PTAB

IPR2014-00075

Medtronic Inc v. NuVasive Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method of Accessing a Surgical Target Site in the Spine
  • Brief Description: The ’767 patent discloses methods for accessing a surgical target site, such as a spinal disc, using minimally invasive instruments and techniques. The core method of claim 1 combines three main features: (1) the use of specific access instruments, including an inner wire, sequential dilators, and a multi-blade retractor assembly; (2) performing the procedure along a lateral, trans-psoas path to the lumbar spine; and (3) using an integrated nerve monitoring system to detect nerve proximity during instrument insertion.

3. Grounds for Unpatentability

Ground 1: Obviousness over Cistac, Obenchain, Kelleher, Drongelen, and Koros ’493 - Claims 1, 2, 4, 5, 10, and 15 are obvious over Cistac, Obenchain, Kelleher, Drongelen, and Koros ’493.

  • Prior Art Relied Upon: Cistac (German Patent Pub. No. DE 100 48 790 A1), Obenchain (Patent 5,313,962), Kelleher (WO 01/37728 A1), Drongelen (Patent 6,224,549), and Koros ’493 (Patent 6,139,493).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued this combination teaches all key features of the challenged method. Cistac was asserted to teach the fundamental surgical access method, including an inner wire, sequential dilators (termed "sleeves"), and a retractor assembly with pivotable arms and a knob-and-rack mechanism for blade adjustment. Obenchain was cited for disclosing the specific lateral, trans-psoas surgical path to the spine for a lumbar discectomy, the same type of procedure described in Cistac. Kelleher taught a nerve monitoring system using a stimulation electrode on a surgical tool (e.g., a cannula) to detect nerve proximity via EMG signals. Drongelen supplemented Kelleher by disclosing a video display for EMG monitoring that included a graphical representation of the patient. Finally, Koros ’493 was argued to teach retractor features not explicitly detailed in Cistac, such as using fixation screws to secure retractor blades to vertebrae for stability and light-emitting devices for illumination.
    • Motivation to Combine: A POSITA would combine these references to create a safer and more effective minimally invasive spinal surgery. The primary motivation was to incorporate the known safety feature of nerve monitoring (Kelleher, Drongelen) into the known surgical access method (Cistac) when using a known surgical path (Obenchain) that traverses the psoas muscle, an area known to contain critical nerves. A POSITA would be motivated to add the retractor fixation screws of Koros ’493 to the Cistac system to achieve predictable stability during surgery. Each component was argued to perform its known function to yield a predictable result.
    • Expectation of Success: A POSITA would have a high expectation of success, as the combination involved the straightforward application of known nerve monitoring systems and retractor stabilization features to a well-established minimally invasive surgical procedure.

Ground 8: Obviousness over Branch, Obenchain, Blewett, and Koros ’493 - Claims 1, 2, 4, 5, 10, 15, 17, and 18 are obvious over Branch, Obenchain, Blewett, and Koros ’493.

  • Prior Art Relied Upon: Branch (Patent 6,945,933), Obenchain (Patent 5,313,962), Blewett (WO 03/005887), and Koros ’493 (Patent 6,139,493).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner presented this as an alternative ground where Branch, instead of Cistac, served as the primary reference for the surgical access instruments. Branch was argued to teach a method using a guidewire, sequential dilators, and a multi-bladed retractor assembly. Petitioner contended that all features of the claimed retractor assembly were present in Branch by combining elements from different disclosed embodiments (e.g., substituting a knob/rack mechanism from one figure for a handle mechanism in another). Blewett, instead of Kelleher and Drongelen, was asserted to teach a comprehensive nerve monitoring system that included electrodes on access instruments (K-wire, dilating cannula) and a video display that showed numeric stimulation thresholds and a graphical representation of the patient. Obenchain again supplied the teaching of a lateral, trans-psoas path, and Koros ’493 provided the use of fixation screws for retractor stability.
    • Motivation to Combine: The motivation was again to enhance safety and functionality. A POSITA performing the minimally invasive procedure of Branch via the lateral path of Obenchain would be motivated to integrate the nerve monitoring system of Blewett to safely navigate past nerves in the psoas muscle. The combination of different retractor mechanisms within Branch was presented as a simple substitution of known mechanical equivalents to achieve a predictable function. Adding fixation screws from Koros ’493 to the Branch retractor was argued to be an obvious way to improve stability.
    • Expectation of Success: Success was expected because the combination integrated known components for their established purposes without changing their principles of operation.
    • Key Aspects: Petitioner emphasized that this combination was not redundant to the first, as Branch taught a different retractor structure and Blewett provided a more detailed disclosure of the claimed nerve monitoring display features.

  • Additional Grounds: Petitioner asserted additional obviousness challenges based on incremental additions to the primary combinations. Grounds 2 and 3 added Jones (Patent 4,595,013) and the NIM Guide (a Medtronic user manual) to the Ground 1 combination to teach specific nerve monitoring features of claims 17 and 18, such as an electrode harness and patient module details. Grounds 4-7 added Mathews (Patent 5,171,279), Foley (Patent 5,792,044), and Marino (WO 00/38574) to the primary combinations to further support teachings related to wire placement in the disc annulus, the use of a specific number of dilators, and implant insertion.

4. Key Claim Construction Positions

  • "Elongate stimulation instrument": Petitioner argued this term should be construed as a dilator or distractor equipped with a stimulation electrode. This construction was based on the specification, which describes an "initial dilator" that may include a stimulation electrode, while not using the exact claim term.
  • "Teeth of a rack member": The specification does not use the terms "rack member" or "teeth." However, it describes a translation member with "ratchet-like grooves" moved by a knob. Petitioner argued that, under the broadest reasonable interpretation, "teeth" should include these grooves and the "rack member" is the structure that moves in response to force on the teeth.
  • "Articulating arm": The patent provides minimal description for this term recited in claim 15. Citing a dictionary definition for "articulation," Petitioner argued the term should be construed as a jointed or interrelated arm structure that allows the arm to be moved and fixed into a position at the operative site.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1, 2, 4, 5, 10, 15, 17, and 18 of Patent 8,016,767 as unpatentable under 35 U.S.C. §103.