Federal Circuit Rejects Ensnarement Defense and Finds that the Ensnarement Defense is an Issue of Law

In DePuy Spine, Inc. v. Medtronic, Inc., Civ. Case Nos. 90 USPQ2d 1865 (Fed. Cir. 2009), DePuy owns U.S. Pat. No. 5,207, 678 (the ‘678 patent).  The ‘678 patent is directed to a medical device that is a pedicle screw used in spinal surgeries.  DePuy sued Medtronic, accusing Medtronic of infringing the ‘678 patent with Medtronic’s Vertex pedicle screws.  The U.S. District Court for the District of Massachusetts denied Medtronic’s ensnarement defense, found that Medtronic engaged in litigation misconduct, with both decisions being appealed before the Federal Circuit Court.  Additionally, DePuy cross-appeals from the District Court’s granting of Medtronic’s motion for judgment as a matter of law (JMOL) of no willful infringement and from the denial of DePuy’s motion for a new trial for reasonable royalty damages. 

In a prior appeal, the Federal Circuit Court upheld the District Court’s granting of summary judgment as per Medtronic not literally infringing the ‘678 patent with Medtronic’s Vertex pedicle screws.  However, the Federal Circuit Court reversed the District Court’s granting of summary judgment of noninfringement under the doctrine of equivalents.  In the prior appeal, the Federal Circuit Court remanded the case because it found a question of fact existed on whether the Vertex screw’s conical shape was insubstantially different from the ‘678 patent’s screw having a limitation in claim 1 of the patent reciting a “spherically-shaped portion.  In the remanded case, Medtronic asserted an “ensnarement” defense against the doctrine of equivalents issue, wherein the Medtronic asserted that the scope of equivalency of the ‘678 patent would “ensnare” the prior art.  Continue reading