Smith & Nephew Inc v. Arthrex Inc

1. Case Identification

• Case #: IPR2016-00484
• Patent #: 6,214,031
• Filed: January 22, 2016
• Petitioner(s): Smith & Nephew, Inc. & Arthrocare Corporation
• Patent Owner(s): Arthrex, Inc.
• Challenged Claims: 1, 11, 12, 14, 16, 18-22

2. Patent Overview

• Title: Suture Anchor
• Brief Description: The ’031 patent discloses a screw-based suture anchor for affixing suture to bone, particularly soft cancellous bone. The invention purports to provide exceptional pull-out strength by employing specific screw features, including a tapered central body and a thread with particular depth and thickness characteristics.

3. Grounds for Unpatentability

Ground 1: Obviousness/Anticipation over Arthrex Brief - Claims 1, 11, 12, 16, and 18-22

• Prior Art Relied Upon: Arthrex Brief (a 1999 court brief filed by Patent Owner), and Arthrex Product Catalog (a 1998-1999 product catalog).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that the Arthrex Brief, a public document predating the ’031 patent’s effective filing date, anticipated most challenged claims. The brief included a drawing of Arthrex’s "Corkscrew" suture anchor that Petitioner asserted was nearly identical to Figure 1 of the ’031 patent. This drawing allegedly disclosed all key limitations of claim 1, including a tapered central body, a thread thickness that increases proximally, an outer-to-inner thread diameter ratio of at least 2:1, a drive head, and an eyelet. For claim 21, which requires "two lengths of suture," Petitioner contended it was obvious to use the Arthrex Brief's anchor with two sutures as taught by the Arthrex Product Catalog, which advertised the same "Corkscrew" product with "two strands" of suture.
  • Motivation to Combine (for §103 grounds): A POSITA would combine the teachings of the Arthrex Brief and its corresponding Product Catalog because both documents described the same commercial product. The combination was motivated by the known clinical need for "multiple suture fixation" to securely attach soft tissue to bone.
  • Expectation of Success (for §103 grounds): A POSITA would have had a high expectation of success in using two sutures with the anchor, as this was a common and predictable modification for suture anchors at the time.

Ground 2: Obviousness/Anticipation over Rosenberg - Claims 1, 11, 12, 16, 18-22

• Prior Art Relied Upon: Rosenberg ’463 File (the publicly available file history of Patent D331,463), and Stone (Patent 5,370,662).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that the drawings in the Rosenberg ’463 File, a design patent file history, disclosed all screw-related features of the challenged claims and therefore anticipated claims 1, 11, 12, 16, 18, 19, and 22. The drawings allegedly showed a suture anchor with a tapered central body, a tip with a greater taper, a continuous thread with a proximally increasing thickness, and an outer-to-inner diameter ratio of at least 2:1. For claim 20 (“channels for suture”) and claim 21 (“two lengths of suture”), which were not explicitly shown in Rosenberg, Petitioner asserted obviousness in view of Stone. Stone taught an integrated drive head and eyelet design with channels to prevent suture interference with the driver and disclosed the benefits of "multiple suture fixation."
  • Motivation to Combine (for §103 grounds): A POSITA would combine Rosenberg with Stone to improve the functionality of Rosenberg’s anchor. Given Rosenberg’s disclosure of using a driver, a POSITA would have been motivated to incorporate Stone’s channels to prevent suture interference, a known problem. Similarly, the known need for stronger tissue fixation would motivate a POSITA to attach two sutures, as taught by Stone, to Rosenberg’s anchor.
  • Expectation of Success (for §103 grounds): A POSITA would have reasonably expected success, as incorporating features like suture channels and using multiple sutures were well-established and predictable design choices for improving suture anchors.

Ground 3: Obviousness over Nazre in view of Huebner - Claims 1, 11, 12, 14, 16, 18-22

• Prior Art Relied Upon: Nazre (Patent 5,573,548), Huebner (Patent 5,456,685), and a POSITA's general knowledge.
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Nazre disclosed almost all features of claim 1, including a tapered central body, a tip with a greater taper, a drive head, and an eyelet. However, Nazre taught threads with a constant thickness and did not explicitly disclose an outer-to-inner diameter ratio of at least 2:1. Petitioner argued that Huebner remedied the first deficiency by expressly teaching an orthopedic screw with a thread thickness that increases proximally to reduce the possibility of the screw loosening. The second deficiency was remedied by a POSITA’s knowledge that increasing thread depth (i.e., the outer-to-inner diameter ratio) was a known parameter to optimize for increasing pull-out strength in cancellous bone.
  • Motivation to Combine (for §103 grounds): A POSITA seeking to improve the pull-out strength of Nazre’s suture anchor would have been motivated to incorporate the proximally increasing thread thickness taught by Huebner. Further, a POSITA would have been motivated by well-known principles to optimize Nazre’s thread depth, a known result-effective variable, to achieve a ratio of at least 2:1 to maximize holding power.
  • Expectation of Success (for §103 grounds): Success was predictable, as both modifications involved applying known principles (from Huebner and general knowledge) to achieve their expected results of improved screw stability and pull-out strength.

4. Key Claim Construction Positions

• "Outer and Inner Thread Diameter": Petitioner argued that the claim limitation "outer diameter of the thread is at least twice the inner diameter of the thread along a portion of the thread" should be interpreted under an "Incontestable Claim Scope." This interpretation would require measuring the outer diameter (crest-to-crest) and the adjacent inner diameter (root-to-root) over the shortest possible portion, such as a half-revolution of the thread. Petitioner asserted this was consistent with the specification’s goal of increasing thread surface area and was the standard approach in the prior art. This construction was central to Petitioner's argument that the prior art drawings in the Arthrex Brief and Rosenberg ’463 File met the limitation.

5. Key Technical Contentions (Beyond Claim Construction)

• Applicable Priority Date: A central contention was that most challenged claims (1, 11, 12, 16, and 18-22) were not entitled to the asserted priority date of August 5, 1996. Petitioner argued the priority documents only disclosed a specific outer-to-inner diameter ratio range of "between 2.25 and 2.75" (as in claim 14) and provided no written description support for the broader, open-ended range of "at least twice" required by the other claims. Therefore, these claims were only entitled to the patent’s actual filing date of June 5, 2000, which made the 1999 Arthrex Brief and 1998 Arthrex Product Catalog valid prior art references under pre-AIA 35 U.S.C. §102(b).

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1, 11, 12, 14, 16, and 18-22 of the ’031 patent as unpatentable.