(19)
(11)EP 3 735 204 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
06.09.2023 Bulletin 2023/36

(21)Application number: 18839735.0

(22)Date of filing:  30.12.2018
(51)International Patent Classification (IPC): 
A61F 2/30(2006.01)
A61B 17/17(2006.01)
A61B 17/16(2006.01)
A61F 2/46(2006.01)
(52)Cooperative Patent Classification (CPC):
A61F 2/30756; A61B 17/1604; A61B 17/1615; A61B 17/1635; A61B 17/1659; A61B 17/17; A61B 17/1764; A61F 2/4618; A61B 2017/0046; A61F 2002/30759
(86)International application number:
PCT/IL2018/051413
(87)International publication number:
WO 2019/135216 (11.07.2019 Gazette  2019/28)

(54)

IMPLANTATION TOOL FOR OPTIMIZED SOLID SUBSTRATES PROMOTING CELL AND TISSUE GROWTH

IMPLANTATIONSWERKZEUG FÜR OPTIMIERTE SOLIDE SUBSTRATE ZUR FÖRDERUNG VON ZELL- UND GEWEBEWACHSTUM

OUTIL D'IMPLANTATION POUR SUBSTRATS SOLIDES OPTIMISÉS FAVORISANT LA CROISSANCE CELLULAIRE ET TISSULAIRE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 02.01.2018 US 201862612735 P
21.12.2018 US 201862783221 P

(43)Date of publication of application:
11.11.2020 Bulletin 2020/46

(73)Proprietor: Cartiheal (2009) Ltd.
Kfar Saba 4464313 (IL)

(72)Inventor:
  • ALTSCHULER, Nir
    4580800 Tzur Yitzchak (IL)

(74)Representative: Wohlfahrt, Jan Günther et al
Gleiss Große Schrell und Partner mbB Patentanwälte Rechtsanwälte Leitzstraße 45
70469 Stuttgart
70469 Stuttgart (DE)


(56)References cited: : 
US-A- 5 490 852
US-A1- 2014 065 573
US-A1- 2013 006 248
US-A1- 2017 281 198
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    BACKGROUND OF THE INVENTION



    [0001] Tissue growth, regeneration and repair are often necessary to restore function and reconstruct the morphology of the tissue, for example, as a result of exposure to trauma, neoplasia, abnormal tissue growth, aging, and others. The closest prior art to the present invention is disclosed in document US 2017/0281198 A1, which defines the preamble of claim 1.

    [0002] Articular cartilage is a highly specialized tissue that covers the surfaces of long bones to allow almost frictionless motion under large loads. In the healthy skeleton, this articulating function allows bones to change their relative angular relationship about a joint, as in the hip and the knee joints. This function of joints occurs painlessly and virtually without additional effort due to the low friction of mating joint surfaces which arises from the properties of the synovial fluid within the joint, and the smooth topography of the cartilage surfaces.

    [0003] A number of diseases/conditions arise due to cartilage damage, which may range from localized tears, to focal areas of loss of coverage of the underlying bone, to degenerative conditions, such as osteo- and rheumatoid arthritis in which the entire cartilage layer and underlying (subchondral) bone can be affected. Generalized or degenerative conditions, most commonly osteoarthritis, are frequently treated with total joint replacement in which the cartilage surface and underlying bone are completely replaced with artificial materials that articulate with minimal friction.

    [0004] Synthetic materials have been used as a substrate for promoting ex-vivo tissue assembly and repair, and similarly for restoring and reconstructing such tissues, for example for bone, for many years, with mixed success.

    [0005] Another possibility is autologous tissue grafting, although the supply of autologous tissue is limited and its collection may be painful, with the risk of infection, hemorrhage, cosmetic disability, nerve damage, and loss of function. In addition, significant morbidity is associated with autograft harvest sites. These problems may be overcome by engineering tissue using solid substrates made of synthetic or natural biomaterials that promote the adhesion, migration, proliferation, and differentiation of stem cells, for example, mesenchymal stem cells (MSCs).

    [0006] Many diseases and conditions whose treatment is sought would benefit from the ability to promote cell and tissue growth in a site-specific manner, promoting growth and incorporation of new tissue within a damaged or diseased site.

    [0007] In bone and cartilage applications, the immediate microenvironment and the three-dimensional (3D) organization are important factors in differentiation in general and particularly in chondrogenic and osteogenic differentiation.

    [0008] Some bone tissue engineering scaffolds consists of natural polymers, such as collagen, alginate, hyaluronic acid, and chitosan. Natural materials offer the advantages of specific cell interaction, easy seeding of cells because of their hydrophilic interactions, low toxicity and low chronic inflammatory response. However, these scaffolds often are mechanically unstable and do not readily contribute to the creation of tissue structures with a specific predefined shape for transplantation. To obtain mechanical strength, chemical modification is required, which may lead to toxicity.

    [0009] Defects and degeneration of the articular cartilage surfaces of joints causes pain and stiffness. Damage to cartilage which protects joints can result from either physical injury as a result of trauma, sports or repetitive stresses (e.g., osteochondral fracture, secondary damage due to cruciate ligament injury) or from disease (e.g. osteoarthritis, rheumatoid arthritis, aseptic necrosis, osteochondritis dissecans).

    [0010] Osteoarthritis (OA) results from general wear and tear of joints, most notably hip and knee joints. Osteoarthritis is common in the elderly but, in fact, by age 40 most individuals have some osteoarthitic changes in their weight bearing joints. Another emerging trend increasing the prevalence of osteoarthritis is the rise in obesity. The CDC estimates that 30% of American adults (or 60 million people) are obese. Obese adults are 4 times more likely to develop knee OA than normal weight adults Rheumatoid arthritis is an inflammatory condition which results in the destruction of cartilage. It is thought to be, at least in part, an autoimmune disease with sufferers having a genetic predisposition to the disease.

    [0011] Orthopedic prevention and repair of damaged joints is a significant burden on the medical profession both in terms of expense and time spent treating patients. In part, this is because cartilage does not possess the capacity for self-repair. Attempts to re-grow hyaline cartilage for repair of cartilage defects remain unsuccessful. Orthopedic surgery is available in order to repair defects and prevent articular damage in an effort to forestall serious degenerative changes in a joint. The use of surgical techniques often requires the removal and donation of healthy tissue to replace the damaged or diseased tissue. Techniques utilizing donated tissue from autografts, allografts, or xenografts are wholly unsatisfactory as autografts add additional trauma to a subject and allografts and xenografts are limited by immunological reactivity to the host subject and possible transfer of infective agents. Surgical attempts to utilize materials other than human or animal tissue for cartilage regeneration have been unsuccessful.

    [0012] As each joint is unique in terms of the geometry of its articulating surfaces, another challenge in successful grafting/implantation has been deemed the requirement for a most perfect topographic match as attainable.

    [0013] An ideal means and materials restoring tissue function and facilitating reconstruction of the morphology of such tissue is as yet, lacking.

    SUMMARY OF THE INVENTION



    [0014] The present invention is defined in claim 1.

    [0015] As is described herein, for example, with regard to Figures 1A-1S, unexpected superior healing and/or bone regeneration and/or greater chondrogenesis was found with the application of optimally selected solid substrates specifically implanted within a site of tissue repair in a press fit/fight fit with respect to the length and width of the implantation site, yet the height of the solid substrate is approximately 2 mm below the articular cartilage layer in cartilage tissue proximal to the site of implantation. Figure 3 specifically demonstrates improved healing and articular cartilage regeneration at the apical region above the implantation site, as a consequence of the methods of implantation as described and exemplified herein. In some aspects, the tools and protocols to accomplish same are exemplified with respect to the description of Figures 1A-1S, and in some aspects, the cartilage cutter as herein described is uniquely adapted to perfect the methods/uses of this invention promoting ideal cartilage trimming to achieve the ability to position the solid substrate in a press fit/tight fit manner, and 2 mm below the articular cartilage layer in cartilage tissue proximal to the site of implantation.

    [0016] In some aspects, and representing embodiments of this invention, the cartilage cutter head region connects to the elongated handle portion for ease of gripping, which in some aspects is ergonomic. In some aspects, the cartilage cutter head region basal portion inserts within an implantation site; and is angled by means of the first and second angled side regions of the head region, which angled side regions taper from the apical portion toward said basal portion; and such tapering promotes a proper fit within the implantation site being produced for insert of a tapered solid substrate therewithin.

    [0017] It will be understood that the term "tapered" with respect to elements of the cartilage cutter refers to the incremental angling or taper with respect to a longitudinal axis through such implantation site.

    [0018] The first angled side region of the cartilage cutter head region will further comprise a tapered blade surface and a supporting tapered angled surface opposingly positioned to the tapered blade surface; and a hollowed region located therebetween. As will be appreciated by the skilled artisan, such arrangement of the tapered blades surface, supporting tapered angled surface opposingly positioned to the tapered blade surface; and hollowed region located therebetween facilitates insertion of the tissue in contact with the tapered blade surface and cut thereby therewithin and further regulates the thickness of the tissue being cut thereby for insertion within said hollowed region.

    [0019] In some embodiments, the interior region between said first and second angled side regions is substantially hollowed, or in some embodiments, the interior region between said first and second angled side regions is substantially solid but contains a hollowed region into which the cut tissue may insert.

    [0020] In some embodiments, the basal surface of the cartilage cutter head region is substantially flat or in some embodiments, is ensured to smoothly insert within the implantation site so that insertion of the cartilage cutter within the implantation site does not in any way negatively impact insertion of the solid substrate within the implantation site..

    [0021] In some embodiments, the cartilage cutter handle contains an elongated portion to be comfortably gripped by the user and in some embodiments, the handle has a grip surface and in some embodiments, the elongated handle is constructed to be ergonomic. In some embodiments, the elongated handle may be removably attached to said head region. For example and referring to Figure 5F, the handle may be removable by adaptation of the connector region of the handle and head region.

    [0022] The skilled artisan will appreciate that various permutations/solutions may be devised to removably connect the head region and handle, and the connection point may be at any appropriate location, such as, for example, immediately proximal to the head region, or at a reasonable distance from the base of the head region, etc.

    [0023] In some embodiments the head region is scalable to accommodate a range in dimensions of a tissue site where cartilage cutting is desired.

    [0024] The invention may be provided by a kit of parts comprising the cartilage cutter as herein described. For example, the tools depicted in Figures 1A-1S may all be provided in a single kit or select tools from the complement of tools depicted in Figures 1A - 1S may be provided as part of a kit, and same is envisioned as an embodied aspect of the subject application.

    [0025] The invention may be used in a method for optimal implantation of a solid substrate for promoting cell or tissue growth or restored function for the treatment of osteoarthritis, bone disorders, osteochondral defects, or cartilage lesions in a subject in need thereof, said method comprising:
    • selecting and preparing a solid substrate for the treatment of or promoting cell or tissue growth or restored function for stable implantation in a region traversing bone and cartilage in a subject, which solid substrate has a length and width or that promotes a tight fit within the boundaries of the implantation site and is further characterized by a height sufficient such that when a first terminus of said solid substrate is implanted within bone in a site for implantation, a second terminus of said solid substrate is at a height at least 2 mm less than an articular cartilage layer surface or proximal to a tide mark region in said implantation site;
    • implanting said selected and prepared solid substrate within a site for implantation to span a basal to apical long axis of said site for implantation, wherein a first terminus of said implant is implanted within bone at the basal surface and a second terminus is oriented apically such that said second terminus is at a height at least 2 mm less than an articular cartilage layer surface or is proximal to a tide mark region in said implantation site such that a void is formed between an apical surface of said substrate and an articular cartilage layer; wherein said site of implantation has been prepared for insertion of said solid substrate by creating a void of desired dimensions in terms of depth, length and width, and the side walls of the site for implantation have been created to contain a taper, and cartilage tissue within said site for implantation has been removed with the aid of the cartilage cutter as herein described, and optionally
    • applying a biocompatible polymer layer or hydrogel or therapeutic compound or cell population or combination thereof, to an apical surface of said implant to fill said void formed between said second terminus and said articular cartilage layer surface.


    [0026] Where number ranges are given in this document, endpoints are included within the range. Furthermore, it is to be understood that unless otherwise indicated or otherwise evident from the context and understanding of one of ordinary skill in the art, values that are expressed as ranges can assume any specific value or sub-range within the stated ranges, optionally including or excluding either or both endpoints, in different embodiments of the invention, to the tenth of the unit of the lower limit of the range, unless the context clearly dictates otherwise. Where a percentage is recited in reference to a value that intrinsically has units that are whole numbers, any resulting fraction may be rounded to the nearest whole number.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0027] 

    Figures 1A-1S schematically depict a generalized procedure for preparing a defect site for implantation. Figures 1A-1E depict applying an implantation alignment tool 1-10 and inserting therethrough a rod-like structure 1-20, therethrough, at an angle essentially 90 degrees/perpendicular to the tissue surface, whereby the rod-like structure is the drilled into the underlying subchondral bone 1-30 (Figure 1D) and the alignment tool may contain markings 1-50 (Figure 1D) serving as indicator for the depth at which the rod-like structure may be drilled/advanced therein and subsequent removal of the alignment tool. Figures 1F-1H depict drilling/expanding the site for implant insertion. A drill sleeve 1-60 is placed over the rod-like structure 1-20, with the sleeve potentially/optionally containing a terminus adapted to insert stably in the underlying tissue and a specialized drill, may be adapted to promote/facilitate rotation of a drill bit 1-70 while placed over the rod-like structure (Figure 1E), but within the drill sleeve 1-60. The drill bit and drill sleeve are then removed (Figure 1H), while the rod-like structure is maintained in place, embedded in the subchondral bone.

    Figures 1I through 1L depict use of a tissue reamer 1-80, which may be rotated as depicted in Figure 1J, with the terminal modifications of the reamer expanding/enlarging the walls of the implantation site within the cartilage and subchondral bone and subsequent removal (Figure 1L) of the reamer followed by tissue site washing, as depicted in Figure 1M. Figures 1N-1Q depict use of a tissue shaper. The tissue walls of the implant may be further processed, using a tissue shaper 1-110, and following completion of the tissue shaping, the shaper, as well may be removed from the site, as depicted in Figure 1Q, followed by washing of the tissue site, as depicted in Figure 1R and the tissue site may be shaped/smoothed/expanded or further shaped/smoothed/expanded with the aid of a cartilage cutter (depicted in Figure 1S) as described further herein or scalpel or other appropriate tool 1-120.

    Figures 2A-2D schematically depict first introduction of an implant in a site in need of osteochondral repair, or bone repair or cartilage repair. The implant 2-130 is inserted in the prepared tissue site manually, as depicted in Figure 2B, pressed to fit therein as depicted in Figure 2C so that the implant is initially introduced/placed within the site of repair as depicted in Figure 2D. A tamper 2-140 as depicted in Figure 2E and 2F is then used to further advance the implant in the site of desired repair, to further advance the implant in a press fit manner, such as that depicted in Figure 2H facilitates implant insertion to the bone in the defect site, where the upper boundary of the implant is no longer flush with the articular cartilage layer, but instead is approximately 2mm below the articular cartilage surface. Figures 2J-2K depict the application of a biocompatible/therapeutic polymer composition to the apex of the implant 2-160 with a syringe 2-170. Figure 2I depicts implantation of more than one solid substrate 2-130, as described. Figure 2L shows a transverse section through the region in Figure 2G of implantation of the substrate at within bone and that the implant spans apically to a region about 2 mm lower than the articular cartilage surface layer.

    Figure 3A-3C describe MRI results of human patients participating in a clinical trial showing full thickness regeneration of the articular cartilage surface in the subjects following their treatment by the embodied methods of this invention.

    Figure 4A-4H describe comparative results of two patients in whom a solid substrate was implanted, and demonstrating unexpectedly superior results in a patient treated according to an embodied method of this invention. Figures 4A-4D, as compared to Figures 4E-4H, demonstrate healing of a defect site, but without reformation of a tidemark and full cartilage thickness in the region most proximal to the implantation site.

    Figure 5A-5I describes the cartilage cutter and highlights certain key features of same.


    DETAILED DESCRIPTION OF THE PRESENT INVENTION



    [0028] This invention provides, inter alia, a cartilage cutter as defined in claim 1.

    [0029] The terms "treating" and "treatment" when used in connection with a disease or condition refer to executing a protocol that may include a cartilage, bone and/or osteochondral repair procedure, in an effort to alleviate signs or symptoms of the disease or condition or immunological response. Alleviation can occur prior to signs or symptoms of the disease or condition appearing, as well as after their appearance. Thus, treating or treatment includes preventing or prevention of disease or undesirable condition. In addition, treating, treatment, preventing or prevention do not require complete alleviation of signs or symptoms, does not require a cure, and specifically includes protocols that have only a marginal effect on the patient. In some embodiments, the bone, cartilage and/or osteochondral repair implant can be used to treat subchondral, osteochondral, or cartilage defects.

    [0030] The term "subchondral" includes an area underlying the articular cartilage. The term "subchondral bone" includes a layer of bone just below a zone of cartilage. "Osteochondral" includes a combined area of cartilage and bone where a lesion or lesions can occur. "Osteochondral defect" includes a lesion which is a composite lesion of cartilage and subchondral bone. "cartilage" includes cartilage containing groups of isogenous chondrocytes located within lacunae cavities which are scattered throughout an extracellular collagen matrix.

    [0031] Methods/uses/tools/kits are described that improve bone, cartilage and/or osteochondral repair. Through the methods as described herein for implantation of the described substrate, the growth of bone, cartilage and/or related tissue may be facilitated particularly when repairing bone, cartilage and/or osteochondral defects.

    [0032] In some embodiments, methods of implantation of solid substrates for the treatment of bone, cartilage and/or osteochondral repair are provided, comprising a tissue scaffold configured to allow growth of at least bone and/or cartilage.

    [0033] The tissue scaffolds provides a matrix for the cells to guide the process of tissue formation in vivo in three dimensions. The morphology of the scaffold guides cell migration and cells are able to migrate into or over the scaffold, respectively, and the creation of a discrete void in the cartilage layer above the solid substrate, for example for application of the hydrogel or therapeutic solution incorporation reduces inflammation/irritation at the implantation site and/or otherwise promotes incorporation of the implant, regeneration of cartilage and/or bone tissue and/or healing at the site.

    [0034] Such method for optimal implantation of a solid substrate for promoting cell or tissue growth or restored function in an osteochondral, bone or cartilage tissue in a subject in need thereof comprises the step of selecting and/or preparing a solid substrate for promoting cell or tissue growth or restored function for implantation, which solid substrate has a length and width or that promotes a tight fit within the boundaries of the length and width of the implantation site and is further characterized by a height sufficient such that when a first terminus of said solid substrate is implanted within bone in the implantation site, a second terminus of said solid substrate is at a height at least 2 mm less than an articular cartilage layer surface or is proximal to a tide mark region in said implantation site.

    [0035] The method comprises the step of implanting a solid substrate within a site for implantation to span a long axis of said site for implantation, wherein a first terminus of said implant is implanted within bone and a second terminus is oriented apically such that said second terminus is at a height at least 2 mm less than an articular cartilage layer surface or is proximal to a tide mark region in said implantation site.

    [0036] It will be understood that reference to the term "tide mark" is meant to convey the plain and conventional meanings of same. For example, and in some embodiments, the term "tide mark" encompasses the layer of calcified cartilage separating hyaline cartilage from bone in a joint. In some aspects, the term "tide mark" is meant to refer to the calcified cartilage layer attaching hyaline cartilage to bone. In some aspects, reference to the term "tide mark" is with regard to the boundary line between the calcified cartilage and hyaline cartilage. In some aspects, the term "tide mark" refers broadly to the entire region of tissue bridging the cartilage to bone tissues in a joint.

    [0037] It will be further appreciated that the methods/uses and means contemplate implantation of the solid substrate as described, where an apical surface of the substrate reaches to the lower 1/3 of the cartilage layer into which the substrate is being implanted.

    [0038] For example, if the cartilage layer is thicker, then implantation may be such that the apical region of the substrate is more than 2 mm from the articular cartilage surface. Implantation may occur at or near the tidemark, and the implant may be within the lower third of the cartilage layer and the upper two thirds of the cartilage layer are open to the environment and same may be a height of more than 2 mm. For example, if the cartilage layer is thinner, then implantation may be such that the apical region of the substrate is less than 2 mm from the articular cartilage surface. Implantation may occur at or near the tidemark, and the implant may be within the lower third of the cartilage layer and the upper two thirds of the cartilage layer are open to the environment and same may be a height of less than 2 mm.

    [0039] It will be appreciated that the invention contemplates means where the solid substrate is implanted within bone spanning upward toward the cartilage layer, whereby the apex of the implant is: 1) at least 2 mm below the articular cartilage layer; or 2) at or proximal to the tidemark; or 3) within the lower 1/3 of the full cartilage tissue proximal to the site of implantation and all of the above are to be considered envisioned embodiments of the invention.

    [0040] Tools for use with the implants/solid substrates and methods/uses of this invention include those as described in PCT International Patent Application Publication Number 2014/072982. Tools may be modified to in turn comprise/accommodate a surface characterized by a radius of curvature, which radius of curvature may be substantially similar to a radius of curvature of a tissue surface to which a tool and/or solid substrate as herein described is being applied. Referring to Figure 1, the tools may comprise an implantation alignment tool 1-10 placed over the site of desired implantation, to promote insertion of a rod-like structure therethrough to within the tissue site of repair at an angle essentially 90 degrees/perpendicular to the tissue surface, which, in turn may attach to a drill and thereby be drilled into the underlying subchondral bone. A specialized drill, such as, for example, as described in WO 2014/072982, may be adapted to promote/facilitate rotation of a drill bit while placed over the rod-like structure but within the drill sleeve. A tissue reamer may be further applied and applied over the K-wire, and rotated to expand/enlarge the walls of the implantation site within the cartilage and subchondral bone. The tissue walls of the implant may be further processed, e.g. further smoothed using a tissue tapered shaper, which in turn may also insert over the rod-like structure, and rotated to smooth the tissue walls of the implantation site.

    [0041] The tissue site may be shaped/smoothed/expanded or further shaped/smoothed/expanded with the aid of a cartilage cutter 1-120 or scalpel or other appropriate tool. The cartilage cutters of this invention comprise a head region and elongated body connected thereto, whereby the elongated body promotes proper grasping of the cartilage cutter tool.

    [0042] A cartilage cutter according to the invention is defined in claim 1.

    [0043] The basal surface is substantially flat. In some embodiments, the interior region between said first and second angled side regions is substantially hollowed, or in some embodiments, the interior region between said first and second angled side regions is substantially solid but contains a hollowed region into which the cut tissue may insert.

    [0044] In some embodiments, the elongated handle has a grip surface and in some embodiments, the elongated handle is constructed to be ergonomic. In some embodiments, the elongated handle may be removably attached to said head region.

    [0045] In some embodiments the head region is scalable to accommodate a range in dimensions of a tissue site where cartilage cutting is desired.

    [0046] Figures 1A-1S illustrate methods and tools for preparing a tissue site for implantation in a site in need of osteochondral repair. Importantly, as noted in the methods as described herein, the tissue site preparation includes creating a smooth site of insertion promoting insertion of a therapeutic implant, which penetrates to the underlying bone.

    [0047] The term "comprise" or grammatical forms thereof, refers to the inclusion of the indicated components of this invention, as well as inclusion of other active agents, and pharmaceutically acceptable carriers, excipients, emollients, stabilizers, etc., as are known in the pharmaceutical industry.

    [0048] The term "about" refers to a variance of from 1- 10%, or in another embodiment, 5 - 15%, or in another embodiment, up to 10%, or in another embodiment, up to 25% variance from the indicated values, except where context indicates that the variance should not result in a value exceeding 100%.

    [0049] The term "a combined preparation" defines especially a "kit of parts" in the sense that the combination partners as defined above can be used independently or in different combinations i.e., simultaneously, concurrently, separately or sequentially.

    [0050] While the invention will be described in conjunction with the illustrated embodiments, it will be understood that they are not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover all alternatives within the scope as defined by the appended claims.

    EXAMPLES


    EXAMPLE 1


    Optimized Methods of implantation of Solid Substrates



    [0051] A variety of tools and implants are envisioned for use for implantation in osteochondral defects, and are to be considered as equivalents for use in the methods/processes of this invention.

    [0052] A generalized procedure for preparing a defect site 1-05 is described by Figures 1A-1S. In this illustrated process, an osteochondral defect in a condyle is treated. As a first step, a region in need of osteochondral repair is exposed, via conventional means. Prior to implantation of the osteochondral inductive implant, the implantation site is prepared. As a first matter, and as described in WO 2014/072982, an implantation alignment tool 1-10 is placed over the site of desired implantation, which tool promotes insertion of a rod-like structure, such as a k-wire 1-20, therethrough, for insertion within the tissue site of repair at an angle essentially 90 degrees/perpendicular to the tissue surface. Figure 1B depicts the ability to attach the rod-like structure within a drill, for insertion in the lumen 1-40 of the implantation alignment tool (Figure 1C). The rod-like structure is the drilled into the underlying subchondral bone 1-30 (Figure 1D) and the alignment tool may contain markings 1-50 (Figure 1D) serving as indicator for the depth at which the rod-like structure may be drilled/advanced therein.

    [0053] Once the rod-like structure 1-20 is secured, the implantation alignment tool 1-10 may be removed, leaving the rod-like structure embedded through the cartilage and within the subchondral bone at the site of desired repair. For proper insertion of a therapeutic implant, the region of tissue into which an implant will be inserted needs to be vacated and appropriately prepared for insertion of an implant therein. Toward this end, the implantation site may be properly exposed via drilling/expanding the site for implant insertion.

    [0054] Figure 1F depicts placement of a drill sleeve 1-60 over the rod-like structure 1-20, with the sleeve potentially/optionally containing a terminus adapted to insert stably in the underlying tissue. A specialized drill, such as, for example, as described in WO 2014/072982, may be adapted to promote/facilitate rotation of a drill bit 1-70 while placed over the rod-like structure (Figure 1E), but within the drill sleeve 1-60. The drill bit and drill sleave are then removed (Figure 1H), while the rod-like structure is maintained in place, embedded in the subchondral bone.

    [0055] Thus, an expanded insert site is created/drilled in the underlying defect site through the cartilage and within the bone, creating an insertion region there through within the bone . While drilling alone may be sufficient, it is possible that additional processing/smoothing of the tissue circumference surrounding the implantation site is needed/desired. Toward this end, and also as described in WO 2014/072982, it may be desired to apply a tissue reamer 1-80 as depicted in Figures 1I-1L.

    [0056] The reamer 1-80 is applied over the K-wire, as depicted in Figure 1I and upon accommodation within the drilled exposed site of repair, the reamer may be rotated as depicted in Figure 1J, with the terminal modifications of the reamer thereby expanding/enlarging the walls of the implantation site within the cartilage and subchondral bone. The reamer may further contain an indicator line 1-85, which provides a measure of depth for insertion and preparing of the tissue. For example, and as depicted in Figure 1K when implanting within a central trochlear lesion, the indicator line reaches the articular surface level of the sulcus, for best insertion therein. Upon completion of the tissue modification, the reamer is removed (Figure 1L) and the tissue site may be washed, e.g. with saline, via use of a syringe 1-100, as depicted in Figure 1M.

    [0057] The tissue walls of the implant may be further processed, e.g. further smoothed using a tissue tapered shaper 1-110, which in turn may also insert over the rod-like structure Figure 1N. Similar to that achieved with the tissue reamer, rotation of the tissue shaper (Figure 1O) may smooth the tissue walls of the implantation site, and the shaper may as well have an indicator line 1-115, to apprise the user of the appropriate depth for insertion (Figure 1P). Upon completion of the tissue shaping, the shaper, as well may be removed from the site, as depicted in Figure 1Q.

    [0058] The tissue site may again be washed, e.g. with saline, via use of a syringe 1-100, as depicted in Figure 1R and the tissue site may be shaped/smoothed/expanded or further shaped/smoothed/expanded with the aid of the cartilage cutter 1-120 or in some examples, with the aid of a scalpel or other appropriate tool.

    [0059] Thus Figures 1A-1S describe certain embodied methods and tools for preparing a tissue site for implantation in a site in need of osteochondral repair. Importantly, as noted in the methods as described herein, the tissue site preparation includes creating a smooth site of insertion promoting insertion of a therapeutic implant, which penetrates to the underlying bone.

    [0060] It will be appreciated that any of the tools may be so constructed to allow for a common handle to attach to the tool, for example, being adapted for a screw in or snap connection. In some aspects, such handle may be of ergonomic design to promote ideal manipulation of the tool.

    [0061] Figures 5A-5E show an enlarged view and highlight additional features of the cartilage cutter 1-120 according to the invention and as depicted in Figure 1S. The cartilage cutter 5-120 contains an elongated body comprising a handle portion 5-230 and a head portion 5-220. In some aspects the cutter handle may comprise a rough surface (knerling) to prevent slipping of the fingers when grasping the tool. The skilled artisan will appreciate that any appropriate material may be used in the construction of the elongate body and/or hand portion of the device.

    [0062] The cartilage cutter 5-120 head portion 5-220 is so constructed to provide an angled insertion region facilitating insertion of the head within the implantation site (Figures 5A-5I). The head portion 5-220 is further adapted to contain a blade edge 5-250, which as the cutter is rotated within the site, promotes the ability to trim the cartilage around the circumference of the hole/implantation site created. This ensures that any cartilage remnants protruding in the implantation site can be cut away with a safe and precision tool. The head region containing the blade edge 5-250 is so constructed to contain a region wherein the cut cartilage can insert therethrough 5-240 during cutting. Essentially the width between supporting part 5-260 and the blade edge 5-250 provides a hollowed groove through which the cut cartilage can insert 5-240 and be advanced as trimming is accomplished, in some embodiments circumferentially. The supporting part 5-260 is positioned opposingly to said blade edge 5-250, as is evident in Figures 5B, 5E, etc..

    [0063] An second tapered surface 5-270 is shown, which may in some embodiments be smooth to ensure smooth trimming as the tool is rotated in the implantation site, and angled comparably to the blade-containing part angle.

    [0064] In some aspects the second tapered surface 5-270 is flat but this is optional. The second tapered surface and overall dimensions and geometry of the cartilage cutter are so chosen/constructed to ensure ideal positioning of the cutter so that the blade surface is best positioned to trim the circumference of the implantation site for ideal insertion of the implant.

    [0065] In some aspects, the interior 5-280 of the cartilage cutter is hollowed and in some aspects the interior 5-280 is filled. In some embodiments, the hollowed interior 5-280 facilitates easier and cleaner trimming of the cartilage, which may rotatingly insert therein during use. In some embodiments, the hollowed interior 5-280 facilitates ease of visualization of the implantation site on all sides during the trimming process (See Figures 5B, and a rotated view of Figure 5B presented in Figure 5E).

    [0066] The cutter head 5-220 may be so adapted to accommodate replaceable blade containing parts, or in some embodiments, the cutter head itself 5-220 may be replaceable (Figure 5F). Referring to Figure 5C and Figure 5D, the cutter head 5-220 may be adapted so that a blade-containing edge 5-250 part assembles onto the cutter head 5-220, to add the blade surface 5-250 whereas the head portion connected to the handle portion 5-230 contains the opposing supporting surface 5-260 and groove 5-240 into which the trimmed cartilage inserts, and the second tapered edge 5-270 may snap onto a similar tapered edge on the cutter head 5-220, so that only the blade containing part is replaced, exchanged. It will be apparent to the skilled artisan that other means of blade-edge specific replacement are considered, for example, similar to blade exchange on scalpel handles, and other configurations, as well.

    [0067] In some aspects, the cutter head 5-220 is attachable to the cutter handles 5-230, for example as depicted in Figure 5F, and any connecting system, e.g. snap connectors, screw-type arrangement and others is envisioned.

    [0068] Figures 5G 5I depict various implantation sites, which may vary in size, for example, in terms of the depth and width of same and that the cartilage cutter 5-120, and in particular the dimensions of the cartilage cutter head portion 5-220 may be varied/adjusted in terms of overall size to suit application to a given implantation site, for optimal trimming of the cartilage.

    [0069] Figures 2A-2D depict first introduction of an implant in a site in need of osteochondral repair, or bone repair or cartilage repair.

    [0070] The implant 2-130 may be inserted in the prepared tissue site manually, as depicted in Figure 2B, pressed to fit therein as depicted in Figure 2C so that the implant is initially introduced/placed within the site of repair as depicted in Figure 2D, where an upper boundary of the implant is essentially flush with or slightly raised above the articular cartilage surface.

    [0071] While any appropriate implant for same is envisioned for use, in this embodied aspect, the implant as described in WO 2016/178226 is considered for use, in particular. The tools for use in preparing the site for implantation, as well, as described in WO 2016/178226 may be used to prepare the site for implantation, but in accordance with the methods of this invention, care is taken to ensure that site preparation includes the ability to implant a therapeutic solid substrate within a site of repair, whereby the implant apically abuts or reaches the tide mark, as herein described.

    [0072] Similarly, any therapeutic implant is envisioned for use, for example, as described in U.S. 8,932,581 or U.S. 8,808,725, or U.S. 8,790,681 or WO 2014/125478.

    [0073] A tamper 2-140 such as depicted in Figure 2E and 2F may be further used which tamper contains modified termini 2-150 that when used to further advance the implant in the site of desired repair, mitigate any damage to the implant. For example, the termini may be comprised of a durable silicon, such that same provides a non-stick, protective surface when applied to the implant, whereby applying force to the tamper 2-170 to further advance the implant in a press fit manner, such as that depicted in Figure 2H facilitates implant insertion to the bone in the defect site, where the upper boundary of the implant is no longer flush with the articular cartilage layer, but instead is approximately 2mm below the articular cartilage surface.

    [0074] Furthermore the methods include when more than one therapeutic implant is being introduced that each implant is similarly implanted reaching the bone in each repair site, and being advanced such that the upper boundary of each implant is approximately 2mm below the articular cartilage layer surface at each respective defect site. The two implants, in this circumstance should not abut each other, and instead an approximate 5 mm tissue distance between implant boundary sites should be preserved, as depicted in Figure 2I.

    [0075] Figure 2J depicts another embodied aspect of the optimized method whereby the upper boundary of the therapeutic implant is approximately 2 mm below the articular cartilage surface in the defect site and a biocompatible/therapeutic polymer composition may be applied to the apex of the implant, as depicted in Figure 2J. For example, a hyaluronic acid solution or hyaluronic acid hydrogel may be applied to the site 2-160 with a syringe 2-170, so that as depicted in Figure 2K, the cartilage layer has a narrow, approximately 2 mm region 2-180 which is not filled in by the implant. Figure 2L shows a transverse section through the region in Figure 2J, of implantation of the substrate in underlying bone 2-210 and that the implant spans apically to a region about 2 mm lower 2-230 than the articular cartilage surface layer 2-220.

    EXAMPLE 2


    Improved Solid Substrate Incorporation as a Function of Positioning of a Coralline-Based Solid Subtrate Per the Methods of this Invention



    [0076] Coral plugs were prepared as described in PCT International Patent Application Publication Number WO2010058400 and implants were introduced into defect sites prepared as described in same.

    [0077] Patients were evaluated at 6, 12, 18 and 24 months post-implantation and assessed for their pain level, function, daily activities (ADL), quality of life (QOL), involvement/ease of participating in sports, using validated questioners Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) (0=worse, 100=best). Additionally MRI and X-ray images were taken to evaluate the repaired tissue in terms of quality and overall appearance.

    [0078] Figure 3A taken at 3 months following implantation shows that the implant 3-10 was specifically positioned to be below the articular cartilage surface 3-200. The recess of the implant manifested as a region devoid of articular cartilage over the implant as depicted in the figure at point 3-210. Over time, cartilage regeneration occurs and the implant is being resorbed/resolved, as well. Figure 3B shows that as early as 6 months post implanation, cartilage growth 3-200 over the implant region readily occurs. By 12 months post implantation, full thickness articular cartilage 3-200 has regenerated over the implant 3-10, which in turn is becoming fully integrated with underlying subchondral bone.

    [0079] The images in Figure 3 are representative and of the more than 200 patients in which coral based implants were provided via the method as described, remarkably in all cases, full thickness articular cartilage regeneration and resorption/incorporation of the implant in the underlying subchondral bone was seen.

    [0080] To further highlight the unexpectedly improved outcome as a consequence of pursuit of the implantation procedures as described herein, pairwise comparisons of patients operated on at the same hospital at around the same time were conducted.

    [0081] Figure 4A-4H provides a representative comparison. Two male patients of similar age exhibiting similar cartilage defects, having previous ligament repair (ACL) were treated with implants of the same size (10 mm into the left knee, lateral condyle in the first patient, medial condyle in the second patient). The clinical outcome of both patients was excellent, in that both patients were completely pain free at 2 years and able to perform all activities, including strenuous sport activity.

    [0082] Excellent cartilage repair was noted in both cases. Nonetheless, the patient in which the implant was specifically inserted to span through bone and into the cartilage layer, yet below the articular cartilage surface demonstrated superior cartilage thickness upon repair and formation of a precise tidemark between the regenerated cartilage and the regenerated bone. Figures 4A-4D depict images of the patients progress, following implantation of an implant as described herein. Figure 4A is a photograph of the implantation site, whereby the implant (4-10) spanned through bone and cartilage, filling the tissue implantation site and being placed flush with the articular cartilage surface (4-200). Figure 4B is an X-ray of the implantation site following implantation, whereby the implant 4-10 most apically spans beyond the tidemark, to the level of the articular surface 4-200. MRI images taken 2 years post implantation at lower (Figure 4C) and higher (Figure 4D) magnification demonstrate a reconstruction of the articular surface 4-195 and repaired cartilage similar to native cartilage in signal, however, the repaired cartilage proximal to the implantation site is thinner than native cartilage and no reconstruction of the tidemark was evident.

    [0083] The table below provides an assessment of the patient progress from baseline through 2 years post-implantation. [ see www.aaos.org/uploadedFiles/PreProduction/Quality /Measures/IKDCEnglishUS.pdf; www.koos.nu/].
    Patient 1
     DCinDLartOL
    seline 57.45 61.1 86.76 60 50
    M 60.92 91.67 92.65 0 50
    2M 79.31 91.7 98.5 75 68.8
    3M 94.25 100 100 100 87.5
    4M 96.55 100 100 100 87.5


    [0084] As is evident from the table, the patient demonstrated full healing and functional return of quality of life as a result of the treatment.

    [0085] Figures 4E-4H depict images of the patients progress, following implantation of an implant as described herein, in accordance with embodied methods of this invention. Figure 4E is a photograph of the implantation site, whereby the implant (4-10) spanned through bone and cartilage, filling the tissue implantation site and being placed 2mm below the articular cartilage surface, at the level of the tidemark (4-200). Figure 4F is an X-ray of the implantation site following implantation, whereby the implant 4-10 most apically is now flush with the tidemark 4-200. MRI images taken 2 years post implantation at lower (Figure 4G) and higher (Figure 4H) magnification demonstrate a reconstruction of the articular surface 4-195 and repaired cartilage similar to native cartilage in signal and in thickness, and full reconstruction of the tidemark was evident 4-200.

    [0086] The table below provides an assessment of this patient's progress from baseline through 2 years post-implantation.
    Patient 2
     DCinOLartOL
    seline 37.93 69.4 75 50 31.3
    M 79.31 100 100 75 81.3
    2M 75.86 97.2 97.1 85 87.5
    3M 85.06 100 100 90 87.5
    4M 90.8 100 100 100 100


    [0087] Thus in methods of similar implantation, whereby the implant was essentially implanted flush with the articular cartilage surface, same provides for healing of the osteochondral defects in thus treated patients. Surprisingly, however, when the methods as embodied herein were pursued, the timing, quantity and quality of articular cartilage regeneration was dramatically improved in comparison to same, especially when evaluating the thickness of the regenerated cartilage and the formation of the tidemark

    [0088] It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention as set forth in the appended claims. ,

    [0089] In one embodiment of this invention, "about" refers to a quality wherein the means to satisfy a specific need is met, e.g., the size may be largely but not wholly that which is specified but it meets the specific need of cartilage repair at a site of cartilage repair. In one embodiment, "about" refers to being closely or approximate to, but not exactly. A small margin of error is present. This margin of error would not exceed plus or minus the same integer value. For instance, about 0.1 micrometers would mean no lower than 0 but no higher than 0.2. In some embodiments, the term "about" with regard to a reference value encompasses a deviation from the amount by no more than 5%, no more than 10% or no more than 20% either above or below the indicated value.

    [0090] In the claims articles such as "a", "an" and "the" mean one or more than one unless indicated to the contrary or otherwise evident from the context. Claims or descriptions that include "or" or "and/or" between members of a group are considered satisfied if one, more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process unless indicated to the contrary or otherwise evident from the context. The invention includes embodiments in which exactly one member of the group is present in, employed in, or otherwise relevant to a given product or process. The invention also includes embodiments in which more than one, or all of the group members are present in, employed in, or otherwise relevant to a given product or process. Furthermore, it is to be understood that the invention provides, in various embodiments, all variations, combinations, and permutations in which one or more limitations, elements, clauses, descriptive terms, etc., from one or more of the listed claims is introduced into another claim dependent on the same base claim unless otherwise indicated or unless it would be evident to one of ordinary skill in the art that a contradiction or inconsistency would arise. Where elements are presented as lists, e.g. in Markush group format or the like, it is to be understood that each subgroup of the elements is also disclosed, and any element(s) can be removed from the group. It should be understood that, in general, where the invention, or aspects of the invention, is/are referred to as comprising particular elements, features, etc., certain embodiments of the invention or aspects of the invention consist, or consist essentially of, such elements, features, etc. For purposes of simplicity those embodiments have not in every case been specifically set forth in haec verba herein. Certain claims are presented in dependent form for the sake of convenience.


    Claims

    1. A cartilage cutter (120), comprising:

    - an elongated handle (230);

    - a head region (220) connected to said elongated handle (230), said head region further comprising

    • an apical portion which connects with said elongated handle; and

    • a basal portion which inserts within an implantation site, the basal portion having a basal surface (290) that is substantially flat;

    characterised in that the head region (220) further comprises a first angled side region and a second angled side region (270), wherein said two angled side regions taper from said apical portion toward said basal portion;

    said first angled side region further comprising:

    • a tapered blade surface (250),

    • a supporting tapered angled surface (260) positioned opposingly to said tapered blade surface (250); and

    • a hollowed region (240) located between said tapered blade surface (250) and said supporting tapered angled surface (260), wherein said hollowed region (240) is sized such that when tissue in contact with said tapered blade surface (260) is cut it is of a thickness accommodating insertion within said hollowed region (240).


     
    2. The cartilage cutter (120) of claim 1, wherein an interior region (280) between said first and second angled side regions is substantially hollowed.
     
    3. The cartilage cutter (120) of claim 1, wherein an interior region (280) between said first and second angled side regions is substantially solid but contains a hollowed region into which the cut tissue may insert.
     
    4. The cartilage cutter (120) of claim 1, wherein said elongated handle (230) has a grip surface.
     
    5. The cartilage cutter (120) of claim 1, wherein said elongated handle (230) is constructed to be ergonomic.
     
    6. The cartilage cutter (120) of claim 1, wherein said elongated handle (230) may be removably attached to said head region.
     
    7. The cartilage cutter (120) of claim 1, wherein said head region (220) is scalable to accommodate a range in dimensions of a tissue site where cartilage cutting is desired.
     


    Ansprüche

    1. Knorpelschneider (120), umfassend:

    - einen länglichen Griff (230);

    - einen Kopfbereich (220), der mit dem länglichen Griff (230) verbunden ist, wobei der Kopfbereich ferner umfasst

    • einen apikalen Abschnitt, der mit dem länglichen Griff verbunden ist; und

    • einen basalen Abschnitt, der in eine Implantationsstelle eingeführt wird, wobei der basale Abschnitt eine basale Oberfläche (290) aufweist, die im Wesentlichen flach ist;

    dadurch gekennzeichnet, dass der Kopfbereich (220) ferner einen ersten gewinkelten Seitenbereich und einen zweiten gewinkelten Seitenbereich (270) umfasst, wobei die beiden gewinkelten Seitenbereiche sich von dem apikalen Abschnitt zu dem basalen Abschnitt hin verjüngen; wobei der erste gewinkelte Seitenbereich ferner umfasst

    • eine sich verjüngende Klingenoberfläche (250),

    • eine stützende, sich verjüngende, gewinkelte Oberfläche (260), die gegenüber der sich verjüngenden Klingenoberfläche (250) angeordnet ist; und

    • einen hohlen Bereich (240), der zwischen der sich verjüngenden Klingenoberfläche (250) und der stützenden, sich verjüngenden, gewinkelten Oberfläche (260) angeordnet ist, wobei der hohle Bereich so groß ist, dass Gewebe, wenn es in Kontakt mit der sich verjüngenden Klingenoberfläche (260) geschnitten wird, eine Dicke aufweist, die das Einführen in den hohlen Bereich (240) ermöglicht.


     
    2. Knorpelschneider (120) gemäß Anspruch 1, wobei ein innerer Bereich (280) zwischen dem ersten und dem zweiten gewinkelten Seitenbereich im Wesentlichen hohl ist.
     
    3. Knorpelschneider (120) nach Anspruch 1, wobei ein innerer Bereich (280) zwischen dem ersten und dem zweiten gewinkelten Seitenbereich im Wesentlichen fest ist, jedoch einen hohlen Bereich enthält, in den das geschnittene Gewebe eingeführt werden kann.
     
    4. Knorpelschneider (120) nach Anspruch 1, wobei der längliche Griff (230) eine Haftoberfläche aufweist.
     
    5. Knorpelschneider (120) nach Anspruch 1, wobei der längliche Griff (230) ergonomisch gestaltet ist.
     
    6. Knorpelschneider (120) nach Anspruch 1, wobei der längliche Griff (230) abnehmbar an dem Kopfbereich angebracht werden kann.
     
    7. Knorpelschneider (120) gemäß Anspruch 1, wobei der Kopfbereich (220) skalierbar ist, um sich an einen Bereich von Abmessungen eines Gewebes anzupassen, in dem ein Knorpelschneiden gewünscht ist.
     


    Revendications

    1. Un cutter de cartilage (120), comprenant :

    - une poignée allongée (230) ;

    - une région de tête (220) connectée à ladite poignée allongée (230), ladite région de la tête comprenant en outre

    • une partie apicale qui se connecte à ladite poignée allongée ; et

    • une partie basale qui s'insère à l'intérieur d'un site d'implantation, la partie basale ayant une surface basale (290) qui est substantiellement plate ;

    caractérisée en ce que la région de tête (220) comprend en outre une première région latérale angulaire et une deuxième région latérale angulaire (270), dans laquelle lesdites deux régions latérales angulaires se rétrécissent de ladite partie apicale vers ladite partie basale ; ladite première région latérale angulaire comprend en outre :

    • une surface de lame conique (250),

    • une surface angulaire conique de support (260) positionnée à l'opposé de ladite surface de lame conique (250) ; et

    • une région creuse (240) située entre ladite surface de lame conique (250) et ladite surface angulaire conique de support (260), dans laquelle ladite région creuse est dimensionnée de telle sorte que lorsque le tissu en contact avec ladite surface de lame conique (260) est coupé, il est d'une épaisseur permettant l'insertion dans ladite région creuse (240).


     
    2. Le cutter de cartilage (120) selon la revendication 1, dans lequel une région intérieure (280) entre lesdites première et seconde régions latérales angulaires est substantiellement creusée.
     
    3. Le cutter de cartilage (120) selon la revendication 1, dans lequel une région intérieure (280) entre lesdites première et seconde régions latérales angulaires est substantiellement solide mais contient une région creuse dans laquelle le tissu coupé peut s'insérer.
     
    4. Le cutter de cartilage (120) selon la revendication 1, dans lequel ladite poignée allongée (230) a une surface de préhension.
     
    5. Le cutter de cartilage (120) selon la revendication 1, dans lequel ladite poignée allongée (230) est construite pour être ergonomique.
     
    6. Le cutter de cartilage (120) selon la revendication 1, dans lequel ladite poignée allongée (230) peut être fixée de manière amovible à ladite région de tête.
     
    7. Le cutter de cartilage (120) selon la revendication 1, dans lequel ladite région de tête (220) est extensible pour s'adapter à une gamme de dimensions d'un tissu où la coupe de cartilage est souhaitée.
     




    Drawing



































    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description