DePuy: Patent Amendments Block Equivalents
DePuy’s core attack leans heavily on prosecution history estoppel—a doctrine that stops patent owners from reclaiming territory they narrowed during the application process. According to DePuy, RSB Spine amended its patent to avoid conflicts with earlier inventions by restricting the orientation of a screw hole.
“By amending claim 1 to overcome prior art, RSB surrendered claim scope,” DePuy argues, saying its own devices fall squarely within that surrendered ground. The company adds that RSB gave up additional equivalence rights through positions it previously took before the Patent Trial and Appeal Board.
A Challenge to the Heart of the Patent
DePuy also contends the jury’s equivalence finding effectively erased key patent limitations. In one vivid example, the company drew a hard line between bone with a lip osteophyte and bone without one—arguing the two are clinical opposites and cannot be treated as equivalents without destroying the patent’s meaning altogether.
