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:
TIBIAL PROSTHESIS
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 medical prosthesis. More particularly, the present disclosure relates to a tibial prosthesis.
BACKGROUND OF INVENTION
[2] Knee replacement surgery, also known as knee arthroplasty, is a medical procedure aimed at relieving pain and restoring function in severely damaged knee joints. This procedure is typically considered when conservative treatments like medication and physiotherapy no longer provide adequate relief from pain and immobility caused by conditions, such as, osteoarthritis, rheumatoid arthritis, or traumatic injury.
[3] Knee arthroplasty encompasses two types of surgery i.e., total knee replacement and unicompartmental knee replacement. Total knee replacement involves replacing the entire knee joint with prosthetic components such as, for example, a femoral component, a tibial component, a patellar component and a liner. On the other hand, unicompartmental knee replacement, also known as partial knee replacement, targets replacing only affected portion of knee joint. For example, if one side of the tibial joint is affected, the affected part is replaced with prosthetic components such as, for example, a tibial prosthesis having a tibial component and a tibial liner.
[4] In unicompartmental knee arthroplasty, upon implementation, the tibial component acts as a natural tibial joint and the tibial liner act as a cushion between the tibial component and other natural joints and/or prosthesis joints. The tibial liner is coupled with the tibial component. It is critical that the tibial liner remains in place and provides a smooth articulating surface for other natural joints and/or prosthesis joint.
[5] Various tibial liners and tibial components are currently available; however, conventional tibial liners heavily suffer from problems, such as, dislocation, wear and premature failure, etc. due to improper or loose coupling and/or locking with the tibial components. This may lead to a revision surgery, which not only increases the patient’s trauma but also their medical costs.
[6] Thus, there arises a need for a tibial 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 tibial prosthesis. In an embodiment, the tibial prosthesis includes a tibial component, a tibial liner and a locking member. The tibial component has a cavity. The cavity is provided on an upper surface of the tibial component. The tibial liner has a protrusion provided on a bottom surface of the tibial liner. The protrusion is configured to fit within the cavity. The protrusion includes a slot provided peripherally towards the bottom surface. The locking member is configured to lock the tibial liner with the tibial component. The locking member is configured to reside between a face of the cavity and a face of the slot.
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 cross sectional view of a tibial prosthesis 100, in accordance with an embodiment of the present disclosure.
[11] Fig. 2 depicts a perspective view of a tibial component 110 of the tibial prosthesis 100, in accordance with an embodiment of the present disclosure.
[12] Fig. 3 depicts a perspective view of a locking member 120 of the tibial prosthesis 100, in accordance with an embodiment of the present disclosure.
[13] Fig. 4 depicts a perspective view of a tibial liner 130 of the tibial prosthesis 100, in accordance with 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 discloses a tibial prosthesis. The tibial prosthesis of present disclosure includes a tibial component, a locking member and a tibial liner. The tibial component is securely coupled with the tibial liner using the locking member. This prevents loosening of the coupling between the tibial component and the tibial liner. Consequently, the proposed tibial prosthesis avoids dislocation of the tibial liner from the tibial component. This minimizes the failure chances of the tibial prosthesis and improves patient outcome.
[19] Referring to figures, Fig. 1 depicts a cross sectional view of a tibial prosthesis 100, according to an embodiment of the present disclosure. The tibial prosthesis 100 is used to replace a damaged or diseased tibial joint during a partial knee replacement surgery. In an embodiment, the tibial prosthesis 100 is used to replace/repair injuries in one half of the tibial joint. The tibial prosthesis 100 mimics the structure and function of the natural tibial joint, allowing or improved mobility and reduced pain. Though the present disclosure has been explained in the context of the partial knee replacement surgery, the teachings of the present disclosure can be applied to a tibial prosthesis in a total knee replacement surgery and the same is within the scope of the present disclosure. The tibial prosthesis 100 includes a tibial component 110, a locking member 120 and a tibial liner 130. It should be understood that the tibial component 110 and the tibial liner 130 illustrated herein are merely exemplary and teachings of the present disclosure can be extended to any suitable tibial components and tibial liners and the same is within the scope of the present disclosure.
[20] Fig. 2 depicts the tibial component 110, according to an embodiment of the present disclosure. The tibial component 110 replaces the damaged or diseased portion of the tibia (shinbone) in patients suffering from severe knee arthritis or injury. In an embodiment, the tibial component 110 is used to replace one half of the natural tibial joint.
[21] In an embodiment, the tibial component 110 has a D-shape, though it may have any other suitable shape. The tibial component 110 includes a cavity 111 provided on an upper surface 110a of the tibial component 110. In an exemplary embodiment, the cavity 111 is disposed centrally on the upper surface 110a.
[22] In an embodiment, the cavity 111 is circular in shape, though it may have any other suitable shape (e.g., elliptical, square, rectangular, hexagonal, etc.). The cavity 111 is configured to receive the locking member 120 and a portion of the tibial liner 130 (explained later).
[23] The tibial component 110 includes a cut-out 113 provided on the perimeter of the cavity 111 to engage with the locking member 120 (explained later). In an embodiment, the cut-out 113 has a rectangular shape, though it may have any other suitable shape.
[24] In an embodiment, the upper surface 110a of the tibial component 110 may include one or more additional cavities. In an exemplary embodiment, the tibial component 110 includes two additional cavities 115 and 117. The cavities 115 and 117 are disposed, for example, on either side of the cavity 111.
[25] The cavities 115 and 117 may have the same or different shapes. In an embodiment, the cavities 115 and 117 are trapezoidal, though they may have any other suitable shape. The first cavity 115 and the second cavity 117 are configured to receive a portion of the tibial liner 130 (explained later). The one or more additional cavities (e.g., the cavities 115, 117) provide a more stable coupling between the tibial component 110 and the tibial liner 130.
[26] In an embodiment, the tibial component 110 includes one or more studs (e.g., studs 119a and 119b) and/or a keel 119c integrally extending from a bottom surface (not shown) of the tibial component 110. The plurality of studs and the keel 119c ensure a secured coupling of the tibial component 110 with the tibial bone, which prevents dislocation/de-attachments of the tibial component 110 from the tibial bone. The plurality of studs and the keel 119c may have any suitable shape based upon the requirements.
[27] The dimensions of the tibial component 110 may vary according to or based upon the anatomy of the patient and/or of the patient population in consideration. The tibial component 110 may be made of a biocompatible material including, but not limited to, cobalt-chromium (Co-Cr), titanium, stainless steel, etc. In an embodiment, the tibial component 110 is made of cobalt-chromium (Co-Cr).
[28] Fig. 3 depicts a locking member 120, according to an embodiment of the present disclosure. The locking member 120 is configured to securely lock the tibial component 110 with the tibial liner 130. The locking member 120 ensures the stability and longevity of the coupling of the tibial component 110 and the tibial liner 130 and thus, prevents loosening of the tibial liner 130. The locking member 120 is configured to be disposed within the cavity 111.
[29] In an embodiment, the locking member 120 includes a cut-out portion 121 provided on the perimeter of the locking member 120. A first arm 121a and a second arm 121b are provided on either side of the cut-out portion 121. The first arm 121a and the second arm 121b are configured to be disposed within the cut-out 113 of the tibial component 110. In an embodiment, the locking member 120 is a ring.
[30] To insert the locking member 120 into the cavity 111, the first arm 121a and the second arm 121b are pushed towards each other. In response to the first arm 121a and the second arm 121b are pushed towards each other, the locking member 120 is configured to radially contract so that the locking member 120 can be easily inserted into the cavity 111. Once the locking member 120 is disposed within the cavity 111, the first arm 121a and the second arm 121b are released. As a result, the locking member 120 comes to its original shape and fits within the cavity 111. When the locking member 120 is disposed inside the cavity 111, the outer face 120a of the locking member 120 mates with the face 111a of the cavity 111, an outer face (not shown) of the first arm 121a mates with a first face 113a (depicted in Fig. 2) of the cutout 113 and an outer face 121b1 of the second arm 121b mates with a second face (not shown) of the cutout 113, the second face of the cut-out 113 being opposite to the first face 113a.
[31] The cross-sectional shapes and dimensions of the locking member 120 and the cavity 111 match with each other so that the locking member 120 snugly fits within the cavity 111. The locking member 120 may be made of a biocompatible material including, but not limited to, cobalt-chromium (Co-Cr), titanium, stainless steel, etc. In an embodiment, the locking member 120 is made of cobalt-chromium (Co-Cr).
[32] Fig. 4 depicts a tibial liner 130, according to an embodiment of the present disclosure. The tibial liner 130 replaces the natural cartilage tissues and provides an articulating surface to a femoral component of the knee prosthesis. The tibial liner 130 facilitates smooth movement within the joint, mimicking the natural gliding motion of a healthy knee cartilage. In an embodiment, the tibial liner 130 is used to replace one half of the natural tibial joint.
[33] In an embodiment, the tibial liner 130 has a D-shape, though it may have any other suitable shape. The tibial liner 130 includes a protrusion 131 provided on a bottom surface 130a. The protrusion 131 forms an integral structure with the tibial liner 130, for example, the protrusion 131 may be extruded from the bottom surface 130a. The protrusion 131 is positioned such that it aligns with position of the cavity 111. In an exemplary embodiment, the protrusion 131 is disposed centrally on the bottom surface 130a. A top surface (not shown) of the tibial liner 130 is configured to articulate with the femoral condyles and/or the femoral component of the knee prosthesis.
[34] The protrusion 131 is configured to fit within the cavity 111 of the tibial component 110. The shape and dimensions of the protrusion 131 correspond to the shape and dimensions of the cavity 111 so that the protrusion 131 can snugly fit within the cavity 111.
[35] The protrusion 131 has a slot 132 provided peripherally towards the bottom surface 130a. The locking member 120 is configured to reside between a face 131b of the slot 132 and the face 111a of the cavity 111 such that the outer face 120a of the locking member 120 is configured to mate with the face 111a of the cavity 111 and an inner face 120b of the locking member 120 is configured to mate with the face 131b of the slot 132.
[36] In an embodiment, the tibial liner 130 may include one or more additional protrusions (e.g., protrusions 133 and 135) provided on the bottom surface 130a. In an embodiment, the one or more additional protrusions are extruded from the bottom surface 130a. Each protrusion of the one or more protrusions is configured to fit within a corresponding cavity of the one or more additional cavities of the tibial component 110. For example, the protrusions 133 and 135 fit within the cavities 115 and 117, respectively. The protrusions 133 and 135 have shapes and dimensions corresponding to that of the cavities 115 and 117, respectively, so that they snugly fit with each other. In the depicted embodiment, the protrusions 133 and 135 have a trapezoidal shape.
[37] The dimensions of the tibial liner 130 may vary according to or based upon the anatomy of the patient and/or of patient population in consideration. The tibial liner 130 may be made of a biocompatible material including, but not limited to, Ultra-High Molecular Weight Polyethylene (UHMWPE) including vitamin E, high cross-linked polyethylene (HXLPE), ceramic, etc. In an embodiment, the tibial liner 130 is made of high cross-linked polyethylene (HXLPE).
[38] An embodiment of coupling the tibial liner 130 with the tibial component 110 is now explained. The locking member 120 is disposed within the tibial component 110 as described earlier. The tibial liner 130 is aligned with and disposed over the tibial component 110. For example, the protrusion 131 aligns with the cavity 111 and the protrusions 133 and 135 align with the cavities 115 and 117 respectively. The top surface of the tibial liner 130 is then impacted (e.g., using a mallet). As a result, the protrusion 131 moves into the cavity 111. As a face 131a of the protrusion 131 moves downwards, the face 131a causes the locking member 120 to expand slightly. When the face 131a moves further down, the locking member 120 contracts back to its rest shape and the inner face 120b of the locking member 120 mates with the face 131b of the slot 132. Thus, locking member 120 securely grips the protrusion 131. Further, a face 131a and a face 131c of the protrusion 131 mate with the face 111a and a face 111b of the cavity 111, respectively. Further, a face 133a of the protrusion 133 mates with a face 115a of the cavity 115 and a face 135a of the protrusion 135 mates with a face 117a of the cavity 117. In addition, the upper surface 110a of the tibial component 110 mates the bottom surface 130a of the tibial liner 130. Thus, the tibial liner 130 is assembled with the tibial component 110. A cross-sectional view of the assembled tibial liner 130 and the tibial component 110 is depicted in Fig. 1. Since the diameter of the face 131b is smaller than the diameter of the face 131a, it keeps the locking member 120 in place between the slot 132 and the face 111a of the cavity 111, which in turn prevents any relative movement between the tibial liner 130 and the tibial component 110. Thus, the tibial component 110 and the tibial liner 130 are securely locked with each other via the locking member 120 and any chances of dislocation or loosening are eliminated.
[39] The present disclosure provides several advantages. For example, unlike the conventional prosthesis which are more prone to dislocation and loosening of the conventional tibial liner from the conventional tibial component, the tibial liner in the present disclosure is securely coupled to the tibial component using the locking member. The locking member ensures a firm locking of the tibial liner with the tibial components. This prevents dislocation and loosening. This reduces the chances of failure and increases the life of the proposed tibial prosthesis. This improves the overall patient outcome.
[40] 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 tibial prosthesis (100) comprising:
a. a tibial component (110) comprising a cavity (111) provided on an upper surface (110a) of the tibial component (110);
b. a tibial liner (130) comprising a protrusion (131) provided on a bottom surface (130a) of the tibial liner (130) and configured to fit within the cavity (111) of the tibial component (110), the protrusion (131) having a slot (132) provided peripherally towards the bottom surface (130a); and
c. a locking member (120) configured to reside between a face (111a) of the cavity (111) and a face (131b) of the slot (132) of the protrusion (131) and configured to lock the tibial liner (130) with the tibial component (110).
2. The tibial prosthesis (100) as claimed in claim 1, wherein the locking member (120) comprises a first arm (121a) and a second arm (121b) provided on either side of a cut-out portion (121) of the locking member (120), the first arm (121a) and the second arm (121b) are configured to be disposed within a cut-out (113) provided on a side of a perimeter of the cavity (111) of the tibial component (110).
3. The tibial prosthesis (100) as claimed in claim 1, wherein the locking member (120) is a ring.
4. The tibial prosthesis (100) as claimed in claim 1, wherein tibial liner (130) comprises one or more additional protrusions (133, 135) provided on the bottom surface (130a) of the tibial liner (130), each protrusion (133, 135) of the one or more additional protrusions (133, 135) are configured to fit within a corresponding cavity (115, 117) of one or more additional cavities (115, 117) provided on the upper surface (110a) of the tibial component (110).
5. The tibial prosthesis (100) as claimed in claim 1, wherein a face (131a) of the protrusion (131) of the tibial liner (130) is configured to mate with the face (111a) of the cavity (111) of the tibial component (110).