Prior art

To identify the most relevant prior art for US patent 11864755, I will search the USPTO database for the patent and then examine its cited references.

Here is the analysis of the most relevant prior art for US patent 11864755, based on the citations provided within the patent document itself:

US Patent 11864755 - Artificial expandable implant systems

Most Relevant Prior Art (based on internal citations and relevance to the independent claims):

1. US 7,704,279 B2

   • Full Citation: US 7,704,279 B2, "Bi-directional fixating transvertebral body screws, zero-profile horizontal intervertebral miniplates, expansile intervertebral body fusion devices, and posterior motion-calibrating interarticulating joint stapling device for spinal fusion," issued April 27, 2010. [cite: US11864755B2 - Google Patents]
   • Publication/Filing Date: The filing date of the application that matured into US 7,704,279 B2 was August 23, 2005, and it claims benefit from Provisional Application No. 60/670,231, filed on April 12, 2005. [cite: US11864755B2 Description] The publication date is April 27, 2010. [cite: US11864755B2 - Google Patents]
   • Brief Description: This patent describes bidirectional fixating transvertebral (BDFT) screws, zero-profile horizontal intervertebral miniplates, expansile intervertebral body fusion devices (IBFDs), and a posterior motion-calibrating interarticulating joint stapling device for spinal fusion. It specifically details BDFT screw mechanisms, including those that achieve bi-directional movement via a central gear engaging left and right screws (similar to Embodiment I of US11864755) and designs where a narrower solid screw is buried within a wider hollow screw for greater expansion (similar to Embodiments II and III of US11864755). It also introduces the concept of IBFDs with ratchetable shells and spikes for engaging vertebral endplates, and mentions an optional porous elastomeric balloon sheath for bone fusion material. [cite: US11864755B2 Description]
   • Potential Anticipation (35 U.S.C. § 102): US 7,704,279 B2 is explicitly identified as a parent patent (US application Ser. No. 11/208,644) from which US11864755 claims benefit. Therefore, its content is considered prior art to US11864755 and is highly relevant. It appears to anticipate many aspects of Claims 1 and 12, particularly the core concepts of an expansile spinal implant with vertebral-engaging features, an internal expansion mechanism (screw/gear driven), and shells (e.g., "expansile titanium or PEEK shells" and their spikes). [cite: US11864755B2 Description] For example, the description of IBFD device 700 with "ratchetable titanium or PEEK shells 710, 711 which can expand geometrically in two dimensions" and "spikes 713 inserting themselves into and purchasing the endplates 401" directly anticipates the first and second shells with engagement features of claims 1 and 12. [cite: US11864755B2 Description] The "four fixed height screws 712" for height expansion could also anticipate the expansion mechanism. [cite: US11864755B2 Description] The BDFT screws themselves, described in detail in US 7,704,279 B2, are also incorporated into the IBFD device 700. [cite: US11864755B2 Description]

2. US 7,951,180 B2

   • Full Citation: US 7,951,180 B2, "Bi-directional fixating transvertebral body screws, zero-profile horizontal intervertebral miniplates, expansile intervertebral body fusion devices, and posterior motion-calibrating interarticulating joint stapling device for spinal fusion," issued May 31, 2011. [cite: US11864755B2 - Google Patents]
   • Publication/Filing Date: The filing date of the application that matured into US 7,951,180 B2 was December 31, 2008, and it is a continuation of US application Ser. No. 11/208,644 (US 7,704,279 B2). [cite: US11864755B2 Description]
   • Brief Description: As a continuation patent, it shares significant disclosure with US 7,704,279 B2, covering the BDFT screws, mini-plates, expansile IBFDs, and facet stapling devices for spinal fusion. [cite: US11864755B2 Description]
   • Potential Anticipation (35 U.S.C. § 102): This patent, being a continuation of the direct parent, would also anticipate the same elements of Claims 1 and 12 for the same reasons as US 7,704,279 B2. [cite: US11864755B2 Description]

3. US 9,924,940 B2

   • Full Citation: US 9,924,940 B2, "Bi-directional fixating transvertebral body screws, zero-profile horizontal intervertebral miniplates, expansile intervertebral body fusion devices, and posterior motion-calibrating interarticulating joint stapling device for spinal fusion," issued March 27, 2018. [cite: US11864755B2 - Google Patents]
   • Publication/Filing Date: The filing date of the application that matured into US 9,924,940 B2 was April 25, 2011, and it is a continuation of US application Ser. No. 13/093,812. [cite: US11864755B2 Description]
   • Brief Description: Another continuation patent in the family, it further elaborates on the BDFT screws, zero-profile mini-plates, expansile IBFDs, and facet stapling for spinal fusion. [cite: US11864755B2 Description]
   • Potential Anticipation (35 U.S.C. § 102): As another continuation, US 9,924,940 B2 would similarly anticipate relevant aspects of Claims 1 and 12, given its shared lineage and disclosure with the earlier patents in the family. [cite: US11864755B2 Description]

4. US 10,251,643 B2

   • Full Citation: US 10,251,643 B2, "Bi-directional fixating transvertebral body screws, zero-profile horizontal intervertebral miniplates, expansile intervertebral body fusion devices, and posterior motion-calibrating interarticulating joint stapling device for spinal fusion," issued April 9, 2019. [cite: US11864755B2 - Google Patents]
   • Publication/Filing Date: The filing date of the application that matured into US 10,251,643 B2 was March 23, 2018, and it is a continuation of US application Ser. No. 15/934,622. [cite: US11864755B2 Description]
   • Brief Description: This patent is another continuation, covering the same core inventions of BDFT screws, mini-plates, expansile IBFDs, and facet stapling devices. [cite: US11864755B2 Description]
   • Potential Anticipation (35 U.S.C. § 102): Being a continuation of the family, this patent also fully anticipates the elements of Claims 1 and 12 for the same reasons as the previous family members. [cite: US11864755B2 Description]

5. US 10,952,723 B2

   • Full Citation: US 10,952,723 B2, "Artificial intervertebral implant," issued March 9, 2021. [cite: US11864755B2 - Google Patents]
   • Publication/Filing Date: The filing date of the application that matured into US 10,952,723 B2 was March 22, 2019, and it is a continuation of US application Ser. No. 16/362,152. [cite: US11864755B2 Description]
   • Brief Description: This patent is a direct parent to US11864755. It focuses on artificial intervertebral implants. [cite: US11864755B2 Description] Given that US11864755 is a continuation of this patent, it will contain substantially similar or identical disclosures regarding the core implant structures and expansion mechanisms.
   • Potential Anticipation (35 U.S.C. § 102): As the immediate parent, US 10,952,723 B2 would anticipate all the claimed features in Claims 1 and 12 that were disclosed in its own specification. This would include the shells, engagement features, and the fundamental expansion mechanism using a tool-engagement surface and internal mechanics.

Summary of Anticipation:

The most relevant prior art for US patent 11864755 are its own parent and grandparent applications (US 7,704,279 B2, US 7,951,180 B2, US 9,924,940 B2, US 10,251,643 B2, and US 10,952,723 B2). These patents, all from the same family and by the same inventors, disclose substantially the same subject matter regarding expandable spinal implants, BDFT screws, and IBFDs with expanding shells and engagement features. Therefore, many if not all elements of Claims 1 and 12 of US11864755 are directly anticipated by the earlier disclosures within this patent family. The specific details of the shells, engagement features (spikes), and the various screw/gear-driven expansion mechanisms are extensively described in these prior art documents, which form the basis for the present patent.