Paragon 28 Inc v. Wright Medical Technology Inc

1. Case Identification

• Case #: IPR2019-00895
• Patent #: 9,259,252
• Filed: March 28, 2019
• Petitioner(s): Paragon 28, Inc.
• Patent Owner(s): Wright Medical Technology, Inc.
• Challenged Claims: 17-27

2. Patent Overview

• Title: Orthopedic Plate for Use in Small Bone Repair
• Brief Description: The ’252 patent discloses methods and systems for orthopedic internal fixation. The technology involves using a pre-contoured bone plate with an elongate trunk and diverging arms, which is secured to a bone using locking screws during surgery.

3. Grounds for Unpatentability

Ground 1: Claims 17-27 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 Kay, which is the published version of the parent application to the ’252 patent, disclosed most of the claimed elements. This included a pre-contoured bone plate with an elongate trunk, asymmetrically diverging arms, and screw holes configured to prevent screws from impinging. However, Kay primarily taught the use of non-locking screws. Chan was cited for its teaching of a bone plate system with threaded screw holes specifically designed to receive locking and variable-angle locking screws. Petitioner contended that Chan’s system, which used "discrete columns of teeth or thread segments" in the screw holes, explicitly addressed the problem of screw loosening and provided increased pullout strength.
  • Motivation to Combine: Petitioner asserted that both Kay and Chan recognized the clinical problem of screw loosening and the need for greater pullout strength in bone fixation. A person of ordinary skill in the art (POSITA), reading Kay’s stated goal of achieving "increase[d] pullout strength," would combine Kay’s plate geometry with Chan’s well-known locking screw technology. This combination would predictably improve the stability and performance of the Kay plate system by preventing screw back-out, a known issue with the non-locking screws taught by Kay.
  • Expectation of Success: The use of locking screws to enhance fixation was a well-established and successful technique in the field of orthopedics. Petitioner argued a POSITA would have had a high expectation of success in incorporating Chan's locking features into Kay's plate design. The components were mechanically straightforward, and there was no technical reason to believe the combination would not function as intended to create a more secure construct.

Ground 2: Claims 17-21 and 23-27 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: Petitioner asserted that Grusin taught a pre-contoured, T-shaped plating system for distal radius fractures. Grusin’s plate included an elongate trunk, divergent arms, and "spherically recessed" screw holes incorporating a "locking feature." To supply the specific locking mechanism of the challenged claims, Petitioner cited Fernandez, which disclosed a "Variable Angle Locked Bone Fixation System." Fernandez taught polyaxial locking screws with threaded, spherical heads that engaged corresponding threaded holes, allowing a surgeon to lock a screw at a selected angle for optimal fixation.
  • Motivation to Combine: According to Petitioner, a POSITA would combine these references to improve upon Grusin’s system. Grusin is directed to fractures of the distal radius, an area subject to significant stress from hand and arm movement, making a secure fixation critical. A POSITA reviewing Grusin’s general disclosure of a "locking feature" would look to prior art for advanced, reliable locking mechanisms. Fernandez provided such a solution, offering both a solid lock and the added surgical flexibility of variable-angle placement. The combination would provide a low-profile, high-strength fixation, consistent with the goals of Grusin.
  • Expectation of Success: Petitioner argued that the combination would have been straightforward with a high expectation of success. Both references disclosed compatible features, such as spherically recessed holes. Given that variable-angle locking technology was known in the art, a POSITA would have reasonably expected that incorporating the polyaxial locking screws of Fernandez into the Grusin plate would successfully create a superior fixation system without undue experimentation.

4. Key Technical Contentions (Beyond Claim Construction)

• Priority Date Challenge: A foundational argument of the petition was that the challenged claims were not entitled to the priority date of the 2006 parent application. Petitioner argued that the key limitation of a "locking screw," defined in the ’252 patent as having external threads on the screw head, was new matter first introduced in the 2009 continuation-in-part (CIP) application. Because the 2006 application allegedly failed to provide written description support for a threaded screw head, its publication (Kay) became prior art under 35 U.S.C. §102(b) against the challenged claims, which were only entitled to the 2009 filing date.

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 17-27 of the ’252 patent as unpatentable.