NuVasive, Inc. (defendant), held a patent for a spinal implant that used radiopaque markers next to its medial plane to align the implant. Medtronic, Inc. (plaintiff), petitioned the Patent Trial and Appeal Board (PTAB), arguing that combining four existing implant devices with information about radiopaque markers in other applications was obvious. The PTAB found that a person having ordinary skill in the art (PHOSITA) would combine the prior art and additional information to use radiopaque markers, rendering the claim invalid for obviousness. However, in reaching that conclusion, the PTAB credited expert testimony that the markers provided better alignment based on benefits recognized after the priority date of NuVasive’s patent. The ruling did not discuss benefits obtainable solely by combining only prior art references nor what would motivate a PHOSITA to combine them. Medtronic appealed, arguing that the PTAB erred.