Stryker Corporation v. KFx Medical, LLC

1. Case Identification

• Case #: IPR2019-00817
• Patent #: 7,585,311
• Filed: March 20, 2019
• Petitioner(s): Stryker Corporation and Howmedica Osteonics Corp.
• Patent Owner(s): KFX Medical, LLC
• Challenged Claims: 1-3, 5-12, 14, 15, 21-26, 28-30

2. Patent Overview

• Title: System and Method for Attaching Soft Tissue to Bone
• Brief Description: The ’311 patent discloses surgical methods and systems for reattaching soft tissue, such as a tendon, to bone. The invention is particularly directed to knotless "double-row" rotator cuff repair techniques involving a first (medial) anchor placed under the soft tissue and a second (lateral) anchor placed beyond the tissue edge, where a suture is tensioned and fixedly secured to the second anchor after its implantation.

3. Grounds for Unpatentability

Ground 1: Obviousness over Colleran and Millett - Claims 1-3, 5-12, 14, 15, 21-25, and 28-30 are obvious over Colleran in view of Millett.

• Prior Art Relied Upon: Colleran (Application # 2003/0088250) and Millett (a 2004 presentation titled "Mattress Double Anchor Arthroscopic Rotator Cuff Repair").
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Colleran discloses all elements of the claimed method except for the specific placement of the second anchor "beyond the edge of the soft tissue." Colleran taught a knotless, double-row repair method where suture could be tensioned after anchor implantation to solve the same problems addressed by the ’311 patent. Millett, a presentation on rotator cuff repair techniques, was argued to explicitly teach the missing element: placing a lateral anchor beyond the tissue edge to pull the rotator cuff laterally, compress it onto its anatomical footprint, and maximize the healing area.
  • Motivation to Combine: A person of ordinary skill in the art (POSA) would have been motivated to apply the specific, beneficial lateral anchor placement from Millett's rotator cuff technique to the general knotless, double-row procedure of Colleran. The motivation was to achieve the predictable benefits described in Millett—namely, a better and more anatomically correct repair—within the advanced knotless framework provided by Colleran.
  • Expectation of Success: Petitioner argued a POSA would have had a reasonable expectation of success because combining the references involved the simple substitution of a known surgical step (Millett's lateral anchor placement) into a compatible and analogous surgical method (Colleran's knotless procedure) to achieve a predictable improvement.

Ground 2: Obviousness over Colleran and Lubbers - Claims 1-3, 5-12, 14, 15, 21-26, and 28-30 are obvious over Colleran in view of Lubbers.

• Prior Art Relied Upon: Colleran (Application # 2003/0088250) and Lubbers (WO 03/034895 A2).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground presented a similar argument to Ground 1, with Lubbers supplying the teachings of lateral anchor placement. Petitioner argued Colleran taught the foundational knotless, double-row method. Lubbers was asserted to teach placing a lateral anchor beyond the soft tissue edge for rotator cuff repairs to pull the tendon laterally. Furthermore, Lubbers disclosed a knotless anchor with a crimpable aperture that allowed the suture to be tensioned after implantation and then "fixedly secured" by crimping, preventing movement in either direction and thus meeting even the strictest definition of the claim term.
  • Motivation to Combine: The motivation was identical to Ground 1: a POSA would combine the known lateral anchor placement technique from Lubbers with the broader knotless method of Colleran to achieve the known benefits of lateralization in rotator cuff repair. The compatibility of the methods, both being directed to knotless soft tissue repair, would have made the combination straightforward.
  • Expectation of Success: Success would have been expected and predictable, as it involved incorporating a known surgical technique and a compatible knotless anchor design (Lubbers) into a similar, established surgical method (Colleran).

4. Key Claim Construction Positions

• "suture": Petitioner contended this term should be understood by its express definition in the ’311 patent specification: "any flexible structure that can be stretched between two or more anchors, and includes, without limitation, traditional suture material, single or multiple stranded threads, or a mesh structure."
• "fixedly securing...without tying knots": The petition argued that the construction adopted in prior litigation was incomplete. Petitioner proposed an amended construction reflecting the express definition in the specification: "the first length of suture within the securing mechanism of the second anchor cannot be easily moved relative to the second anchor and that this step is completed without tying any knots." This emphasized the role of the anchor's internal mechanism, which is critical for mapping prior art like Colleran and Lubbers.
• "coupled": Petitioner asserted this term is expressly defined in the specification as meaning "that the suture is attached to the bone anchor but not fixedly secured, such that the suture can move to some extent relative to the bone anchor."

5. Arguments Regarding Discretionary Denial

• Petitioner argued that institution should not be denied under §325(d) because the primary prior art and arguments presented in the petition are new and were not substantively considered by the USPTO during original prosecution or the subsequent ex parte reexamination.
• Specifically, Petitioner noted that Colleran (Application # 2003/0088250) was never of record, and while a related application (Colleran ’309) was cited in reexamination, it was only as a secondary reference against dependent claims and was never applied to the limitations of claim 1.
• The Millett and Lubbers references were also not previously considered by the examiner. Therefore, Petitioner contended the grounds relied on a new combination of art and new arguments that raised substantial new questions of patentability.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-3, 5-12, 14, 15, 21-26, and 28-30 of the ’311 patent as unpatentable.