Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

1. TITLE OF THE INVENTION:
STEM IMPLANT
2. APPLICANT:
Meril Corporation (I) Private Limited, an Indian company of the address Survey No. 135/139, Muktanand Marg, Bilakhia House, Pardi, Vapi, Valsad-396191 Gujarat, India.

The following specification particularly describes the invention and the manner in which it is to be performed:

FIELD OF INVENTION
[1] The present disclosure relates to a bio-medical implant. More particularly, the present disclosure relates to a stem implant.
BACKGROUND OF INVENTION
[2] Joints in a human body are structures that join two or more adjacent elements of the skeleton system. Joints are major means for movement of the limbs of the human body and provide support to the body.
[3] One of the major and strongest joints in the human body is the shoulder joint. The shoulder acts as a multi-axial, ball-and-socket joint upon which the upper body is balanced during stances and gait. The shoulder joint is a stable and multifunctional joint; the major function being load bearing. It also offers a range of motions during normal daily activities. The stability of the shoulder joint is provided by its relatively rigid ball and socket type configuration, its ligaments and by the large, strong muscles across it.
[4] In certain traumatic situations and arthritic conditions due to aging, the shoulder joint can be very debilitating; not only causing pain, but also limiting the ability to perform normal activities. Such conditions can be treated by various shoulder replacement procedures which often help minimizing or eliminating the pain and improve mobility in patients. In a typical shoulder replacement procedure, the natural bearing of the joint is replaced by an artificial bearing and a structure to support the bearing.
[5] Conventionally available implants may have problems for example, the implants are not capable of osteointegration due to the design of the implant and due to lack of support caused by insufficient bone growth the implants tend to sink inside the bone cavity.
[6] Thus, there arises a need for a prosthesis that overcomes the problems associated with the conventional prosthesis.
SUMMARY OF INVENTION
[7] Particular embodiments of the present disclosure are described herein below with reference to the accompanying drawings, however, it is to be understood that the disclosed embodiments are mere examples of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.
[8] The present disclosure relates to an implant. The implant includes a neck and a body. The body is provided with a proximal portion and a distal portion. The proximal portion of the body is coupled to the neck. The distal portion of the body includes one or more hollow tubular structures concentrically placed with each other. Each tubular structure includes a plurality of bars interwoven with a plurality of lateral structures defining a spider web.
BRIEF DESCRIPTION OF DRAWINGS
[9] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the apportioned drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentality disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[10] Fig. 1 depicts a front view humeral stem 100, according to an embodiment of the present disclosure.
[11] Fig. 2 depicts a neck of the humeral stem 100, according to an embodiment of the present disclosure.
[12] Fig. 3A depicts a structure of a distal portion 130 of the humeral stem 100, according to an embodiment of the present disclosure.
[13] Fig. 3B depicts a distal end 130b of the distal portion 130, according to an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE DRAWINGS
[14] Prior to describing the invention in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like. Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[15] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[16] Although the operations of exemplary embodiments of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses.
[17] Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages of the embodiments will become more fully apparent from the following description and apportioned claims, or may be learned by the practice of embodiments as set forth hereinafter.
[18] The present disclosure relates to a biomedical implant such as a humeral prosthetic implant (or humeral implant or stem implant). The humeral implant incudes a glenoid component, humeral head, standard taper adaptor and a humeral stem. The glenoid forms the scapula part and the humeral head and the humeral stem forms the humeral part. Though the invention has been described in the context of a humeral stem, the teachings of the present invention extend to other biomedical implants including a humeral trial, a femoral implant or a femoral trial.
[19] The humeral stem of the humeral implant can be implanted through a shoulder replacement surgery in a patient dealing with Osteoarthritis, Rheumatoid arthritis, dislocation or fracture, or in cases where the bone has collapsed or deformed. In an embodiment, the humeral stem includes a distal portion made of a plurality of bars interwoven with a plurality of lateral structures in a mesh for example, a spider web, a Fibonacci structure, or a honeycomb structure, etc. Further, the humeral stem includes one or more hollow tubular structures concentrically placed inside one another. The humeral stem once fixed into the site, helps in better fixation of the shoulder prosthetic implant with the bone by promoting better bone in-growth and/or creating interconnections between the shoulder implant and the bone which help in preventing the implant from sinking over a period of time. The humeral stem of the present disclosure thus provides better osseointegration and also, better load distribution.
[20] Fig. 1 depicts a front view of a humeral stem 100, in accordance with an embodiment of the present disclosure. The humeral stem 100 may be implanted inside a native bone (for example, a humeral head) via an uncemented/ cemented implantation procedure. The humeral stem 100 includes a proximal end 100a and a distal end 100b. The humeral stem 100 includes a body 103 having a neck 101 such that the neck 101 is aligned towards the proximal end 100a of the humeral stem 100.
[21] The humeral stem 100 is coupled to a native taper adaptor via the neck 101 in a suitable fashion. The coupling mechanism includes without limitation press fit, snap fit, etc. In an embodiment, the neck 101 has a predefined width ‘w’ (shown in fig. 2) that is selected based on the native humeral head. Further, the neck 101 is provided with a cavity 110c that runs at least partially along the width of the neck 101. The cavity 110c may have a shape such as without limitation circular, oval, etc. In an embodiment, the cavity 110c is circular. The cavity 110c is provided to receive the native taper adaptor (not shown) which fits in the cavity 110c to form an assembly.
[22] Further, on the other side, the neck 101 is coupled to a proximal end 103a of the body 103 at an offset angle (shown in Fig. 2). The offset angle may vary from patient to patient. In an embodiment, the neck 101 and the body 103 are a single integral structure. Alternately, the neck 101 may be coupled to the body 103 using screws, a press fit mechanism, etc. as depicted in Fig. 2.
[23] The neck 101 can be made up of materials including, but not limited to, Titanium, CoCr, HNSS, SS316L, or any other suitable medical grade metal. In an embodiment, the neck 101 is made of Titanium. The shape and the dimension of the neck 101 may vary depending upon the design/dimensions of the shoulder prosthetic implant. For example, the neck 101 may be in the shape of a rectangular block with two opposite curved ends.
[24] The body 103 includes a proximal end 103a and a distal end 103b. The body 103 of the humeral stem 100 helps in fixation of the humeral stem 100 with the native humerus bone. The humeral stem 100 may be secured in the medullary canal of the patient’s humeral bone through a press fit mechanism forming a tight and secured fit between the body 103 and the native humeral bone. In an embodiment, the body 103 is situated within a cavity formed within the cancellous bone of the medullary canal.
[25] The body 103 may be of a wedge shape with a taper towards the distal end 103b, according to an embodiment. The body 103 can be made up of materials such as, not limited to, Titanium, CoCr, stainless steel, or any other suitable medical grade biocompatible metal. In an embodiment, the body 103 is made of Titanium. It should be appreciated that any suitable shape and dimensions of the body are within the scope of the teachings of the present disclosure which allow the body to perform the functions as described herein.
[26] The body 103 is provided with a proximal portion 120 and a distal portion 130. The proximal portion 120 is situated towards the proximal end 103a of the body 103. The proximal portion 120 has a proximal end 120a and a distal end 120b. The proximal portion 120 has a taper towards its distal end 120b. The proximal portion 120 may be provided with an aperture 120c situated towards the proximal end 120a of the proximal portion 120. The aperture 120c may have a shape such as without limitation circular, oval, etc. In an embodiment, the aperture 120c has a circular shape. In addition, at least a portion of the proximal end 120a may be sliced forming a slant corresponding to the offset angle of the neck 101. The proximal end 120a of the proximal portion 120 may thus have a nearly flat surface followed by a slant on which the neck 101 is attached.
[27] The proximal portion 120 may have a surface coating. The surface coating may be of material such as Titanium, Hydroxyapatite (HA), etc. In an embodiment, the proximal portion 120 may have a surface coating of Titanium. The surface coating on the proximal portion 120 helps in interconnection between the humeral stem 100 and the native humerus bone by promoting the bone in-growth therebetween.
[28] The distal end 120b of the proximal portion 120 is coupled to the proximal end 130a of the distal portion 130. In an embodiment, the proximal portion 120 and the distal portion 130 is a single integrated structure.
[29] The distal portion 130 is situated towards the distal end 103b of the body 103. The distal portion 130 has a proximal end 130a and a distal end 130b. The distal portion 130 has a taper towards the distal end 130b. Further, in an embodiment, the distal portion 130 includes a curved distal tip 130d at the distal end 130b. The distal tip 130d may have any other suitable shape include, but not limited to, round, bullet, pointed, etc. The curved distal tip 130d helps in improved fit, stability, load transfer, fixation and range of motion in shoulder replacement surgeries, ultimately enhancing the longevity and performance of the implant. The distal tip 130d may be an integral structure of the distal portion 130 or a separate attachment affixed to the end of the distal portion 130.
[30] The distal portion 130 includes a plurality of bars 301 interwoven with a plurality of lateral structures 303 defining a hollow tubular structure (shown in Figs. 3A and 3B). Further, the distal portion 130 may include one or more hollow tubular structures concentrically placed inside one another as described below. The bars 301 may be vertically or nearly vertically oriented while a lateral structure 303 may be horizontally or nearly horizontally oriented. Each bar 301 may make an angle ranging between 0 degrees to 90 degrees, with respect to the longitudinal axis of the humeral stem 100. Each lateral structure 303 may make an angle ranging between an acute to an obtuse angle with respect to the longitudinal axis of the humeral stem 100.
[31] The lateral structure 303 may be in the form of a circular arc, though the lateral structure 303 may include shapes such as elliptical structure, parabolic structure, hyperbolic structure. In an embodiment, the interconnection of the lateral structures 303 and the bars 301 depict a spider web as shown in Fig. 3A. Alternately, the lateral structures 303 and the bars 301 may form structures such as Fibonacci, honeycomb, etc. The spider web structure offers numerous advantages including without limitation stability, even load distribution, sufficient bone in growth and negligible risk of sinking of the humeral stem inside the native humeral bone. The lateral structure 303 may be made up of a material such without limitation, Titanium, CoCr, stainless steel, or any other suitable medical grade biocompatible metal. In an embodiment, the lateral structure 303 is made of Titanium.
[32] In an embodiment, to attain a flat surface of the humeral stem 100 for better alignment with the native bone, the bars 301 of the outer tubular structure 305a may be semi-circular as clearly depicted in Fig. 3A. In the depicted embodiment, while the inner surface of the bars 301 directed towards the central axis is curved, the outer exposed surface of the bar 301 to mate with the bone, is flat. This leads to a larger contact area between the humeral stem 100 and the surrounding bone. This increased contact area helps in even load distribution, reducing stress concentrations and minimizing the risk of implant loosening or failure. Additionally, it helps in fixation, stability, load transfer and ease in manufacturing. The humeral stem 100 thus attains a flat outer surface, free of any grooves or undulations.
[33] The distal portion 130 includes a taper towards the distal end 130b as stated above. Due to the varying diameter of the distal portion 130, the bars 301 that originate at the proximal end 130a of the distal portion 130 extend at least partially along the length of the distal portion 130. For example, some of the bars 301 may extend from the proximal end 130a to the distal end 130b of the distal portion 130 however, some of the bars 301 may terminate in between without extending throughout the length of the distal portion 130. This arrangement of bars 301 helps in attaining the required taper and increases the utility of the implant as the implant closely resembles the taper of the native anatomy. The ends of the bars 301 that terminate in between may be smoothened to alleviate trauma to the native bone/tissues. The bars 301 may be made up of a material such without limitation, Titanium, CoCr, stainless steel, or any other suitable medical grade biocompatible metal. In an embodiment, the bars 301 is made of Titanium.
[34] As stated above, the distal portion 130 may include one or more hollow tubular structures concentrically placed inside one another. Multiple tubular structures help in providing stability, even load distribution, sufficient bone in growth to the implant. In an embodiment, the distal portion 130 is a dual layered tubular structure (shown in Fig. 3A and 3B). Each tubular structure may be formed of interwoven bars 301 and lateral structures 303. As stated above, the outer tubular structure 305a may include semi-circular bars 301 interwoven with the lateral structures 303 while the inner concentric tubular structure 305b may include bars 301 which are for example round, oval, flat, etc., interwoven with the lateral structures 303.
[35] The two tubular structures are further interconnected by way of struts 307. The struts 307 may be straight or curved and besides connecting the two tubular structures, serve to provide structural stability the distal portion 130. While an exemplary depiction of Fig. 3B illustrates two concentric tubular structures constituting the implant, the number of tubular structures may vary depending upon desired width, native bone density, patient anatomy, etc. The struts 307 may be made of a material such as without limitation, Titanium, CoCr, stainless steel, or any other suitable medical grade biocompatible metal. In an embodiment, the struts 307 are made of Titanium.
[36] Though the teachings of the present disclosure are described in the context of a humeral stem, the same can be applied to a humeral trial, a femoral implant or a femoral trial which in turn is affixed to the respective native bone.
[37] The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. , Claims:WE CLAIM:
1. An implant (100) comprises:
a. a neck (101); and
b. a body (103) including a proximal portion (120) and a distal portion (130), the proximal portion (120) of the body (103) being coupled to the neck (101);
wherein the distal portion (130) includes one or more hollow tubular structures concentrically placed with each other, each tubular structure including a plurality of bars (301) interwoven with a plurality of lateral structures (303) defining a mesh.
2. The implant (100) as claimed in claim 1, wherein the proximal portion (120) and the distal portion (130) is a single integrated structure.
3. The implant (100) as claimed in claim 1, wherein the proximal portion (120) is provided with a surface coating.
4. The implant (100) as claimed in claim 1, wherein the plurality of bars (301) is one of vertically or nearly vertically oriented.
5. The implant (100) as claimed in claim 1, wherein each bar of the plurality of bars (301) extends at least partially along the length of the distal portion (130).
6. The implant (100) as claimed in claim 1, wherein the bars (301) are one of round, oval, or semi-circular in shape.
7. The implant (100) as claimed in claim 1, wherein the plurality of lateral structures (303) is one of horizontally or nearly horizontally oriented.
8. The implant (100) as claimed in claim 1, wherein the lateral structure (303) is one of a circular arc, an elliptical structure, a parabolic structure, or a hyperbolic structure.
9. The implant (100) as claimed in claim 1, wherein the mesh includes one of a spider web, a Fibonacci structure, or a honeycomb structure.
10. The implant (100) as claimed in claim 1, wherein the one or more hollow tubular structure includes an inner tubular structure and an outer tubular structure (305a).
11. The implant (100) as claimed in claim 1, wherein the tubular structures are interconnected by way of straight or curved struts (307).