6 mm.

[0150] Preferably, the semi-finished product 300 has a width of between 0.1 and 50 mm, for example equal to approximately 6 mm.

[0151] The semi-finished product 300 is made of biocompatible material, preferably silicone. In this situation, the semi-finished product 300 has a rigidity consistent with the relative rigidity of a human acetabular lip “L” in such a way as to be able to adapt to the shape / curvature of the hip of the patient. The invention achieves the preset aims eliminating the drawbacks of the prior art.

[0152] In particular, the method for making a synthetic acetabular lip is fast, precise and practical. The method according to the invention makes the arthroscopy operation less invasive for the patient.

[0153] The semi-finished product for making a synthetic acetabular lip according to the invention allows a synthetic acetabular lip to be quickly obtained which can be easily adapted to the patient.

Claims

CLAIMS1. A method for making a synthetic acetabular lip, comprising the following steps:- forming a semiproduct (300) extending longitudinally from a first to a second end (300a, 300b), the semiproduct (300) having a transverse cross section that is shaped to match a corresponding cross section of a human acetabular lip (L);- cutting the semiproduct (300) along a direction perpendicular to a main direction of extension (X) of the semiproduct (300) to obtain a synthetic acetabular lip whose length is equal to a reference size.

2. The method according to claim 1 , comprising a step of obtaining the reference size by capturing a size data item representing a length of a damaged portion (P) of a patient's acetabular lip (L).

3. The method according to claim 1 or 2, wherein the step of forming is carried out through a 3D printing process.

4. The method according to claim 1 or 2, wherein the step of forming comprises the following steps:- providing at least one open-top mould (100), on the top surface (100a) of which a cavity (200) extending longitudinally from a first to a second end (200a, 200b) is made, the cavity (200) having a transverse cross section that is shaped to match a corresponding cross section of a human acetabular lip (L);- filling the cavity (200) with a filling material;- hardening the filling material in the cavity (200) so as to obtain a semiproduct (300) whose transverse cross section replicates the cross section of a human acetabular lip (L);- extracting the semiproduct (300) from the mould (100).

5. The method according to claim 4, wherein the step of forming comprises, after the step of filling, a step of levelling the filling material to define a smooth top surface coplanar with the top surface (100a) of the mould (100).

6. The method according to claim 5, wherein the step of forming comprises a step of removing in which any filling material deposited on the top surface (100a of the mould (100) is removed, the step of removing being simultaneous with the step of levelling.

7. The method according to any one of claims 4 to 6, wherein the step of providing comprises a sub-step of making the cavity (200) through a stock removal process, preferably milling.

8. The method according to any one of claims 4 to 7, wherein the mould (100) is made from teflon.

9. The method according to any one of claims 4 to 8, wherein the mould (100) has an elongated, rectilinear shape.

10. The method according to any one of the preceding claims, wherein the cavity (200), in a transverse cross section, comprises:- a first rectilinear stretch (A);- a second rectilinear stretch (B) at a right angle to the first rectilinear stretch (A);- a third rectilinear stretch (C) substantially at a right angle to the second rectilinear stretch (B), the third rectilinear stretch (C) extending substantially parallel to the first rectilinear stretch (A) on the same side as the first rectilinear stretch (A);- a fourth curved stretch (D), preferably defining a circular arc, joining the first rectilinear stretch (A) to the third rectilinear stretch (C).

11. The method according to any one of claims 4 to 10, wherein the step of providing comprises the following sub-steps:- providing a first open-top mould (400), on which a cavity (200) extending longitudinally from a first to a second end (200a, 200b) is made, the cavity (200) having a transverse cross section that is shaped to match a corresponding cross section of a human acetabular lip (L);- providing a second mould (500) substantially identical to the first mould;- providing a third open-top mould (600), on which two cavities (200) symmetrical to each other and extending longitudinally from a first to a second end (200a, 200b) are made, the cavities (200) having a transverse cross section that is shaped to match a corresponding cross section of a human acetabular lip (L);- providing a pair of containing elements (700);- juxtaposing the first, second and third mould (400, 500, 600) in such a way that the third mould (600) is interposed between the first and the second mould (400, 500);- juxtaposing one of the containing elements (700) to the first mould (400) and the other containing element (700) to the second mould (500); wherein the cavities (200) of the first, second and third mould (400, 500, 600) are made from consecutive surfaces of the respective moulds (400, 500, 600), in particular from respective top surfaces (400a, 500a, 600a) and from respective lateral surfaces perpendicular to the corresponding top surfaces (400a, 500a, 600a), and wherein in the step of juxtaposing, the moulds (400, 500, 600) are juxtaposed in such a way that the cavities (200) are laterally delimited by an uninterrupted side wall of the adjacent mould (400, 500, 600) or of the containing element (700).

12. The method according to any one of the preceding claims, wherein the semi-finished product (300) is made of silicone.

13. The method according to any one of the preceding claims, wherein the semi-finished product (300) has a length, measured between the first and the second ends (300a, 300b), of between 5 and 400 mm.

14. A semiproduct (300) for making a synthetic acetabular lip, extending longitudinally between a first and a second end (300a, 300b), the semiproduct (300) having a transverse cross section that is shaped to match a corresponding cross section of a human acetabular lip (L) and comprising at least acetabular lip one rectilinear stretch and at least one curved stretch.

15. The semiproduct according to claim 14, comprising:- a first rectilinear stretch (A');- a second rectilinear stretch (B') at a right angle to the first rectilinear stretch (A');- a third rectilinear stretch (C) substantially at a right angle to the second rectilinear stretch (B'), the third rectilinear stretch (C) extending substantially parallel to the first rectilinear stretch (A') on the same side as the first rectilinear stretch (A');- a fourth curved stretch (D'), preferably defining a circular arc, joining the first rectilinear stretch (A') to the third rectilinear stretch (C).

16. The semiproduct according to claim 14 or 15, having a length, measured between the first and the second end (300a, 300b), of between 5 and 400 mm.

17. The semiproduct according to any one of the preceding claims, wherein the semiproduct (300) is made from silicone.

18. A synthetic acetabular lip, comprising a semi-finished product according to any one of claims 14 to 17, cut transversely to a maindirection of extension (X) of the semi-finished product (300).

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