US6231609B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disc replacement prosthesis
Assignee: Individual
•
Filing: 1999-02-10
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Granted: 2001-05-15
•
Expires: 2019-02-10
Abstract
Abstract A disc replacement prosthesis is described which is placed within the intradiscal space vacated by a removed deteriorated disc, and which affords mobility rather than fusion between adjacent vertebral bodies. The prosthesis also protects remaining discs from deterioration by providing a shock absorbing prosthesis portion. Structure is provided that affords resistance to shear force applied to the shock absorbing portion. The prosthesis adheres initially mechanically to the vertebral bodies and adheres through arthrodesis over a period of time.
Inventors
- 👤 Hamid M. Mehdizadeh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:21
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/44; A61F2/441; A61F2/442; A61F2/4425; A61F2/46; A61F2/4603; A61F2/4611; A61F2002/30001; A61F2002/30316; A61F2002/30535; A61F2002/30565; A61F2002/30566; A61F2002/30568; A61F2002/30576; A61F2002/30578; A61F2/30767; A61F2/30771; A61F2002/30772; A61F2002/30784; A61F2002/3085; A61F2002/443; A61F2002/448; A61F2310/00; A61F2310/00005; A61F2310/00011
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
110 words
A disc replacement prosthesis for positioning between adjacent superior and inferior vertebral bodies, comprising upper means for contacting and gripping a lower surface on the superior vertebral body, lower means for contacting and gripping an upper surface on the inferior vertebral body, resilient intermediate means affixed to and extending between said upper and lower means for contacting and gripping, and a dual stiffness spring extending between said upper and lower means for contacting and gripping, said dual stiffness spring having a first stiffness aligned to absorb forces placing said resilient intermediate means in shear, and a second low stiffness aligned to absorb forces placing said resilient intermediate means in compression.
Claim 2
Dependent Claim
110 words
A disc replacement prosthesis for positioning between adjacent superior and inferior vertebral bodies, comprising upper means for contacting and gripping a lower surface on the superior vertebral body, lower means for contacting and gripping an upper surface on the inferior vertebral body, resilient intermediate means affixed to and extending between said upper and lower means for contacting and gripping, and a dual stiffness spring extending between said upper and lower means for contacting and gripping, said dual stiffness spring having a first stiffness aligned to absorb forces placing said resilient intermediate means in shear, and a second low stiffness aligned to absorb forces placing said resilient intermediate means in compression.
Claim 3
Dependent Claim
29 words
The disc replacement prosthesis of claim 1 wherein said dual stiffness spring comprises flat spring means fixed to and between said upper and lower means for contacting and gripping.
Claim 4
Dependent Claim
39 words
The disc replacement prosthesis of claim 1 wherein said dual stiffness spring comprises spring means captured between and extending between said upper and lower means for contacting and gripping, and means for retaining said spring means in captured position.
Claim 5
Dependent Claim
16 words
The disc replacement prosthesis of claim 3 wherein said dual stiffness spring comprises a flat spring.
Claim 6
Dependent Claim
60 words
The disc replacement prosthesis of claim 1 wherein said upper means comprises an upper cylindrical section, wherein said lower means comprises a lower cylindrical section, and wherein said resilient intermediate means comprises an intermediate cylindrical section, said lower, upper and intermediate sections forming a cylinder having an exterior surface when joined together, further comprising screw threads on said exterior surface.
Claim 7
Dependent Claim
31 words
The disc replacement prosthesis of claim 5 wherein said cylinder has an anterior end and a posterior end, comprising means at said anterior end for engagement by a prosthesis insertion instrument.
Claim 8
Dependent Claim
24 words
The disc replacement prosthesis of claim 5 wherein said cylinder has a channel extending axially therealong, comprising body compatible elastomeric substance within said channel.
Claim 9
Dependent Claim
55 words
The disc replacement prosthesis of claim 1 wherein said upper and lower means for contacting have outer surfaces, having apertures therein in communication with at least one internal chamber therewithin, whereby bone cell growth from adjacent bone structure through said apertures into said at least one internal chamber fixes the disc replacement prosthesis in place.
Claim 10
Dependent Claim
29 words
The disc replacement prosthesis of claim 1 wherein said upper and lower means for contacting comprise metallic members, said metallic members having surface treatment for enhancing bone cell growth.
Claim 11
Independent Claim
165 words
A method of making a disc replacement prosthesis having an upper and a lower body compatible rigid member and an intermediate body compatible resilient member subject to shear force in one direction and subject to compressive force in a direction orthogonal to said one direction, comprising the steps of treating the upper and lower rigid members to enhance bone cell growth into the surfaces thereof, positioning and fixing the upper and lower rigid members on opposing sides of the intermediate resilient member, providing a dual stiffness spring having a high spring stiffness for resisting force applied thereto in one direction and a low spring stiffness for resisting force applied thereto orthogonally to said one direction, and mounting said dual stiffness spring between said upper and lower body compatible rigid members with said high spring stiffness aligned to resist shear force in said intermediate body compatible resilient member and with said low spring stiffness aligned to resist compressive force in said intermediate body compatible resilient member.
Claim 12
Independent Claim
165 words
A method of making a disc replacement prosthesis having an upper and a lower body compatible rigid member and an intermediate body compatible resilient member subject to shear force in one direction and subject to compressive force in a direction orthogonal to said one direction, comprising the steps of treating the upper and lower rigid members to enhance bone cell growth into the surfaces thereof, positioning and fixing the upper and lower rigid members on opposing sides of the intermediate resilient member, providing a dual stiffness spring having a high spring stiffness for resisting force applied thereto in one direction and a low spring stiffness for resisting force applied thereto orthogonally to said one direction, and mounting said dual stiffness spring between said upper and lower body compatible rigid members with said high spring stiffness aligned to resist shear force in said intermediate body compatible resilient member and with said low spring stiffness aligned to resist compressive force in said intermediate body compatible resilient member.
Claim 13
Dependent Claim
38 words
The method of claim 10 wherein the upper and lower rigid members fixed on opposing sides of the intermediate resilient member form a compartment therebetween, comprising the step of filling the compartment with a body compatible resilient substance.
Claim 14
Dependent Claim
37 words
The method of claim 10 wherein the step of mounting said dual stiffness spring comprises the step of capturing the spring between the upper and lower body compatible rigid members in parallel with the intermediate resilient member.
Claim 15
Dependent Claim
184 words
A disc replacement prosthesis for positioning between adjacent superior and inferior vertebral bodies in the spine comprising upper means for contacting and gripping the superior vertebral body lower surface, lower means for contacting and gripping the inferior vertebral body upper surface, resilient intermediate means affixed to and extending between said upper and lower means for contacting and gripping, wherein said upper means comprises an upper cylindrical section, said lower means comprises a lower cylindrical section, and said resilient intermediate means comprises an intermediate cylindrical section, said upper cylindrical section, lower cylindrical section and intermediate cylindrical section forming a cylinder having an exterior surface when joined together, further comprising a spring assembly extending between said upper means and said lower means, said string assembly having a dual spring stiffness, wherein a first lower spring stiffness is aligned to absorb force applied to said upper means and said lower means that compresses said resilient intermediate means and wherein a second higher spring stiffness is aligned to absorb force applied to said upper means and said lower means that induces shear stress in said resilient intermediate means.
Claim 16
Dependent Claim
184 words
A disc replacement prosthesis for positioning between adjacent superior and inferior vertebral bodies in the spine comprising upper means for contacting and gripping the superior vertebral body lower surface, lower means for contacting and gripping the inferior vertebral body upper surface, resilient intermediate means affixed to and extending between said upper and lower means for contacting and gripping, wherein said upper means comprises an upper cylindrical section, said lower means comprises a lower cylindrical section, and said resilient intermediate means comprises an intermediate cylindrical section, said upper cylindrical section, lower cylindrical section and intermediate cylindrical section forming a cylinder having an exterior surface when joined together, further comprising a spring assembly extending between said upper means and said lower means, said string assembly having a dual spring stiffness, wherein a first lower spring stiffness is aligned to absorb force applied to said upper means and said lower means that compresses said resilient intermediate means and wherein a second higher spring stiffness is aligned to absorb force applied to said upper means and said lower means that induces shear stress in said resilient intermediate means.
Claim 17
Dependent Claim
16 words
The disc replacement prosthesis of claim 13 wherein said spring assembly comprises, crossed flat spring means.
Claim 18
Dependent Claim
25 words
The disc replacement prosthesis of claim 13 wherein said upper and lower cylindrical sections have opposing keyways therein configured to receive a prosthesis insertion instrument.
Claim 19
Independent Claim
185 words
A method of providing a prosthetic replacement for a vertebral disc removed from an intradiscal space between adjacent superior and inferior vertebral bodies, wherein the superior and inferior vertebral bodies have lower and upper surfaces respectively adjacent the intradiscal space, comprising the steps of fabricating an upper and a lower rigid member having surfaces thereon which are porous to living bone cells, configuring the upper and lower rigid members for at least temporary retention by the adjacent lower and upper surfaces on the superior and inferior vertebral bodies respectively, attaching a resilient member to and between the upper and lower rigid members to produce a disc prosthesis, engaging the lower and upper surfaces on the vertebral bodies with the upper and lower rigid members respectively, providing a dual stiffness spring having a high spring stiffness for resisting force applied in one direction and a low spring stiffness for resisting force applied orthogonally to said one direction, aligning said high spring stiffness to resist force placing said resilient member in shear, and aligning said low spring stiffness to resist force placing said resilient member in compression.
Claim 20
Independent Claim
185 words
A method of providing a prosthetic replacement for a vertebral disc removed from an intradiscal space between adjacent superior and inferior vertebral bodies, wherein the superior and inferior vertebral bodies have lower and upper surfaces respectively adjacent the intradiscal space, comprising the steps of fabricating an upper and a lower rigid member having surfaces thereon which are porous to living bone cells, configuring the upper and lower rigid members for at least temporary retention by the adjacent lower and upper surfaces on the superior and inferior vertebral bodies respectively, attaching a resilient member to and between the upper and lower rigid members to produce a disc prosthesis, engaging the lower and upper surfaces on the vertebral bodies with the upper and lower rigid members respectively, providing a dual stiffness spring having a high spring stiffness for resisting force applied in one direction and a low spring stiffness for resisting force applied orthogonally to said one direction, aligning said high spring stiffness to resist force placing said resilient member in shear, and aligning said low spring stiffness to resist force placing said resilient member in compression.
Claim 21
Dependent Claim
151 words
A prosthesis for replacing a disc removed from an intradiscal space between adjacent superior and inferior vertebral bodies, comprising an upper prosthesis member having a contact surface configured to engage and become fixed to a lower surface on the superior vertebral body, a lower prosthesis member having a contact surface configured to engage and become fixed to an upper surface on the inferior vertebral body, an intermediate elastomeric prosthesis member fixed to and extending between said upper and lower prosthesis members, a crossed flat spring assembly extending between said upper and lower prosthesis members aligned to absorb compression within and to impart shear strength to said intermediate elastomeric prosthesis member, and means for securing said upper and lower prosthesis members in place in contact with the superior and inferior vertebral bodies respectively, said upper and lower prosthesis member contact surfaces having a porosity for admitting bone cell growth for enhancing arthrodesis.
Claim 22
Dependent Claim
151 words
A prosthesis for replacing a disc removed from an intradiscal space between adjacent superior and inferior vertebral bodies, comprising an upper prosthesis member having a contact surface configured to engage and become fixed to a lower surface on the superior vertebral body, a lower prosthesis member having a contact surface configured to engage and become fixed to an upper surface on the inferior vertebral body, an intermediate elastomeric prosthesis member fixed to and extending between said upper and lower prosthesis members, a crossed flat spring assembly extending between said upper and lower prosthesis members aligned to absorb compression within and to impart shear strength to said intermediate elastomeric prosthesis member, and means for securing said upper and lower prosthesis members in place in contact with the superior and inferior vertebral bodies respectively, said upper and lower prosthesis member contact surfaces having a porosity for admitting bone cell growth for enhancing arthrodesis.
Claim 23
Dependent Claim
56 words
The prosthesis of claim 17 wherein said upper prosthesis member comprises an upper cylindrical section, said lower prosthesis member comprises a lower cylindrical section and said intermediate elastomeric member comprises an intermediate cylindrical section, so that the prosthesis is a cylinder having a cylindrical surface, said means for securing comprising screw threads on said cylindrical surface.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-05-14 | 2004-11-13 | 2005-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-05-14 | 2008-11-13 | 2009-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-05-14 | 2012-11-13 | 2013-05-15 | $7700.00 | Window Closed / Lapsed |