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:
IMPLANT EXTRACTOR INSTRUMENT

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 instrument. More particularly, the present disclosure relates to a femoral implant extractor.
BACKGROUND OF INVENTION
[2] Partial knee replacement is a surgical procedure intended to replace the affected portion of the knee. Knee joint is the engagement between the femur bone and the tibia bone. The partial knee replacement targets a specific compartment like the medial, lateral, or patella-femoral compartment of the knee joint. A prosthetic is implanted after removing the damaged portion of the knee.
[3] During the implantation procedure, a trial prosthesis, for example, a trial femoral component may need to be inserted several times. This is done to perform trial reduction of the knee joint to assess fit, stability, and a range of motion using the trial femoral component before a final femoral implant is implanted. A femoral implant extractor (or femoral extractor) is used to extract the trial femoral component from the femoral condyle compartment. The femoral extractor is an instrument that grips the trial femoral component and allows the surgeon to extract it.
[4] Conventionally available femoral extractor instruments have a complex design with several components. They are also difficult to handle and use during the medical procedures. For example, the conventional instruments typically include a complex mechanism to ensure that the trial femoral component is locked with the instrument. The difficultly in operating the conventional instruments makes the overall surgical procedure more complicated and time consuming. Further, the conventionally available femoral extractors have complex designs, which increases the manufacturing cost.
[5] Thus, there arises a need for a device that overcomes the problems associated with the conventional devices.
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 an instrument. In an embodiment, the instrument includes a handle, a first arm, a second arm and a locking member. The first arm and the second arm are coupled to the handle. The first arm comprises a first clamp at a distal end of the first arm. The second arm comprises a second clamp at a distal end of the second arm. The locking member is provided at a distal end of the instrument and is slidably coupled with a distal portion of the second arm using a second fastener. The locking member includes a pair of slots disposed opposite to each other on a top face and a bottom face of the locking member. Each slot of the pair of slots is slanted from a first end of the slot towards the second end of the slot. A projection of the second fastener is disposed within a corresponding slot of the pair of slots and is movable between the first end and the second end of the corresponding slot.
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 perspective view of an instrument 100, according to an embodiment of the present disclosure.
[10] Fig. 1B depicts an exploded view of the instrument 100, according to an embodiment of the present disclosure.
[11] Fig. 2 depicts a handle 110 of the instrument 100, according to an embodiment of the present disclosure.
[12] Fig. 3A depicts a front view of a locking member 200 of the instrument 100, according to an embodiment of the present disclosure.
[13] Fig. 3B depicts a perspective view of the locking member 200 of the instrument 100, according to an embodiment of the present disclosure.
[14] Fig. 4 depicts a second fastener 500b of the instrument 100, according to an embodiment of the present disclosure.
[15] Fig. 5A depicts an assembly of the instrument 100 with a femoral component 400, according to an embodiment of the present disclosure.
[16] Fig. 5B depicts the assembly of the instrument 100 with the femoral component 400, according to an embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE DRAWINGS
[17] 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.
[18] 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.
[19] 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.
[20] 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.
[21] The present disclosure relates to a femoral extractor instrument (or instrument). The instrument includes a handle, a pair of arms and a locking member. The instrument is used during partial knee replacement surgeries. The instrument facilitates the extraction of partial knee femoral component in a precise and controlled manner thereby enhancing the efficiency of the surgical procedure.
[22] Fig. 1A depicts an assembled view of an instrument 100 and Fig. 1B is an exploded view of the instrument 100, according to an embodiment. The instrument 100 is used for extracting a trial femoral implant or a femoral implant during the implantation procedure. The instrument 100 has a proximal end 100a and a distal end 100b. The instrument 100 includes a handle 110, a first arm 120a, a second arm 120b and a locking member 200. The instrument 100 has a simple design with minimal components and is easier to operate than the conventional instruments.
[23] The handle 110 is situated at the proximal end 100a of the instrument 100. In an embodiment, the handle 110 has a flat U-shaped structure, though the handle 110 may have any other suitable shape. The handle 110 may have a concave shaped profile at its lateral sides as shown. The concave shaped profile of the handle 110 results in a more ergonomic design and provides a better grip to user. The handle 110 may be provided with a plurality of serrations 110n on lateral sides of the handle 110. The plurality of serrations 110n are provided to ensure a firm grip to the user during the medical procedures. The handle 110 is designed such that the handle 110 exhibits a spring action which aids in its operational function. During medical procedures, the incorporated spring action of the instrument 100 provides an elastic force to achieve a certain clamping force. This provides more stability to the instrument 100 and enhances usability of the instrument 100. The handle 110 may be made of a material, for example, a medical grade stainless steel. In an embodiment, the handle 110 is made of 17-4 PH stainless steel.
[24] Referring to Fig. 2, the first arm 120a and the second arm 120b are disposed distally to the handle 110 with each lateral side of the handle 110 coupled to one arm of the first arm 120a and the second arm 120b. In an embodiment, the handle 110, the first arm 120a and the second arm 120b form a single integrated structure. In an example implementation, the handle 110, the first arm 120a and the second arm 120b are manufactured as an integrated structure using a wire-cut technology. It should be understood that, in an embodiment, the first arm 120a and the second arm 120b may be separate components coupled to the handle 110 using any suitable coupling mechanism. In an embodiment, the first arm 120a and the second arm 120b have an undulating shape, though they may have any other suitable shape. The first arm 120a and the second arm 120b may be made of a material, for example, a medical grade stainless steel. In an embodiment, the first arm 120a and the second arm 120b are made of 17-4 PH stainless steel.
[25] In an embodiment, the first arm 120a has a first clamp 120a1 at a distal end of the first arm 120a and the second arm 120b has a second clamp 120b1 at a distal end of the second arm 120b. The first clamp 120a1 and the second clamp 120b1 may have a pre-defined shape such as, without limitation, J shaped, L shaped, etc. In an embodiment, the first clamp 120a1 and the second clamp 120b1 are L shaped. The first arm 120a includes a first hole 120c situated proximal to the first clamp 120a1. Similarly, the second arm 120b includes a second hole 120d situated proximal to the second clamp 120b1. Each of the first hole 120c and the second hole 120d are configured to accommodate a portion of a first fastener 500a and a second fastener 500b, respectively (described later). The first clamp 120a1 and the second clamp 120b1 are configured to grip a trial femoral component or a femoral component during the implantation procedure.
[26] Referring to Figs. 3A – 3B, the locking member 200 is provided towards the distal end 100b of the instrument 100. The locking member 200 has a proximal end 200a and a distal end 200b. The locking member 200 has a proximal face 200j, a distal face 200f, a top face 200g and a bottom face 200h. In an embodiment, the locking member 200 has a rectangular shape with curved edges, though it may have any other suitable shape. The locking member 200 may be made of a material, for example, a medical grade polymeric material. In an embodiment, the locking member 200 is made of polyphenylsulfone (e.g., Radel R-5000).
[27] According to an embodiment, the locking member 200 includes a first slot 200e disposed towards a lateral side of the locking member 200 as shown in Fig. 3B. The first slot 200e is a through-slot extending between the proximal face 200j and the distal face 200f. The first slot 200e is configured to receive a distal portion of the first arm 120a with the first clamp 120a1 disposed outside of the first slot 200e (as shown in Fig. 1). The first slot 200e has a generally rectangular shape with a curved edge towards a medial side of the locking member 200, though it may have any other shape.
[28] In an embodiment, the distal portion of the first arm 120a is fixedly coupled with the locking member 200 using the first fastener 500a, though any other suitable fastener may be used without deviating from the scope of the present disclosure. A pair of apertures 200i are provided in the locking member 200. One aperture of the pair of apertures 200i is provided on each of the top face 200g and the bottom face 200h. The pair of apertures 200i are aligned with the first hole 120c of the first arm 120a. The first fastener 500a passes through the pair of apertures 200i and the first hole 120c so that a projection (not shown) provided on each end of the first fastener 500a resides within a corresponding aperture 200i of the pair of apertures 200i and the remaining portion of the first fastener 500a resides within the first hole 120c. The cross-sectional shape and dimensions of the pair of apertures 200i correspond to the cross-sectional shape and dimensions of the first fastener 500a. In an embodiment, the aperture 200i is circular. Once the first fastener 500a is coupled to the locking member 200 and the distal portion of the first arm 120a, the first arm 120a does not move. Thus, the first arm 120a is fixedly coupled with the locking member 200.
[29] According to an embodiment, the locking member 200 includes a second slot 200d disposed towards the other lateral side of the locking member 200. The second slot 200d is a through-slot extending between the proximal face 200j and the distal face 200f. The second slot 200d is configured to receive a distal portion of the second arm 120b with the second clamp 120b1 being disposed outside of the second slot 200d (as shown in Fig. 1). In an embodiment, the second slot 200d is generally rectangular with a curved edge towards the medial side of the locking member 200, though it can have any other suitable shape.
[30] In an embodiment, the distal portion of the second arm 120b is slidably coupled with the locking member 200. In an embodiment, the distal portion of the second arm 120b is coupled with the locking member 200 using the second fastener 500b, though any other suitable fastener may be used. The locking member 200 includes a pair of slots 200c disposed opposite to each other on the top face 200g and the bottom face 200h, respectively. Each slot 200c has a first end 200c1 and a second end 200c2 as shown in Fig. 3B. The second fastener 500b passes through the pair of slots 200c and the second hole 120d to couple the distal portion of the second arm 120b with the locking member 200. Further, the distal portion of the second arm 120b is slidably disposed with the second slot 200d, i.e., the distal portion of the second arm 120b is configured to slide within the second slot 200d. In an embodiment, each slot 200c of the pair of slots 200c is slanted from the first end 200c1 towards the second end 200c2 (i.e., slanted from a lateral side towards a medial side) of the locking member 200, thereby defining a slanted path.
[31] In an embodiment, the first fastener 500a and the second fastener 500b are pins, though any suitable fasteners may be used without deviating from the scope of the present disclosure. An exemplary second fastener 500b is depicted in Fig. 4. In an embodiment, the second fastener 500b has a cylindrical shape, though it may have any other shape. In an embodiment, the second fastener 500b includes a projection 500b1 at each end of the second fastener 500b. In an embodiment, the projections 500b1 have a hemispherical shape, though they may have any other suitable shape. Each of the projections 500b1 is configured to reside within a corresponding slot 200c of the pair of slots 200c and is movable within the corresponding slots 200c between the first end 200c1 and the second end 200c2. In response to applying a pressure on the second arm 120b towards the medial side, the projections 500b1 of the second fastener 500b are configured to slide within the pair of slots 200c from the first end 200c1 towards the second end 200c2 along the slanted path and the distal portion of the second arm 120b also moves within the second slot 200d in a corresponding slanted path. Consequently, the second clamp 120b1 too moves in the corresponding slanted path. Effectively, the second clamp 120b1 not just moves in a medial direction towards the first clamp 120a1 but also in a proximal direction. The slanted profile of the pair of slots 200c ensure a proper locking of the trial femoral component or the femoral component with the instrument 100 during the operation of the instrument 100. Further, as the second arm 120b and the second clamp 120b1 are adjustable (i.e., their positions can be adjusted), the instrument 100 can be used for extracting different sizes of the trial femoral implants or the femoral implants, thereby improving the overall applicability of the instrument 100.
[32] The first fastener 500a is similar to the second fastener 500b. Its structure can be referred from the corresponding structure of the second fastener 500b and is not repeated for the sake of brevity. A projection (not shown) of the first fastener 500a provided at a respective end of the first fastener 500a is configured to reside within a corresponding aperture 200i of the pair of apertures 200i.
[33] Referring back to Fig. 2, a hole 300 may be provided at the proximal end of the handle 110. The hole 300 is configured to couple with a slap hammer adaptor for application of external force during the implantation procedures to extract the trial femoral component or the femoral component and/or to insert it.
[34] During the partial knee replacement surgery, the instrument 100 is used to grip a trial femoral component 400. Though the operation of the instrument 100 is explained below with the help of the trial femoral component, the instrument 100 can also be used to extract a femoral implant actually implanted in the patient during, for example, a revision surgery. The instrument 100 is held such that a bottom surface (not shown) of the trial femoral component 400 contacts the distal surface 200f of the locking member 200 as shown in Fig. 5A. Further, the first clamp 120a1 grips a first slot 400a of the trial femoral component 400. The user then presses the handle 110, i.e., applies pressure towards the medial direction of the instrument 100. Since the first arm 120a (and the first clamp 120a1) is fixedly coupled to the locking member 200, the second arm 120b moves towards the first arm 120a. The distal portion of the second arm 120b and the second clamp 120b1 move along the slanted path as explained earlier towards the first clamp 120a1. The second clamp 120b1 engages with a second slot 400b, respectively, provided on the trial femoral component 400. Consequently, the trial femoral component 400 is securely coupled with the instrument 100 (depicted in Fig. 5B). The first clamp 120a1 and the second clamp 120b1 remain securely engaged with the first slot 400a and the second slot 400b, respectively. The trial femoral component 400 is then pulled by the user either by a manual force or by impacting a slap hammer coupled to the instrument 100 via a slap hammer adapter coupled to the hole 300. Once the trial femoral component 400 is pulled out, the handle 110 is pressed slightly, to de-engage the second clamp 120b1 from the second slot 400b. The handle 110 can then be released. Upon releasing the handle 110, the second clamp 120b1 and the distal portion of the second arm 120b move to their original position due to the inherent spring-action of the handle 110.
[35] Though the use of the instrument 100 has been described to extract a trial femoral component, it should be appreciated that the instrument 100 can also be used to insert the trial femoral component during knee replacement surgeries.
[36] The proposed instrument provides several advantages. The proposed instrument has a simple design with minimal components, thereby reducing the cost of the instrument. Further, the proposed instrument is easier to operate compared to the conventional instruments. This reduces the overall procedure time and increases efficiency of the implantation procedure. The proposed instrument is also versatile and can be used for different sizes of the trial femoral implants or femoral implants. Further, due to its simple design, the manufacturing is easier and consequently, the manufacturing cost is lower compared to the conventional devices.
[37] The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used. , Claims:WE CLAIM
1. An instrument (100) comprising:
a. a handle (110);
b. a first arm (120a) coupled to the handle (110), the first arm (120a) comprising a first clamp (120a1) provided at a distal end of the first arm (120a);
c. a second arm (120b) coupled to the handle (110), the second arm (120b) comprising a second clamp (120b1) provided at a distal end of the second arm (120b); and
d. a locking member (200) provided at a distal end (100b) of the instrument (100) and slidably coupled with a distal portion of the second arm (120b) using a second fastener (500b) comprising a projection (500b1), the locking member (200) comprising a pair of slots (200c) disposed opposite to each other on a top face (200g) and a bottom face (200h) of the locking member (200), each slot (200c) of the pair of slots (200c) is slanted from a first end (200c1) of the slot (200c) towards a second end (200c2) of the slot (200c);
e. wherein the projection (500b1) of the second fastener (500b) is disposed within a corresponding slot (200c) of the pair of slots (200c) and is movable between the first end (200c1) and the second end (200c2) of the corresponding slot (200c).
2. The instrument (100) as claimed in claim 1, wherein a distal portion of the first arm (120a) is fixedly coupled with the locking member (200) using a first fastener (500a).
3. The instrument (100) as claimed in claim 2, wherein the first arm (120a) comprises a first hole (120c) configured to receive a portion of the first fastener (500a) and wherein the locking member (200) comprises a pair of apertures (200i) with one aperture (200i) of the pair of apertures (200i) being provided on each of the top face (200g) and the bottom face (200h) of the locking member (200), wherein a projection of the first fastener (500a) resides in a corresponding aperture (200i) of the pair of aperture (200i).
4. The instrument (100) as claimed in claim 2, wherein the locking member (200) comprises a first slot (200e) extending between a proximal face (200j) and a distal face (200f) of the locking member (200), the first slot (200e) is configured to receive the distal portion of the first arm (120a).
5. The instrument (100) as claimed in claim 1, wherein the handle (110), the first arm (120a) and the second arm (120b) form an integrated structure.
6. The instrument (100) as claimed in claim 1, wherein the second arm (120b) comprises a second hole (120d) configured to receive a portion of the second fastener (500b).
7. The instrument (100) as claimed in claim 1, wherein the locking member (200) comprises a second slot (200d) extending between a proximal face (200j) and a distal face (200f) of the locking member (200), wherein the distal portion of the second arm (120b) is configured to slide within the second slot (200d).
8. The instrument (100) as claimed in claim 1, wherein the first fastener (500a) and the second fastener (500b) are pins.
9. The instrument (100) as claimed in claim 1, wherein the handle (110) comprises a hole (300) provided at a proximal end of the handle (110), the hole (300) is configured to couple with a slap hammer adaptor.