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:
HIP PROSTHETIC IMPLANT

2. APPLICANT:
Meril Healthcare Pvt. Ltd., an Indian company of Survey No. 135/139, Bilakhia House, Muktanand Marg, Chala, Vapi- 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 hip prosthetic implant.
BACKGROUND OF INVENTION
[2] Joints in human body are structures that separates two or more adjacent elements of the skeleton system. It is a connection that occurs between bones in the skeleton system. Joints are major means for movement and provide support to the body.
[3] One of the major and strongest joints in the human body is the hip joint. The hip acts as a multi-axial, ball-and-socket joint upon which the upper body is balanced during stances and gait. The hip 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 hip 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 hip 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 hip replacement procedures which often help minimizing or eliminating the pain and improve mobility in patients. In a typical total hip replacement procedure, the natural bearing of the joint is replaced by an artificial bearing and a structure to support the bearing.
[5] However, these hip replacement procedures may lead to some clinical complications such as unstable component fixation, osteolytic destruction of bones and displacement of the implant.
[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 a femoral stem. In an embodiment, the femoral stem includes a body including at least one surface. The femoral stem includes a plurality of scales provided on the at least one surface of the body. Each scale of the plurality of scales includes a protruding portion protruding out from the at least one surface forming a gap between the protruding portion and the at least one surface.
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 of a femoral stem 100, according to an embodiment of the present disclosure.
[11] Fig. 2A depicts a front view of a scale 109n, according to an embodiment of the present disclosure.
[12] Fig. 2B depicts a side view of the scale 109n, according to an embodiment of the present disclosure.
[13] Fig. 2C depicts an isometric view of the scale 109n, according to an embodiment of the present disclosure.
[14] Fig. 3 depicts a perspective view of the femoral stem 100, according to an embodiment of the present disclosure.
[15] Fig. 4 depicts a side view of the femoral stem 100, according to an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[16] Prior to describing the disclosure 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.
[17] 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.
[18] 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.
[19] 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.
[20] The present disclosure relates to a bio-medical implant such as a hip prosthetic implant. The hip prosthetic implant includes an acetabular shell, a liner, a femoral head and a femoral stem. The acetabular shell and the liner form an acetabular component of the hip prosthetic implant. The femoral head and the femoral stem form a femoral component of the hip prosthetic implant.
[21] The present disclosure proposes a femoral stem that can be used in a hip prosthetic implant. The hip prosthetic implant can be implanted through a hip replacement surgery in a patient dealing with Osteoarthritis, Rheumatoid arthritis, dislocation or fracture, or in cases where the bone has been collapsed or deformed. The femoral stem is inserted into the patient’s body during the hip replacement surgery. In an embodiment, the proposed femoral stem includes a body and a plurality of scales. The plurality of scales is provided on at least one surface of the body. Each scale of the plurality of scales are coupled to the body of the femoral stem such that there is a gap between a protruding portion of each scale and a respective surface of the at least one surface of the body. The proposed femoral stem once fixed into the site may help in better fixation of the hip prosthetic implant with the bone by promoting better bone in-growth and/or creating interconnections between the hip prosthetic implant and the bone which help in preventing implant sinking over a period of time. In an embodiment, the femoral stem is an uncemented femoral stem.
[22] Fig 1. depicts a front view of a femoral stem 100, in accordance with an embodiment of the present disclosure. In an embodiment, the femoral stem 100 is an uncemented femoral stem. In an embodiment, the femoral stem 100 includes a proximal end 100a and a distal end 100b. The femoral stem 100 includes a head portion 103 and a body 105. The head portion 103 includes a trunnion 102 and a neck 104. The body 105 includes a proximal end 105a and a distal end 105b. In an embodiment, the femoral stem 100 may be secured in the medullary canal of the patient’s femur through a press fit mechanism forming a tight and secured fit between the body 105 and the femur bone.
[23] The trunnion 102 is situated at the proximal end 100a of the femoral stem 100. The trunnion 102 has a proximal end 102a and a distal end 102b. The femoral stem 100 is coupled to a femoral head of a hip prosthetic implant using the trunnion 102 in a suitable fashion. For example, the trunnion 102 has a taper (e.g., a male taper) at the proximal end 102a and the femoral head may have a corresponding taper (e.g., a female taper) to couple the femoral head with the femoral stem 100. In another embodiment, the trunnion 102 has no taper. In an embodiment, the distal end 102b of the trunnion 102 is coupled to a proximal end 104a of the neck 104. The trunnion 102 may be coupled to the neck 104 using screws, a press fit mechanism, etc. In an embodiment, the trunnion 102 and the neck 104 are a single integral structure. The trunnion 102 in the femoral stem 100 may also act as a closed environment which prevents ion diffusion. The trunnion 102 can be made up of materials such as, but not limited to, Titanium, CoCr, HNSS, SS316L, and any other suitable medical grade metal. In an embodiment, the trunnion 102 is made up of Titanium. The dimensions of the trunnion 102 may vary depending upon the design of the hip prosthetic implant.
[24] The neck 104 has a proximal end 104a and a distal end 104b. The neck 104 has a generally cylindrical shape. The neck 104 may have a taper at the distal end 104b. The neck 104 extends upwardly (i.e., in a proximal direction) from the body 105. The distal end 104b of the neck 104 is coupled to a proximal end 105a of the body 105 at an offset angle. The offset angle may vary depending upon the patient population or individual patient. The neck 104 may be coupled to the body 105 using screws, a press fit mechanism, etc. In an embodiment, the neck 104 and the body 105 are a single integral structure. The neck 104 can be used as the base for anchoring the femoral stem 100 to the femur. The neck 104 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 104 is made of Titanium. The shape and the dimension of the neck 104 may vary depending upon the design of the hip prosthetic implant.
[25] The body 105 of the femoral stem 100 helps in fixation of the femoral stem 100 with the femur bone. In an embodiment, the body 105 is situated within a cavity formed within the cancellous bone of the medullary canal. In an embodiment, the body 105 has a proximal end 105a and a distal end 105b. The body 105 has a wedge shape with a taper at the distal end 105b, according to an embodiment. The body 105 has a curved distal end 105b, in an embodiment. The distal end 105b may have any other suitable shape include, but not limited to, round, bullet, pointed, etc. The body 105 can be made up of materials such as, not limited to, Titanium, CoCr, HNSS, SS316L, or any other suitable medical grade metal. In an embodiment, the body 105 is made of Titanium. It should be appreciated that the body 105 may have any suitable shape and dimensions without deviating from the scope of the present disclosure.
[26] The body 105 includes at least one surface. In an embodiment, the body 105 includes surfaces 107a and 107b on anterior and posterior side of the body 105, respectively and surfaces 106a and 106b on lateral and medial side of the body 105, respectively. According to an embodiment, the surfaces 107a and 107b are substantially straight and the surfaces 106a and 106b are curved.
[27] In an embodiment, the body 105 includes a surface coating on the at least one surface. The surface coating helps in promoting the bone growth and to create interconnections between the femoral stem 100 and the bone after the implantation. In an embodiment, the surface coating is made of any medical grade metallic biocompatible materials including, but not limited to hydroxyapatite (HA), titanium (TA), TiNbN, etc. In an embodiment, the surface coating is made of titanium (TA).
[28] In an embodiment, the femoral stem 100 includes a plurality of scales 109 (also, referred to as the scales 109) as shown in Figs. 1 and 3. The scales 109 help in the fixation of the femoral stem 100 with the bone and prevent sinking of the implant within the bone over a period of time. The scales 109 may have a pre-defined shape. In an embodiment, each scale of the plurality of scales 109 may have a fin-like shape. The scales 109 may also have shapes such as, but not limited to, diamond, triangular, etc. The scales 109 are provided on the at least one surface of the body 105, i.e., on at least one surface of the surfaces 107a, 107b, 106a and 106b. In an embodiment, the scales 109 may be present on only one of the surfaces 107a, 107b, 106a and 106b. In another embodiment, the scales 109 may be present on two or more surfaces of the surfaces 107a, 107b, 106a and 106b. In an embodiment, the scales 109 may be present on all surfaces, i.e., the surfaces 107a, 107b, 106a and 106b, of the body 105. In the depicted embodiment, the scales 109 are provided on the surfaces 107a and 107b. Further, in an embodiment, the scales 109 are provided at least partially along a length of the at least one surface. The scales 109 may be provided at least partially along the length of the at least one surface from the proximal end 105a or from the distal end 105b, or both. The scales 109 may be provided along a partial length of one or more surfaces of the surfaces 107a, 107b, 106a and 106b and along entire length of one or more other surfaces of the surfaces 107a, 107b, 106a and 106. In an embodiment, the scales 109 are provided along the entire length of the at least one surface. In the depicted embodiment, the scales 109 are provided along partial length of the surfaces 107a and 107b.
[29] Each scale of the scales includes a contacting portion and a protruding portion. The protruding portion of each scale protrudes out from the at least one surface forming a gap between the protruding portion and the at least one surface (further explained in detail in Figs. 2A – 2C). The contacting portion of each scale is coupled to the at least one surface. In an embodiment, the scales 109 and the body 105 form an integral structure. The gap between the at least one surface and the protruding portion of each scale 109n helps in osseointegration due to bone in-growth. In an embodiment, the scales 109 are extruded. The scales 109 can be made up of materials including, but not limited to, Titanium, CoCr, HNSS, 316L, etc. In an embodiment, the scales 109 are made up of Titanium.
[30] The scales 109 may be arranged in a pre-defined pattern. In an embodiment shown in Fig. 1, the scales 109 are arranged linearly in a plurality of rows and columns. The scales 109 may be arranged in any other suitable pattern including, without limitation, circular, zig-zag, mesh, slanted mesh, etc.
[31] Figs. 2A – 2C illustrate different views of one scale 109n of the scales 109, according to an embodiment. Each scale 109n includes a contacting portion 109a and a protruding portion 109b. The contacting portion 109a includes a surface 109a1. The protruding portion 109b includes a surface 109b1. The contacting portion 109a is coupled to the at least one surface of the body 105 such that the surface 109a1 of the contacting portion 109a contacts the at least one surface. In the depicted embodiment, the contacting portion 109a forms an integral structure with the at least one surface. In an embodiment, during manufacturing of the femoral stem 100, the scale 109n is extruded individually from the at least one surface (say, the surface 107a) converging at the protruding portion 109b and a part of the protruding region (e.g., an underside in the depicted embodiment) may be cut to form a gap between the protruding portion 109b and the at least one surface. The scale 109n may also be formed by other suitable methods such as, without limitation, 3D printing. In an embodiment shown in Fig. 2B, the surface 109b1 of the protruding portion 109b forms an angle a° with the at least one surface. The angle a° is the angle between the at least one surface (say the surface 107a) and the surface 109b1 of the protruding portion 109b. The angle (a°) can be between 1° and 90°.
[32] The femoral stem 100 having the scales 109 presents several advantages. The gap (denoted by the angle a°) between the scales 109 and the at least one surface of the body 105 allows the bone to grow into the gap, thereby allowing better fixture of the femoral stem 100 with the bone. When the patient is performing several physical activities, load on the hip prosthetic implant increases. The scales 109 help to transfer this load optimally from the body 105 of the femoral stem 100 to the trabeculae of the cancellous region of the femur bone. The scales 109 also help withstand excessive loading conditions by distributing the load evenly across the body 105 of the femoral stem 100. This leads to low stress levels across the surface and strengthening of the femoral stem 100. This reduces the chances of failure of the femoral stem 100, thereby, improving the outcome for the patient.
[33] The scales 109 also oppose the sinkage of the hip prosthetic implant into the bone. The scales 109 act as a supporting element and provide resistance during the sinking of the femoral stem 100 and also helps in osseointegration due to bone in-growth.
[34] 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. A femoral stem (100) comprising:
a) a body (105) comprising at least one surface; and
b) a plurality of scales (109) provided on the at least one surface with each scale (109n) of the plurality of scales (109) comprises a protruding portion (109b) protruding out from the at least one surface forming a gap between the protruding portion (109b) and the at least one surface.
2. The femoral stem (100) as claimed in claim 1, wherein the plurality of scales (109) and the body (105) form an integral structure.
3. The femoral stem (100) as claimed in claim 1, wherein a surface (109b1) of the protruding portion (109b) forms an angle a with the at least one surface.
4. The femoral stem (100) as claimed in claim 3, wherein the angle a is between 1° and 90°.
5. The femoral stem (100) as claimed in claim 1, wherein the plurality of scales (109) is provided at least partially along a length of the at least one surface.
6. The femoral stem (100) as claimed in claim 1, wherein the plurality of scales (109) is extruded.
7. The femoral stem (100) as claimed in claim 1, wherein the plurality of scales (109) has a pre-defined shape.
8. The femoral stem (100) as claimed in claim 1, wherein each scale (109n) comprises a contacting portion (109a) coupled to the at least one surface.
9. The femoral stem (100) as claimed in claim 1, wherein the plurality of scales (109) is arranged in a pre-defined pattern.
10. The femoral stem (100) as claimed in claim 1, wherein the body (105) comprises a surface coating.