Smith & Nephew Inc v. Arthrex Inc

1. Case Identification

• Case #: IPR2016-00485
• Patent #: 7,195,634
• Filed: January 22, 2016
• Petitioner(s): Smith & Nephew, Inc. & Arthrocare Corporation
• Patent Owner(s): Arthrex, Inc.
• Challenged Claims: 1-4

2. Patent Overview

• Title: Suture Anchor
• Brief Description: The ’634 patent is directed to a screw-based suture anchor assembly for affixing suture to bone, particularly soft cancellous bone. The invention purports to provide exceptional "pull-out" strength through specific features, including a tapered central body and a unique thread geometry.

3. Grounds for Unpatentability

Ground 1: Claims 1-4 are anticipated under 35 U.S.C. §102 by Schmieding.

• Prior Art Relied Upon: Schmieding (Application # 08/954,206).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that the ’634 patent is not entitled to its earliest claimed priority date of August 5, 1996. The priority documents allegedly fail to provide adequate written description for the claimed thread diameter ratio of "at least twice," instead only disclosing a narrower range "between 2.25 and 2.75." Without priority, the patent's effective filing date is July 11, 2005, making Schmieding—an application in the patent’s own family tree that became public in 2000—anticipatory prior art under §102(b). Petitioner asserted that Schmieding discloses every limitation of claims 1-4, including the tapered body, proximally increasing thread thickness (inherently from its drawings), and a preferred diameter ratio of 2.5, which satisfies the "at least twice" requirement for anticipation purposes.

Ground 2: Claims 1 and 4 are anticipated under §102 by Rosenberg ’463 File; Claims 1-4 are obvious under 35 U.S.C. §103 over Rosenberg ’463 File in view of Stone.

• Prior Art Relied Upon: Rosenberg ’463 File (File History of Patent D331,463), Stone (Patent 5,370,662).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that the drawings in the Rosenberg ’463 File, a design patent file history, disclose all "Screw Features" of the challenged claims. This includes a tapered central body, proximally increasing thread thickness, and a thread diameter ratio of at least 2.0. Rosenberg also allegedly discloses the "Suture Anchor Features" of claims 1 and 4, such as a drive head and eyelet on the proximal end, thus anticipating those claims. For claims 2 and 3, Stone was introduced to render the remaining limitations obvious. Stone teaches common suture anchor features, including channels on the drive head (claim 2) and the use of two strands of suture for "multiple suture fixation" (claim 3).
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine Stone’s well-known suture management features with Rosenberg’s anchor design for predictable results. Specifically, a POSA would incorporate channels to prevent suture interference with the driver, a known problem with a known solution. Similarly, using multiple sutures as taught by Stone was a common technique to improve soft tissue repair.
  • Expectation of Success: A POSITA would have a high expectation of success, as combining these standard, well-documented features would involve nothing more than applying known techniques to improve the functionality of the Rosenberg anchor in a predictable manner.

Ground 3: Claims 1-4 are obvious over Nazre in view of Huebner and the knowledge of a POSA.

• Prior Art Relied Upon: Nazre (Patent 5,573,548), Huebner (Patent 5,456,685).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued Nazre discloses a suture anchor with nearly all claimed features, including a tapered central body, a drive head, and a suture eyelet. Nazre lacks two key features: a thread with proximally increasing thickness and an outer-to-inner diameter ratio of "at least twice." Huebner, an orthopedic fixation screw, explicitly teaches increasing the thread thickness proximally to reduce the possibility of the screw "coming loose." The claimed diameter ratio was argued to be an obvious design choice based on the well-known principle that deeper threads (i.e., higher ratios) increase pull-out strength in cancellous bone.
  • Motivation to Combine: A POSITA would combine Huebner's teaching of proximally increasing thread thickness with Nazre's suture anchor to solve the known problem of anchor "backing out" and improve pull-out strength, a primary goal in suture anchor design. Furthermore, a POSITA would have optimized Nazre’s thread depth to achieve a ratio of at least 2.0 as a matter of routine experimentation to enhance holding power, a known result-effective variable.
  • Expectation of Success: A POSITA would have a reasonable expectation of success because both references are from the orthopedic screw field, and the combination applies a known solution (increasing thread thickness and depth) to achieve a predictable and desired result (increased holding strength).

4. Key Claim Construction Positions

• "outer diameter of the thread" is "at least twice the inner diameter of the thread": Petitioner argued this limitation should be interpreted under an "Incontestable Claim Scope." This requires measuring the outer diameter (crest-to-crest) of a half-revolution of thread and comparing it to the inner diameter of the immediately adjacent root. Petitioner asserted this is the standard approach and is consistent with the patent’s stated goal of increasing thread surface area for each turn of the screw. This construction was central to showing that the prior art's illustrated proportions met the claim limitation.

5. Key Technical Contentions (Beyond Claim Construction)

• Lack of Written Description Support for Priority Claim: A central contention underpinning Ground 1 was that the ’634 patent is not entitled to its claimed priority date. Petitioner argued that the priority documents, which only disclose a specific thread diameter ratio "between 2.25 and 2.75," do not provide written description support for the broader, open-ended limitation of "at least twice." This alleged failure to support the full scope of the claims breaks the priority chain, making intervening publications like Schmieding valid prior art.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-4 of Patent 7,195,634 as unpatentable.