Arthrex Inc v. MedShape Inc

1. Case Identification

• Case #: IPR2025-00053
• Patent #: 7,985,222
• Filed: October 18, 2024
• Petitioner(s): Arthrex, Inc.
• Patent Owner(s): Medshape, Inc.
• Challenged Claims: 1-10

2. Patent Overview

• Title: Method for Bone Fracture Fixation
• Brief Description: The ’222 patent relates to methods for fixing bone fractures using devices made from a shape memory alloy (SMA), such as Nitinol. The method involves stretching the device to induce a phase transformation that generates and maintains compressive force across the fracture site.

3. Grounds for Unpatentability

Ground 1: Claims 1-2 and 5-10 are obvious over Monassevitch.

• Prior Art Relied Upon: Monassevitch (Patent 6,685,708).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Monassevitch discloses all limitations of the challenged claims. Monassevitch teaches bone staples made of SMA used for fracture fixation. The method involves inserting the staple into two bone fragments, stretching the staple along its longitudinal axis to increase its span, and thereby creating a stress-induced martensitic phase. This stretching occurs at a temperature above the austenite finish temperature (Af) to leverage the SMA's superelastic properties. The staple is then fixed in place, where its tendency to revert to its original shape provides compression. Petitioner asserted that Monassevitch’s disclosure of stretching the staple and then inserting it into bone teaches the claimed sequence of stretching before final fixing. Dependent claims related to performing steps while the device is in an austenitic phase were allegedly taught by Monassevitch’s disclosure that superelasticity occurs when stretching a fully austenitic SMA element.

Ground 2: Claims 1-10 are obvious over Bolesky in view of Hoffman.

• Prior Art Relied Upon: Bolesky (Patent 4,275,717) and Hoffman (Patent 5,035,712).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Bolesky discloses a fracture fixation device with most of the claimed method steps but lacks the use of an SMA. Bolesky teaches an intramedullary device that is inserted into two bone fragments and uses a tensioned rod to create compression across the fracture. A nut is tightened to first fix one end of the device and then to stretch the rod. Petitioner argued that Hoffman supplies the missing element, teaching a similar orthopedic device that uses a tensioned rod made of an SMA (Nitinol) to provide compression. Hoffman explicitly discloses stretching the SMA rod while it is in its austenitic phase to create stress-induced martensite, thereby generating a constant compressive force. The combination of Bolesky’s mechanical construct and method with Hoffman’s SMA rod allegedly renders claim 1 obvious. Dependent claims were argued to be obvious for the same reasons, as Hoffman teaches performing the stretching at body temperature, which is above the engineered Af of the SMA.
  • Motivation to Combine: A POSITA seeking to improve the sustained compression of Bolesky’s device would combine it with Hoffman’s teachings. Both references are analogous art, addressing the problem of maintaining compression in orthopedic implants inserted into long bones. Hoffman directly teaches using an SMA rod to provide superior, continuous compression compared to traditional materials, solving a known issue of compression loss over time. The structural similarity of the devices—both using a tensioned rod mechanism—would have made the combination a predictable and obvious design choice.
  • Expectation of Success: A POSITA would have had a high expectation of success. By the filing date of the ’222 patent, Nitinol was well-known to be biocompatible and was routinely used in orthopedic devices for its superelastic properties. Modifying Bolesky’s stainless steel rod to one made of Nitinol, as taught by Hoffman, was a straightforward substitution of materials to achieve a known benefit (sustained compression).

4. Key Claim Construction Positions

• “Bone Fragment”: Petitioner noted that while both parties appear to agree on the plain and ordinary meaning, the Patent Owner has asserted the term also covers intact bones. Petitioner argued that the prior art renders the claims obvious under either interpretation, as the references clearly disclose fixation between pieces of a broken bone.
• “Substantially in an Austenitic Phase”: Petitioner asserted that in co-pending litigation, it contends this term is indefinite. For the purposes of the IPR, Petitioner adopted the Patent Owner’s apparent interpretation: that an SMA is “substantially in an austenitic phase” if only a part of it is transformed into martensite during a claimed step or if the SMA is above its austenite finish temperature.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should not discretionarily deny institution under §314(a). The petition asserted it presents a compelling case of unpatentability, which, under the Director’s Interim Procedure, weighs against denial based on Fintiv factors. Further, Petitioner argued that the parallel district court case is at a very early stage, with an answer recently filed and no discovery or trial timeline set, meaning an IPR would be a more efficient resolution.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-10 of the ’222 patent as unpatentable.