PTAB

IPR2016-00486

Smith & Nephew Inc v. Arthrex Inc

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1. Case Identification

2. Patent Overview

  • Title: Suture Anchor
  • Brief Description: The ’499 patent discloses a screw-based suture anchor for affixing suture to bone, particularly soft or cancellous bone. The invention purports to improve pull-out strength by employing a tapered central body and specific thread characteristics, such as a large ratio of the thread’s outer diameter to its inner diameter.

3. Grounds for Unpatentability

Ground 1: Anticipation over Schmieding - Claims 5-7 are anticipated by Schmieding under 35 U.S.C. §102(b).

  • Prior Art Relied Upon: Schmieding (Application # 08/954,206).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that claims 5-7 are not entitled to their asserted priority date of August 5, 1996. The priority documents only disclosed a thread diameter ratio "between 2.25 and 2.75," which fails to provide written description support for the broader claimed range of "at least twice." Therefore, the claims’ effective filing date is the patent’s actual filing date of April 3, 2001. Schmieding, an application in the ’499 patent’s priority chain, was published as prior art before this date. Petitioner asserted that Schmieding’s specification is nearly identical to that of the ’499 patent and discloses every limitation of claims 5-7, including examples of anchors with ratios falling within the claimed range.
    • Key Aspects: This ground’s viability hinges on successfully challenging the ’499 patent’s claim to priority.

Ground 2: Obviousness over Rosenberg Combination - Claims 5-7 are obvious over the Rosenberg ’463 File in view of Rosenberg ’520.

  • Prior Art Relied Upon: Rosenberg ’463 File (file history for Patent D331,463) and Rosenberg ’520 (Patent 5,139,520).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that the drawings in the Rosenberg ’463 File disclose a suture anchor with all the screw and suture anchor features recited in claim 5. This includes a tapered central body, a thread with proximally increasing thickness, a drive head with an eyelet, and a thread diameter ratio of at least 2:1. Rosenberg ’520 was cited for disclosing all the claimed driver tool features, teaching a cannulated driver with a handle and a post (a "cleat") for securing a suture, enabling it to hold an anchor at its distal end.
    • Motivation to Combine: A POSITA would combine these references because the Rosenberg ’463 File taught using a "hand-held driver instrument" without specifying its details, and Rosenberg ’520 provided a well-suited, contemporary driver designed for the same purpose: placing a temporary suture anchor during ACL surgery. The shared intended use and complementary nature of the disclosures provided clear motivation for the combination.
    • Expectation of Success: Given the predictability of mechanical arts and the parallel functions of the components in the prior art, a POSITA would have had a reasonable expectation of successfully creating the claimed assembly.

Ground 3: Obviousness over Nazre Combination - Claims 5-7 are obvious over Nazre in view of Lasner, Goble, and Cerier.

  • Prior Art Relied Upon: Nazre (Patent 5,573,548), Lasner (Patent 5,120,171), Goble (Patent 5,851,219), and Cerier (Patent 5,100,417).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Nazre disclosed a tapered suture anchor with most of the claimed screw features but lacked a proximally increasing thread thickness and an explicit outer-to-inner diameter ratio of at least 2:1. Lasner taught modifying a bone screw to include proximally increasing thread thickness to enhance pull-out resistance in cancellous bone. Goble disclosed the claimed suture anchor features, namely a drive head with a centrally located eyelet. Cerier disclosed a complete driver assembly with all the claimed features, including a cannulated shaft and a handle with a fixation post ("cleat") and slot.
    • Motivation to Combine: A POSITA would combine Nazre and Lasner to improve the anchor's pull-out strength, a known objective in the field. The resulting anchor would then be combined with Goble's drive head configuration and Cerier's driver to create a complete, functional, and manufacturable surgical assembly. The combination represented the integration of known, advantageous features from the prior art to solve the common problem of securely anchoring sutures in bone.
    • Expectation of Success: The combination involved applying known design principles (e.g., increasing thread thickness for strength) to a known device (a suture anchor) and pairing it with standard, compatible components (a drive head and driver). This assembly of known elements to achieve predictable results would have been straightforward for a POSITA.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge substituting Huebner (Patent 5,456,685) for Lasner, arguing that Huebner likewise taught the benefits of proximally increasing thread thickness for improving a screw's engagement with bone.

4. Key Claim Construction Positions

  • Petitioner argued that the key limitation "the outer diameter of the thread being at least twice the inner diameter of the thread" should be interpreted under an "Incontestable Claim Scope." This scope requires measuring the inner diameter at the thread root immediately adjacent to the half-revolution of the thread where the outer diameter (crest-to-crest) is measured. This construction was presented as the standard approach in the prior art and was central to Petitioner's contention that the references met the limitation.
  • For dependent claims 6 and 7, "cleat" was construed broadly as "a device around which suture can be wrapped," and "slot" as a "narrow opening" for holding the suture.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 5-7 of the ’499 patent as unpatentable.