Obviousness

To analyze the obviousness of US patent 9,005,293 under 35 U.S.C. § 103, we need to identify combinations of prior art references that would render the claims obvious and explain the motivation for combining them. Obviousness means that the differences between the claimed invention and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art (PHOSITA). Prior art includes information publicly known before the effective filing date, such as U.S. patents and published applications, foreign patents, and other printed publications.

The patent US9005293B2 itself references several co-pending patent applications from which it claims priority, and these co-pending applications are considered prior art for certain aspects of the invention if they were published before the filing date of US9005293B2. Specifically, the patent states: "This application is a Continuation Application of application Ser. No. 11/842,855, filed on Aug. 21, 2007, now U.S. Pat. No. 7,942,903 issued on May 17, 2011, which is a Continuation-In-Part Application of application Ser. No. 11/536,815, filed on Sep. 29, 2006, now U.S. Pat. No. 7,846,188 issued on Dec. 7, 2010, which is a Continuation-In-Part Application of application Ser. No. 11/208,644, filed on Aug. 23, 2005, now U.S. Pat. No. 7,704,279 issued on Apr. 27, 2010, for which priority is claimed under 35 U.S.C. §120; and this application also claims priority under 35 U.S.C. §119(e) of U.S. provisional application No. 60/670,231, filed on Apr. 12, 2005; the entire contents of all the above identified patent applications are hereby incorporated by reference." [cite: The patent text provided by the user includes this information in the "CROSS-REFERENCE TO RELATED APPLICATIONS" section.]

The relevant prior art for this analysis are:

• US Patent No. 7,704,279 (filed Aug. 23, 2005, issued Apr. 27, 2010)
• US Patent No. 7,846,188 (filed Sep. 29, 2006, issued Dec. 7, 2010)
• US Patent No. 7,942,903 (filed Aug. 21, 2007, issued May 17, 2011)
• US Provisional Application No. 60/670,231 (filed Apr. 12, 2005)

Since the filing date of US9005293B2 is May 16, 2011, and the listed patents (US7704279B2, US7846188B2, US7942903B2) were issued before this date, they can serve as prior art for claims in US9005293B2 that are not adequately supported by the earlier provisional or parent applications such that they would receive the earlier priority date. Additionally, the description within US9005293B2 refers to "Previous improvements included a novel calibrated lumbar/thoracic facet stapling device which staples the inferior articulating facet of the superior segment to the superior articulating facet of the caudal vertebral segment unilaterally or bilaterally, which may minimize motion until interbody fusion occurs." and "In the present patent application we introduce a new design of the staple enhancing its calibrating capability." This explicitly states that aspects of the lumbar facet stapling device were previously disclosed and improved upon in this patent.

Here's an analysis of potential obviousness combinations based on the patent's own disclosures:

Obviousness of the Self-Drilling Bone Fusion Screw Apparatus (Claims 1, 12, 14, 19)

Prior Art References for Combination:

• US Patent No. 7,704,279
• US Patent No. 7,846,188
• US Patent No. 7,942,903

Reasoning for Obviousness:
The current patent (US9005293B2) describes "multiple device embodiments which combine in a single construct the dual functions of an intervertebral spacer maintaining disc space height, and transvertebral body fusion screws." It also states, "In this current application one or more of the described embodiments may eliminate the intervening wormed driving screws and gears required by previous designs, e.g., a gearless screw box is achieved." [cite: The patent text provided by the user includes this information in the "SUMMARY" section.] This clearly indicates that prior designs, described in the earlier co-pending applications (which are now patents US7704279B2, US7846188B2, US7942903B2), also utilized bi-directional transvertebral screws and intervertebral spacers.

The '293 patent then introduces variations such as:

• A gearless screw box [cite: The patent text provided by the user includes this information in the "SUMMARY" section.].
• An expanding screw box with sliding triangular bases and a built-in screw adjuster [cite: The patent text provided by the user includes this information in the "SUMMARY" section.].
• A screw box housing only one screw, designed to be used bilaterally [cite: The patent text provided by the user includes this information in the "SUMMARY" section.].
• A horizontal mini-plate to prevent upward bone graft intrusion [cite: The patent text provided by the user includes this information in the "SUMMARY" section.].
• Combination with a circumferential cage [cite: The patent text provided by the user includes this information in the "SUMMARY" section.].

A PHOSITA would have been motivated to combine the teachings of the earlier patents (US7704279B2, US7846188B2, US7942903B2) with general engineering principles to arrive at the inventions claimed in US9005293B2. For example:

• Motivation for a "gearless screw box": Simplifying the mechanism for driving bi-directional screws would be an obvious engineering goal to reduce complexity, manufacturing cost, and potential points of failure, which a PHOSITA would recognize.
• Motivation for an "expanding screw box with sliding triangular bases and a built-in screw adjuster": The earlier patents describe expandable fusion cages. Improving the expansion mechanism with more robust and precise means, such as sliding triangular bases and a screw adjuster, is a natural evolution in mechanical design for orthopedic implants to achieve better custom fitting and stability.
• Motivation for a "screw box housing only one screw": To reduce the width of the device, especially to minimize nerve root retraction, as explicitly stated in the '293 patent, a PHOSITA would consider reducing the number of screws per box and using multiple smaller boxes. [cite: The patent text provided by the user includes this information in the "SUMMARY" section.]
• Motivation for the "horizontal mini-plate" and "circumferential cage": The problem of bone graft intrusion into the thecal sac and nerve roots is explicitly mentioned in the background of the '293 patent as a complication of existing interbody fusion devices. [cite: The patent text provided by the user includes this information in the "BACKGROUND OF THE INVENTION" section.] Therefore, adding a physical barrier, such as a mini-plate or integrating the screw boxes into a circumferential cage, would be an obvious solution to address this known problem, readily apparent to a PHOSITA designing spinal fusion devices.

The tool assembly described in Claim 19, including a handle, gripper, and screw guide, would also be an obvious combination in light of the earlier inventions. Tools for guiding and inserting spinal implants and screws are standard in the art, and a PHOSITA would naturally design specific tools to facilitate the implantation and adjustment of the described screw boxes.

Obviousness of the Cervical Facet Staple (Claims 23, 26)

Prior Art References for Combination:

• US Patent No. 7,704,279
• US Patent No. 7,846,188
• US Patent No. 7,942,903

Reasoning for Obviousness:
The '293 patent states, "In this patent application we also introduce a novel posterior cervical facet stapling device which staples the inferior articulating facet of the superior cervical segment with the superior articulating facet of the caudal vertebral segment unilaterally or bilaterally." It then emphasizes the advantages of speed and safety, obviating risks associated with pedicle screw fixation. [cite: The patent text provided by the user includes this information in the "SUMMARY" section.] This implies that while the specific cervical facet staple is "novel," the concept of facet stapling (and its advantages over pedicle screws) was already known from the applicant's earlier work on lumbar/thoracic facet stapling.

The patent explicitly notes, "Previous improvements included a novel calibrated lumbar/thoracic facet stapling device..." [cite: The patent text provided by the user includes this information in the "SUMMARY" section.] Therefore, the idea of using staples for facet joint fusion to minimize motion was already in the prior art. Adapting a known lumbar/thoracic facet stapling concept to the cervical spine, requiring adjustments in size, curvature (a "curved staple base" as per Claim 23), and prong configuration to conform to cervical anatomy, would be a matter of routine design choice for a PHOSITA. The motivation would be to extend the known benefits of facet stapling (speed, safety, reduced risks compared to pedicle screws) to the cervical region. The impaction tool (Claim 26) would be an obvious accompanying device for such a staple, as impaction is a common method for implanting staples in bone, and features like a handle, stem, and wings for contacting the staple are standard design elements for such tools.

Obviousness of the Lumbar Facet Staple with Calibrated Ratcheting Mechanism (Claim 29)

Prior Art References for Combination:

• US Patent No. 7,704,279 (corresponds to Ser. No. 11/208,644)
• US Patent No. 7,846,188 (corresponds to Ser. No. 11/536,815)

Reasoning for Obviousness:
The '293 patent explicitly states regarding the lumbar facet staple: "This lumbar facet staple has been thoroughly described in our previous co-pending patent application Ser. No. 11/536,815, filed on Sep. 29, 2006, and Ser. No. 11/208,644, filed on Aug. 23, 2005, the relevant portion of each of which is hereby incorporated by reference hereinafter." It then highlights "the new improvement of this device includes a ratchet 1201." This statement makes the prior existence of a lumbar facet staple (without the specific ratcheting mechanism) abundantly clear from the applicant's own earlier disclosures.

A PHOSITA would be motivated to add a ratcheting mechanism to a known lumbar facet staple (as described in US7846188B2 and US7704279B2) to achieve "increasing calibrated levels of lumbar facet joint fusion, and conversely diminishing joint flexibility." The concept of calibrated or adjustable fixation for spinal implants is a desirable characteristic in the art, aimed at providing flexible fusion and reducing adjacent segmental disease. Implementing a ratchet and spur mechanism for incremental closure and calibration is a well-known mechanical engineering solution for achieving adjustable, incremental fixation. Therefore, combining the existing lumbar facet staple with a ratcheting mechanism for calibrated closure would be an obvious design improvement to a PHOSITA seeking to enhance the functionality of such a device.