Paragon 28 Inc v. Wright Medical Technology Inc

1. Case Identification

• Case #: IPR2019-00898
• Patent #: 9,259,253
• Filed: March 29, 2019
• Petitioner(s): Paragon 28, Inc.
• Patent Owner(s): Wright Medical Technology, Inc.
• Challenged Claims: 1, 3-9, 12-15, 17-19, 46-48, 50-53

2. Patent Overview

• Title: Orthopedic Plate for Use in Small Bone Repair
• Brief Description: The ’253 patent discloses an orthopedic plate and screw system for the surgical fixation of small bones. The invention relates to customizable, anatomically shaped bone plates featuring specific arm configurations and screw holes designed to accept screws for stabilizing bone fractures.

3. Grounds for Unpatentability

Ground 1: Claims 13-15, 17-19, 46-48, and 50-53 are obvious over Kay in view of Chan

• Prior Art Relied Upon: Kay (Application # 2006/0173459) and Chan (Application # 2008/0140130).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that these claims, which recite a "locking screw," are not entitled to the priority date of the 2006 application that matured into the ’253 patent. Therefore, the published version of that application, Kay, is prior art. Kay was asserted to teach the core elements of the challenged claims, including a bilaterally asymmetrical plate with an elongate central trunk and asymmetrically diverging arms (forming Y- or X-shapes). However, Kay disclosed only non-locking screws. Chan was asserted to remedy this deficiency by disclosing a bone plate system with screw holes constructed to receive locking or variable-angle locking screws, which have threaded heads that mate with threads in the screw hole to prevent loosening. The combination of Kay's plate shape with Chan's locking screw technology allegedly rendered the challenged claims obvious.
  • Motivation to Combine: A POSITA would combine Kay and Chan to improve the fixation strength and prevent screw loosening, a problem recognized by both references. Kay emphasized the need for "increase[d] pullout strength," and Chan taught that its locking screws provided high resistance to shear, torsional, and bending forces, which directly addressed Kay’s objective. The desire for a more stable and reliable fixation system would have motivated a POSITA to incorporate the well-known locking screw technology from Chan into the plate design of Kay.
  • Expectation of Success: Petitioner contended that a POSITA would have a high expectation of success. Chan described locking screws as a "known embodiment," and the advantages of threaded screw holes were well-established in the art. The compatibility was further suggested by both references disclosing screw holes that allow for a similar range of conical rotation (30 degrees), indicating that Chan’s locking screws could be successfully incorporated into Kay’s plate design without undue experimentation.

Ground 2: Claims 1, 3-9, and 12 are obvious over Grusin in view of Fernandez

• Prior Art Relied Upon: Grusin (Patent 6,283,969) and Fernandez (Application # 2005/0165400).
• Core Argument for this Ground:
  • Prior Art Mapping: Grusin was asserted to disclose a low-contour, T-shaped bone plate for distal radius fractures, teaching an elongate central trunk portion with a pair of divergent arms. Grusin also disclosed spherically recessed screw holes with a "locking feature." Fernandez was asserted to teach a variable-angle locked bone fixation system with polyaxial locking screws. These screws feature threaded, spherical heads that engage protrusions within hourglass-shaped screw holes, allowing for strong locking at a variety of surgeon-selected angles. Petitioner argued that modifying Grusin’s plate to incorporate the advanced variable-angle locking mechanism of Fernandez would render claims 1, 3-9, and 12 obvious.
  • Motivation to Combine: The primary motivation was to enhance the functionality of Grusin’s plate by incorporating the superior locking strength and angular flexibility of Fernandez. For fractures of the distal radius, as addressed by Grusin, strong fixation is critical due to stresses from hand and arm movement. Fernandez’s system offered the combined benefits of increased hold strength via a locking mechanism, maintenance of a low profile, and freedom for the surgeon to select the optimal screw angle. A POSITA would combine these teachings to create a more robust and versatile fixation plate.
  • Expectation of Success: A POSITA would have expected success in this combination because both Grusin and Fernandez taught spherically recessed screw holes, suggesting inherent compatibility and minimizing the protrusion of the screw head, a key objective of Grusin. The use of threaded screws to lock into a plate was a well-known technique, and incorporating Fernandez's specific implementation into Grusin’s plate would have been a predictable design choice.

4. Key Technical Contentions (Beyond Claim Construction)

• Disputed Priority Date: A central contention of the petition was that a majority of the challenged claims (those in Ground 1) were not entitled to their asserted 2006 priority date. Petitioner argued the "locking screw" limitation, defined in the ’253 patent as a screw with external threads on its head, was first introduced in a 2009 continuation-in-part application. The original 2006 application (Kay) allegedly only disclosed non-locking screws with unthreaded, rounded heads. This lack of written description support in the 2006 application, Petitioner argued, made its published version (Kay) valid §102(b) prior art against the later-claimed subject matter.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1, 3-9, 12-15, 17-19, 46-48, and 50-53 as unpatentable.