DePuy Synthes v. Rasmussen Instruments: Federal Circuit Vacates Attune Knee Patent Ruling
DePuy Synthes Products and DePuy Synthes Sales brought an infringement action against Rasmussen Instruments over two patents covering the Attune Knee System. After 748 days, the Federal Circuit vacated the lower court’s decision and remanded the case, nullifying the prior ruling and sending the dispute back for further proceedings.
Federal Circuit Wipes the Slate: Attune Knee Patent Dispute Sent Back
DePuy Synthes Products, Inc. and DePuy Synthes Sales, Inc. — collectively a major orthopedic implant group within the Johnson & Johnson MedTech portfolio — filed this infringement action against Rasmussen Instruments, LLC, a specialist surgical instrument developer. The dispute centres on two patents, US10517583B2 and US9492180B2, both directed to technology embodied in DePuy’s Attune Knee System, a widely deployed total knee replacement platform. The appeal was filed at the Court of Appeals for the Federal Circuit on 19 September 2023.
On 6 October 2025, after 748 days of appellate proceedings, the Federal Circuit issued its order vacating the lower court’s decision and remanding the case. A vacatur is a formal nullification: the prior ruling no longer stands as binding, and the case is returned — typically to the district court — for reconsideration in line with the Federal Circuit’s guidance. This outcome means neither party secured a final resolution on the merits at this stage, and DePuy’s infringement claims against Rasmussen Instruments remain unresolved.
A vacatur-and-remand after over two years of appellate proceedings typically signals that the Federal Circuit identified a substantive legal error below — commonly in claim construction, the application of patentability standards, or procedural handling — rather than a straightforward affirmance. The public record does not disclose the precise grounds for vacatur, leaving the scope of error and the district court’s mandate unclear. Practitioners should monitor the remand proceedings closely, as the Federal Circuit’s reasoning will set the framework for how the Attune Knee System patents are evaluated going forward.
Filing to Vacated and Remanded in 748 days
748 days — above the median duration for Federal Circuit patent appeals
Federal Circuit vacates: what the remand means for both parties
Vacatur nullifies the lower ruling — nothing stands
When the Federal Circuit vacates a decision, it formally voids the lower court’s ruling. Unlike an affirmance or reversal, a vacatur does not substitute a new judgment — it wipes out the existing one and typically remands the matter for reconsideration. This means no prior finding on infringement, validity, or damages from the lower court carries forward as binding. The remand order is likely accompanied by specific instructions that will govern the district court’s next steps.
No binding lower court rulingDePuy gets a second chance — but no win yet
For DePuy Synthes, a vacatur-and-remand is neither a victory nor a defeat. Any adverse ruling below has been erased, which removes an unfavourable precedent from the books. However, DePuy must now re-litigate the matter at the district level under the Federal Circuit’s corrected framework. The Attune Knee System patents remain in force, but enforceability against Rasmussen Instruments is still unresolved, sustaining commercial and competitive uncertainty.
Dispute unresolved — remand requiredRasmussen avoids a final adverse judgment — for now
Rasmussen Instruments benefits from the erasure of any lower court ruling that may have gone against it, but a vacatur does not end the litigation. The case returns to district court, where Rasmussen must defend against DePuy’s infringement claims again under whatever legal standard the Federal Circuit has prescribed. The absence of a final judgment means Rasmussen cannot claim victory, and continued litigation costs remain a material business risk for a specialist instrument developer of its scale.
No final judgment — proceedings continueOrthopedic implant IP: remand prolongs sector uncertainty
The Federal Circuit’s decision to vacate rather than decide on the merits suggests that foundational legal questions about these knee system patents — likely claim construction or validity framing — remain unsettled. For orthopedic device manufacturers and surgical instrument developers operating near the Attune Knee System’s design space, this prolongs the period of IP uncertainty. Competitors and licensees should treat both US10517583B2 and US9492180B2 as live enforcement risks until the remand concludes with a final disposition.
Elevated IP risk — monitor remandFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | DePuy Synthes Products, Inc. | Company | Orthopedic implant group — holder of US10517583B2 and US9492180B2 covering the Attune Knee SystemSearch in Eureka ↗ |
| Co-Plaintiff | DePuy Synthes Sales, Inc. | Company | Search in Eureka ↗ |
| Defendant | Rasmussen Instruments, LLC | Company | Rasmussen Instruments, LLC — surgical instrument developer and accused infringerSearch in Eureka ↗ |
| Plaintiff counsel | Christopher Morrison | Attorney | Counsel for DePuy Synthes Products, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Jones Day | Law Firm | Representing DePuy Synthes Products, Inc.Search in Eureka ↗ |
| Defendant counsel | Kurt Louis Glitzenstein | Attorney | Counsel for Rasmussen Instruments, LLCSearch in Eureka ↗ |
| Defendant counsel | Nitika Gupta Fiorella | Attorney | Counsel for Rasmussen Instruments, LLCSearch in Eureka ↗ |
| Defendant law firm | Fish & Richardson LLP | Law Firm | Representing Rasmussen Instruments, LLCSearch in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | Court of Appeals for the Federal CircuitSearch in Eureka ↗ |
Official order — verbatim text
The Federal Circuit’s order — ‘VACATED AND REMANDED’ — formally nullifies the lower tribunal’s ruling without substituting a merits judgment. At the appellate level, vacatur typically signals that the court identified reversible legal error: commonly a misapplication of claim construction standards, an incorrect legal framework applied to validity or infringement, or a procedural deficiency. The remand instruction obliges the lower court to reconsider the dispute within the bounds of the Federal Circuit’s mandate. Neither party emerges with a final adjudication on the infringement claims, and the scope of the Federal Circuit’s corrective guidance will be determinative of how the Attune Knee System patents are evaluated in subsequent proceedings.
US10517583B2 & US9492180B2 — Attune Knee System orthopedic implant technology
US10517583B2 (application no. US15/351135) and US9492180B2 (application no. US14/531749) are both directed to the orthopedic technology underlying DePuy Synthes’ Attune Knee System, a total knee replacement platform designed to deliver enhanced stability and range of motion. The patents cover aspects of the implant’s structural design and associated surgical instrumentation, placing them squarely within the high-value musculoskeletal device segment. Both patents are granted utility patents in force before the USPTO, and their assertion in this infringement action confirms DePuy’s active enforcement posture in the knee implant space.
The Attune Knee System is one of DePuy’s flagship knee replacement products, and patent protection around it is commercially material in a market with multiple competing total knee arthroplasty platforms. US9492180B2, as the earlier-filed of the two, likely covers foundational design elements, while US10517583B2 may extend claims to refinements or instrumentation systems developed in a subsequent application. For surgical instrument developers and competitor implant manufacturers, the scope of these claims — still to be finally adjudicated on remand — represents a significant design-around and clearance challenge. The Federal Circuit’s intervention suggests the claim boundaries are genuinely contested.
Should your team run an FTO against US10517583B2 and US9492180B2?
Any company developing total knee replacement systems, tibial or femoral implant components, or surgical instrumentation that interfaces with knee arthroplasty platforms should treat these two DePuy Synthes patents as priority FTO subjects. The vacatur-and-remand means the claim construction framework is actively in flux — making a current clearance opinion based on prior court rulings unreliable. R&D and regulatory teams preparing new knee system designs or surgical instrument kits should commission an updated FTO that reflects the Federal Circuit’s corrected legal standard once the remand guidance is published.
PatSnap Eureka’s FTO Search Agent allows IP and product teams to map their knee implant and surgical instrument designs against the full claim trees of US10517583B2 and US9492180B2 in minutes. Eureka surfaces claim-level overlap, identifies file history estoppel risks, and flags continuation applications in the same patent families that may extend coverage beyond the two asserted patents. For a dispute of this complexity — two patents, a Federal Circuit vacatur, and an active remand — automated portfolio-level monitoring through Eureka ensures your team is alerted to any claim amendments or new filings that could affect your FTO position before they become enforcement risks.
Run a freedom-to-operate analysis on US10517583B2 to assess your product’s exposure
Run FTO in Eureka →Similar Federal Circuit patent appeals in orthopedic implant technology
Federal Circuit appeals involving orthopedic implant and surgical instrumentation patents, including vacatur-and-remand outcomes in the medical device space.
What this case signals for the orthopedic implant IP landscape
A Federal Circuit vacatur in a knee implant patent dispute puts the entire sector on notice: foundational claim questions are unresolved.
Vacatur signals a likely claim construction error below
Federal Circuit vacatur-and-remand orders most commonly arise from errors in claim construction or the application of legal standards. For orthopedic device companies, this suggests the lower court’s interpretation of the Attune Knee System patent claims was flawed. Any FTO or clearance opinion built on that prior ruling should be reviewed and, if necessary, updated to reflect the corrected framework the Federal Circuit will have articulated.
Both Attune Knee System patents remain live enforcement risks
US10517583B2 and US9492180B2 are in force and the infringement dispute is unresolved. Surgical instrument developers and knee implant manufacturers operating in adjacent design spaces should not treat the vacatur as a green light. Until the remand produces a final ruling on validity and infringement, these patents retain their potential enforceability and should be included in active IP monitoring programmes.
DePuy v Rasmussen — key questions answered
The Federal Circuit’s vacatur nullifies the lower court’s ruling, meaning no prior judgment on infringement or validity stands. The case is remanded for reconsideration under the Federal Circuit’s corrected legal framework. Neither party has obtained a final determination, and the infringement claims covering the Attune Knee System patents remain unresolved.
DePuy Synthes asserted two patents: US10517583B2 (application no. US15/351135) and US9492180B2 (application no. US14/531749). Both patents relate to the Attune Knee System, DePuy’s total knee replacement platform, covering aspects of implant design and surgical instrumentation.
The litigation centres on DePuy Synthes’ Attune Knee System, a total knee replacement platform. DePuy alleged that Rasmussen Instruments infringed patents protecting the system’s design and associated surgical instrumentation. The Federal Circuit’s vacatur means the infringement determination is yet to be finally made.
Federal Circuit vacatur-and-remand orders most commonly result from errors in claim construction, incorrect application of validity standards such as obviousness or anticipation, or procedural deficiencies in how the lower tribunal handled the record. In patent cases, claim construction errors are the single most frequent ground for vacatur, as the scope of patent claims is a question of law reviewed de novo by the Federal Circuit.
Companies operating in the knee implant and surgical instrumentation space should: (1) treat US10517583B2 and US9492180B2 as live enforcement risks; (2) review or commission updated FTO opinions that do not rely on the now-vacated lower court ruling; (3) monitor the remand docket for the district court’s revised claim construction; and (4) audit their product portfolios against the Attune Knee System patent family for design-around opportunities. Continuation applications in these patent families may also warrant monitoring.
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