Rasmussen Instruments v. DePuy Synthes: Federal Circuit Vacates & Remands
Rasmussen Instruments, LLC challenged DePuy Synthes over two orthopedic surgical sizer patents — US10517583B2 and US9492180B2 — covering the Attune Balanced Sizer. The Federal Circuit vacated the lower court’s ruling and remanded the case, keeping the infringement dispute alive after 721 days of litigation.
Surgical sizer patent dispute sent back to square one by Federal Circuit
Rasmussen Instruments, LLC filed this appeal at the Court of Appeals for the Federal Circuit on October 16, 2023, asserting infringement of US10517583B2 and US9492180B2 — two patents covering orthopedic surgical sizer technology — against DePuy Synthes Products, Inc., DePuy Synthes Sales, Inc., and Medical Device Business Services, Inc. The accused product is the Attune Balanced Sizer, a device used in knee arthroplasty procedures and sold under the DePuy Synthes brand, which is part of Johnson & Johnson’s MedTech division.
The Federal Circuit closed the appeal on October 6, 2025, issuing an order to vacate and remand. A vacatur at the appellate level means the court found a legal or procedural error significant enough to nullify the lower court’s judgment entirely — without ruling on the merits of infringement itself. The case now returns to the originating forum for proceedings consistent with the Federal Circuit’s guidance, leaving the substantive infringement question unanswered for the time being.
The 721-day duration of this appellate proceeding is consistent with complex Federal Circuit patent appeals, which typically require extensive briefing cycles and, in some cases, oral argument scheduling delays. The vacatur outcome suggests the Federal Circuit identified a foundational issue — potentially claim construction, standing, or procedural error — that it deemed dispositive, though the public record does not specify the precise grounds. What remains unknown is the exact basis for vacatur and whether the remand will result in a new trial, summary judgment, or some other disposition.
Filing to Vacated and Remanded in 721 days
721 days — a two-year appellate journey from filing to Federal Circuit decision
Federal Circuit vacates: what the remand means for both parties
Vacatur nullifies the lower court’s judgment entirely
When the Federal Circuit vacates a lower court decision, it renders that judgment legally void — not merely reversed on a single point. The lower court’s ruling carries no precedential or preclusive weight going forward. This is distinct from an affirmance or reversal: vacatur signals the Federal Circuit identified a foundational error that prevents any merits ruling from standing, requiring the case to be reconsidered from a corrected legal or procedural baseline.
Decision nullified — no merits rulingRasmussen gets a second chance on its infringement claims
For Rasmussen Instruments, vacatur and remand is a meaningful procedural win. The lower court’s adverse ruling — whatever it held — no longer stands. Rasmussen retains its patents US10517583B2 and US9492180B2 and can re-litigate its infringement claims against the Attune Balanced Sizer under corrected legal standards. The outcome suggests Rasmussen successfully identified an error in the lower court’s analysis, though the ultimate merits outcome remains unresolved.
Claims survive — remand grantedDePuy Synthes loses its lower court victory — for now
DePuy Synthes, DePuy Synthes Sales, and Medical Device Business Services had likely secured a favorable ruling below, which is now nullified. The Attune Balanced Sizer faces renewed infringement scrutiny on remand. DePuy must re-engage in proceedings with an enlarged legal team — represented by Jones Day — and the commercial risk associated with the asserted patents remains live. Clearance arguments that prevailed below may need to be reconstructed under new standards.
Prior win vacated — re-litigation riskOrthopedic sizer market faces continued IP uncertainty
The Federal Circuit’s vacatur extends uncertainty for manufacturers and distributors of orthopedic surgical sizing instruments, particularly those whose products may overlap with the claims of US10517583B2 and US9492180B2. Competitors and potential licensees should monitor the remand proceedings closely. Until the infringement question is resolved on the merits, these patents carry unresolved enforcement risk — and any freedom-to-operate analysis predicated on the vacated ruling should be revisited.
IP risk remains unresolvedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Rasmussen Instruments, LLC | Company | Orthopedic surgical instrument IP licensor — holder of US10517583B2 and US9492180B2Search in Eureka ↗ |
| Defendant | DePuy Synthes Products, Inc. | Company | DePuy Synthes Products, Inc. — orthopedic device manufacturer, J&J MedTech subsidiarySearch in Eureka ↗ |
| Co-Defendant | DePuy Synthes Sales, Inc. | Company | Search in Eureka ↗ |
| Co-Defendant | Medical Device Business Services, Inc. | Company | Search in Eureka ↗ |
| Plaintiff counsel | Kurt Louis Glitzenstein | Attorney | Counsel for Rasmussen Instruments, LLCSearch in Eureka ↗ |
| Plaintiff counsel | Nitika Gupta Fiorella | Attorney | Counsel for Rasmussen Instruments, LLCSearch in Eureka ↗ |
| Plaintiff law firm | Fish & Richardson LLP | Law Firm | Representing Rasmussen Instruments, LLCSearch in Eureka ↗ |
| Defendant counsel | Calvin Griffith | Attorney | Counsel for DePuy Synthes Products, Inc.Search in Eureka ↗ |
| Defendant counsel | Christopher Morrison | Attorney | Counsel for DePuy Synthes Products, Inc.Search in Eureka ↗ |
| Defendant counsel | Gregory A. Castanias | Attorney | Counsel for DePuy Synthes Products, Inc.Search in Eureka ↗ |
| Defendant counsel | Patrick Norton | Attorney | Counsel for DePuy Synthes Products, Inc.Search in Eureka ↗ |
| Defendant law firm | Jones Day | Law Firm | Representing DePuy Synthes Products, Inc.Search 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’ — is a dispositive appellate outcome that renders the lower court’s judgment legally void and returns jurisdiction to the originating forum. At the Federal Circuit, vacatur typically follows a finding that the lower court committed a reversible legal error, such as erroneous claim construction, improper summary judgment standards, or a jurisdictional defect. The appellate court applies de novo review to claim construction and legal questions, making these the most common bases for vacatur. Neither party has prevailed on the infringement merits; the remand signals further substantive proceedings are required before any final determination on US10517583B2 and US9492180B2 can be issued.
US10517583B2 & US9492180B2 — orthopedic surgical sizer technology
US10517583B2 (application no. US15/351135) and US9492180B2 (application no. US14/531749) protect orthopedic surgical sizer technology attributed to Rasmussen Instruments, LLC. These patents cover instruments used to measure and balance soft-tissue tension during knee replacement surgery — a technically precise step that influences implant alignment and patient outcomes. The earlier application number for US9492180B2 suggests it represents foundational claims, with US10517583B2 potentially covering continuation or expanded embodiments. Both patents are asserted against the DePuy Synthes Attune Balanced Sizer, a commercially significant product in the total knee arthroplasty market.
The orthopedic surgical instrument space is heavily contested, with major medtech players holding broad portfolios covering sizer, balancer, and tensioning device designs. Rasmussen’s assertion of two patents against a flagship DePuy Synthes product — backed by Fish & Richardson — suggests a deliberate enforcement strategy targeting commercially impactful product lines. The Federal Circuit’s decision to vacate and remand rather than affirm or dismiss indicates these patents have sufficient legal merit to warrant full merits adjudication. Any company developing or distributing soft-tissue balancing instruments for knee arthroplasty should treat US10517583B2 and US9492180B2 as active enforcement risks.
Should you run an FTO against US10517583B2 and US9492180B2?
R&D teams and product managers working on orthopedic surgical sizers, knee arthroplasty instruments, or soft-tissue balancing devices should treat these two patents as live risks. The Federal Circuit’s vacatur means no court has yet cleared the field — the infringement question remains open. Any prior clearance opinion referencing the now-void lower court judgment is unreliable. New entrants and existing players developing instruments that measure or balance joint tension during knee replacement surgery should commission fresh FTO analysis before product launch or design modification.
PatSnap Eureka’s FTO Search Agent can map the independent and dependent claims of US10517583B2 and US9492180B2 against your product specifications, identify prior art that may support invalidity arguments, and surface related patents in Rasmussen’s portfolio or competitor filings that could create additional exposure. Given the two-patent structure of this assertion, Eureka can run parallel claim-mapping workflows to ensure your design-around strategy addresses both patent families simultaneously — reducing the risk of clearing one claim set while inadvertently infringing the other.
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 surgical instruments
Cases involving Federal Circuit vacatur and remand in orthopedic medtech patent disputes — relevant to practitioners tracking surgical instrument claim construction outcomes.
What this case signals for orthopedic surgical device IP strategy
A Federal Circuit vacatur in a medtech infringement appeal is a warning sign for how lower courts approach claim construction and patent validity in surgical instruments.
Vacatur resets the clock — prior clearance opinions may no longer hold
Any FTO or non-infringement opinion built on the now-vacated lower court judgment should be treated as unreliable. The Federal Circuit’s intervention signals a legal error material enough to void the entire ruling. Companies relying on that decision for product launch or licensing decisions should seek updated counsel before proceeding.
DePuy Synthes must re-litigate; Attune Balanced Sizer faces live patent risk
The Attune Balanced Sizer remains commercially active while the remand proceeds. Competing surgical instrument developers should note that Rasmussen’s two patents survived appellate scrutiny procedurally, and the infringement question may still be decided in Rasmussen’s favor on remand — creating licensing or design-around obligations for the broader market.
Rasmussen v DePuy — key questions answered
The Federal Circuit vacated the lower court’s judgment and remanded the case, meaning the prior ruling is legally void and the infringement dispute over US10517583B2 and US9492180B2 must be reconsidered by the originating court under corrected legal standards. No merits determination on infringement has been issued.
Rasmussen Instruments asserted two patents: US10517583B2 (application US15/351135) and US9492180B2 (application US14/531749), both covering orthopedic surgical sizer technology used in knee arthroplasty procedures. The accused product is the DePuy Synthes Attune Balanced Sizer.
The Attune Balanced Sizer is a DePuy Synthes surgical instrument used to measure and balance soft-tissue tension during total knee replacement surgery. Rasmussen Instruments alleges it infringes the claims of US10517583B2 and US9492180B2. DePuy Synthes is a subsidiary of Johnson & Johnson’s MedTech division and a major player in orthopedic implant and instrument markets.
Rasmussen Instruments was represented by Fish & Richardson LLP, with attorneys Kurt Louis Glitzenstein and Nitika Gupta Fiorella on record. DePuy Synthes was represented by Jones Day, with Gregory A. Castanias, Calvin Griffith, Christopher Morrison, and Patrick Norton appearing for the defendants.
Yes. Any FTO or non-infringement opinion that relied on the now-vacated lower court judgment should be revisited. The vacatur renders that ruling legally void, meaning the infringement question under US10517583B2 and US9492180B2 remains open. Companies with products in the orthopedic surgical sizer space should commission updated FTO analysis before relying on prior clearance conclusions.
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