PTAB

IPR2016-01874

Smith & Nephew Inc v. ConforMIS Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Patient-Specific Orthopedic Surgical Cutting Guides
  • Brief Description: The ’953 patent discloses a surgical instrument, such as a cutting guide for knee arthroplasty, that is customized for an individual patient. The instrument features an inner surface with a shape or curvature based on imaging data (e.g., MRI or CT scans) of the patient's diseased articular joint surface, and at least one slit that defines a cutting path for a surgical tool.

3. Grounds for Unpatentability

Ground 1: Obviousness over Radermacher and Alexander - Claims 1-6, 10, 12-16, 19, 21-26, 30, 32-36, 40, 50-53, and 55-61 are obvious over Radermacher alone or in combination with Alexander.

  • Prior Art Relied Upon: Radermacher (International Publication No. WO 93/25157) and Alexander (International Publication No. WO 00/35346).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Radermacher discloses all basic elements of the invention. Specifically, Radermacher taught creating a patient-specific "individual template" for knee surgery using CT or MRI data. This template included an inner surface ("contact faces") that copies the "natural... surface of the osseous structure" for a precise fit and tool guides, such as cutting slots. Petitioner contended this anticipates or renders obvious the broad claims. For claims specifically requiring the inner surface to match the cartilage, Petitioner asserted that Alexander explicitly taught using MRI to create detailed 3D reconstructions of a patient’s cartilage surface to assess disease.
    • Motivation to Combine (for §103 grounds): Petitioner argued a person of ordinary skill in the art (POSITA) would combine Radermacher's patient-specific template with Alexander's detailed cartilage imaging. Both references address treating damaged knee joints and use the same imaging technology (MRI). The motivation would be to apply Radermacher's guide-making concept to the natural, untreated joint surface (including cartilage) as detailed by Alexander, thereby simplifying the surgical procedure by eliminating the need to first remove cartilage for the guide to fit.
    • Expectation of Success (for §103 grounds): A POSITA would have had a high expectation of success because combining known imaging techniques for cartilage (Alexander) with known methods for creating guides from imaging data (Radermacher) was a predictable application of existing technologies.

Ground 2: Obviousness over Radermacher, Alexander, and Carignan - Claims 7-9, 11, 17-18, 20, 27-29, 31, 37-39, 41-49, and 54 are obvious over Radermacher alone or in combination with Alexander and Carignan.

  • Prior Art Relied Upon: Radermacher (WO 93/25157), Alexander (WO 00/35346), and Carignan (Patent 6,712,856).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground targeted claims requiring the instrument's inner surface to match the subchondral bone. Petitioner argued Radermacher's teaching of matching the "natural... surface" inherently includes any exposed subchondral bone where cartilage is worn away. Alexander further taught imaging both bone and cartilage. The combination is strengthened by Carignan, which explicitly disclosed a patient-specific template created from CT data with an inner surface designed to match the subchondral bone surface after the surgeon removes any remaining cartilage. This directly teaches the key limitation of these claims.
    • Motivation to Combine (for §103 grounds): A POSITA would be motivated to combine these references as they all address the same problem (creating patient-specific guides for knee surgery) using the same technology (CT/MRI imaging). A POSITA would look to Carignan's method of matching the subchondral bone to ensure the stable and accurate placement sought by Radermacher, especially in cases of significant cartilage degradation.
    • Expectation of Success (for §103 grounds): The combination represented a choice between predictable solutions (matching cartilage vs. matching bone), both of which were known to be achievable with existing imaging and manufacturing methods.

  • Additional Grounds: Petitioner asserted parallel obviousness challenges in Grounds 3 and 4. These grounds substituted Fell (International Publication No. WO 00/59411) for Alexander, arguing Fell also taught using MRI to determine the size and shape of articular cartilage to create a patient-specific device that mates with the cartilage surface. The motivation and mapping arguments were analogous to those presented for Alexander.

4. Key Claim Construction Positions

  • Petitioner proposed that the term "articular joint surface" should be construed to mean "the bone surface and/or cartilage surface of an articulating portion of a joint."
  • This construction was central to Petitioner's argument, as it allowed art disclosing a guide that conforms to the "osseous structure" or bone (like Radermacher) to meet claim limitations reciting "articular joint surface," because the term encompasses both tissue types.

5. Relief Requested

  • Petitioner requests institution of inter partes review and cancellation of claims 1-61 of Patent 9,055,953 as unpatentable.