Stryker Corp v. OsteoMed LLC

1. Case Identification

• Case #: IPR2021-01450
• Patent #: 8,529,608
• Filed: August 30, 2021
• Petitioner(s): Stryker Corporation and Wright Medical Technology, Inc.
• Patent Owner(s): OsteoMed LLC
• Challenged Claims: 1-6, 8-14, and 17

2. Patent Overview

• Title: Bone Plate with a Transfixation Screw Hole
• Brief Description: The ’608 patent is directed to a system for securing two discrete bones across a joint, such as a failed metatarsophalangeal joint. The system uses a bone plate with a transfixation screw hole designed to guide a screw across the joint to absorb tensile loads and stabilize the bones.

3. Grounds for Unpatentability

Ground 1: Anticipation by Slater - Claims 1-5, 9-14, and 17 are anticipated by Slater.

• Prior Art Relied Upon: Slater (WO 2007/131287).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Slater, which discloses an ankle fusion plate, teaches every limitation of the challenged claims. Slater shows an elongate bone plate with first and second ends having fixation points and inner surfaces that conform to the anatomy of the tibia and talus, respectively. The plate includes a bridge portion spanning the ankle joint that is explicitly described as having its "maximum thickness" over the joint, which is greater than the tapered ends of the plate. Slater further discloses a transfixation screw hole for implanting a screw at an angle to pass through the tibia, the joint, and into the talus, thereby transferring tensile load to the bridge portion.
  • Key Aspects: Petitioner noted that Slater also discloses features recited in the dependent claims, including the transfixation screw crossing a neutral bending axis, specific transfixation angles (31°, 47°, 57°), the use of a lag screw, and a plate angle conforming to the natural bend of the joint.

Ground 2: Anticipation by Falkner - Claims 1-3, 6, 8-13, and 17 are anticipated by Falkner.

• Prior Art Relied Upon: Falkner (Application # 2005/00171544).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Falkner, which was not considered during prosecution, anticipates the claims. Falkner teaches a bone plate system that can be sized and shaped to conform to bones and explicitly contemplates its use to span a joint, such as the one between the tibia and talus. The plate includes first and second ends with fixation points, a bridge portion, and a transfixation screw hole (oblique opening 44) to direct a screw across the joint. Falkner also recognizes that the plate's thickness may be varied, making it "thicker to increase structural stability" in regions like the bridge portion, thus disclosing the thickened bridge limitation. Additionally, Falkner teaches that screw holes may be threaded to lockably engage screw heads, anticipating claims 6 and 8.

Ground 3: Obviousness over Arnauld and Slater - Claims 1-5, 9-14, and 17 are obvious over Arnauld in view of Slater.

• Prior Art Relied Upon: Arnauld (EP 1897509) and Slater (WO 2007/131287).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that Arnauld, an arthrodesis plate for a metatarsophalangeal joint, discloses every element of independent claim 1 except for the thickened bridge portion. Arnauld shows a plate with an elongate spine, anatomically conforming first and second ends, a bridge portion spanning the joint, and a transfixation screw hole directing a screw across the joint to absorb bending stress.
  • Motivation to Combine: A POSITA would combine Arnauld with Slater's teaching of a thickened bridge portion to strengthen Arnauld's plate. Arnauld's stated purpose is to provide a durable fixation for the metatarsophalangeal joint, which is subject to high cyclical stress. Slater teaches that thickening the bridge portion of a joint fusion plate provides maximum strength where the highest loading occurs. Therefore, a POSITA would apply this known and predictable strengthening technique to the high-stress bridge region of Arnauld's plate.
  • Expectation of Success: A POSITA would have a reasonable expectation of success in strengthening the Arnauld plate by incorporating Slater’s thickened bridge portion, as it was a simple application of a known design principle to improve durability with no change in function.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including that claims 6 and 8 are obvious over Slater in view of Weaver (Patent 6,623,486) for adding known locking screw technology, and that claims 4, 5, and 14 are obvious over Falkner in view of Arnauld to arrive at specific transfixation angles for a metatarsophalangeal joint application. A final ground argued claims 6 and 8 are obvious over the combination of Arnauld, Slater, and Weaver.

4. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under 35 U.S.C. §325(d), contending the PTO materially erred by not substantively considering the primary prior art. While Slater and Arnauld were among nearly 200 references cited during prosecution, they were never used in a rejection or addressed by the examiner; Falkner was never before the PTO at all.
• Petitioner also argued against discretionary denial under Fintiv, noting that the parallel district court cases were in their infancy with no trial date set, discovery had just begun, and investment was minimal. Petitioner further stated that upon institution, it would not pursue the same invalidity grounds in the parallel litigation, mitigating concerns of inefficiency.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-6, 8-14, and 17 of the ’608 patent as unpatentable.