As a man of letters, I am often astounded by the power of certain small and simple expressions to remain in the general consciousness for decades.
Why does taco Tuesday still ring so true? Any number of callow admen must have attempted to start Fish Friday (a natural choice for many reasons), macaroni Monday, or Waldorf Salad Wednesday, yet all of these efforts are long forgotten.
Will any of us recognize the next great cultural alliteration when it arrives, or will it be known only in history's telling?
All of this is only in reference to the title, so if you've read it so far please see me for a coupon redeemable for a discount at any Macaroni Monday.
Anyway.
Today's case deals with a procedure that is all but extinct in the modern patent practice -- the interference. As a brief rundown, this odd procedure allowed the Court to determine priority between two patents that "interfered" with one another -- i.e., each would render the other anticipated or obvious. Thus the owner of a patent with a later priority date on its face could seek to invalidate an earlier patent by arguing that they had actually been the first to invent.
As an additional advantage, the pleading party need only show anticipation or obviousness by a preponderance, rather than clear and convincing evidence.
This procedure, like fish Friday, was abrogated by the America Invents Act and thus only applies to patents with effective filing dates before March 16, 2013. So enjoy this one folks, as you may not see another.
Other than the interference, RSB Spine, LLC v. Depuy Synthes Sales, Inc, C.A. No. 19-1515-RGA (D. Del. Aug. 27, 2025), was a normal -- if ancient -- case. After many twists and turns, RSB had won a jury verdict of infringement. Judge Andrews subsequently held a bench trial on the interference counterclaim.
Now the thing you may have forgotten about interferences, is that they can lead to somewhat wacky results. Here, the problem for Depuy was that their own patent incorporated several novel elements that were not present in RSB's earlier '207 patent. while this is normally good news, here it doomed the interference because Depuy could not meet the threshold showing that both patent's rendered each other invalid:
Accordingly, claim 17 of the '207 patent is not obvious in light of claims 10 and 14 of the '537 patent. As an interference requires obviousness in both directions, this finding alone is sufficient for a finding of no interference-in-fact. I find no interference-in-fact between the '207 and '537 patents.
Id. at 18-19.
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