DCT
1:20-cv-00648
Orthopaedic Hospital v. Globus Medical Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Orthopaedic Hospital d/b/a Orthopaedic Institute For Children (California)
- Defendant: Globus Medical, Inc. (Delaware)
- Plaintiff’s Counsel: McDermott Will & Emery LLP
- Case Identification: 1:20-cv-00648, D. Del., 05/15/2020
- Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant is a Delaware corporation.
- Core Dispute: Plaintiff alleges that Defendant’s orthopedic joint replacement products, which incorporate a specialized polyethylene material, infringe five patents related to methods for manufacturing oxidation-resistant and wear-resistant polyethylene implants.
- Technical Context: The technology concerns ultra-high molecular weight polyethylene (UHMWPE), a material critical for the bearing surfaces of artificial joints, and methods to improve its durability by increasing wear-resistance without inducing oxidative degradation.
- Key Procedural History: The complaint notes that two of the patents-in-suit (’347 and ’710 Patents) were previously asserted against DePuy Orthopaedics. In that context, DePuy filed petitions for inter partes review (IPR) against both patents, which the Patent Trial and Appeal Board (PTAB) denied at the institution phase, finding DePuy had not established a reasonable likelihood of prevailing. The complaint also states the patents-in-suit are currently asserted against DJO Global, Inc. in a separate litigation.
Case Timeline
| Date | Event |
|---|---|
| 2000-04-27 | Earliest Patent Priority Date for all Patents-in-Suit |
| 2011 | Defendant (as StelKast) began selling products with EXp™ polyethylene |
| 2011 | FDA clearance for Defendant's EXp™ Acetabular Liners |
| 2013 | FDA approval for Defendant's EXp™ for Proven Gen-Flex™ Total Knee System |
| 2014-02-24 | Plaintiff filed litigation against DePuy asserting related patents |
| 2014-02-25 | ’710 Patent Issued |
| 2014-08-05 | ’347 Patent Issued |
| 2015-10-13 | ’817 Patent Issued |
| 2016-01-26 | ’025 Patent Issued |
| 2016-04-05 | ’028 Patent Issued |
| 2018 | FDA approval for Defendant's GENflex2™ Total Knee Replacement system |
| 2018-11-16 | DePuy litigation voluntarily dismissed |
| 2019-05-23 | Plaintiff filed litigation against DJO Global asserting Patents-in-Suit |
| 2019-07-26 | Plaintiff sent letter to StelKast, Inc. notifying of infringement |
| 2019-08 | Globus Medical, Inc. acquired StelKast, Inc. |
| 2020-05-15 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,796,347 - “Oxidation-Resistant and Wear-Resistant Polyethylenes for Human Joint Replacements and Methods for Making Them,” issued August 5, 2014
The Invention Explained
- Problem Addressed: The patent describes a trade-off in manufacturing polyethylene joint implants. While irradiating the material improves wear-resistance by crosslinking polymer chains, it also generates free radicals. These radicals react with oxygen, causing oxidation that weakens the implant and can lead to failure (Compl. ¶¶24-25; ’347 Patent, col. 1:55-col. 2:2). Conventional post-irradiation thermal treatments (remelting or annealing) to remove these free radicals could further weaken and deform the implant (Compl. ¶¶26-27).
- The Patented Solution: The invention proposes a method that avoids this trade-off. The process begins with a polyethylene that is already oxidation-resistant, achieved by adding an antioxidant such as vitamin E (Compl. ¶31; ’347 Patent, col. 7:26-32). Because the antioxidant neutralizes free radicals generated during irradiation, the material can be subjected to a higher radiation dose (above 5 Mrad) to achieve superior wear-resistance, without requiring a subsequent, mechanically weakening thermal treatment step (Compl. ¶31; ’347 Patent, col. 6:53-col. 7:15).
- Technical Importance: This method allows for the creation of an orthopedic implant that is simultaneously highly wear-resistant and resistant to oxidative degradation, thereby potentially extending the functional life of artificial joints (Compl. ¶¶28-29).
Key Claims at a Glance
- The complaint asserts at least Claim 1 (Compl. ¶89).
- Independent Claim 1 is a method claim with the following essential elements:
- Providing an oxidation-resistant medical implant comprising a polyethylene component.
- Irradiating the implant at a radiation dose of above 5 Mrad to about 25 Mrad to crosslink it.
- Performing the irradiation step without thermally treating the implant to extinguish free radicals during or subsequent to irradiation.
- The implant contains an antioxidant that renders it resistant to oxidation caused by free radicals from the irradiation step.
U.S. Patent No. 8,658,710 - “Oxidation-Resistant and Wear-Resistant Polyethylenes for Human Joint Replacements and Methods for Making Them,” issued February 25, 2014
The Invention Explained
- Problem Addressed: The technical problem is identical to that described for the ’347 Patent, as they share a common specification. The goal is to enhance wear resistance through irradiation without compromising the material’s strength due to oxidation or subsequent heat treatments (’710 Patent, col. 1:55-col. 2:2).
- The Patented Solution: The proposed solution is also the same as the ’347 Patent: using an antioxidant-blended polyethylene that can be irradiated at a high dose to improve wear resistance, thereby eliminating the need for post-irradiation thermal treatments to remove free radicals (’710 Patent, col. 7:16-32).
- Technical Importance: This approach seeks to provide a superior implant material that resolves the historical compromise between wear resistance and mechanical integrity in irradiated polyethylene components (Compl. ¶¶28-29).
Key Claims at a Glance
- The complaint asserts at least Claim 1 (Compl. ¶137).
- Independent Claim 1 is a method claim that largely mirrors Claim 1 of the ’347 Patent but adds specific, measurable physical properties for the final product. Its essential elements are:
- Providing an oxidation-resistant medical implant comprising a polyethylene component.
- Irradiating the implant at a dose of above 5 Mrad to about 25 Mrad, without a subsequent thermal treatment to extinguish free radicals.
- The implant contains an antioxidant.
- The final irradiated implant possesses specific characteristics: a degree of swelling between 1.7 and 3.6; a molecular weight between crosslinks of 400 to 3,500 g/mol; and a gel content between 95% and 99%.
Multi-Patent Capsule: U.S. Patent No. 9,155,817
- Patent Identification: U.S. Patent No. 9,155,817, “Oxidation-Resistant and Wear-Resistant Polyethylenes for Human Joint Replacements and Methods for Making Them,” issued October 13, 2015.
- Technology Synopsis: This patent, part of the same family, claims a method for creating a durable orthopedic implant. The method involves irradiating an oxidation-resistant polyethylene at a high dose without subsequent thermal treatment, resulting in a final product that is "highly resistant to oxidation" (Compl. ¶190).
- Asserted Claims: At least Claim 1 (Compl. ¶188).
- Accused Features: The accused features are Defendant’s manufacturing process for its EXp™ polyethylene components and the resulting implant products (Compl. ¶¶188, 191).
Multi-Patent Capsule: U.S. Patent No. 9,242,025
- Patent Identification: U.S. Patent No. 9,242,025, “Oxidation-Resistant and Wear-Resistant Polyethylenes for Human Joint Replacements and Methods for Making Them,” issued January 26, 2016.
- Technology Synopsis: This patent claims a multi-step manufacturing method that includes providing an oxidation-resistant polyethylene material, forming it into an implant, packaging it, sterilizing it, and irradiating it at a high dose (above 5 Mrad) without a subsequent thermal treatment to extinguish free radicals (Compl. ¶237).
- Asserted Claims: At least Claim 1 (Compl. ¶234).
- Accused Features: The complaint alleges that the process used to manufacture Defendant's EXp™ implant products performs each step of the claimed method (Compl. ¶235).
Multi-Patent Capsule: U.S. Patent No. 9,302,028
- Patent Identification: U.S. Patent No. 9,302,028, “Oxidation-Resistant and Wear-Resistant Polyethylenes for Human Joint Replacements and Methods for Making Them,” issued April 5, 2016.
- Technology Synopsis: Similar to the '710 Patent, this patent claims a method of producing a wear- and oxidation-resistant implant by irradiating an antioxidant-containing polyethylene without thermal treatment. The claim requires that the final irradiated product possess a specific "gel content of between about 95% to about 99%" (Compl. ¶290).
- Asserted Claims: At least Claim 1 (Compl. ¶287).
- Accused Features: The manufacturing process for Defendant's EXp™ polyethylene is accused of meeting the method steps, and the resulting product is alleged, upon information and belief, to have the claimed gel content (Compl. ¶¶288, 305).
III. The Accused Instrumentality
Product Identification
The accused instrumentalities are Defendant’s EXp™ polyethylene material and the orthopedic implant components made from it. These components are used across Defendant’s hip and knee reconstruction product lines, including the GENflex2™ Total Knee Replacement, Proven Gen-Flex™ Unicondylar and Revision Knee Replacement systems, and the Provident™ Acetabular System (Compl. ¶¶56, 69, 70).
Functionality and Market Context
The complaint alleges that EXp™ polyethylene is a blend of ultra-high molecular weight polyethylene (UHMWPE) and vitamin E, an antioxidant (Compl. ¶¶56, 59). The manufacturing process is alleged to involve blending vitamin E into the raw polyethylene, compression molding the material, irradiating it with a dose of approximately 75 kGy (7.5 Mrad) to create crosslinks for wear resistance, and then sterilizing the finished implant with ethylene oxide (Compl. ¶¶59, 60). A key feature alleged in the complaint is that this process "requires no thermal processing or infusion of antioxidants to stabilize the material" after irradiation (Compl. ¶61). A marketing slide provided in the complaint shows that the material is "γ-irradiation crosslinked with 75kGy" (Compl. ¶60). Defendant’s materials allegedly state that EXp™ is more resistant to oxidation than conventional polyethylene and retains its mechanical performance after aging (Compl. ¶¶97, 102).
IV. Analysis of Infringement Allegations
’347 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| (I) providing an oxidation-resistant medical implant of a joint prosthesis comprising a polyethylene component | Defendant manufactures an implant component (EXp™) made of polyethylene blended with vitamin E, an antioxidant, rendering it oxidation-resistant. | ¶¶95, 96, 105 | col. 7:26-39 |
| (II) irradiating the oxidation-resistant medical implant at a radiation dose of above 5 Mrad to about 25 Mrad so as to crosslink the implant thereby improving its wear resistance | Defendant irradiates the EXp™ component with a gamma radiation dose of 75kGy, which is equivalent to 7.5 Mrad and falls within the claimed range. | ¶¶99, 100 | col. 12:40-43 |
| without thermally treating the implant to extinguish free radicals in the irradiated and crosslinked implant during or subsequent to irradiating the oxidation-resistant implant | Defendant’s marketing materials state that the EXp™ manufacturing process "requires no thermal processing" to stabilize the material after irradiation. | ¶¶100, 103 | col. 7:16-24 |
| wherein the oxidation-resistant implant contains an antioxidant rendering it resistant to oxidation caused by free radicals generated by the irradiation of step (II) | The EXp™ component contains α-Tocopherol (vitamin E), an antioxidant that allegedly renders the component resistant to oxidation from free radicals. | ¶¶104, 105 | col. 7:26-32 |
’710 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| [Steps (I), (II), and first "wherein" clause are substantially the same as in the '347 Patent analysis above] | [Allegations for these elements are substantially the same as in the '347 Patent analysis above, citing Compl. ¶¶143-154] | ¶¶143-154 | col. 7:16-39 |
| and the irradiated oxidation-resistant implant possesses the characteristics of: a degree of swelling of between about 1.7 to about 3.6; a molecular weight between crosslinks of between about 400 to about 3,500 g/mol; and a gel content of between about 95% to about 99% | The complaint alleges, upon information and belief, that the irradiated EXp™ component possesses a degree of swelling, molecular weight between crosslinks, and gel content that fall within the claimed ranges. | ¶¶155, 156, 157 | col. 13:10-14 |
- Identified Points of Contention:
- Evidentiary Questions: For the ’710 Patent, as well as the ’028 Patent, a central dispute may arise from the claims to specific physical properties. The complaint alleges "upon information and belief" that the accused products meet the claimed ranges for swelling, molecular weight between crosslinks, and gel content (Compl. ¶¶155-157). The case may turn on what evidence Plaintiff can produce through discovery and expert testing to substantiate these allegations.
- Scope Questions: An issue for all asserted patents may be the construction of the negative limitation "without thermally treating the implant to extinguish free radicals." The complaint alleges the accused process uses ethylene oxide for sterilization (Compl. ¶59). The question for the court may be whether any heat applied during this or other steps in the process constitutes a "thermal treatment" as contemplated by the patents, or if the term is limited to the specific, high-heat remelting or annealing processes designed to quench free radicals that the patents sought to avoid. A marketing material excerpted in the complaint states EXp™ "requires no thermal processing... to stabilize the material" (Compl. ¶103).
V. Key Claim Terms for Construction
- The Term: "without thermally treating the implant to extinguish free radicals"
- Context and Importance: This negative limitation is central to the patents’ asserted novelty over prior art methods that used post-irradiation heating to improve oxidation resistance at the cost of mechanical strength. The infringement analysis for all five patents depends on whether Defendant’s accused manufacturing process, which allegedly includes ethylene oxide sterilization, performs a "thermal treatment" within the meaning of the claims. Practitioners may focus on this term because its scope will likely be a primary non-infringement or invalidity argument.
- Intrinsic Evidence for Interpretation:
- Evidence for a Narrower Interpretation: The patent specifications repeatedly frame the disfavored thermal treatments in the context of specific, high-heat processes intended to eliminate free radicals, such as "remelting, or heating the implant above its melt temperature, and annealing, or heating the implant below its melt temperature" (’347 Patent, col. 6:33-37). Plaintiff may argue that "thermally treating" should be construed narrowly to mean only these specific types of high-temperature steps performed for the express purpose of extinguishing free radicals.
- Evidence for a Broader Interpretation: The plain language of the claim is simply "without thermally treating." Defendant may argue that this encompasses any application of heat subsequent to the primary irradiation step, regardless of its purpose or temperature, if it has the incidental effect of affecting free radicals. Such a construction could bring a lower-temperature sterilization process into the scope of the excluded step.
VI. Other Allegations
- Indirect Infringement: The complaint alleges induced infringement, stating that Defendant, with knowledge of the patents, instructs and encourages its customers (physicians) and end-users (patients) to purchase and use the accused products made by the patented methods (Compl. ¶¶124-125). The complaint points to Defendant's advertising and its website, which provides a resource for patients to find surgeons who use the accused products, as evidence of inducement (Compl. ¶¶130-131).
- Willful Infringement: Willfulness is alleged based on Defendant’s purported knowledge of the patents-in-suit and its continued infringement. The complaint alleges knowledge from multiple sources: constructive notice from the patent issue dates beginning in 2014; awareness of competitor litigations (against DePuy and DJO) involving the same patents; and actual notice via a letter sent to Defendant’s predecessor, StelKast, Inc., on July 26, 2019 (Compl. ¶¶109, 81, 85, 111).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of evidentiary proof: For the patents that claim specific, measurable physical outcomes ('710 and '028), can Plaintiff develop sufficient factual evidence through discovery and testing to prove that Defendant’s final products meet the claimed numerical ranges for properties like swelling, molecular weight, and gel content, given that these are currently alleged only on "information and belief"?
- The case will also likely turn on a question of definitional scope: How will the court construe the negative limitation "without thermally treating the implant to extinguish free radicals"? The resolution will depend on whether this term is limited to the specific high-heat, free-radical-quenching processes described in the patents’ specifications, or if it can be read more broadly to include other manufacturing steps involving heat, such as the accused ethylene oxide sterilization process.