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Acromed Corporation v. Sofamor Danek Group, Inc. And Danek Medical, Inc., Defendants
Citations: 253 F.3d 1371; 59 U.S.P.Q. 2d (BNA) 1130; 2001 U.S. App. LEXIS 11912; 2001 WL 631334Docket: 00-1163
Court: Court of Appeals for the Federal Circuit; June 8, 2001; Federal Appellate Court
AcroMed Corporation, holder of U.S. Patent No. 4,696,290 ('290 patent), successfully argued in the Federal Circuit that the patent is not invalid due to improper inventorship. The jury found that Sofamor Danek Group, Inc. and Danek Medical, Inc. (collectively Danek) infringed both the '290 patent and U.S. Patent No. 4,854,311 ('311 patent), with the claims of the '311 patent also deemed valid. The court affirmed the district court's judgment, concluding there was insufficient evidence to invalidate the '290 patent and upholding the jury's findings.
The '290 patent, invented by Dr. Arthur D. Steffee, pertains to a plate designed for surgical implantation on a spinal column to correct deformities caused by conditions like disc degeneration or fractures, thereby relieving pain and improving mobility. Initially, Dr. Steffee utilized a rod and wire method for spine straightening, which proved inadequate due to slippage. He then developed a plate-and-screw system, which was more effective but difficult to install due to fixed screw hole placements that did not accommodate anatomical variances among patients.
In 1982, while at a Cleveland hospital, Dr. Steffee innovated further by creating a headless screw system that allowed for optimal screw placement in vertebrae, thus enhancing the adaptability of the installation process. He collaborated with a machinist to modify regular bone screws and sought to redesign the plate to incorporate slotted holes, improving the system's flexibility for different patient anatomies.
Dr. Steffee identified a design issue with a spinal plate where slots could slide along screws, compromising fixation. To address this, he instructed Mr. Janson to create a plate where the Hagie pin nut would be secured in place. Mr. Janson implemented this by adding nests to the slots, resulting in a combination that is claimed in the '290 patent. This patent describes a spine plate with elongated slots featuring nests that align to prevent sliding of the plate relative to both the fastener and the vertebrae.
Additionally, Dr. Steffee enhanced the design of a headless bone screw, detailed in the '311 patent. This bone screw includes an elongated shank with distinct segments: a threaded portion for a nut, a cylindrical body for engaging the bone, and another threaded portion for securing the screw to the bone. The screw design aims to prevent effluence from leaking out of the bone, which can weaken the screw, by incorporating a shoulder that acts as a stopper.
Dr. Steffee and a colleague founded AcroMed in 1983, where he assigned his rights to the '290 and '311 patents. After CRI disbanded in 1988, Mr. Janson joined AcroMed, signing an Employment Agreement that required him to disclose any prior inventions. He indicated that he had no such property at the time of signing.
Mr. Janson worked as a machinist and consultant for AcroMed until 1994, when he declined to sign a declaration and assignment for the '290 patent, despite AcroMed's request to add him as a co-inventor. Instead, he assigned his patent rights to Danek for $150,000 in January 1995. AcroMed had previously sued Danek for infringing the '290 patent in 1988, leading to a settlement that granted Danek a limited license until 1996. In 1993, AcroMed filed another suit against Danek, asserting that its DYNA-LOK and Z-PLATE systems infringed the '311 and '290 patents, while Danek counterclaimed the '290 patent's invalidity for failing to name Janson as an inventor and claimed anticipation of the '311 patent based on the Konstantinou patent.
After a jury trial, the district court upheld the validity of the '290 patent regarding inventorship and found that Danek's products infringed both the '290 and '311 patents. The jury ruled against Danek's claims of invalidity and awarded AcroMed $32,913,444 in damages, later increased to $47,806,701 to include post-verdict damages and prejudgment interest. Danek's subsequent motions for JMOL regarding invalidity and non-infringement were denied by the district court. The court's decisions on JMOL are reviewed without deference, under established legal standards.
Literal infringement of a means-plus-function claim necessitates proving that the accused device performs the exact function specified in the claims, requiring claim language construction. Claim construction is reviewed de novo, while applying the claim to the accused device involves factual determination with substantial deference. Anticipation is also factual, focusing on whether elements are inherent in prior art, with jury findings reviewed for substantial evidence. Each patent is presumed valid, including the presumption that named inventors are the true inventors; this presumption can only be rebutted with clear and convincing evidence of an omitted inventor. All inventors must jointly apply for a patent, and omission can invalidate it unless unintentional. Danek claims Mr. Janson was an inventor of the '290 patent, arguing that his omission suggests patent invalidity. Inventorship hinges on actual contribution to conception, requiring corroborating evidence. Testimony alone is insufficient for proof, and contributions must be substantial rather than merely explaining known concepts. Danek asserts Mr. Janson conceived specific features of the '290 patent, but lacks corroborating evidence to support this claim.
Mr. Janson claimed to have conceived a spine plate with conical nuts and arcuate recesses to prevent sliding before Dr. Steffee raised concerns about plate sliding. He asserted he was the first to develop the plate-and-screw combination, including transforming regular bone screws into machine-threaded screws for a slotted plate. However, Danek failed to provide supporting evidence, such as witnesses or dated drawings, to validate Mr. Janson's claims, and he admitted he did not communicate his ideas to anyone.
On appeal, Danek cited Dr. Steffee's testimony as corroboration of Mr. Janson's claims regarding the arcuate recesses. Dr. Steffee acknowledged that Mr. Janson created these recesses, but he emphasized that he had instructed Mr. Janson on the design of the plate, suggesting that Mr. Janson's contribution was merely a routine application of skills expected from a machinist. The district court concluded that Dr. Steffee was the sole inventor of the invention.
Danek contended that the prosecution history of the '290 patent demonstrated that the arcuate recesses were an inventive feature. Although AcroMed argued during prosecution that prior art did not disclose an elongated plate with slots having arcuate recesses, it did not claim that the recesses alone made the invention patentable. Instead, AcroMed indicated that it was the combination of features that blocked sliding movements which was innovative. Ultimately, Danek did not present substantial evidence to prove that Mr. Janson's work exceeded the capabilities of an ordinarily skilled machinist.
Claim 1 of the '290 patent is identified as a combination claim, which can include new configurations of existing elements, making such combinations potentially novel and patentable. The court references established case law affirming that the novelty of a claim can arise from the unique combination of old elements, even if all components were previously known. Specifically, the '290 spine plate is noted to resemble the Egger's plate, and prior patents show that elements like countersinking and elongated slots existed in the art before the patent's filing. Despite the elements being known, their combination in claim 1 is deemed to create a new, nonobvious invention.
Danek failed to provide sufficient evidence that Mr. Janson's modification of countersinking represented an inventive contribution, leading to a judgment supporting the validity of the '290 patent.
In terms of infringement, the district court construed claim 5 of the '311 patent as a means-plus-function claim, defining 'engaging' as 'fitting together.' Danek contested this interpretation, arguing that the term should imply a narrower meaning related to the physical action of the screw's body in manipulating bone tissue, particularly for screws with a diameter greater than 5.5 mm, which they claimed could not displace material as required by the patent.
The court clarified that 'engage' means 'to interlock' or 'mesh,' consistent with its usage throughout the '311 patent. The patent's written description supports a broad interpretation of 'engage,' applicable to three specific interfaces involving the screw's interaction with bone and other components. The court emphasized the need for consistency in interpreting terms across claims within the same patent, as established in prior case law.
The term 'engage' in the context of the patent cannot be limited to merely 'pushing material forward and outward'; instead, it should be interpreted as 'fitting together.' This interpretation allows for the seat portion of the screw to properly interact with the spine plate, helping to position it along the bone screw. The body and tapering shoulder portions of the screw also 'fit together' with the surrounding bone to restrict movement and block effluence.
Danek's argument that the claims necessitate a screw with a body diameter equal to or greater than the crest diameter of the threaded portion is rejected. The written description includes a screw with a body diameter that is substantially equal to the crest diameter, but the court emphasizes that it cannot impose unnecessary structural limitations from the written description onto the claims. The court correctly identified the functions of 'blocking effluence and restricting transverse movement' and found that both the body and shoulder portions serve these roles. Limiting the body portion's diameter to match the crest diameter would incorrectly import specific dimensions from a preferred embodiment, which is not permissible when the claim language indicates broader coverage.
Danek's challenge to the trial court's claim construction fails, as the court finds the construction correct and supports the jury's finding of infringement of the '311 patent by the accused bone screws. Regarding anticipation, Danek argues that if the claims can encompass a body portion with a smaller diameter than the thread, the Konstantinou patent would anticipate the claims. Danek contends that the shank and head portions of the Konstantinou screw fulfill the 'means integral' requirement of the '311 patent and perform the 'engaging' function as described in its claims.
To invalidate a patent by anticipation, a prior art reference must disclose all limitations of the claim. However, it can still anticipate if limitations not explicitly stated are inherently present. Claim 5 specifies that the 'means integral' must project into the bone and engage the bone surface. The district court interpreted 'means integral' to include both the body portion and the tapered shoulder of the screw. The Konstantinou patent must inherently or explicitly disclose these functions, but it fails to do so, placing the burden on Danek to prove that the missing elements are necessarily present in the reference.
Although the Konstantinou screw's long shank may represent a body portion, it lacks a tapering shoulder as required. Danek argued that the lower half of the screw head could fulfill this role, but AcroMed provided evidence from the Konstantinou patent and expert testimony showing the absence of a tapering shoulder. Furthermore, the rounded head of the Konstantinou screw does not project into the bone or restrict movement, as AcroMed's evidence indicated it remains outside the cortical bone. Consequently, the district court correctly declined to grant judgment as a matter of law (JMOL) regarding anticipation of the '311 patent by the Konstantinou patent. The court affirmed the district court’s judgments, with each party bearing its own costs.