United States Court of Appeals 

for the Federal Circuit ______________________ 

STRYKER CORPORATION, STRYKER PUERTO 

RICO, LTD., AND STRYKER SALES CORPORATION,

Plaintiffs-Appellees,

v.

ZIMMER, INC. AND ZIMMER SURGICAL, INC.,

Defendants-Appellants,

AND

ZIMMER ORTHOPAEDIC SURGICAL PRODUCTS,

Defendant.

______________________ 

2013-1668

______________________ 

Appeal from the United States District Court for the 

Western District of Michigan in No. 10-CV-1223, Judge 

Robert J. Jonker.

______________________ 

Decided: December 19, 2014

______________________ 

SHARON A. HWANG, McAndrews, Held & Malloy, Ltd., 

of Chicago, Illinois, argued for plaintiffs-appellees. With 

her on the brief were GREGORY J. VOGLER, DEBORAH A.

LAUGHTON, and CAROLINE A. TEICHNER. 
2 STRYKER CORPORATION v. ZIMMER, INC. 

DONALD R. DUNNER, Finnegan, Henderson, Farabow, 

Garrett & Dunner, LLP, of Washington, DC, argued for 

defendants-appellants. With him on the brief were KARA

F. STOLL and GARTH D. BAER. Of counsel was BENJAMIN 

THOMAS SIROLLY. 

______________________ 

Before PROST, Chief Judge, NEWMAN and HUGHES, Circuit 

Judges.

PROST, Chief Judge. 

Zimmer, Inc., Zimmer Surgical, Inc., and Zimmer Orthopaedic Surgical Products (collectively “Zimmer”) appeal from the final judgment of the United States District 

Court for the Western District of Michigan that U.S. 

Patent Nos. 6,022,329 (“’329 patent”), 6,179,807 (“’807 

patent”), and 7,144,383 (“’383 patent”) were valid and 

willfully infringed. For the reasons stated below, we 

affirm the jury’s findings that the patents were valid and 

infringed, and the jury’s award of damages to plaintiffappellees Stryker Corporation, Stryker Puerto Rico, Ltd., 

and Stryker Sales Corporation (collectively “Stryker”). 

However, we reverse the district court’s judgment that 

Zimmer’s infringement was willful, and, accordingly, we 

vacate its award of treble damages. Finally, we vacate 

and remand the district court’s finding of exceptional case 

and its award of attorneys’ fees.

I 

The patents at issue concern pulsed lavage devices. 

Pulsed lavage devices deliver pressurized irrigation for 

certain medical therapies, including orthopedic procedures and cleaning wounds. The particular devices at 

issue in this case are portable, battery powered, and 

handheld. They include both suction and discharge tubes, 

so they both spray fluid from an external source and also

suction off fluid and debris. These devices represent an 

improvement over older pulsed lavage systems that 
STRYKER CORPORATION v. ZIMMER, INC. 3

required a central power source and external mechanical 

pumps, which meant that they needed to be wheeled 

around the hospital.

Stryker and Zimmer are the two main competitors in 

the orthopedic pulsed lavage device market. Stryker 

began bringing battery-powered, handheld pulsed lavage 

devices to the marketplace in 1993. That same year, 

Stryker filed the application which eventually gave rise to 

the patents at issue. In February 2000, the first of these 

patents, the ’329 patent, issued. Later that year Stryker 

sued another manufacturer, Davol Inc., for infringement. 

That suit settled in 2001, and Davol took a license on 

the ’329 patent. The ’807 patent subsequently issued in 

January 2001, and the ’383 patent issued in December 

2006.

Zimmer introduced its first portable pulsed lavage device, the Var-A-Pulse, in 1996. In 1998, Zimmer began to 

develop a new design, which came to market soon thereafter as the Pulsavac Plus range of products. Zimmer’s 

Pulsavac Plus products achieved a peak of $55 million in 

annual sales in late 2007, before they were withdrawn 

from the marketplace due to a product recall, after which 

sales resumed in December 2008.

In 2010, Stryker sued Zimmer, alleging that Zimmer’s 

Pulsavac Plus devices infringed various claims of 

the ’329, ’807, and ’383 patents. The district court granted partial summary judgment in favor of Stryker, finding 

infringement of the ’807 and ’383 patents’ asserted claims. 

The question of whether Zimmer infringed the single

asserted claim of the ’329 patent, as well as Zimmer’s 

invalidity defenses against all of the asserted claims, 

went to trial. The jury found that the products infringed 

claim 2 of the ’329 patent and that all the asserted claims 

were valid. The jury also awarded $70 million in lost 

profits. It further found that Zimmer had willfully infringed all three patents. The jury also found that 
4 STRYKER CORPORATION v. ZIMMER, INC. 

Stryker had marked substantially all of its products that 

commercially embodied the patents in suit during the 

period it sought damages, pursuant to 35 U.S.C. § 287(a).

In August 2013, the district court issued an order rejecting Zimmer’s motions for judgment as a matter of law 

(“JMOL”) on various issues, affirming the jury’s verdict, 

awarding trebled damages for willful infringement, finding an exceptional case and thus awarding attorneys’ fees 

to Stryker, and imposing a permanent injunction. The 

district court subsequently entered final judgment pursuant to its order.

Zimmer appeals. We have jurisdiction under 28 

U.S.C. § 1295(a)(1).

II

We turn first to Zimmer’s appeal on the issues of 

claim construction, infringement, and validity.

Claim construction is an issue of law that we review 

de novo. Lighting Ballast Control LLC v. Philips Elecs. N. 

Am. Corp., 744 F.3d 1272, 1276-77 (Fed. Cir. 2014) (en 

banc). In construing a claim term, we look at the term’s 

plain and ordinary meaning as understood by a person of 

ordinary skill in the art. Phillips v. AWH Corp., 415 F.3d 

1303, 1313 (Fed. Cir. 2005) (en banc). There is an exception to this general rule when a patentee sets out a definition and acts as her own lexicographer. Thorner v. Sony 

Computer Entm’t Am., LLC, 669 F.3d 1362, 1365 (Fed. 

Cir. 2012). Infringement is a question of fact. Lucent 

Techs., Inc. v. Gateway, Inc., 580 F.3d 1301, 1309 (Fed. 

Cir. 2009). Invalidity by reason of anticipation under 35 

U.S.C. § 102 is a question of fact. Atlas Powder Co. v. 

Ireco, Inc., 190 F.3d 1342, 1346 (Fed. Cir. 1999). Invalidity by reason of obviousness under 35 U.S.C. § 103 is a 

legal conclusion based on underlying facts. Allergan, Inc. 

v. Sandoz Inc., 726 F.3d 1286, 1290 (Fed. Cir. 2013). 

Zimmer has the burden to prove invalidity by clear and 
STRYKER CORPORATION v. ZIMMER, INC. 5

convincing evidence. Galderma Labs., L.P. v. Tolmar, 

Inc., 737 F.3d 731, 736 (Fed. Cir. 2013).

On the issues of infringement and validity that the jury decided, Zimmer appeals the district court’s denials of 

its motion for JMOL. Generally, a district court grants 

JMOL and sets aside the jury’s verdict if it “finds that a 

reasonable jury would not have a legally sufficient evidentiary basis to find for the party on that issue.” Fed. R. 

Civ. P. 50(a). We apply the law of the regional circuit to 

our review of the district court’s grant or denial of a 

motion for JMOL. ClearValue, Inc. v. Pearl River Polymers, Inc., 668 F.3d 1340, 1343 (Fed. Cir. 2012). The 

Sixth Circuit reviews the district court’s decision on a 

motion for JMOL de novo. Barnes v. City of Cincinnati, 

401 F.3d 729, 736 (6th Cir. 2005). “Judgment as a matter 

of law may only be granted if, when viewing the evidence 

in a light most favorable to the non-moving party, giving 

that party the benefit of all reasonable inferences, there is 

no genuine issue of material fact for the jury, and reasonable minds could come to but one conclusion in favor of 

the moving party.” Id.

For the reasons stated below, we affirm the district 

court’s judgment on the various defenses of noninfringement and invalidity that Zimmer raises across the 

three asserted patents. However, we also find that each 

of these defenses was not unreasonable. 

The ’329 Patent

The only asserted claim of the ’329 patent, claim 2, 

describes features of a “pulsed irrigation surgical handpiece.” According to this claim, the handpiece comprises a 

“hollow housing,” which includes a “handle,” and, in 

relevant part in this case, “an electric motor spaced 

between the top and bottom of said handle and located in 

said handle” adjacent to an irrigation tube within the 

housing. ’329 patent col. 22 ll. 5-7 (emphases added). 

Zimmer contends that this limitation is critical for the 
6 STRYKER CORPORATION v. ZIMMER, INC. 

purposes of infringement because, as indicated by the 

arrows below, the motor in its accused Pulsavac Plus 

device is not located in the handle—rather, it is located in 

the “nub” of the handpiece, the protrusion behind the 

barrel. 

Appellees’ Br. 11 (red arrows added).

During claim construction, Zimmer took the position 

that no construction was necessary and that the claim 

term “handle” could be understood as having its plain and 

ordinary meaning to a person of ordinary skill in the art. 

Stryker Corp. v. Zimmer, Inc., No. 10-1223, slip op. at 6 

(W.D. Mich. Feb. 1, 2012), ECF No. 106 (“Claim Construction Order”). Stryker proposed to construe the term 

“handle” as “a portion of a device designed to be held by a 

hand or hands.” Id. The district court adopted Stryker’s 

proposed construction.

Stryker argued that nothing in the patent’s specification otherwise limited the meaning of “handle,” and that

its definition for “handle” was consistent with general 

dictionaries. Zimmer argued that Stryker’s express 

construction of the term, however, was too broad and read 

out the specification’s consistent distinction between the 

“handle” and “barrel” portions of the claimed device.

The ’329 patent generally describes various embodiments, all of which comprise a “hand-held housing having 
STRYKER CORPORATION v. ZIMMER, INC. 7

a handle and a barrel which extends from the upper end 

of the handle.” ’329 patent col. 3 ll. 28-31. Zimmer further supported its position with the language of claim 4, 

which depends on claim 2. Claim 4 separately describes 

both a “handle” and a “barrel,” which Zimmer argued 

meant that the patentee maintained the distinction 

between the two parts of the handpiece.

However, the district court ultimately agreed with the 

Stryker that a device that met claim 2 did not need to 

have a discrete barrel joined to the handle, since this 

claim could cover wand-shaped devices that existed in the 

prior art in which the entire handpiece functioned like a 

handle and no separate barrel was joined at an angle. 

The district court reasoned that since claim 4 is a dependent claim, it could cover the pistol-shaped design described in the specification, while claim 2 would more 

broadly cover wand-shaped devices as well.

On appeal, Zimmer also raises the prosecution history 

of U.S. Patent Application No. 08/559,133 (“’133 application”), the parent of the application that issued as the ’329 

patent. During the ’133 application’s prosecution, Stryker 

sought to overcome a rejection of claim 39 based on a prior 

art reference which described a pistol-shaped device with 

a barrel and a handle. Stryker traversed the rejection by 

arguing that the motor of the prior art handpiece was “not 

in the handle or at an angle to the barrel.” Zimmer 

contends that claim 39 included the limitation “locating 

said motor in said handle,” which is the same as the one 

at issue in the construction of “handle” in claim 2 of 

the ’329 patent. Therefore, Zimmer argues, Stryker’s 

statement disclaimed designs in which the motor is 

located in the barrel or nub of a pistol-shaped handpiece. 

See Gemalto S.A. v. HTC Corp., 754 F.3d 1364, 1371 (Fed. 

Cir. 2014) (“[W]hen multiple patents derive from the same 

initial application, the prosecution history regarding a 

claim limitation in any patent that has issued applies 

with equal force to subsequently issued patents that 
8 STRYKER CORPORATION v. ZIMMER, INC. 

contain the same claim limitation.”); Microsoft Corp. v. 

Multi-Tech Sys., Inc., 357 F.3d 1340, 1349 (Fed. Cir. 

2004); Elkay Mfg. Co. v. EBCO Mfg. Co., 192 F.3d 973, 

980 (Fed. Cir. 1999). 

Zimmer did not raise its prosecution history argument

during its claim construction briefing and the Markman

hearing before the district court. The district court indicated that it would not alter the claim construction but, 

nevertheless, determined that it would still consider this

argument in deciding Zimmer’s motion for summary 

judgment of non-infringement. Stryker Corp. v. Zimmer, 

Inc., No. 10-1223, slip op. at 3 (W.D. Mich. Nov. 29, 2012), 

ECF No. 248 (“Summary Judgment Order I”). The district court nevertheless denied Zimmer’s motion, finding

that the prosecution disclaimer was insufficiently “clear 

and unmistakable” because claim 39 of the ’133 application had additional limitations that were absent in claim 

2 of the ’329 patent. Id. at 4-5. 

The district court’s analysis was flawed, however, because this was not a case in which the “purported disclaimers are directed to specific claim terms that have 

been omitted or materially altered in subsequent applications (rather than to the invention itself).” Saunders 

Grp., Inc. v. Comfortrac, Inc., 492 F.3d 1326, 1333 (Fed. 

Cir. 2007).1 There was no difference in the language 

1 The limitation at issue in the original claim 39 of 

the ’133 application was, in full: “a handpiece housing 

containing said pump and shell, said handpiece housing 

being elongate [sic] and bent and comprising a handle and 

a barrel, said barrel being open to and extending forward 

from an intersection with the top of the handle at an 

angle thereto, said hollow shell extending lengthwise 

along and within said handle into said angled intersection 

of said handle and barrel and locating said motor in said 

 
STRYKER CORPORATION v. ZIMMER, INC. 9

describing the limitations as between the two claims at 

issue, rather, the limitation of claim 2 was included 

within claim 39. There is no reason why a disclaimer on a 

limitation within a narrower claim would not apply to the 

identical limitation within the broader claim, as the same 

concerns about the prior art would relate to both. See, 

e.g., Gemalto, 754 F.3d at 1371 (applying a common 

disclaimer to both an independent and narrower dependent claim containing the same term).2 That said, the 

district court did not err in rejecting Zimmer’s argument 

as it related to claim construction, while still entertaining 

it in the context of infringement. See SuperGuide Corp. v. 

DirecTV Enters., Inc., 358 F.3d 870, 889-90 (Fed. Cir. 

2004) (affirming the district court’s construction on the 

grounds that a proffered alternative construction was 

handle remote from said angled intersection, said link 

extending at said angle from said shell and handle forwardly into and along the length direction of said barrel, 

said pump movable member extending along the length 

direction of said barrel and being reciprocatingly driven 

by said link in said length direction of said barrel.” J.A. 

16672 (emphasis added).

2 This is unlike the case cited by Stryker and the 

district court for the contrary proposition, Middleton, Inc. 

v. Minnesota Mining and Manufacturing. Co., 311 F.3d 

1384, 1388-89 (Fed. Cir. 2002), in which the term at issue, 

“uniform” in the context of floor coverings, would potentially have a different meaning if it applied to the narrower claim—limited to smooth sporting surfaces—and a 

subsequent, broader claim that contemplated other kinds 

of surfaces. Here, a limitation on the location of the motor 

within the handpiece would mean the same thing in the 

context of either claim.

 
10 STRYKER CORPORATION v. ZIMMER, INC. 

untimely raised). Therefore, we review Zimmer’s argument only as it relates to infringement.

Infringement is a question of fact, and we must give a 

substantial degree of deference to the jury’s verdict. At 

trial, Stryker presented evidence indicating that a medical professional could hold Zimmer’s Pulsavac Plus by the 

nub behind the barrel, where the motor was located. In 

addition, Stryker presented evidence that the barrel of 

the Pulsavac Plus was called a “barrel grip” in an associated patent application, and the barrel included indentations that would allow the device to be used while held by 

the barrel. Stryker also persuaded the jury that it was 

reasonable to infer that if the nub behind the barrel was 

also shaped such that it was at least capable of being

held, then it would be “a portion of the device designed to 

be held by hand,” in accordance with the district court’s 

construction of “handle” in the claim at issue. In light of 

the evidence presented at trial as a whole, along with the 

prosecution history, we do not find that “reasonable minds 

could come to but one conclusion” that Zimmer did not 

infringe claim 2 of the ’329 patent. Barnes, 401 F.3d at

736. Accordingly, we affirm, though Zimmer’s claim 

construction and non-infringement positions were not 

unreasonable. 

The ’807 Patent

Infringement

Zimmer argues that the district court erred in granting summary judgment of infringement of the ’807 patent’s asserted claims. We review the district court’s 

grant of summary judgment de novo. Dixon v. Univ. of 

Toledo, 702 F.3d 269, 273 (6th Cir. 2012). “Summary 

judgment is proper where there exists no issue of material 

fact and the moving party is entitled to judgment as a 

matter of law.” ETW Corp. v. Jireh Publ’g, Inc., 332 F.3d 

915, 920 (6th Cir. 2003) (citing Fed. R. Civ. P. 56(c)). All 
STRYKER CORPORATION v. ZIMMER, INC. 11

reasonable factual inferences are drawn in favor of the 

nonmoving party. Id.

Zimmer’s argument on appeal centers on whether its 

products include, as required for all the asserted claims,

“a front end for receiving the discharge tube and the 

suction tube.” ’807 patent col. 27 ll. 35-37 (emphasis 

added).3 This limitation describes the interface between 

the nozzles at the front end of the handpiece and the 

nozzles of a removable tip that includes discharge and 

suction tubes. Zimmer argues that the claim language 

requires that there be male openings on the tip that fit 

into the female nozzles on the handpiece. Therefore, 

Zimmer contends that the accused devices do not infringe 

because they are designed with female openings on the tip 

that fit into tapered male nozzles on the handpiece. To 

support its position, Zimmer relies on various dictionary 

definitions of “receive,” which it argues all have some 

variant of the verbs “to contain” or “to hold.” See Appellants’ Br. 57. Zimmer argues that this meaning is consistent with the specification, which discloses a single

embodiment in which the neck of the suction tube “seats 

in” the drain tube—and, specifically, that this configuration is designed to avoid “leakage of the fluid and material 

as it flows in the drain tube.” ’807 patent col. 11 ll. 29-34; 

see also Figure 8.

As an initial matter, Stryker’s argument that Zimmer 

waived a narrower construction of the term “receive” is 

unavailing. The parties and the district court directly 

addressed this issue during the summary judgment 

proceedings. Moreover, unlike the dispute concerning the 

meaning of “handle” in the ’329 patent, the district court 

did not note any waiver and expressly considered the 

3 Stryker asserted claim 45 and certain of its dependent claims.

 
12 STRYKER CORPORATION v. ZIMMER, INC. 

scope of “receive” in evaluating whether Zimmer’s design 

infringed. See Pfizer, Inc. v. Teva Pharm., USA, Inc., 429 

F.3d 1364, 1377 (Fed. Cir. 2005) (contemplating “rolling 

claim construction, in which the court revisits and alters 

its interpretation of the claim terms as its understanding 

of the technology evolves”).

Stryker further argues that the specification provides 

a broader disclosure of “an irrigation handpiece to which 

complementary tips can be readily coupled.” ’807 patent 

col. 1 ll. 10-12 (emphasis added); see also col. 2 ll. 45-47 

(disclosing “a tip assembly [that] readily seals to a complementary handpiece”) (emphasis added). Stryker also

points to Zimmer’s own lay witnesses, who admitted that 

its Pulsavac Plus handpiece “receives” the tips.4

The district court noted that, in its view, “Zimmer’s 

reading of ‘receive’ is artificially narrow.” Stryker Corp. v. 

Zimmer, Inc., No. 10-1223, slip op. at 8 (W.D. Mich. Nov. 

29, 2012), ECF No. 247 (“Summary Judgment Order II”). 

Instead, the district court reasoned that “[t]he word 

“receives” in this context can only mean that one part of 

the device connects directly with another part of the 

device.” Id. Thus, the district court found that Zimmer 

infringed. While it is a close case, we do not find that the 

district court erred in granting summary judgment of 

infringement based on the record before it.

4 Stryker also argues that Zimmer’s invalidity argument relies on the prior art Var-A-Pulse device including the “receive” limitation—even though it has the same 

kind of tip assembly as the Pulsavac Plus. We note, 

however, that nothing precludes Zimmer from arguing for 

a narrower application of the limitation on the infringement context, while also arguing, in the alternative, 

that—if the district court were to disagree—the patent 

claim would be so broad as to be invalid.

 
STRYKER CORPORATION v. ZIMMER, INC. 13

Invalidity

Zimmer also appeals the district court’s holding that 

the asserted claims of the ’807 patent were anticipated by 

its prior art Var-A-Pulse device, the predecessor of the 

Pulsavac Plus. Stryker argues that the Var-A-Pulse 

device does not anticipate because it is missing the “lock 

assembly” limitation of the asserted claims, which require 

that there be “a lock assembly mounted to the front end of 

said body for releasably securing the discharge tube and 

the suction tube to said body.” ’807 patent col. 27 ll. 35-

37. The district court adopted Stryker’s proposed construction of the term “lock assembly” as “components that 

work together to secure or fasten the tip to the handpiece.” Claim Construction Order at 16. In the Var-APulse device, the tip was attached to the handpiece in 

such a way that the tip nozzles fit into interior housing 

grooves at the front of the handpiece, which were then 

held together by friction. Zimmer argues that under the 

district court’s construction, the limitation was present in 

the prior art because the nozzles were “secured or fastened” when they were fit in the interior housing groove.

At trial, Zimmer presented evidence that included the 

Var-A-Pulse’s technical documentation, which indicated 

that the tip should be “secured” to the handpiece, as well 

as testimony from various Stryker witnesses admitting 

that the tip nozzles were fastened to the handpiece when 

they were inserted. Stryker argued that, unlike the 

accused Pulsavac Plus devices, which include a locking 

ring to secure the tip, there is no separate part or assembly in the Var-A-Pulse. Stryker also contended the prior

art device did not include the full claim limitation, which 

requires that the lock assembly be “mounted” to the front 

end of handpiece. Stryker argued that because Zimmer

identified a “lock assembly” that itself included the housing groove that is part of the front end, Zimmer was

essentially arguing that the lock assembly was mounted 

to itself, thus nullifying the limitation. Stryker also 
14 STRYKER CORPORATION v. ZIMMER, INC. 

presented evidence to the jury showing that the Var-APulse tips readily fell off the front end of the handpiece, 

and that this led the development of the locking ring in

the Pulsavac Pulse.

The jury ultimately found that there was no clear and 

convincing evidence that the Var-A-Pulse device anticipated the ’807 patent’s asserted claims. In light of the 

evidence that was presented, we find that a reasonable 

jury could have reached this verdict. Accordingly, we 

affirm.

The ’383 Patent

At trial, Zimmer argued that the asserted claims of 

the ’383 patent were obvious at the time of the invention

in light of U.S. Patent No. 5,046,486 (“Grulke”), U.S.

Patent No. 4,817,599 (“Drews II”), and U.S. Patent No. 

5,350,356 (“Bales”). Zimmer contends that all of the

limitations of the ’383 patent’s asserted claims were 

collectively present in the prior art references. Stryker 

does not directly dispute this point. Instead, it principally

argues that because the designs claimed by Grulke and 

Drews II each exclude certain components described in 

the claims, one of ordinary skill in the art would not have 

been motivated to combine these references. In brief, 

Grulke disclosed a pulsed lavage system that uses a 

pneumatic, rather than an electric, motor. Drews II 

disclosed a pulsed irrigation system, powered by an 

electric motor, that is used as an eye wash.

At trial, Zimmer argued that it would have been obvious to one of ordinary skill to try to replace the pneumatic 

motor of Grulke with the electric motor in Drews II. 

Zimmer further argued that any reconfiguration of Grulke 

to accommodate an electric motor could be done by one of 

ordinary skill. See In re ICON Health & Fitness, Inc., 496 

F.3d 1374, 1382 (Fed. Cir. 2007) (“[W]e do not ignore the 

modifications that one skilled in the art would make to a 

device borrowed from the prior art.”). Zimmer also argued 
STRYKER CORPORATION v. ZIMMER, INC. 15

that even though the Grulke reference was directed to 

orthopedic pulsed lavage systems, and the Drews II 

reference was directed to eyewash systems, they both 

described pressured water irrigation in hospitals and 

clinics. Zimmer contended that that a person of ordinary 

skill in the art of pulsed lavage devices would thus be 

aware of the art in both fields and would be motivated to 

combine features from each of them. See KSR Int’l Co. v. 

Teleflex Inc., 550 U.S. 398, 420 (2007) (“Common sense 

teaches, however, that familiar items may have obvious 

uses beyond their primary purposes, and in many cases a 

person of ordinary skill will be able to fit the teachings of 

multiple patents together like pieces of a puzzle.”). 

Zimmer also presented evidence of the examiner’s rejection of certain claims in Stryker’s prosecution of U.S. 

Patent Application No. 11/563,504 (“’504 application”), a 

continuation of the ’383 patent, which occurred during the 

discovery phase of this case. During that patent application’s prosecution, the examiner issued a non-final office 

action, rejecting certain claims of the ’504 application as 

obvious over Grulke “and further in view of Drews II.” 

J.A. 17226. Stryker did not attempt to traverse the 

rejection and instead ultimately abandoned the application. Stryker principally argued that because the claim at 

issue in the ’504 application included certain different 

limitations, the examiner’s rejection did not have any 

relevance to the ’383 patent’s claims. We note, however,

that the difference in the detail of the claims is immaterial as to whether it would have been obvious to combine 

Grulke and Drews II. While persuasive, the examiner’s 

proffered rejection is not on its own dispositive, in large 

part because the U.S. Patent and Trademark Office 

(“PTO”) and district courts “take different approaches in 

determining invalidity and on the same evidence could 

quite correctly come to different conclusions.” Ethicon, 

Inc. v. Quigg, 849 F.2d 1422, 1428 (Fed. Cir. 1988). 
16 STRYKER CORPORATION v. ZIMMER, INC. 

Stryker also argued that the Grulke device differed 

substantially from the Drews II device. For example, it 

was designed for surgery rather than eyewashing. Grulke 

also disclosed a large device that was wheeled into an 

operating room that had many components that differed 

from those in the portable device disclosed Drews II. 

Stryker presented expert testimony rebutting Zimmer’s 

evidence that it would have been obvious to combine these 

references. 

On the basis of the record presented at trial, we agree 

with the district court that a reasonable jury could conclude that one of ordinary skill in the art would not have 

been motivated to combine the Grulke and Drews II 

references, even in light of the examiner’s rejection of 

related claims on the basis of this combination. This is 

sufficient to affirm the district court’s determination that

Zimmer did not show, by clear and convincing evidence, 

that the ’383 patent’s claims were obvious. 

For this reason, we need not reach other issues, including the evidence of secondary considerations of nonobviousness. Therefore, we affirm the district court’s 

determination that the ’383 patent’s asserted claims were 

not obvious over the combination of Grulke, Drews II, and 

Bales.5

5 Zimmer also appeals the jury’s finding that 

Stryker’s products were sufficiently marked by the ’383 

patent during part of the period for which it sought damages. We need not reach this issue, because we affirm the 

finding that Zimmer infringed the ’807 and ’329 patents, 

which is sufficient to support all of Stryker’s award of 

damages for lost profit. However, we note that the jury 

was indeed incorrectly instructed that it should consider 

“whether some portion of the Stryker products not 

 
STRYKER CORPORATION v. ZIMMER, INC. 17

III

Willful Infringement

To establish willful infringement, the patentee has 

the burden of showing “by clear and convincing evidence 

that the infringer acted despite an objectively high likelihood that its actions constituted infringement of a valid 

patent.” In re Seagate Tech., LLC, 497 F.3d 1360, 1371 

(Fed. Cir. 2007) (en banc). “The state of mind of the 

accused infringer is not relevant to this objective inquiry.” 

Id. Only if the patentee establishes this “threshold objective standard” does the inquiry then move on to whether 

“this objectively-defined risk (determined by the record 

developed in the infringement proceeding) was either 

known or so obvious that it should have been known to 

the accused infringer.” Id. We have held that objective 

recklessness, even though “predicated on underlying 

mixed questions of law and fact, is best decided by the 

judge as a question of law subject to de novo review.” 

marked with a particular patent number were marked 

with other related patent notices.” Stryker Corp. v. Zimmer, Inc., No. 10-1223, slip op. at 18 (W.D. Mich. Aug. 7, 

2013), ECF No. 537 (“Post-Verdict Order”) (emphasis 

added). Because of this instruction, the jury could have 

been misled to consider a product marked with the number of a patent related to the ’383 patent—but not with 

the ’383 patent number itself—as being sufficiently 

marked. While the district court appears to have relied 

on cases that suggest that there is some flexibility in what 

constitutes sufficient marking, the statute is not so broad 

as to allow marking with a different patent—with different claims—to provide sufficient notice to the public. 

Rather, the plain language of the marking statute provides that the patented article be marked with the “number of the patent.” 35 U.S.C § 287(a) (emphasis added). 

 
18 STRYKER CORPORATION v. ZIMMER, INC. 

Bard Peripheral Vascular, Inc. v. W.L. Gore & Assocs., 

Inc., 682 F.3d 1003, 1007 (Fed. Cir. 2012). Objective 

recklessness will not be found where the accused infringer’s “position is susceptible to a reasonable conclusion of 

no infringement.” Uniloc USA, Inc. v. Microsoft Corp., 

632 F.3d 1292, 1310 (Fed. Cir. 2011).

The district court failed to undertake an objective assessment of Zimmer’s specific defenses to Stryker’s 

claims. Instead, the district court’s analysis of objective 

reasonableness summarily asserted that the “jury heard 

testimony” that Zimmer “all but instructed its design 

team to copy Stryker’s products.” Post-Verdict Order at 

23. The district court further concluded that the “pioneering” nature of Stryker’s inventions and the secondary 

considerations of non-obviousness “made it dramatically 

less likely that Zimmer’s invalidity arguments were 

reasonable.” Id.

An objective assessment of the case shows that Zimmer presented reasonable defenses to all of the asserted 

claims of Stryker’s patents.

First, with respect to the ’329 patent, the motor in the 

Zimmer’s Pulsavac Plus is located in the nub at the rear 

of the barrel of its pistol-shaped device. Stryker’s infringement case relied on first persuading the district 

court to broadly construe the claim term “handle” to 

include the barrel of a pistol-shaped device—even though 

the patent specification only describes the handle and 

barrel separately. Then, Stryker had to persuade the jury 

that the barrel nub was a part of the device “designed to 

be held by hand,” even in light of prosecution history in 

which Stryker distinguished between the location of the 

motor in the handle as opposed to the barrel. Though 

Stryker ultimately prevailed, Zimmer’s arguments were 

not unreasonably founded on the plain meaning of “handle” in the context of a pistol-shaped device, the specification’s exclusive disclosure of pistol-shaped devices, and
STRYKER CORPORATION v. ZIMMER, INC. 19

the prosecution history—all on which it could have relied 

to provide notice of what the patent claims covered. 

Second, with respect to the ’807 patent, the specification only disclosed female nozzles on the front end of the 

device and male nozzles on the removable tip, which

would be consistent with the claim requiring that the 

front end “receive” the tip. Zimmer’s devices had the 

exact opposite configuration: tapered male nozzles on the

front end and female nozzles on the tip. Furthermore, the 

prior art Var-A-Pulse devices included all of the asserted 

claims’ limitations except one. In light of the district 

court’s claim construction, Stryker’s defense to Zimmer’s 

argument relied on persuading the jury that even though

the tip’s nozzles could fit into the handpiece and be held 

in place through friction with internal housing grooves, 

that did not mean they were “secured or fastened.” Again, 

though Stryker prevailed, Zimmer’s defenses were not 

unreasonable. 

Third, with respect to the ’383 patent, Zimmer’s obviousness argument relied on a combination of references 

that was also raised by a PTO examiner during Stryker’s

prosecution of a related patent application—in an office 

action that occurred during discovery in this litigation. 

Zimmer’s reliance on this combination was not without 

reason, in particular since the references related to pressured water irrigation systems used in hospitals and 

clinics. Therefore, even if Zimmer’s defenses failed at 

trial, it still made a reasonable case that the ’383 patent’s 

asserted claims were obvious and thus invalid. 

In sum, we find that Zimmer’s defenses to the infringement of each patent claim that Stryker asserted

were not objectively unreasonable, and, therefore, it did 

not act recklessly.
20 STRYKER CORPORATION v. ZIMMER, INC. 

Attorneys’ Fees

As the court reversed the district court’s determination of willful infringement, and the district court’s award 

of attorneys’ fees was based on that determination, we 

vacate the district court’s grant of attorneys’ fees. However, because there exist further allegations of litigation 

misconduct in this case and because the standard for 

finding an exceptional case has changed since the district 

court issued its finding regarding attorneys’ fees, we 

remand this issue for further consideration by the district 

court.

IV

For the aforementioned reasons, we affirm the jury’s 

verdict of infringement and validity of all three patents at 

issue, as well as its award of lost profits. However, we 

reverse the district court’s determination of willful infringement and thus vacate its award of trebled damages. 

We also vacate and remand the district court’s finding of 

an exceptional case and its award of attorneys’ fees. The 

case is remanded for further proceedings consistent with 

this opinion.

AFFIRMED-IN-PART, REVERSED-IN-PART, 

VACATED-IN-PART, AND REMANDED