PTAB

IPR2017-00115

Smith & Nephew Inc v. ConforMIS Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Patient-Specific Orthopedic Instruments
  • Brief Description: The ’025 patent describes a surgical system for joint repair, such as knee arthroplasty. The system includes a patient-specific surgical tool created from medical imaging data, featuring a surface that is substantially a negative of the patient's cartilage and at least two guides (e.g., cutting slots or drill holes) aligned relative to a biomechanical or anatomical axis of the joint.

3. Grounds for Unpatentability

Ground 1: Obviousness over Radermacher, Alexander, and Woolson - Claims 1, 2, 5-16, 19, and 20 are obvious over Radermacher alone or in combination with 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 the primary reference, Radermacher, disclosed all key elements of the claimed surgical system. Radermacher taught creating a patient-specific “individual template” from CT or MRI data with a surface that is a negative copy of the patient’s “natural...osseous structure” and includes multiple predetermined guides for cutting and drilling. To the extent Radermacher did not explicitly teach creating the template surface as a negative of the cartilage surface, Petitioner asserted this was taught by Alexander. Alexander disclosed using MRI to create a three-dimensional model of a patient’s knee joint, including detailed mapping of both bone and cartilage surfaces, to guide joint replacement surgery. Finally, Petitioner argued that the limitation of aligning the guides relative to a biomechanical axis was taught by Woolson, which described that aligning cutting paths perpendicular to the patient’s mechanical axis was “necessary” for the long-term success of all total knee implantation systems.
    • Motivation to Combine: A POSITA would combine Radermacher with Alexander because both references addressed methods for treating diseased knee joints using the same MRI technology. Alexander’s specific teachings on cartilage imaging represented a predictable application of the general imaging techniques in Radermacher. The motivation was to simplify surgery by creating a template that fits over existing cartilage, eliminating the need for pre-treatment cartilage removal. A POSITA would combine these teachings with Woolson because aligning implants and cutting guides to the mechanical axis was a fundamental, critical, and universally accepted principle in knee arthroplasty for achieving proper post-surgical alignment and better long-term results.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success because the combination involved applying a known imaging technique (cartilage mapping from Alexander) to a known surgical guide system (Radermacher) to achieve a well-established surgical objective (proper alignment per Woolson). This represented a choice from a finite number of predictable solutions.

Ground 2: Obviousness over Radermacher/Fell/Woolson - Claims 1, 2, 5-16, and 19-20 are obvious over Radermacher in combination with 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 combination where Fell was substituted for Alexander. Petitioner argued that Fell, like Alexander, disclosed using MRI data to determine the shape of articular cartilage for creating a patient-specific device. Fell described producing a contour plot of the femoral and tibial mating surfaces, "complete with articular cartilage," to create custom-tailored meniscal devices. The teachings of Radermacher (patient-specific template with guides) and Woolson (alignment with mechanical axis) were applied as in Ground 1.
    • Motivation to Combine: The motivation to combine Radermacher and Fell was similar to that for combining with Alexander. Both references were in the field of knee joint repair, used MRI, and involved creating patient-specific devices that match a patient's natural joint surface. Radermacher itself stated that surgical procedures were “lagging behind the technology of implant manufacture,” which Petitioner argued provided an express motivation for a POSITA to adapt patient-specific implant technologies (like Fell’s) to Radermacher’s cutting guides. The motivation to incorporate Woolson remained the same: achieving the known, critical goal of proper surgical alignment.

Ground 3: Obviousness with Biscup - Claims 3-4 and 17-18 are obvious over the combinations in Grounds 1 or 3, further in view of Biscup.

  • Prior Art Relied Upon: The references from Grounds 1 or 3, plus Biscup (Application # 2004/0117015).
  • Core Argument for this Ground:
    • Prior Art Mapping: Claims 3-4 and 17-18 added the limitation that an implant selected from a preexisting system is further shaped based on the patient's image data. Petitioner argued this was taught by Biscup, which disclosed a method for producing a customized prosthetic implant by first selecting a "standard prosthetic implant" that closely matches the patient's data, and then shaping it with a molding material based on MRI data to customize it for the patient.
    • Motivation to Combine: A POSITA would have been motivated to modify the systems of Ground 1 or Ground 3 to include Biscup’s teachings. Both Radermacher and Biscup were in the field of joint surgery and used MRI to create custom devices. Given Radermacher's acknowledgment that implant technology was more advanced than surgical procedures, a POSITA would have recognized that Radermacher’s patient-specific template could be used to prepare a joint for a more advanced, patient-specific implant like the one taught by Biscup. This combination represented the simple exchange of one known technology (standard implants) for another known technology (patient-specific implants) to achieve improved results.

4. Relief Requested

  • Petitioner requests the institution of an inter partes review and cancellation of claims 1-20 of the ’025 patent as unpatentable.