Medtronic Inc v. NuVasive Inc

1. Case Identification

• Case #: IPR2014-00076
• Patent #: 8,016,767
• Filed: October 21, 2013
• Petitioner(s): Medtronic, Inc.
• Patent Owner(s): NuVasive, Inc.
• Challenged Claims: 1, 2, 4, 5, 10, 15, 17-18

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 in the spine using a combination of minimally invasive access instruments (e.g., dilators, retractors), a lateral, trans-psoas surgical path, and intraoperative nerve monitoring to avoid nerve damage during the procedure.

3. Grounds for Unpatentability

Ground 1: Obviousness over Cistac, Obenchain, JJB, and Koros ’493 - Claims 1, 2, 4, 5, 10, 15, 17-18 are obvious over Cistac in view of Obenchain, JJB, and Koros ’493.

• Prior Art Relied Upon: Cistac (German Patent Pub. No. DE 100 48 790 A1), Obenchain (Patent 5,313,962), JJB (FDA 510(K) No. K013215), and Koros ’493 (Patent 6,139,493).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued the claims were an obvious combination of three known concepts in minimally invasive spinal surgery. Cistac was asserted to teach a method of accessing the spine using an inner wire, sequential dilators ("sleeves"), and a retractor assembly with pivotable arms and a knob-based adjustment mechanism. Obenchain taught performing a lumbar discectomy via a lateral, trans-psoas approach to avoid bowel perforation. JJB taught a nerve monitoring system that uses a dilating cannula with a stimulation electrode at its tip to detect nerve proximity via electromyographic (EMG) activity, displaying results on a screen. Koros ’493 was cited for teaching the use of removable fixation screws that engage retractor blades to secure them to adjacent vertebrae, enhancing stability.
  • Motivation to Combine: A POSITA would combine these references to perform a known procedure (lumbar discectomy) more safely and effectively. It would have been obvious to apply the access instruments of Cistac using the advantageous lateral, trans-psoas path taught by Obenchain for the same type of surgery. Incorporating the nerve monitoring system of JJB was argued to be a known safety precaution, particularly when traversing the psoas muscle where nerves are known to reside. Finally, adding the fixation screws of Koros ’493 to Cistac’s retractor was a predictable way to improve stability.
  • Expectation of Success: The combination involved applying known tools and techniques for their intended purposes, which would have provided a POSITA with a reasonable expectation of success.

Ground 2: Obviousness with Additional Teachings from Mathews and Foley - Claims 1, 2, 4, 5, 10, 15, 17-18 are obvious over the combination of Ground 1, further in view of Mathews and Foley.

• Prior Art Relied Upon: Cistac, Obenchain, JJB, Koros ’493, and additionally Mathews (Patent 5,171,279) and Foley (Patent 5,792,044).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground supplemented Ground 1, arguing that even if a POSITA did not appreciate certain claimed features from the primary combination alone, Mathews and Foley rendered them obvious. Petitioner argued Foley explicitly taught using a sequence of three dilators to progressively enlarge the surgical corridor. Both Mathews and Foley taught the necessity of inserting a fusion implant after a discectomy to stabilize the spinal segment, a step recited in the ’767 patent. Mathews was also cited for teaching the technique of inserting a guidewire into the disc annulus to serve as a guide for subsequent dilators.
  • Motivation to Combine: A POSITA would look to references like Foley and Mathews, which address the same technical problems in minimally invasive spinal surgery, for conventional techniques like sequential dilation and post-discectomy stabilization with an implant. These references provided explicit teachings for steps that were already logical extensions of the primary combination.

Ground 3: Obviousness over Branch, Obenchain, JJB, and Koros ’493 - Claims 1, 2, 4, 5, 10, 15, 17-18 are obvious over Branch in view of Obenchain, JJB, and Koros ’493.

• Prior Art Relied Upon: Branch (Patent 6,945,933), Obenchain (Patent 5,313,962), JJB (FDA 510(K) No. K013215), and Koros ’493 (Patent 6,139,493).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground presented an alternative to Ground 1, substituting Branch for Cistac as the primary reference for the access instruments. Petitioner asserted Branch more clearly taught certain features of the claimed retractor assembly. Branch was asserted to teach forming an initial distraction corridor with a guidewire and dilator, followed by sequential dilation and placement of a multi-bladed retractor assembly. Critically, Branch was argued to disclose all the claimed mechanical features of the retractor, including pivotable arm portions and a knob-and-rack mechanism. Petitioner noted that while different embodiments in Branch showed different handle mechanisms, it would have been an obvious substitution to combine the knob-and-rack from one embodiment with the retractor frame of another. The roles of Obenchain, JJB, and Koros ’493 remained the same as in Ground 1.
  • Motivation to Combine: The motivation was identical to Ground 1, with Branch simply providing an alternative, and allegedly more complete, disclosure of the claimed access instruments. The combination of different embodiments within Branch was presented as a simple substitution of known mechanical parts to achieve a predictable result.

4. Key Claim Construction Positions

• "Elongate stimulation instrument": Petitioner argued this term, not found in the specification, should be construed as a dilator/distractor with a stimulation electrode. This construction was based on the specification’s description of an "initial dilator" that may have a stimulation electrode, allowing prior art stimulating dilators to be directly mapped to this limitation.
• "Teeth of a rack member": As the specification did not use the term "rack member," Petitioner contended that based on the figures and description of a translation member with "ratchet-like grooves" moved by a knob, the term "teeth" should be construed to include grooves. This construction was crucial for mapping the retractor mechanisms of Cistac and Branch to the claim language.

5. Relief Requested

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