FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
LOCKING MECHANISM FOR PROVISIONAL TIBIAL AUGMENTS
BIORAD MEDISYS PRIVATE LIMITED
AN INDIAN COMPANY HAVING OFFICE ADDRESS AT
Survey No. 48, 3 & 48 7, Pashan - Sus Rd, Sus, Pune,
Maharashtra 411021
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

TECHNICAL FIELD
[001] This invention is generally in the field of medical devices and relates
to orthopaedic prosthesis. More particularly, the invention relates to an
augment system that stabilize tibial support structures for use with a knee
5 prosthesis.
BACKGROUND
[002] The natural human knee joint involves the distal end of the femur, the proximal end of the tibia and a meniscus bearing there in between. Knee replacement surgery methods and knee joint prostheses are known in the
10 art. A typical knee joint prosthesis includes a femoral component implanted
on the distal end of the femur, which articulates with a tibial component implanted on the proximal end of a tibia to replicate the function of a healthy natural knee. When such knee replacement surgery is performed, an incision is made to expose the knee joint to enable removal of both the
15 proximal portion of the tibia and the distal portion of the femur, which
creates surfaces upon which the tibial and femoral components of the knee prosthesis can be attached.
[003] To ensure that the natural joint line is preserved in the joint replacement procedure, the distal portion of the femur and proximal
20 portion of the tibia may each be resected by an amount corresponding to
the thicknesses of femoral and tibial components, respectively, such that effective overall lengths of the femur and tibia remain unchanged after implantation of prosthetic components. However, in some cases the proximal tibia or distal femur may have severe degeneration, trauma, or
25 other pathology which necessitates resection of more bone than can be
compensated for by traditional femoral and tibial components. The prior art prosthetic members have not been wholly satisfactory for knee

implantation because they do not provide for the complexity involved
when flexing the tibia relative to the femur. In such cases, augments may be
used to effectively increase the thickness of the implanted component,
thereby compensating for the additional thickness of the bone resection.
5 The augment system can be used with a tibial baseplate and can offer
versatility, flexibility, and structural support, while compensating for bone damage or other deficiencies of the tibia. Depending on the amount of bone loss or deterioration, tibial augments may be used with the tibial tray to increase the overall volume of the tibial tray and compensate for the loss of
10 bone in particular areas. Additionally, such tibial augments may improve
fixation of the tibial tray to a patient's tibia by reducing the amount of bone cement or other adhesive required to secure the tibial tray to the patient's tibia. [004] In some prior arts, an augment system can include two or more
15 stackable augments configured to attach to a tibial baseplate and be located
between the tibial baseplate and a resected surface of a tibia. The augment system can include plates of variable thickness and plates formed of different materials. The augment system can facilitate restoration of the anatomic joint line and address bone deficits on all or some of the
20 proximal surface of a patient's tibia. Furthermore, in some cases, a surgeon
may opt for a second kind of augment, such as an augment having a generally cone-shaped outer profile corresponding to the generally cone-shaped bone defect typically encountered within the tibia. Sometimes, while performing surgery it is difficult to hold the augment with tibial
25 component which results in the chances of misalignment as well as
dislocation of augment with tibial tray.
[005] Accordingly, there is a need for augments which do not increase the complexity of reconstruction and overcome the prior art problems. This invention is therefore directed towards providing an improved augment

assembly with a locking mechanism to provide better/superior bone integration and stability which is relatively simple in design and structure and is highly effective for its intended purpose.
SUMMARY
5 [006] Embodiment of the present disclosure present technological
improvements as solutions to one or more of the above-mentioned technical problems recognized by the inventor(s).
[007] An object of the present invention is to provide a knee joint augment having an anatomical shape of a structure that allows lost bone to be
10 reinforced as much as possible through the augment having the shape
conforming to the anatomical shape of a tibia.
[008] Another object of the present invention is to provide a knee joint augment having an anatomical shape capable of preventing an implant from protruding when replacing lost bone using an augment including an
15 outer surface formed as a curved surface.
[009] Yet another object of the invention is to provide a knee joint augment having an anatomical shape capable of increasing the life of an implant by preventing damage of the implant or bone through a normal load distribution.
20 [0010] Still another object of the invention is to provide a locking
mechanism of knee joint augment with tibial component that will provide enhanced/ superior bone integration and stability.
[0011] The present invention discloses a provisional half tibial augment
with bone anatomical shape comprising a locking mechanism to
25 secure/connect an augment with the tibial component. The locking
mechanism comprises of a flower lock component dimensioned to press fit into a recess on the tibial half augment. The tibial half augment is assembled

to a tibial component wherein the flower lock component is inserted into the coupling hole on the tibial component.
[0012] These and other features and advantages of the present invention
will become apparent from the following description of the invention that
5 is provided in connection with the accompanying drawings and illustrated
embodiments of the invention.
[0013] It will be appreciated that features of the present disclosure are
susceptible to being combined in various combinations without departing
from the scope of the present disclosure as defined by the detailed
10 description and drawings below
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0014] The summary above, as well as the following detailed description of illustrative embodiment, is better understood when read in conjunction with the appended drawings. For illustrating the present disclosure,
15 example constructions of the disclosure are shown in the drawings.
However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
20 [0015] Embodiment of the present disclosure will now be described, by way
of example only, with reference to the following diagrams wherein. [0016] Figure 1 illustrates anatomical shape of provisional tibial half augment in accordance with an exemplary embodiment of the present disclosure.
25 [0017] Figure 2(a) – 2(d) illustrates exploded as well as assembled view of
provisional tibial half augment in different thickness with locking mechanism with an exemplary embodiment of the present disclosure.

[0018] Figure 3(a) and 3(b) illustrates the flower lock component utilized in present invention.
[0019] Figure 3(c) and 3(d) illustrates exploded view of an exemplary
embodiment of flower lock component.
5 [0020] Figure 4(a)- 4(d) illustrates the assembly of provisional tibial half
augment with an exemplary embodiment of the present disclosure. [0021] In the above accompanying drawings, a number relates to an item identified by a line linking the number to the item. When a number is accompanied by an associated arrow, the number is used to identify a
10 general item at which the arrow is pointing. Further the figures depict
various embodiments of the present subject matter for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiment of the structures and methods illustrated herein may be employed without departing from the
15 principles of the present subject matter described herein.
DETAILED DESCRIPTION
[0022] The following detailed description illustrates embodiment of the present disclosure and manners by which they can be implemented. The words "comprising," "having," "containing," and "including," and other
20 forms thereof, are intended to be equivalent in meaning and be open ended
in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items or meant to be limited to only the listed item or items. It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural
25 references unless the context clearly dictates otherwise.
[0023] As used herein, the terms "proximal" and "distal" should be given their generally understood anatomical interpretation. The term "proximal" refers to a direction generally towards the torso of a patient and "distal"

refers to the opposite direction of proximal, that is, against the torso of a
patient. It should be understood that the use of the terms "proximal" and
"distal" should be interpreted as if the patient were standing with the knee
joint in extension even though the appliances described herein are generally
5 used with the joint knee in flexion. The intention is to differentiate the terms
"proximal" and "distal" from the terms "anterior" and "posterior" as well as “medial” or “lateral”. As used herein, the terms "anterior" and "posterior" should be given their generally understood anatomical interpretation. Thus, "posterior" refers to a rear portion of the patient, e.g., a rear portion
10 of the knee. Similarly, "anterior" refers to a front part of the patient, e.g., a
front part of the knee. Thus, "posterior" refers to the opposite direction of "anterior." Similarly, the term "lateral" refers to the opposite direction of "medial." The medial meniscus is on the inner side of the knee joint. The lateral meniscus is on the outside of the knee.
15 [0024] The person skilled in the art will recognize many variations,
alternatives, and modifications of the embodiment of the present disclosure. It should be understood that this invention is not limited to the particular methodology, protocols, and the like, described herein and as such may vary. The terminology used herein is for the purpose of describing
20 particular embodiment only and is not intended to limit the scope of the
present invention, which is defined solely by the claims.
[0025] Referring now to the drawings, in an aspect of the present disclosure, the anatomical shape of the provisional tibial half augment 100 is illustrated in Figure 1. The tibial augment/ tibial half augment 100 has a top surface
25 106, bottom surface 104 and an outer surface. The outer surface may form a
curved surface 102 convexly protruding to the outside of the augment that goes from the bottom surface 104 to the top surface 106 and matches with the anatomical bone shape. Alternatively, geometry of outer surface 102 includes flat surface apart from curved surface and is based on a patient’s

knee anatomy. Additionally, present invention locking mechanism may also be incorporated in a tibial full augment.
[0026] Referring to Figure 2(a) and 2(b), provisional tibial half augments
with locking mechanism of size 5mm thickness is illustrated. The
5 provisional tibial half augment comprises of a guide pin 202 and a flower
lock component 204 dimensioned to press fit into a recess 206. The recess 206 is present onto top surface 106 of provisional tibial augment 100. Similarly, in provisional tibial half augments of sizes 10 mm, 15 mm as shown in exploded and assembled view in figure 2(c) and 2(d) respectively,
10 a guide pin 202 and a flower lock component 204’ dimensioned to press fit
into a recess 206 and a cross pin 208 is configured to be inserted into the hole 210 on the bottom side 304’ [as shown in Fig. 3(c)] of the flower component 204’ through an opening 212 into the augment 100 to secure the flower lock component 204’ in order to eliminate any chances of flower lock
15 component 204’ from getting disengaged/disassembled from the tibial
augment 100 and this way there is restriction in degree of freedom for flower lock component 204/204’ to enable secure alignment and arrangement in between tibial augment and tibial component. Further, the opening 212 is provided onto outer surface of the tibial half augment 100
20 wherein such opening 212 acts as passage for cross pin 208 which align
within a hole 210.
[0027] Figure 3(a) and 3(b) illustrates the flower lock component 204/204’ having a head side 302 and a bottom side 304 for 5mm thickness and 10, 15 mm thickness tibial augment 100. The head side 302 of the flower lock
25 component 204/204’ comprises of a plurality of slots 306 having a gap that
are spaced equidistantly wherein slots provide formation of plurality of compartment. In one exemplary embodiment, flower lock component (204/ 204’) includes four compartments and may include more number of compartments in accordance with a patient’s knee anatomy. Further, a

minimum of 0.2mm gap is there in between slots 306. In one exemplary
embodiment, gap is in the range 0.65-0.7 mm . The length of the flower lock
204/204’ component ranges in between 8.4-8.5 mm. The bottom side 304 has
diameter that ranges from 6.93-7 mm. The head side 302 has diameter in the
5 range 5.04-5.07 mm. Diamond shaped knurling is provided on the
circumference of the bottom side 304 of flower lock component 204/204’ to eliminate any chances of dislocation.
[0028] Figure 3(c) and 3(d) illustrates exploded view of an exemplary embodiment of flower lock component. The bottom side 304’ for 10 and 15
10 mm thickness tibial augment 100 comprises of a hole 210 to accommodate
cross pin 208. The head side 302’ has diameter in the range 5.04-5.07 mm. The length of the flower lock component 204/204’ ranges in between 13.4-13.5 mm. The bottom side 304’ has diameter that ranges from 5.488-5.5 mm. The bottom side 304’ is chamfered for easy assembly in the tibial augment.
15 The flower lock component 204, 204’ is made up of stainless steel/SS17-4PH
material. Alternatively, flower lock component 204, 204’ can also be made of titanium alloy, CoCr alloy, nitinol, plastic metal, metal, plastic, and so on. The material of flower component 204, 204’ has a predefined stiffness that allow elastic retention of the flower structure/ flower lock component
20 204/204’ to impart feature of spring force mechanism.
[0029] Figure 4(a) - 4(d) illustrates the tibial half augment for left and right knee respectively. The augment according to the present disclosure includes a top surface 106 that comes into contact with the distal surface of the base of tibial component/tray 402, a bottom surface 104 to come into
25 contact with the cut surface of the tibia, a curved side surface 102 connecting
the top surface 106 and the bottom surface 104. Coupling holes 406 are recessed downward from the top surface 404 of tibial component 402 by a predetermined depth to assemble/connect tibial component 402 with the tibial augment 100 having flower lock component 204 and guide pin 202.

Further, by spring force action of flower lock component it is integrated
within coupling holes 406 through its head side 302 and guide pin is
integrated within coupling holes to enable an alignment between tibial
component and tibial augment. Through this way present invention
5 provides better bone integration and stability. The assembled view is shown
in figure 4(b) and 4(d) for tibial half augment for right medial left lateral knee and right lateral left medial knee respectively. It is observed that augments are non-stackable. The chances of dislocation have been eliminated as the flower lock component on augment will provide better
10 stability and eliminate the chances of misalignment and dislocation. The
present invention has both technical as well as economic significance. [0030] While a particular embodiment of the invention has been illustrated and described, modifications thereof will readily occur to those skilled in the art. It is understood that the various embodiments, details and
15 constructions and their features described above and illustrated in the
attached figures may be interchanged among the various embodiment while remaining within the scope of the invention. Additionally, it is understood that various modifications could be made to any of the elements described herein above while remaining within the scope of the invention.
20

We Claim:

1.

A locking mechanism for a tibial augment that includes:

5 - a tibial augment 100 which is connected with a tibial component 402
having a top surface 404; characterized in that the tibial augment 100 comprises:

10
15
20

- a top surface 106 and a bottom surface 104 wherein the top surface 106 is configured to contact with distal surface of base of the tibial component/ tray 402;
- an outer surface convexly protruding to outside of the tibial augment 100 that goes from the bottom surface 104 to the top surface 106;
- a recess 206 onto the top surface 106 to hold a guide pin 202 and a flower lock component 204/204’ wherein the guide pin 202 is configured to direct the tibial augment within the tibial component for their alignment;
- the flower lock component 204/ 204’ having a head side 302 and a bottom side 304, further the flower component 204/204’ has a plurality of slots 306 having a gap spaced at equidistant wherein the slots 306 form a plurality of compartment; and
- an opening 212 onto the outer surface wherein the opening 212 is configured to act as passage for a cross pin 208 which aligns

within a hole 210 of the bottom side 304 of flower lock component 204/ 204’.
2. The locking mechanism as claimed in claim 1, wherein the top
5 surface 404 of the tibial component 402 has a coupling holes 406.
3. The locking mechanism as claimed in claim 2, wherein the coupling
holes 406 is configured to integrate the flower lock component 204/
204’ and the guide pin 202 to provide enhanced bone integration and
stability.
10 4. The locking mechanism as claimed in claim 1, wherein the outer
surface forms a curved surface 102.
5. The locking mechanism as claimed in claim 4, wherein the outer
surface may form a flat surface.
6. The locking mechanism as claimed in claim 1, wherein the flower
15 lock component 204/204’ is made of a material that has a predefined
stiffness to allow its elastic retention.
7. The locking mechanism as claimed in claim 1, wherein the cross pin
208 restrict degree of freedom of the flower lock component 204/
204’.