DESC:F O R M 2

THE PATENT ACT 1970

(Act 39 of 70)

COMPLETE S P E C I F I C A T I O N

“C-Open Cage for Anterior Cervical Fusion”

GESCO HEALTHCARE PRIVATE LIMITED
An Indian Company,
G-6, GEE GEE CRESCENT
114, POONAMALLEE HIGH ROAD
CHENNAI 600084
TAMIL NADU
INDIA

The following specification describes the invention:

The present invention relates to a novel C-shaped Anterior cervical interbody metal cage. One of the most common drawbacks of the currently available cages is that it is technically difficult to pack graft material in them since most of them have small anterior recess. The normal procedure is to usually pack the cages with bone grafts prior to insertion. The present invention seeks to pack to same post insertion. The novelty lies in providing for an opening in the front (Anterior) to enhance fusion.

Background of the invention:

Anterior cervical discectomy with fusion is a common surgical procedure. Although iliac crest bone graft remains the gold standard today, the associated morbidity has inspired the search for alternatives, including allograft, synthetic and factor/cell-based grafts; and has further led to a focus on cage fusion technology. Cage interbody implants have enhanced biomechanical properties, with designs constantly improving to maximise biocompatibility and osseointegration. The present invention relates to a new cagewhich is designed in a C shape, to make the surgical procedures pertaining to anterior cervical spaces easier and to secure larger volume of graft within the cage for fusion and also is designed to maintain lordosis of cervical spine.

Prior art:
https://patents.justia.com/patent/20210085476, discloses a Patent filed in the United States in respect of a standalone anterior cervical interbody spacer that includes a spacer body and cervical plate with a unique locking system rigidly couple the spacer body and cervical plate via two flexible locking pins. The locking system include locking features designed to engage with one or more flexible locking pins to lock the spacer body and cervical plate together. Once the cervical plate and spacer body are completely joined, the flexible pin reaches the lock geometry recess or pocket, allowing the flexible pin to return to its original form in the recess or pocket, thereby locking the spacer body and cervical plate. The pin engaging the recess may provide an audible click sound the let the user know that the parts are joined and locked together. The flexible locking pins are positioned within the spacer body or within the cervical plate.
Publication number: 20210085476
Type: Application
Filed: Sep 24, 2020
Publication Date: Mar 25, 2021
Applicant: Astura Medical Inc. (Carlsbad, CA)
Inventors: Anthony Valkoun (Carlsbad, CA), Thomas Purcell (Carlsbad, CA)
Application Number: 17/031,867
Classifications
International Classification: A61F 2/44 (20060101);

Yet another prior art is the use of a combination of integrated low-profile plating and Ti/PEEK composite cages, wherein the design utilizes a PEEK body with titanium endplates and a low-profile titanium plate with dual opposed locking screws.

However, none of the prior art discloses the present invention which is a uniquely shaped cage design, wherein the design is to engage the cage in the disc space while inserting as well as to later mobilize the case inside the disc space with ease. The curvature of the cage is also to accommodate more graft material and aids in the ease of bone fusion as well as keeping the graft material in place.

Brief description of the drawings:
Part numbers specified in the drawing:
1. (1) Lower surface (flat) & Upper surface ( tapered )
2. (2) Superior & interior surface of C-cage ( wider region )
3. (3) Notches provisions to push C shape in the disc space
4. (4)C- shaped & round area (anterior) opening to accommodate large volume of graft material
5. (5) Front opening (anterior)
6. (6) Unique pyramid teeth (cranial &equadal side )
7. (7) Pyramid alignment to match the contour of adjacent vertebra
8. (8) Novel shape for bony fusion
9. (9) Novel designed shape to reduce area of metal in the disc space
10. (10) Pyramid shape teeth to enhance stability of C-cage.
11. (11) Smoother anterior portion ( no protrusion )
12. (12) Unique wedge to hold cage and holder
13. (13) Provision for bone graft material
14. (14) Novel shape of the inner cage (for graft material filling )
15. (15) Outer shape and size (depicts the Cervical Vertebra shape)
16. (16) Foot prints to enable different patients vertebra
17. (17) Anterior opening which Highly enhanced area of graft volume for anterior opening
18. (18) Maximum area of graft to be accommodated in the cage
19. (19) Metal area of the contact to adjacent body
20. (20) Graft filling area ( novel design )
21. Anterior wall
22. Posterior wall
23. Upper surface
24. Lower surface
25. Closed end of the anterior opening (5)
26. Closed end of the anterior opening (5)
27. End plates

The figures have been disclosed in 3 pages. Fig. 1: Left Perspective View of the ‘C’ cage wherein (1) depicts the flat lower surface; (12) a unique wedge to hold the cage and holder; (16) foot prints to enable different patients vertebra and (7) pyramid alignment to match the contour of adjacent vertebra.

Fig. 2: Top View of the ‘C’ cage wherein the anterior opening of the cavity (5)opens up into the an highly enhanced area of graft volume (17) comprising of a novel shaped space for bony fusion(8); the said novel shape designed so as to reduce the area of the metal in the disc space depicted by the opening of the space (9) inside; the superior and interior surface (2) of the C cage depicting the wider portion; (4) being the ‘C’ shaped rounded area (anterior) opening to accommodate large volume of graft; (13) depicting space for bone graft material; (14) dpeincitng the novel shape of the inner cage for graft filling; (11) depicting the smooth anterior position with no protrusions at all.

Fig. 3: Isometric View

The notches (3) providing the necessary provisions to push the ‘C’shape cage into the disc space and (15) depicting the outer shape and size of the cervical vertebrae shape.

Fig. 4: Front View

(6) depicting the unique pyramidal teeth (10) both on the cranial and equadal side and (16) the footprint to enable different patients vertebrae.

Fig 5: Displaying the space within the ‘C’ cage wherein area of placing the graft is clearly demarcated (20) being the graft filling area; (19) the metal area of the contact to adjacent body and (18) the graft area.

Fig 6 depicts the dimensions of the wedge (12) in one preferred embodiment.
Fig 7 depicts the dimensions relating to the positioning of the notches on the ‘C’ cage outer periphery, the said notches designed to push the ‘C’ cage easily into the disc space by sequential boggling while pushing the the cage inside the disc space.
Fig.8 depicts the dimensions relating to the ‘C’ cage wherein the anterior wall (21) height is more than the posterior wall (22) height, the said height difference helps in keeping the anterior disc space widened in comparison to the posterior disc space, thus helping in facilitating cervical lordosis. The upper surface (23) being tapered towards the posterior wall and the lower surface (24) being flat, designed to engage the cage in the disc space while inserting and later mobilize the cage inside the disc space with ease. The anterior portion (5) of the ‘C’ cage being wider than the posterior end (9), The pyramidal protrusions on both the cranial and caudal side pierces the end plate (27) enhancing the stability of the cage. Each pyramid (28) is aligned in such a manner so as to match the contour of the adjacent vertebrae. The anterior portion has two unique wedge like (12) formations to hold the cage to the holder for insertions. The novel shape enables the bone to grow in the front portion of the cage.
Fig 9 depicts the top view of the ‘C’ cage, wherein the anterior opening (5) on the anterior wall opens into the centre portion (25), the said anterior opening (5) enabling the accommodation of larger volume of graft material, making the surgical procedure easier as the can not only pack the grafts as compact as possible but also visualize the adjacent end plates while packing. The closed ends (25), (26) prevent the graft materials to migrate posteriorly or laterally as well. The anterior open end (5) also facilitates autograft from adjacent vertebrae much easier, without the need to transfer out of wound sites. The anterior opening (5) also enhances fusion.
Fig 10:discloses the dimensions of one preferred embodiment of the perspective view.
Fig 11: discloses the dimensions of the wedge (12) in another preferred embodiment.
Fig 12: discloses the dimensions of rear view of yet another embodiment of the present invention.
Fig 13: discloses the dimensions of a perspective view of yet another embodiment of the invention.
Fig 14 discloses the dimensions of the top view of yet another embodiment of the invention.
Detailed description of the invention:

The present invention relates to a ‘C‘ shaped cage wherein the Anterior wall height is more than the posterior wall. The Upper surface is tapered towards the posterior wall and the Lower surface is flat. This shape is designed to engage the cage in the disc space while inserting and later mobilise the cage inside the disc space with ease. The height difference helps in keeping the anterior disc space widened in comparison to posterior disc space thus facilitating cervical lordosis. Superior and Inferior surface of anterior lateral limbs of C is wider and hence provide more support to the vertebral bodies.The notches provided to lock the introducer is designed in such a way that the C shaped cage can be easily pushed in the disc space by sequential boggling while pushing the cage in position inside the disc space. The ‘C’ shaped cage is provided with an opening on the anterior wall. The centre portion is curved and along with the anterior opening can accommodate large volume of graft material, which is the inventive step and the most unique part of this cage in comparison to the existing cages available. The advantage of anterior opening is appreciated while packing the graft materials after inserting the cage in the disc space first in contrast to the other cages available. This make the surgical procedure much easier and surgeon can pack the grafts as compact as possible and also visualise the adjacent end plates while packing. The closed ends do not allow graft materials to migrate posteriorly or laterally as well. The anterior open end also make transfer of autograft.

(Osteophytes, Corticocancellous bones) from adjacent vertebrae much easier without transferring them out of the wound site. One of the most common drawbacks of the currently available cages is that it is technically difficult to pack graft material in them since most of them have small anterior recess. The normal procedure is to usually pack the cages with bone grafts prior to insertion. The present invention seeks to pack to same post insertion. The novelty lies in providing for an opening in the front (Anterior) to enchase fusion. Furthermore, the C cage implants have Pyramid like Teeth in the cranial and caudal side of the cage which is also unique. The Pyramid shaped teeth in the Cranial and Caudal side pierces the end plate enhancing stability of the cage. Each of the pyramid is aligned in such a way to match the contour of the adjacent Vertebra. The Novel shape improves the scope for fusion of the bones, reduces the area of metal in the disc space.

The anterior portion is smooth so that no hindrance or protrusion is seen in the anterior surface. The cage has two Unique wedge like formation in the anterior portion to hold the cage to the holder for insertion. Provision for Bone graft material in the central portion of the cage and Vertebra is yet another novel feature. The Novel inner shape of the cage allows Bone graft material to be filled in the cage which enables the bone to grow in the front portion of the cage.The outer shape and size depicts the real natural shape of the Cervical vertebrae. The Implants have different foot prints enabling the surgeon to choose specific for each size of the patients Vertebrea. Furthermore, due to the Anterior opening the Volume of graft is highly enhanced when compared to all cages in the market and the area of graft that can be accommodated in the cage is more due to which the area of contact to the adjacent body is more which regenerated bony fusion. Also the metal area of contact to the adjacent body is also reduced due to the Novel shape and design.

The Novel ‘C’ shaped cage design enables the surgeon to fill the cage with Graft even after placement of the cage in the vertebral body without disturbing the adjacent body which is a very important and unique feature.

Preferred embodiment:

The dimensions of the C Cage as disclosed in sheet 2 and 3 of the drawings showing different foot prints of the implants enabling the the surgeon to choose specific for each of the patients’ vertebrae.

Although embodiments of this invention have been shown and described, it is to be understood that various modifications and substitutions, as well as rearrangements of parts and components, can be made by those skilled in the art without departing from the novel spirit and scope of the invention.

Dated this the 16th day of September, 2022.

Sumitha Vibhu
Patent Agent
IN/PA 383

,CLAIMS:We Claim:

A ‘C’ shaped Anterior cervical interbody cage for packing of grafting materials post insertion comprising of :
i. the outer shape and size (15) of the cage depicting the shape of the cervical vertebrae;
ii. the cage shaped in the form of ‘C’ having an anterior opening (5); an hollowed out C space(4) to accommodate large volumes of graft material; a space (8) for bony fusion; a provision for bone graft material (13); an the inner cage space for graft material filling(14); a maximum graft area space accommodated in the cage(18); a metal area of the contact to adjacent body (19); a graft filling area(20);
iii. the said cage having an anterior opening (5) on the anterior disc space (21); the anterior opening (5) facilitating bone growth in the front portion of the cage;
iv. the anterior opening (5) having protruding closed ends (25), (26); the closed ends preventing migrating of graft materials posteriorly as well as laterally;
v. having superior and inferior surfaces(2) of the anterior lateral limbs; these being wider, providing more support to the vertebral bodies;
vi. the said cage having two unique wedge like formations (12) on either side of the anterior opening (5) in the anterior portion to hold the cage to the holder for insertion; the cage having a smoother anterior portion(11) with no protrusion;
vii. the said cage having notches (3) on either side of anterior opening (5) to provide a locking mechanism to the introducer; designed to easily push the cage by sequential boggling into the disc space;
viii. the said cage further comprising of anterior(21) and posterior(22) walls, the said anterior wall (21) height being higher than the posterior wall (22) height; the height difference enabling keeping the anterior disc space widened in comparison to the posterior disc space facilitating cervical lordosis;
ix. the said cage having an upper (23) and lower surface(24) of the surface (1); the upper surface being tapered towards the posterior wall and the lower surface being flat; enabling engaging the cage while inserting and later mobilizing the cage inside the disc space with ease;
x. the said cage having pyramid shaped teeth (10) on both the cranial and caudal side of the cage; the said pyramid like teeth (10) piercing the end plates(27) enhancing the stability of the cage; each pyramid teeth (10) being aligned in such a manner as to match the contour of the adjacent vertebra (7);
xi. the anterior opening (5) allowing packing of graft materials post insertion of the ‘C’ cage; enabling the surgeons to pack the graft material in a compact manner; visualising the end plates whilst packing;
xii. the said shape enabling higher volume of grafting material to be placed within the ‘C’ cage; the increased volume of graft material increasing the area of contact to the adjacent body generated by bony fusion due to lower metal area contact to the adjacent body without disturbance to the adjacent body.

2. The cage as claimed in claim 1 being made of metal.

3. A ‘C’ cage as claimed in claim 1 wherein the anterior opening (5) facilitates autograft from adjacent vertebrae without transferring them out of the wound site.
4. A ’C’ cage as claimed in Claim 1 having different foot prints(16); enabling the surgeon to choose specific sizes for each size of the patients’ vertebrae.
5. A’C’ cage as claimed in claim 3 having foot prints as described in Figures 6,7,8,9,10
6. A’C’ cage as claimed in claim 3 having foot prints as described in Figures 11,12,13,14.