Obviousness

Obviousness Analysis under 35 U.S.C. § 103 for US Patent 10064738

This analysis considers the obviousness of US Patent 10064738, titled "Bi-directional fixating/locking transvertebral body screw/intervertebral cage stand-alone constructs having a central screw locking lever, and pliers and devices for spinal fusion," in light of the prior art explicitly referenced and discussed within the patent document itself. The effective date for this analysis is the priority date of US 10064738, which is April 12, 2005 (based on U.S. Provisional Application No. 60/670,231) and further claims priority through a chain of continuation-in-part applications.

Identified Prior Art References

The patent US 10064738 explicitly identifies the following as relevant prior art:

1. U.S. Pat. No. 4,904,261 (Dove et al.): Discloses a horseshoe implant with cylindrical holes for bone screws, noting "only one stop for the heads of the bone screws to be inserted into them" and a "non-symmetric manner" of five hole placements [cite: "U.S. Pat. No. 4,904,261 ... discloses a horseshoe implant having a plurality of cylindrical holes with smooth inner surfaces and comprise only one stop for the heads of the bone screws to be inserted into them. The placement of five cylindrical holes is oriented within the cage in a non-symmetric manner."].
2. "Aforementioned related applications": This refers to a family of patents and applications by the same inventors, explicitly incorporated by reference and acknowledged as foundational to the present invention's "evolutionary" and "advanced" features. These include:
   • U.S. Pat. No. 7,704,279 (filed Aug. 23, 2005) [cite: "application Ser. No. 11/208,644, filed on Aug. 23, 2005, now U.S. Pat. No. 7,704,279 issued Apr. 27, 2010"]
   • U.S. Pat. No. 7,846,188 (filed Sep. 29, 2006) [cite: "application Ser. No. 11/536,815, filed on Sep. 29, 2006, now U.S. Pat. No. 7,846,188 issued Dec. 7, 2010"]
   • U.S. Pat. No. 7,942,903 (filed Aug. 21, 2007) [cite: "application Ser. No. 11/842,855, filed on Aug. 21, 2007, now U.S. Pat. No. 7,942,903 issued May 17, 2011"]
   • U.S. Pat. No. 7,972,363 (filed Mar. 24, 2008) [cite: "application Ser. No. 12/054,335 filed on Mar. 24, 2008, now U.S. Pat. No. 7,972,363 issued Jul. 5, 2011"]
   • U.S. Pat. No. 8,734,516 (filed May 22, 2009) [cite: "Ser. No. 12/471,340 filed May 22, 2009, now U.S. Pat. No. 8,734,516 issued May 27, 2014"]
   • U.S. Pat. No. 8,257,370 (issued Sep. 4, 2012) [cite: "This application is related to applicants' U.S. Pat. No. 8,257,370 issued Sep. 4, 2012, titled “POSTERIOR CERVICAL AND LUMBAR INTERARTICULATING JOINT STAPLES, STAPLING GUNS, AND DEVICES FOR SPINAL FUSION”"]

A person having ordinary skill in the art (POSITA) in the field of spinal implants and surgical tools would be a mechanical engineer or a surgeon with experience in spinal fusion techniques and medical device design.

Obviousness Combinations and Motivations

The patent US 10064738 presents several distinct improvements over the cited prior art, particularly the inventors' own "related applications." The core argument for obviousness rests on the premise that these improvements are logical, incremental advancements addressing known problems in the art, using conventional mechanical principles.

1. Bi-directional Fixating Transvertebral (BDFT) Screw/Cage Apparatus with Specific Locking Mechanisms

Claimed Features: An intervertebral cage (10) with internal screw guides (18, 20, etc.) for bi-directional screws (12, 14, etc.), combined with either:
* A central, rotatable T-shaped screw locking lever (24) that covers and locks the screws [cite: "a central screw locking lever 24 coupled to the intervertebral cage 10, wherein the central screw locking lever 24 prevents the first screw member 12 and the second screw from pulling-out"].
* A screw locking horizontal bracket (30) with hooks (34) that snap into corresponding slots (36) on the cage and include flexion grips (32) for removal [cite: "a screw locking horizontal bracket 30 ... can be press fit on a top of the intervertebral cage 10 and covers and locks the first screw member 12 and the second screw member 14 in the intervertebral cage 10"].

Combination and Motivation:

• Prior Art Basis: The fundamental concept of a BDFT screw/cage apparatus, which combines an intervertebral spacer with bi-directional transvertebral bone fixating screws, is established in the inventors' "aforementioned related applications" [cite: "The present invention relates to a unique universal bi-directional screw (BDS) system, and in particular its application to the spine, also referred to as bi-directional fixating transvertebral (BDFT) screw/cage constructs which can be used as stand-alone intervertebral devices"]. US 4,904,261 also shows an intervertebral implant with bone screws, albeit with a different configuration and a less sophisticated "stop" mechanism [cite: "U.S. Pat. No. 4,904,261 ... comprise only one stop for the heads of the bone screws to be inserted into them"]. The problem of screw back-out and pull-out in spinal implants is well-known in the prior art, specifically noted in the background of US '738 regarding anterior plating [cite: "Complications of anterior plating in the anterior lumbar spine include potential devastating injury to the major vessels due to chronic vascular erosion of the major vessels, or acute vascular injuries due to partial or complete plate and/or screw back out."].
• Motivation for Combination: A POSITA, building on the BDFT screw/cage designs from the related applications, would be strongly motivated to develop more robust and explicit locking mechanisms to prevent screw pull-out or back-out, thereby enhancing the stability and safety of the construct.
  • For the Central Screw Locking Lever (24): The idea of a rotating lever to secure fasteners is a fundamental mechanical principle. Adapting a T-shaped rotatable lever to cover and lock the heads of bi-directional screws within an intervertebral cage would be an obvious design choice for a POSITA seeking a simple, reversible, and reusable locking solution. The patent itself states this is an "additional evolutionary embodiment not described in the aforementioned related applications," implying that the need for such a mechanism was recognized [cite: "This locking mechanism 24 is an additional evolutionary embodiment not described in the aforementioned related applications."].
  • For the Screw Locking Horizontal Bracket (30): Similarly, snap-fit mechanisms with deformable elements for secure yet releasable attachment are common in mechanical engineering. Designing a horizontal bracket with hooks to engage prefabricated slots on the cage, and including flexion grips for release, is a routine application of known mechanical fastening techniques. The motivation is to provide a positive lock that is both strong and intraoperatively reversible. The patent also describes this as an "additional evolutionary embodiment not described in the aforementioned related applications" [cite: "This locking mechanism is a screw locking horizontal bracket 30 which snaps on to the top of the construct 10 ... This locking mechanism is an additional evolutionary embodiment not described in the aforementioned related applications."].

2. Pliers Device for Inserting/Removing Locking Bracket

Claimed Features: A pliers device (40) with specific features like upper (42) and lower (44) plier tips with stops (46), a limiter (50) and limiting screw (52) to prevent over-pressing, and a leaf spring (48) to bias the handles open [cite: "a pliers device 40 for inserting and removing the locking mechanism ... can include a first arm rotatably coupled to a second arm... upper plier tip 42 and the lower plier tip 44 each include a stop 46 configured to engage the bracket flexion grips 32... a limiter 50 and limiting screw 52"].

Combination and Motivation:

• Prior Art Basis: Pliers are a basic, ubiquitous tool. The screw locking horizontal bracket (30) from US '738 (discussed above) explicitly requires pressure on its "flexion grips (side tabs) 32" to "slightly deform (open) the bracket hooks 34" for removal [cite: "the user needs only to press on the side tabs 32 with the pliers (FIG. 5) to slightly deform (open) the bracket hooks 34, and thereby easily remove the bracket 30"]. This inherent design of the bracket necessitates a plier-like tool for manipulation.
• Motivation for Combination: Given the need for a tool to manipulate the locking bracket (30), it would be obvious for a POSITA to design a specialized pair of pliers. The inclusion of features such as stops (46) for consistent engagement, a limiting screw (52) for controlled force application (to prevent over-pressing and damage to the implant or surrounding tissue), and a leaf spring (48) for ergonomic operation (biasing the handles open for ease of use) are standard, well-known refinements for surgical instruments. These improvements enhance precision, safety, and user-friendliness, all of which are routine objectives in medical tool design.

3. Lumbar Facet Joint Staple Gun with Independent Puller Tip

Claimed Features: A lumbar facet joint staple gun (400) having an independent puller tip (402) that is movable between an open and closed position, specifically designed to swing open when the stapler is at its maximum open position for easy staple insertion/removal, and then locked in a closed position by the cylinder body (412) when the handle is closed [cite: "the puller tip 402 can be moveable between an open position and a closed position when the handle in the open position, and wherein the puller tip 402 is locked in the closed position by the first end of the hollow cylinder 412 body when the handle in the closed position."].

Combination and Motivation:

• Prior Art Basis: The "aforementioned related applications" (e.g., US 8,257,370) disclose earlier versions of lumbar facet joint staple guns. The patent US '738 explicitly states that this new staple gun is an "evolved and lumbar staple gun which is far more user friendly than previously described embodiments by incorporating a new release mechanism, as described in the aforementioned related applications" [cite: "The present invention presents an evolved and lumbar staple gun which is far more user friendly than previously described embodiments by incorporating a new release mechanism, as described in the aforementioned related applications."]. The stated problem with prior designs was that the staple could become loose or fall off during an operation [cite: "This new change ... facilitates easier insertion and removal of the staple decreasing the risk of the staple becoming loose or falling off during an operation."].
• Motivation for Combination: A POSITA would be motivated to improve the user-friendliness, ease of loading, and staple retention of an existing staple gun (from the related applications). Designing a puller tip that securely holds the staple during operation but allows for easy loading/unloading when the device is fully open is a common mechanical design problem. Implementing a puller tip that pivots or "swings open" when the tool is in an open state and is then mechanically constrained by the surrounding body (cylinder) when the tool is closed (i.e., ready for firing) is a well-known engineering solution for secure yet accessible loading mechanisms in various hand tools.

4. Posterior Lumbar Facet Staple with Evolved Ratchet Mechanism (Flexure/Torsional Spring)

Claimed Features: Posterior lumbar facet staples (500, 600) incorporating either a flexure spring (530) ratchet pawl or a torsional spring (630) engaging a brake (680) [cite: "FIGS. 9A-B illustrate an embodiment of a posterior lumbar facet staple 500 having a flexure spring 530. ... FIGS. 10A-C illustrate an embodiment of a posterior lumbar facet staple 600 having a torsional spring 630"]. These are described as being superior to conventional designs in withstanding greater force than a "small external ratchet."

Combination and Motivation:

• Prior Art Basis: The "related applications" (e.g., US 8,257,370) already disclosed lumbar facet staples with a "ratchet" mechanism for incremental closure [cite: "the embodiments illustrated in the related applications included a ratchet. The staple could be incrementally closed with increased ratcheting over increasing number of spurs."]. The present patent aims to provide embodiments that "can withstand much greater force (Newtons) than a small external ratchet" [cite: "the present invention provides two evolved embodiments, which are superior to conventional designs in that the closing mechanisms can withstand much greater force (Newtons) than a small external ratchet."].
• Motivation for Combination: A POSITA, recognizing a limitation in the force-withstanding capability of a "small external ratchet" in existing lumbar facet staples (from the related applications), would be motivated to improve its strength and rigidity. Flexure springs and torsional springs are fundamental mechanical components used to provide resilient forces and engage ratchet teeth. Incorporating these types of springs into the internal design of a ratchet mechanism to achieve specific force characteristics is a routine design choice for a mechanical engineer seeking to optimize the performance and robustness of a known device.

5. Posterior Cervical Facet Staple Gun (Simplified and Economical)

Claimed Features: Posterior cervical facet staple guns (FIGS. 7-8) with internal mechanisms including a handle (802, 902), central plunger (804, 910), and retaining springs (808; 908, 909) designed for simplified, economically efficient, and user-friendly operation, particularly for percutaneous procedures [cite: "In this application, the embodiments can provide more simplified and economically efficient staple guns which are very user friendly and further enhances the application of the cervical staple gun also making posterior cervical facet stapling more amenable to a non-invasive, percutaneous surgical procedure."].

Combination and Motivation:

• Prior Art Basis: The "related applications" introduced "highly evolved cervical staple gun[s] for the two and four pronged cervical staples" [cite: "In the related applications, cervical facet embodiments of a highly evolved cervical staple gun for the two and four pronged cervical staples were introduced."].
• Motivation for Combination: A POSITA would be motivated to refine and improve an existing cervical staple gun (from the related applications) to achieve goals of simplification, economic efficiency, and enhanced user-friendliness, especially to make it "more amenable to a non-invasive, percutaneous surgical procedure." These are common objectives in medical device development. The use of a retaining spring to hold staples and a central plunger/button for release represents a basic and widely used mechanical design solution for loading and releasing components in tools, making it an obvious modification to streamline and simplify the staple gun's operation.

In summary, the key "evolutionary" and "novel" aspects of US 10064738, when viewed through the lens of the inventors' own extensive prior art (the "related applications") and general mechanical knowledge, appear to be routine design choices and optimizations rather than inventive steps. A POSITA would have been motivated to combine the known functional elements from the prior art, along with conventional mechanical components and design principles, to achieve improved performance (e.g., better locking, easier handling, greater strength) in the context of existing spinal fusion devices and tools.