PTAB

IPR2019-00570

RTI Surgical Inc v. LifeNet Health

Log In
Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Composite Bone Graft, Method of Making and Using Same
  • Brief Description: The ’532 patent discloses composite spinal bone grafts for use in spinal fusion procedures. The invention aimed to solve problems associated with single-piece bone grafts, such as physical size limitations, by assembling grafts from two or more distinct bone portions (e.g., cortical and cancellous bone) held together by mechanical connectors to achieve optimal size and load-bearing capacity.

3. Grounds for Unpatentability

Ground 1: Claims 4 and 6-11 are obvious over Grooms in view of McIntyre

  • Prior Art Relied Upon: Grooms (Application # 2002/0138143) and McIntyre (Patent 4,950,296).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Grooms disclosed nearly all elements of independent claim 4, including a composite spinal graft for anterior fusion made from two cortical bone halves fastened by pins. The assembled halves formed a central canal intended to be packed with osteogenic material. However, Grooms did not explicitly teach packing this canal with a "plate-like cancellous bone portion." McIntyre, in the same field, disclosed spinal fusion grafts comprising a cortical shell with a central cavity specifically fitted with a cancellous bone plug, which a person of ordinary skill in the art (POSITA) would consider to be "plate-like."
    • Motivation to Combine: A POSITA would combine McIntyre’s cancellous bone plug with Grooms’s graft structure. McIntyre taught that its cancellous plug was highly osteogenic and provided the "most suitable matrix for rapid bone regeneration and repair." This teaching would have motivated a POSITA to incorporate the advantageous cancellous plug from McIntyre as the osteogenic filler in the Grooms graft to improve the graft’s efficacy and maximize the chances of a successful transplant.
    • Expectation of Success: A POSITA would have had a high expectation of success in making this combination. The modification involved the simple substitution of one known osteogenic material for another within a known graft structure, requiring no more than ordinary skill.

Ground 2: Claims 12 and 20 are anticipated by or obvious over Paul

  • Prior Art Relied Upon: Paul (Patent 6,258,125).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Paul anticipated every limitation of independent claim 12. Paul disclosed a load-bearing cortical bone implant for posterior lumbar interbody fusion, which is placed in the anterior spinal column. The implant was a composite structure made from two distinct C-shaped cortical bone portions that, when joined, formed a central space filled with an osteoconductive material. Paul taught that these portions were secured by locking pins made of allograft bone, which function as the claimed "non-adhesive mechanical connectors." Furthermore, the top and bottom vertebra-engaging surfaces of the Paul implant included a plurality of teeth to prevent expulsion, satisfying the "textured surfaces" limitation.

Ground 3: Claims 12 and 20 are anticipated by Wolter

  • Prior Art Relied Upon: Wolter ("Bone Transplantation in the Area of the Vertebral Column," 1987).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Wolter’s disclosure of a "composite corticospongial block" or "sandwich block" anticipated claim 12. Wolter described a load-bearing graft for anterior spine implantation comprising alternating layers of cortical and cancellous bone, which inherently discloses a first cortical portion, a second cortical portion, and an osteoconductive substance (cancellous bone) disposed between them. Wolter taught that these layers were united into a fixed block by one or two screws, which are "non-adhesive mechanical connectors." The vertebral-engaging surfaces of the block were inherently textured by the surgical saw used to cut and shape the graft, and this saw-cut finish falls within the patent’s definition of "textured."
  • Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations of Paul, Wolter, Grooms, McIntyre, and Coates, relying on similar motivations to substitute known components like bone fillers, connectors, and surface texturing to arrive at the claimed inventions.

4. Key Claim Construction Positions

  • "plate-like": Petitioner argued that this term, which is central to claim 4 but not defined in the patent, should be construed according to its plain and ordinary meaning as "a generally flat portion" of a spinal graft. This construction was asserted to be critical for the argument that the cancellous bone plug disclosed by McIntyre, when sized to fit into the Grooms graft, would be considered "plate-like," thereby rendering the combination obvious.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review (IPR) and the cancellation of claims 4 and 6-21 of the ’532 patent as unpatentable.