ORTHOPEDIC IMPLANT

Abstract

TITLE OF INVENTION: ORTHOPEDIC IMPLANT A trial implant (100) includes a tray (110), a liner (120) and a post (130). The tray (110) includes a wall (115) defining a cavity having a base (117),) and an aperture (111) provided on the base (117). The liner (120) includes a body (125) disposed at a proximal end (120a) of the liner (120) and a slab (127) extending from a bottom surface (125b) of the body (125) towards a distal end (120b) of the liner (120). The slab (127) includes a first projection (121) configured to reside within the aperture (111). The post (130) is coupled to the liner (120). The post (130) includes a body (132) situated towards a distal end (130b) and an extended portion (134) extending from a proximal end (132a) of the body (132) to a proximal end (130a) of the post (130). The extended portion (134) is coupled to the first projection (121) by a threaded coupling. In response to the rotational motion of the post (130), the liner (120) is configured to move in a longitudinal direction to achieve a plurality of offset positions. Fig. 1B

Specification

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:
ORTHOPEDIC 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 an orthopedic assembly. More particularly, the present disclosure relates to a trial implant.
BACKGROUND OF INVENTION
[2] The glenohumeral joint is a highly mobile ball-and-socket joint that connects the upper arm bone (humerus) to the shoulder blade (scapula). It allows for an exceptional range of motion, but it is also prone to instability due to the shallow socket. Surrounding muscles, ligaments, and tendons work together to provide support and facilitate movement. There are several medical conditions that are associated with the glenohumeral joint such as acute proximal humerus fractures, post-traumatic glenohumeral osteoarthritis, chronic irreducible shoulder dislocation, etc. A patient suffering from any of the aforementioned medical condition may face several complications such as stiffness in the joint, loss of partial or full range of motion, pain during movement and so forth.
[3] For the treatment of such medical conditions, a doctor may suggest the patient to undergo reverse total shoulder arthroplasty (RTSA). In RTSA, the ball part is implanted on the scapula and the socket is implanted on the proximal humerus.
[4] The arrangement of the socket and the ball is positioned at an offset which may depend on the anatomy of the patient to obtain the maximum range of motion. Conventionally, a trial implant is used to determine the offset before final implantation. For every offset, there is a separate trial implant. The medical practitioner has to try a number of trial implants before deciding an optimal implant with an offset that offers the maximum range of motion. Thus, the conventional method of determining the offset of the ball and the socket arrangement may increase the overall time required for the surgery and may make the procedure cumbersome. Further, due to implanting and removing multiple trial implants with different offset during the same procedure, trauma caused to the patient is also significant.
[5] Hence, there is a need for a trial implant that overcomes the shortcomings, associated with the trial implants known in the art.
SUMMARY OF INVENTION
[6] 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.
[7] The present disclosure relates to a trial implant. The trial implant includes a tray, a liner and a post. The tray has a proximal end and a distal end. The tray includes a wall defining a cavity having a base and an aperture provided on the base extending to the distal end of the tray. The liner is disposed at a proximal end of the trial implant. The liner includes a body disposed at a proximal end of the liner and a slab extending from a bottom surface of the body towards a distal end of the liner. The slab comprises a first projection provided on a bottom face of the slab and configured to reside within the aperture. The post is provided at a distal end of the trial implant and coupled to the liner. The post includes a body situated towards a distal end of the post and an extended portion extending from a proximal end of the body to a proximal end of the post. The extended portion is coupled to the first projection by a threaded coupling. In response to the rotational motion of the post, the liner is configured to move in a longitudinal direction to achieve a plurality of offset positions.
BRIEF DESCRIPTION OF DRAWINGS
[8] 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.
[9] Fig. 1A depicts a trial implant 100, according to an embodiment of the present disclosure.
[10] Fig. 1B depicts an exploded view of the trial implant 100, according to an embodiment of the present disclosure.
[11] Fig. 2A depicts a perspective view of a tray 110, according to an embodiment of the present disclosure.
[12] Fig. 2B depicts another perspective view of the tray 110, according to an embodiment of the present disclosure.
[13] Fig. 2C depicts a cross-sectional view of the tray 110, according to an embodiment of the present disclosure.
[14] Fig. 3A depicts a front view of a liner 120, according to an embodiment of the present disclosure.
[15] Fig. 3B depicts a bottom view of the liner 120, according to an embodiment of the present disclosure.
[16] Fig. 3C depicts a perspective view of the liner 120, according to an embodiment of the present disclosure.
[17] Fig. 3D depicts another perspective view of the liner 120, according to an embodiment of the present disclosure.
[18] Fig. 4 depicts a pin 140, according to an embodiment of the present disclosure.
[19] Fig. 5A depicts a perspective view of a post 130, according to an embodiment of the present disclosure.
[20] Fig. 5B depicts another perspective view of the post 130, according to an embodiment of the present disclosure.
[21] Fig. 6 depicts a locking member 150, according to an embodiment of the present disclosure.
[22] Fig. 7A depicts a cross-sectional view of the trial implant 100 at a first offset position, according to an embodiment of the present disclosure.
[23] Fig. 7B depicts a cross-sectional view of the trial implant 100 at a second offset position, according to an embodiment of the present disclosure.
[24] Fig. 7C depicts a cross-sectional view of the trial implant 100 at a third offset position, according to an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[25] 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.
[26] 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.
[27] 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.
[28] 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.
[29] The present disclosure relates to a trial implant. The trial implant of the present disclosure is utilized during a reverse total shoulder arthroplasty (RTSA). In an RTSA procedure, the glenoid cavity is replaced with a prosthetic glenoid ball, while the humeral head is replaced with the trial implant of the present disclosure. The trial implant is used to accurately position the humeral plate of the prosthesis with respect to the prosthetic glenoid ball implanted at the glenoid cavity. The multiple offset positions allowed by the trial implant provides a convenient and less traumatic solution for adjusting the position of the prosthetic humeral plate with respect to the prosthetic glenoid ball, thus, providing the maximum range of motion to the patient's glenohumeral joint, with the least or no strain on the muscles, ligaments, and tendons of the glenohumeral joint.
[30] The trial implant is placed on a prosthetic humeral stem that is implanted in the proximal humerus. The trial implant also provides an articulating surface to the prosthetic glenoid ball component that is implanted on the scapula to substitute the ball and socket arrangement of the glenohumeral joint.
[31] The humeral stem and the ball component are to be placed at a vertical or axial displacement offset that offers an optimal range of motion. In the context of the present disclosure, the offset corresponds to a distance between the center of rotation of the prosthetic glenoid ball engaging interface of the trial implant and the prosthetic humeral stem or an axial distance (i.e., height) between a humeral liner and a humeral tray.
[32] In an embodiment, the trial implant includes a tray (or a humeral tray), a liner (or a humeral liner), and a post. The liner and the post are coupled with the tray. The assembly of the liner, post and the tray form the trial implant. The trial implant can be toggled between multiple offsets by rotating the post. The trial implant has an initial height that is defined by the combination of the height of the base and the liner. The height of the trial implant can be adjusted by rotating the post. The rotation of the post increases or decreases the axial displacement between the liner and the tray, to attain different offsets. Thus, the trial implant of the present disclosure is not restricted to a single offset.
[33] The adjustability of the trial implant between multiple offsets allows a medical practitioner to determine the most appropriate offset for the patient, using a single trial implant. Thus, the use of the single trial implant of the present disclosure reduces the overall time of the surgery. The cost of the surgery may also be reduced as instead of using multiple trial implants for different offsets, only one trial implant can be used for multiple offsets. Further, due to the use of the single trial implant, patient trauma is also significantly reduced, as compared to procedures involving multiple separate implants having distinct offsets. The surgical procedure is also simplified by the use of the present trial implant as the medical practitioner does not need to repeat the process of placing and removing multiple trial implants to determine the final offset, optimal for the patient.
[34] Referring now to the figures, Fig. 1A - Fig. 1B depict a trial implant 100 (or implant 100), according to an embodiment. The trial implant 100 has a proximal end 100a and a distal end 100b. The trial implant 100 includes a tray 110, a liner 120, a post 130, a pin 140 and a locking member 150. The trial implant 100 is designed for use in shoulder replacement surgeries. During a shoulder replacement procedure (such as a total shoulder arthroplasty or a reverse shoulder arthroplasty), an optimal offset needs to be determined to achieve the best possible alignment, fit, and function of the shoulder implant according to the needs and anatomy of a patient. Thus, selecting the optimal offset during a trial phase of the shoulder replacement procedure plays an important role to restore natural biomechanics of the humeral joint, ensure proper load distribution, and achieve balance limb length with the help of the final implant. According to the teachings of the present disclosure, the trial implant 100 is adjustable to a plurality of offset positions. During a trial phase of the shoulder replacement surgery, the position of the liner 120 can be adjusted between different offset positions depending desired offsets to be trialed. Thus, the trial implant 100 of the present disclosure is capable of realizing multiple offsets using a single trial implant and eliminates the use of multiple trial implants as seen with conventional systems. Further, the liner 120 and the post 130 are designed in such a way that the position of the liner 120 can be easily adjusted by rotating the post 130 in a clockwise or anti-clock wise direction, thereby providing a streamlined and accurate method for selecting the appropriate offset during a surgery. In the context of the present disclosure, an offset may be defined as an axial distance between the liner 120 and the tray 110. The trial implant 100 of the present disclosure offers increased precision for shoulder replacement procedures. By incorporating multiple offset options into the trial implant 100, the invention simplifies the surgical process and reduces the risk of errors associated with manual tray selection. Thus, trial implant 100 reduces the complexity of the procedure and is also less time consuming, thereby improving the overall patient outcome. The trial implant 100 is also costs effective since multiple trial are not needed.
[35] Fig. 2A - Fig. 2B depict various views of the tray 110, according to an embodiment of the present disclosure. The tray 110 is designed to couple with the liner 120 and the post 130. The tray 110 has a proximal end 110a and a distal end 110b. The tray 110 generally has a circular shape, although the tray 110 may have any other shape, such as, without limitation, oval, trapezoidal, rectangular, etc. The tray 110 may be made of a material, such as, without limitation, Titanium, CoCr, SS316, or any other biocompatible medical grade metal. In an embodiment, the tray 110 is made of Titanium.
[36] A wall 115 may extend upwards from the periphery of the tray 110 towards the proximal end 110a. The wall 115 has an outer surface 115a, an inner surface 115b and a top surface 115c. The wall 115 defines a cavity having a base 117.
[37] In an embodiment, the wall 115 has at least one extended portion. In the depicted embodiment, the wall 115 includes a first extended portion 115e and a second extended portion 115f extending inward from an inner periphery of the wall 115. According to an embodiment, the first extended portion 115e includes a first flat surface 116c and the second extended portion 115f includes a second flat surface 116d. It should be understood that the number of extended portions may vary as required. In an embodiment, the first extended portion 115e and the second extended portion 115f are disposed at the opposite sides of the wall 115. The depicted locations of the first extended portion 115e and the second extended portion 115f are merely exemplary and the first extended portion 115e and a second extended portion 115f may be provided at any other location as needed. The first flat surface 116c and the second flat surface 116d may be circular, rectangular, oval, conical, etc. In an exemplary embodiment, the first flat surface 116c and the second flat surface 116d are rectangular such that a top portion of the cavity defined by the wall 115 has a rectangular shape with curved ends at two sides. The first extended portion 115e and the second extended portion 115f help in easy assembly of the tray 110 with the liner 120 and resist the rotational motion of the liner 120.
[38] The wall 115 provides additional surface area to the tray 110 for contact with surrounding tissues and also contributes to provide stability and secure placement of the trial implant 100 during the trial fitting. The wall 115 may be provided with a plurality of serrations 115n (or serrations 115n). The serrations 115n are carved on the outer surface 115a of the wall 115. The serrations 115n may have a shape, such as, without limitation, circular, plus, cross, zig - zag, etc., or combinations thereof. In an embodiment, the serrations 115n are circular. The serrations 115n facilitate the surgeon to grip the trial implant 100 more easily and securely during the surgical procedure, thereby, reducing the risk of slippage.
[39] In an embodiment, a hole 113 is provided on the first flat surface 116c of the wall 115. The hole 113 extends from the first flat surface 116c to the outer surface 115a of the wall 115 for the entire width of the wall 115. The hole 113 is configured to accommodate the pin 140. The hole 113 may have a pre-defined shape, such as, without limitations, circular, oval, square, etc. In an embodiment, the hole 113 is circular.
[40] The tray 110 is provided with an aperture 111 on the base 117. The aperture 111 extends from the base 117 towards the distal end 110b for the height of the base 117. In an embodiment, the aperture 111 is located at the center of the tray 110. It should be understood that the aperture 111 may be positioned at an offset from the center of the tray 110 based upon requirements. The aperture 111 may have a cross-sectional shape, such as, without limitations, circular, oval, square, etc. In an embodiment, the aperture 111 has a circular cross-section. In an embodiment, the aperture 111 has a proximal portion 111a situated towards the proximal end 110a and a distal portion 111b situated towards the distal end 110b. The diameter of the proximal portion 111a is larger than the diameter of the distal portion 111b, forming a step profile (as shown in Fig. 2C). The aperture 111 is used to couple the liner 120 with the tray 110 (described later). The step-profile of the aperture 111 helps in locking the post 130 with the tray 110.
[41] A slot 112 may be provided on the base 117. The slot 112 extends from the base 117 towards the distal end 110b for a partial height of the base 117. In an embodiment, the slot 112 is situated towards the first flat surface 116c of the wall 115. In another embodiment, the slot 112 may be situated towards the second flat surface 116d. It should be understood that the slot 112 may be situated at any other position based upon requirements. The slot 112 may have a shape, such as, without limitations, square, cuboidal, cylindrical, conical, frustum, tapered, etc. In an embodiment, the slot 112 is cuboidal. The slot 112 is used to couple the liner 120 with the tray 110. The slot 112 also functions to restrict the rotational motion of the liner 120 with respect to the tray 110.
[42] Figs. 3A-3D depict various views of the liner 120, according to an embodiment of the present disclosure. The liner 120 is disposed at the proximal end 100a of the trial implant 100. The liner 120 has a proximal end 120a, and a distal end 120b. The liner 120 may be made of a biocompatible material such as, without limitations, ultra-high molecular weight polyethylene (UHMWPE), Polymethyl methacrylate (PMMA), Highly cross-linked polyethylene (HXLPE) including vitamin E, etc. In an embodiment, liner 120 is made of UHMWPE. The liner 120 includes a body 125 disposed at a proximal end 120a of the liner 120. The body 125 has a top surface 125a and a bottom surface 125b. The body 125 may be slanted. That is, the height of the body 125 reduces from one end to a diametrically opposite end. In the depicted embodiment, L1 and L2 defined the height of the two diametrically opposite ends. In an embodiment, L1 is less than L2. The slant conforms to the underlying human anatomy. The top surface 125a of the body 125 may include a curvature. In an embodiment, the top surface 125a includes a concave structure. The curvature of the top surface 125a of the body 125 is configured to receive a glenoid component (not shown) and provides an articulating surface for the glenoid component. The liner 120 is coupled with the tray 110 (described later).
[43] The tray 110 includes a slab 127 (as shown in fig. 3A). The slab 127 extends away from the bottom surface 125b of the body 125 towards the distal end 120b of the liner 120. In an embodiment, the slab 127 is designed such that the slab 127 defines a gap 126 between the slab 127 and the body 125. In an embodiment, the height of the slab 127 varies with respect to the patient anatomy. The slab 127 helps in coupling the liner 120 with the tray 110. In an embodiment, the slab 127 forms an integrated structure with the body 125. In another embodiment, the slab 127 may be a separate component coupled to the body 125 using, for example, bonding, or any other suitable coupling technique known in the art.
[44] The slab 127 has a bottom surface 127e. In an exemplary embodiment, the slab 127 has a rounded cuboidal shape having a first curved surface 127a, a second curved surface 127b, a first flat surface 127c and a second flat surface 127d. It should be understood that the slab 127 may have any other shape, such as, quadrilateral, cylindrical, frustum, etc. As shown, the first curved surface 127a and the second curved surface 127b are provided at opposite sides of the slab 127. The first curved surface 127a and the second curved surface 127b are configured to mate with the inner surface 115b of the wall 115. The locations of the first curved surface 127a and the second curved surface 127b depicted herein are merely exemplary and the first curved surface 127a and the second curved surface 127b may be provided at any other location as needed.
[45] As shown, the first flat surface 127c and the second flat surface 127d are disposed at opposite sides of the slab 127. The first flat surface 127c and the second flat surface 127d are configured to mate with the first flat surface 116c and the second flat surface 116d, respectively, of the wall 115. The depicted locations of the first flat surface 127c and a second flat surface 127d are merely exemplary and the first flat surface 127c and a second flat surface 127d may be provided at any other location as needed. The first flat surface 127c and a second flat surface 127d may be circular, rectangular, oval, etc. In an exemplary embodiment, first flat surface 127c and a second flat surface 127d are rectangular.
[46] The liner 120 includes a first projection 121 extending from the bottom surface 127e towards the distal end 120b. The first projection 121 may be located at the center of the bottom surface 127e of the slab 127. Alternatively, the first projection 121 may be at an offset from the center of the bottom surface 127e. The first projection 121 is configured to fit in the proximal portion 111a of the aperture 111 of the tray 110. The first projection 121 may have dimensions and shape corresponding to the dimensions and shape of the aperture 111 of the tray 110. In an embodiment, the first projection 121 has a cylindrical shape. In an embodiment, the first projection 121 has a tubular structure and includes a cavity 121a. The cavity 121a extends from a distal end of the first projection 121 into the slab 127 for a pre-defined distance. Further, the cavity 121a is provided with a plurality of internal threads 121n. The plurality of internal threads 121n of the first projection 121 help in coupling the post 130 with the liner 120 and adjust the offset of the liner 120 as explained later.
[47] Further, the liner 120 may include a second projection 122 extending from the bottom surface 127e of the slab 127 towards the distal end 120b. In an embodiment, the second projection 122 may be situated towards the periphery of the slab 127. In the depicted embodiment, the second projection 122 is situated adjacent to the first flat surface 127c of the slab 127 such that a side of the second projection 122 is contiguous with the first flat surface 127c. It should be understood though that the second projection 122 may be situated at any other location as needed. At least a portion of the second projection 122 is configured to fit within the slot 112 of the tray 110. The shape and dimensions of the second projection 122 are complementary to the shape and dimensions of the slot 112 of the tray 110. In an embodiment, the second projection 122 is cuboidal. Though in the depicted embodiment, the first projection 121 and the second projection 122 are shown to form an integrated structure with the slab 127, in another embodiment, either the first projection 121 or the second projection 122 or both may be separate components coupled to the slab 127 using, for example, bonding or any other suitable coupling technique known in the art.
[48] The liner 120 may include a plate 128. The plate 128 may extend from the bottom surface 127e of the slab 127 to the bottom surface 125b of the body 125. The plate 128 may be provided on one of the first flat surface 127c or the second flat surface 127d of the slab 127. In an embodiment, the plate 128 provided on the first flat surface 127c of the slab 127. In an embodiment, plate 128 forms an integrated structure with the liner 120. The plate 128 may have a shape such as, without limitations, rectangular, oval, square, etc. In an embodiment, the plate 128 has a rectangular shape. A plurality of indicators is provided on the plate 128. Each of the plurality of indicators indicates a corresponding offset position of a plurality of offset positions realized by the implant 100. In the depicted embodiment, the implant 100 is designed to achieve three offsets and accordingly, the plurality of indicators includes three indicators, namely, a first indicator 128a, a second indicator 128b and a third indicator 128c. The first indicator 128a, the second indicator 128b and the third indicator 128c correspond to a first offset position, a second offset position and a third offset position, respectively. According to an embodiment, the first offset corresponds to 0 mm, the second offset corresponds to +5 mm and the third offset corresponds to + 10 mm. During medical procedures, the plurality of indicators helps in visually guiding a surgeon to choose a desired offset between the liner 120 and the tray 110. For example, the alignment of the top surface 115c with one of the plurality of indicators indicates that the implant 100 is at the corresponding offset position. An offset position may correspond a distance between the bottom surface 125b of the body 125 of the liner 120 and the top surface 115c of the wall 115 of the tray 110. It should be understood that though the depicted embodiment shows three offsets and corresponding three indicators, the implant 100 may be designed to achieve less than or greater than three offsets and the actual number of indicators varies based upon the number of offsets. Further, the correspondence of the first, second and third offset to 0 mm, +5 mm and + 10 mm, respectively, is merely exemplary, and the first, second and third offsets may correspond to any other offset values.
[49] A vertical slot 129 (as shown in fig. 3D) is provided on the liner 120. The vertical slot 129 may be situated on one the first flat surface 127c or the second flat surface 127d. In an embodiment, the vertical slot 129 is provided on second flat surface 127d of the slab 127. It should be understood though that the vertical slot 129 may be situated at any other location as needed. The vertical slot 129 extends between a distal end of the second projection 122 and a proximal end of the slab 127. The vertical slot 129 may have a cross-section such as, without limitations, oval, semi-circular, cuboidal, etc. In an embodiment, the vertical slot 129 has a rectangular cross-section with curved ends. The vertical slot 129 is configured to accommodate the pin 140.
[50] Fig. 4 depicts an exemplary pin 140. In an embodiment, the pin 140 is cylindrical. The pin 140 has a first end 140a, a second end 140b and a body 140c. The pin 140 extends through the hole 113 of the tray 110 into the vertical slot 129 of the liner 120 such that the first end 140a is disposed within the vertical slot 129 and the second end 140b is disposed on the outer surface 115a of the wall 115. The cross-sectional dimensions of the body 140c are complementary to the cross-sectional dimensions of the hole 113 of the tray 110 and the width of the vertical slot 129 of the liner 120. A portion of the pin 140 is movable within the vertical slot 129. The pin 140 prevents the liner 120 from rotating while allowing a vertical movement of the liner 120 with respect to the tray 110. The pin 140 may be made of a material, such as, without limitations, Titanium, CoCr, SS316, or any other biocompatible medical grade metal. In an embodiment, the pin 140 is made of Titanium.
[51] Figs. 5A-5B depict various views of the post 130. The post 130 is provided at a distal end 100b of the trial implant 100. The post 130 has a proximal end 130a and a distal end 130b. The post 130 is rotatable in a clockwise and an anticlockwise direction. In an embodiment, the post 130 is coupled to the liner 120 via threaded coupling. The post 130 may be made of a material, such as, without limitations, Titanium, CoCr, SS316, or any other biocompatible medical grade metal. In an embodiment, the post 130 is made of Titanium.
[52] The post 130 has a body 132 and an extended portion 134. The body 132 is situated towards the distal end 130b of the post 130. The body 132 has proximal end 132a and a distal end 132b. The body 132 may have a structure, such as, without limitations, cylindrical, cuboidal, oval, etc. In an embodiment, the body 132 is cylindrical. The body 132 may have a taper with a diameter of the body 132 decreasing from the proximal end 132a to the distal end 132b of the body 132. Optionally, a plurality of vertical carvings may be provided on the body 132 along the length of the body 132. The plurality of carving provides a better grip on the post 130 during medical procedures.
[53] The extended portion 134 extends from the proximal end 132a of the body 132 to the proximal end 130a of the post 130. The extended portion 134 may have a shape complementary to the cavity 121a of the first projection 121. In an embodiment, the extended portion 134 is cylindrical. The extended portion 134 partially fits within the cavity 121a of the first projection 121. Further, a part of the extended portion 134 fits within the distal portion 111b of the aperture 111. The cross-sectional shape and dimensions of the extended portion 134 corresponds to the cross-sectional shape and dimensions of the cavity 121a of the first projection 121. The extended portion 134 includes a plurality of external threads 134n. The plurality of external threads 134n may extend to at least a partial length of the extended portion 134. In an embodiment, the plurality of external threads 134n are configured to engage with the plurality of internal threads 121n of the first projection 121. The plurality of external threads 134n are complementary to the plurality of internal threads 121n of the of the first projection 121.
[54] Once assembled, the plurality of external threads 134n of the post 130 and the plurality of internal threads 121n of the first projection 121 form a threaded coupling between the liner 120 and the post 130. As the rotational movement of the liner 120 is prevented by the pin 140, the engagement of plurality of internal threads 121n with the plurality of external threads 134n translates the rotational motion of the post 130 into a longitudinal motion of the liner 120, effectively moving the liner 120 in an upward or downward direction depending upon the rotational direction of the post 130 and creating an offset between the liner 120 and the tray 110. For example, in the depicted embodiment, in response to the post 130 rotating in the anti-clockwise direction, the liner 120 is configured to move in upward direction and in response to the post 130 rotating in the clockwise direction, the liner 120 is configured to move in downward direction. In another embodiment, in response to the post 130 rotating in the clockwise and anti-clockwise direction, the liner 120 is configured to move upward and downward direction, respectively. Though in the depicted embodiment, the post 130 is provided with the plurality of external threads 134n and the first projection 121 is provided with the plurality of internal threads 121n, it should not be considered as limiting. In another embodiment, the extended portion 134 of the post 130 may include a cavity (not shown) provided with a plurality of internal threads and the first projection 121 of the liner 120 may be provided a plurality of external threads that are complementary to and engaging with the plurality of internal threads of the post 130. In this case, the first projection 121 resides within the cavity of the extended portion 134, which in turn resides within the aperture 111.
[55] A groove 134a may be provided circumferentially on the extended portion 134 and situated proximal to the plurality of external threads 134n. The groove 134a may have a cross-section, such as, without limitations, circular, semi-circular, etc. In an embodiment, the groove 134a has a semi-circular cross-section. The groove 134a is configured to accommodate the locking member 150. In an embodiment, groove 134a has a shape and dimensions corresponding to the shape and dimensions of the locking member 150.
[56] The locking member 150 is configured to lock the post 130 with the tray 110. Fig. 6 illustrates an exemplary locking member 150. In an embodiment, the locking member 150 has a ring-shape with open ends (as shown in Fig. 6). In the depicted embodiment, the locking member 150 is a circlip and includes a semi flexible body 151 having an opening 152 and an arm 153 provided on each side of the opening 152. The width of the arms 153 is greater than the width of the body 151. This helps in locking. The arms 153 allow a surgeon to grip the locking member 150. When the arms 153 are pressed towards each other, the opening 152 is narrowed and the internal diameter of the body 151 is reduced. When the arms 153 are released, the body 151 returns to original shape. The locking member 150 fits within the groove 134a of the post 130. The inner diameter of the locking member 150 is equal to the diameter of the groove 134a for a snug-fitting with the post 130. The position of the groove 134a is designed such that, when assembled, the locking member 150 sits within the proximal portion 111a of the aperture 111. The outer diameter of the locking member 150 is designed to be greater than the diameter of the distal portion 111b of the aperture 111, preventing any downward movement of the post 130 when assembled with the tray 110, thereby locking the post 130 with the tray 110. It should be understood that any other locking member 150 coupled to the post 130 and the tray 110 and configured to prevent the downward movement of the post 130 may be used without deviating from the scope of the present disclosure. The locking member 150 may be made of a material, such as, without limitation, Titanium, CoCr, SS316, or any other biocompatible medical grade metal. In an embodiment, the locking member 150 is made of Titanium.
[57] An exemplary process to assemble the trial implant 100 during a medical procedure is explained below. To couple the liner 120 with the tray 110 the first projection 121 and the second projection 122 of the liner 120 are aligned with the aperture 111 and the slot 112, respectively of the tray 110. The liner 120 is then pushed towards until the first projection 121 of the liner 120 fits in the aperture 111 of the tray 110. The pin 140 is then inserted through the hole 113 until the first end 140a of the pin 140 is disposed within the vertical slot 129 of the liner 120. The surgeon slides the extended portion 134 of the post 130 into the cavity 121a of the first projection 121 and couples the post 130 and the first projection 121 with the help of the plurality of external threads 134n and the plurality of internal threads 121n. Once the plurality of external threads 134n and the plurality of internal threads 121n engage with each other, the locking member 150 is inserted and coupled with the groove 134a, locking the post 130 with the tray 110. The surgeon then rotates the post 130 in a second pre-defined direction (e.g., clockwise in the depicted embodiment), causing the liner 120 to move downwards. The surgeon may continue rotating the post 130 until the liner 120 reaches an initial position. In an embodiment, the initial position of the liner 120 may represent the first offset. In the first offset, the slab 127 is disposed within the cavity of the tray 110 such that the first curved surface 127a and the second curved surface 127b mate with the inner surface 115b of the wall 115, the first flat surface 127c of the slab 127 mates with the first flat surface 116c of the wall 115 and the second flat surface 127d of the slab 127 mates with the second flat surface 116d of the wall 115. Further, the second projection 122 fits within the slot 112 and the bottom surface 125b of the body 125 mates with the top surface 115c of the wall 115. In addition, in the first offset, the top surface 115c of the wall 115 aligns with the first indicator 128a. A cross-sectional view of the trial implant 100 in the first offset position (0 mm in the depicted embodiment) is shown in Fig. 7A.
[58] To achieve a desired offset, the surgeon rotates the post 130 in a first pre-defined direction (e.g., anti-clockwise direction in the depicted embodiment). In response to this rotational motion of the post 130, the liner 120 moves in an upward direction, causing the pin 140 to move downward within the vertical slot 129. The post 130 may be rotated until the top surface 115c of the wall 115 aligns with an indicator corresponding to the desired offset. For example, the surgeon may rotate the post 130 in the first pre-defined direction until the top surface 115c of the wall 115 aligns with the second indicator 128b to achieve the second offset (+5 mm in the depicted embodiment). Fig. 7B depicts a cross-sectional view of the trial implant 100 at the second offset. The surgeon may continue rotating the post 130 in the first pre-defined direction until the top surface 115c of the wall 115 aligns with the third indicator 128c to achieve the third offset (+10 mm in the depicted embodiment. Fig. 7C depicts a cross-section view of the trial implant 100 at the third offset.
[59] 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. , C , C , C , Claims:We claim:
1. A trial implant (100) comprising:
a. a tray (110) having a proximal end (110a) and a distal end (110b), the tray (110) comprising:
i. a wall (115) defining a cavity having a base (117);
ii. an aperture (111) provided on the base (117) and extending to the distal end (110b) of the tray (110); and
b. a liner (120) disposed at a proximal end (100a) of the trial implant (100), the liner (120) comprising:
i. a body (125) disposed at a proximal end (120a) of the liner (120); and
ii. a slab (127) extending from a bottom surface (125b) of the body (125) towards a distal end (120b) of the liner (120), the slab (127) comprising a first projection (121) provided on a bottom surface (127e) of the slab (127) and configured to reside within the aperture (111); and
c. a post (130) provided at a distal end (100b) of the trial implant (100) and coupled to the liner (120), the post (130) comprising:
i. a body (132) situated towards a distal end (130b) of the post (130); and
ii. an extended portion (134) extending from a proximal end (132a) of the body (132) to a proximal end (130a) of the post (130), the extended portion (134) is coupled to the first projection (121) by a threaded coupling;
d. wherein, in response to the rotational motion of the post (130), the liner (120) is configured to move in a longitudinal direction to achieve a plurality of offset positions.
2. The trial implant (100) as claimed in claim 1, wherein the first projection (121) comprises a cavity (121a) extending from a distal end of the first projection (121) and provided with a plurality of internal threads (121n), wherein the extended portion (134) partially resides within the cavity (121a) and is provided with a plurality of external threads (134n) configured to engage with the plurality of internal threads (121n) of the first projection (121).
3. The trial implant (100) as claimed in claim 1, wherein the extended portion (134) comprises a cavity provided with a plurality of internal threads, wherein the first projection (121) resides within the cavity of the extended portion (134) and is provided with a plurality of external threads configured to engage with the plurality of internal threads of the extended portion (134).
4. The trial implant (100) as claimed in claim 1, wherein a second projection (122) is provided on the bottom surface (127e) of the slab (127), the second projection (122) is configured to at least partially reside within a slot (112) provided on the base (117) of the tray (110).
5. The trial implant (100) as claimed in claim 4, wherein a side of the second projection (122) is contiguous with a first flat surface (127c) of the slab (127).
6. The trial implant (100) as claimed in claim 1, wherein the trial implant (100) comprises a pin (140) configured to prevent rotational motion of the liner (120), the pin (140) extending through a hole (113) provided on the tray (110) into a vertical slot (129) provided on the slab (127), a portion of the pin (140) is movable within the vertical slot (129).
7. The trial implant (100) as claimed in claim 6, wherein the vertical slot (129) is provided on a first flat surface (127c) or a second flat surface (127d) of the slab (127).
8. The trial implant (100) as claimed in claim 1, wherein the liner (120) includes a plate (128) provided with a plurality of indicators (128a, 128b, 128c), wherein each of the plurality of indicators (128a, 128b, 128c) corresponds to an offset position of the plurality of offset positions.
9. The trial implant (100) as claimed in claim 8, wherein the plate (128) is provided on a first flat surface (127c) or a second flat surface (127d) of the slab (127).
10. The trial implant (100) as claimed in claim 1, wherein:
a. the wall (115) comprises an inner surface (115b), a first extended portion (115e) and a second extended portion (115f), the first extended portion (115e) and the second extended portion (115f) extend inward from an inner periphery of the wall (115) and comprise a first flat surface (116c) and a second flat surface (116d), respectively; and
b. the slab (127) comprises a first curved surface (127a), a second curved surface (127b), a first flat surface (127c) and a second flat surface (127d), wherein the first curved surface (127a) and the second curved surface (127b) are configured to mate with the inner surface (115b) of the wall (115), and the first flat surface (127c) and the second flat surface (127d) of the slab (127) are configured to mate with the first flat surface (116c) and the second flat surface (116d), respectively, of the wall (115).
11. The trial implant (100) as claimed in claim 1, wherein a plurality of serrations (115n) is provided on an outer surface (115a) of the wall (115).
12. The trial implant (100) as claimed in claim 1, wherein the trial implant (100) comprises a locking member (150) coupled to the post (130) and the tray (110) and configured to prevent a downward movement of the post (130).
13. The trial implant (100) as claimed in claim 11, wherein the locking member (150) is disposed in a proximal portion (111a) of the aperture (111) and is configured to fit within a groove (134a) provided on the extended portion (134) of the post (130), the locking member (150) comprises a body (151) having an opening (152) and an arm (153) provided at each side of the opening (152).
14. The trial implant (100) as claimed in claim 1, wherein the aperture (111) of the tray (110) comprises a proximal portion (111a) and a distal portion (111b), the distal portion (111b) having a smaller diameter than the proximal portion (111a), wherein the first projection (121) is configured to reside within the proximal portion (111a) of the aperture (111).

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