Boston Scientific Corp. v. Stryker Corp. — Federal Circuit Upholds Denial of Injunction Against Rival Spine Device

Background

Boston Scientific Corporation and its subsidiary Relievant Medsystems own U.S. Patent No. 12,303,166, which covers a method for ablating (destroying) the basivertebral nerve — the nerve that transmits chronic low back pain originating from damaged vertebral endplates. The patented technique threads a specialized probe through the dense outer bone of a vertebral pedicle into the spongy interior (cancellous bone), where it delivers radiofrequency energy to the nerve.

Stryker Corporation developed its own product, the OptaBlate BVN device, to treat the same type of chronic low back pain. Stryker sought and received FDA clearance using Boston Scientific’s existing product as a predicate device. Shortly after Stryker announced FDA clearance and plans to begin marketing OptaBlate BVN, Boston Scientific filed suit in the District of New Jersey, arguing that physicians following Stryker’s instructions would infringe claims 16 and 21 of its ‘166 patent.

Boston Scientific moved for a preliminary injunction to stop Stryker’s launch. The district court denied that request, finding that Boston Scientific had not established a likelihood of success on the merits because substantial questions existed about whether Stryker’s access cannula — the outer tube that creates the path into the vertebra — actually reaches the cancellous (spongy) interior of the bone as required by the patent. Boston Scientific appealed.

The Court’s Holding

The Federal Circuit, in a nonprecedential opinion by Judge Dyk, unanimously affirmed the district court’s denial of the preliminary injunction. The court focused on the central technical dispute: the patent’s claim requires that the “introducer” (the trocar/access cannula) be inserted “through the pedicle” such that it reaches the “cancellous portion” of the vertebral body. The question was whether Stryker’s instructions direct physicians to position the access cannula with its tip inside that cancellous region, or merely at the border between the outer cortical bone and the spongy interior.

The Federal Circuit agreed with the district court that Stryker’s product literature was ambiguous. Multiple Stryker documents told physicians to place the cannula “just inside the vertebral body” or “inside the posterior wall,” but the court found those phrases could refer either to the cannula tip reaching the cancellous portion or to the stylet tip (a separate inner tool) reaching that point while the cannula itself remained at the cortical boundary. The district court’s reading of this ambiguous evidence was not an abuse of discretion.

The court also rejected Boston Scientific’s alternative doctrine-of-equivalents theory, finding the argument was largely forfeited (it had been raised only in a footnote in the district court briefing) and that, even reaching the merits, Stryker’s competing expert evidence about the functional significance of the cannula’s exact placement created a substantial question that precluded a finding of likelihood of success.

Key Takeaways

• Ambiguous instructions create injunction problems: When product instructions can be read in multiple ways, courts will not assume the worse-for-defendant reading at the preliminary injunction stage. Boston Scientific needed to show the instructions likely directed infringing use — ambiguity is enough to defeat that showing.
• Doctrine-of-equivalents arguments must be developed: Raising an equivalents argument in a footnote, without detailed claim-element mapping, is not enough to preserve the theory for an injunction. Practitioners should fully brief equivalents at the outset if they plan to rely on it.
• FDA predicate-device clearance signals market entry risk: Stryker obtained FDA clearance using Boston Scientific’s own product as a predicate — a standard FDA pathway that does not require independent safety studies. That clearance accelerated Stryker’s time to market and triggered this emergency injunction battle. Device companies should anticipate 510(k) predicate challenges when filing foundational patents.

Why It Matters

The chronic low back pain market is enormous, and basivertebral nerve ablation technology is a growing segment. Boston Scientific invested heavily in developing and patenting the Intracept procedure (now branded through Relievant Medsystems), and Stryker’s entry with a competing product — cleared via the FDA’s expedited 510(k) route — threatens that investment directly. Losing the preliminary injunction means Stryker can begin selling OptaBlate BVN while the full merits of the patent dispute are litigated, which often takes years.

More broadly, the case illustrates a recurring challenge in medical device patent litigation: claim language describing anatomical positions (“reaches the cancellous portion”) can be genuinely ambiguous when applied to real surgical procedures, because the exact placement of each component depends on technique, patient anatomy, and how instructions are written. The Federal Circuit’s affirmance sends a signal that preliminary injunctions in this context require clear, unambiguous proof of infringement — not just the possibility that a physician might use the device in an infringing way.