Many Patent Owners are finding success in undermining the challenge grounds of a Petition by arguing that the Petition fails to make an adequate showing that a person of ordinary skill in the art would have combined the relied-on references. That was the case in Zimmer Holdings, Inc. and Zimmer, Inc. v. Bonutti Skeletal Innovations LLC, involved US Pat. No. 7,837,736, where the Board rejected a Petition due to an inadequate combination argument.

Relying on expert testimony, the Petitioner argued that it would have been obvious to the ordinary artisan to substitute a “dovetail joint” described in one reference (Beuchel) for the “abutment and recess” structure described in a second reference (Walker) to arrive at the ‘736 invention.  Specifically, the expert testified that the “dovetail” joints of Beuchel perform the same function as the “abutment and recess” of Walker—i.e., “constrained movement of meniscal components relative to the tray in mobile bearing knee implants.”  With that predicate, the expert posited that substituting the “dovetail” joints in place of the “abutment and recess” joints was simply a matter of design choice.

The Board disagreed, because Beuchel’s “dovetail” joints had substantially different structure and function than Walker’s “abutement and recess.”  Decision at 20–21.  Specifically, Beuchel’s “dovetail” joint functioned to limit or prevent rotation, while Walker’s “abutment and recess” functioned to facilitate rotation.  Decision at 21.  Accordingly, the Board found that Petitioner failed to support its substitution argument with “adequate articulated reasoning with rational underpinnings.”  Decision at 21 (citing In re Gal, 980 F.2d 717, 719 (Fed. Cir. 1992) (design choice is not a sufficient rationale for obviousness where the structure recited in claim and the function it performs are different from the prior art).  Accordingly, the Board declined to institute review.  Id.