PTAB

IPR2017-00780

Smith & Nephew Inc v. ConforMIS Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Patient-Specific Orthopedic Instruments
  • Brief Description: The ’302 patent discloses patient-specific surgical tools, specifically a cutting or drilling "block" for use in joint replacement surgery. The tool features a surface customized to be a negative of the patient's joint cartilage, ensuring a precise fit, and includes guides for surgical instruments that are aligned relative to the joint's anatomical or biomechanical axes.

3. Grounds for Unpatentability

Ground 1: Claims 95-125 are obvious over Radermacher, Alexander, and Woolson.

  • Prior Art Relied Upon: Radermacher (WO 93/25157), Alexander (WO 00/35346), and Woolson (Patent 4,841,975).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Radermacher disclosed the core invention: a patient-specific surgical "template" (block) created using MRI or CT data with multiple guides for cutting and drilling. The central issue addressed by the combination was whether Radermacher's teaching of matching the "natural surface" of the bone inherently included matching the articular cartilage. Petitioner contended that even if Radermacher did not explicitly disclose this, Alexander taught using MRI and CT to generate detailed 3D images of cartilage surfaces for surgical planning. Therefore, a person of ordinary skill in the art (POSITA) would have found it obvious to apply Alexander’s cartilage imaging techniques to create the patient-specific template taught by Radermacher. Finally, Woolson was cited to supply the limitation of aligning the guides with a biomechanical or anatomical axis. Woolson taught that aligning cutting paths perpendicular to the mechanical axis was "important" and "necessary" for the long-term success of all total knee implantations.
    • Motivation to Combine: A POSITA would combine Radermacher and Alexander because they address the same problem (knee surgery) using the same imaging technology (MRI/CT). Modifying Radermacher's template to match the cartilage surface taught by Alexander would be a simple design choice to simplify surgery by avoiding the need to first remove the cartilage for the guide to fit. The motivation to incorporate Woolson's teachings was strong, as proper alignment relative to the mechanical axis was a universally accepted principle for ensuring the stability and longevity of knee implants.
    • Expectation of Success: A POSITA would have a reasonable expectation of success in combining these references because it involved applying a known imaging technique (Alexander) to a known type of surgical guide (Radermacher) to achieve a predictable improvement in fit, while incorporating a standard, essential alignment principle (Woolson) for knee arthroplasty.

Ground 2: Claims 95-125 are obvious over Radermacher, Fell, and Woolson.

  • Prior Art Relied Upon: Radermacher (WO 93/25157), Fell (WO 00/59411), and Woolson (Patent 4,841,975).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground presented an alternative to Alexander for teaching the creation of a patient-specific surface that negatively matches the articular cartilage. Radermacher and Woolson were asserted for the same purposes as in Ground 1. The key difference was the use of Fell, which disclosed creating a patient-specific implant (a meniscal replacement) customized to match the patient's articular cartilage using MRI data. Fell explicitly stated that the shapes of its custom devices "include the articular cartilage" and are designed to "substantially mate with the corresponding tibial and femoral surfaces." Petitioner asserted that Fell directly taught using MRI to determine the shape of articular cartilage and creating a patient-specific device that is a negative of that surface.
    • Motivation to Combine: The motivation to combine Radermacher and Fell was similar to the motivation for combining with Alexander: both references were in the same field, addressed treating damaged knee cartilage, and used MRI for creating patient-specific devices. Petitioner added a specific motivation from Radermacher itself, which noted that individualized surgical procedures were "lagging behind the technology of implant manufacture." This, Petitioner argued, would have expressly motivated a POSITA to adapt advanced patient-specific implant technologies, such as those in Fell, to the surgical guides taught in Radermacher. The motivation to further combine with Woolson remained the same as in Ground 1.
    • Expectation of Success: A POSITA would expect success for the same reasons as in Ground 1. The combination involved adapting a known patient-specific device manufacturing technique (Fell) to a known surgical guide system (Radermacher) and aligning it using a fundamental, well-established surgical principle (Woolson).

4. Relief Requested

  • Petitioner requested the institution of an inter partes review and cancellation of claims 95-125 of the ’302 patent as unpatentable under 35 U.S.C. §103.