Cross Medical Products, Inc. v. Medtronic Sofamor Danek, Inc.

Error: Bad annotation destination
United States Court of Appeals for the Federal Circuit

05-1043

CROSS MEDICAL PRODUCTS, INC.,

Plaintiff-Appellee,

v.

MEDTRONIC SOFAMOR DANEK, INC.
and MEDTRONIC SOFAMOR DANEK USA, INC.,

Defendants-Appellants.

Bruce D. Kuyper, Latham & Watkins, LLP, of Los Angeles, California, argued for
plaintiff-appellee. With him on the brief were Brian F. McMahon; Mark A. Finkelstein,
Allan Z. Litovsky, and Jordan B. Kushner of Costa Mesa, California.

Dirk D. Thomas, Robins, Kaplan, Miller & Ciresi L.L.P., of Washington, DC,
argued for defendants-appellants. With him on the brief were Robert A. Auchter; Jan M.
Conlin and Munir R. Meghjee, of Minneapolis, Minnesota.

Appealed from: United States District Court for the Central District of California

Senior Judge Gary L. Taylor
 United States Court of Appeals for the Federal Circuit

05-1043

CROSS MEDICAL PRODUCTS, INC.,

Plaintiff-Appellee,

v.

MEDTRONIC SOFAMOR DANEK, INC.
and MEDTRONIC SOFAMOR DANEK USA, INC.,

Defendants-Appellants.

__________________________

DECIDED: September 30, 2005
__________________________

Before SCHALL, GAJARSA, and LINN, Circuit Judges.

LINN, Circuit Judge.

Medtronic Sofamor Danek, Inc. et al. (“Medtronic”) appeals from an order of the

United States District Court for the Central District of California (“district court”)

permanently enjoining Medtronic from infringing claim 5 of U.S. Patent No. 5,474,555

(“the ’555 patent”) owned by Cross Medical Products, Inc. (“Cross Medical”). See Cross

Med. Prods., Inc. v. Medtronic Sofamor Danek, Inc., No. SA CV 03-110-GLT(ANx) (C.D.

Cal. Sept. 28, 2004). The permanent injunction was issued following the grant of Cross

Medical’s motions for partial summary judgment of validity and infringement. See Cross

Med. Prods., Inc. v. Medtronic Sofamor Danek, Inc., No. SA CV 03-110-GLT(ANx) (C.D.

Cal. Aug. 19, 2004) (“Invalidity Opinion”); Cross Med. Prods., Inc. v. Medtronic Sofamor

Danek, Inc., No. SA CV 03-110-GLT(ANx) (C.D. Cal. May 20, 2004) (“Infringement
Opinion”). As a threshold matter, we conclude, over Cross Medical’s objection, that we

have jurisdiction over this appeal. On Medtronic’s challenge to the district court’s claim

construction rulings, we affirm the district court’s construction of the “anchoring means,”

“securing means,” and “bear against said channel” limitations, but modify the district

court’s construction of the “anchor seat means” and “operatively joined” limitations.

Because we find genuine issues of material fact regarding infringement, we reverse the

grant of Cross Medical’s motion for partial summary judgment of infringement and find

no abuse of discretion in the denial of Medtronic’s cross-motion for partial summary

judgment of non-infringement. We also reverse the grant of Cross Medical’s motion for

partial summary judgment that claim 5 is not obvious but affirm the grant of that motion

as to indefiniteness and anticipation. We further conclude that the district court did not

abuse its discretion in denying Medtronic’s cross-motion for summary judgment as to

these invalidity issues. Consequently, we vacate the permanent injunction. Thus, we

affirm-in-part, reverse-in-part, vacate-in-part, and remand.

I. BACKGROUND

This appeal involves orthopedic surgical implants used to stabilize and align the

bones of a patient’s spine. A common problem with spinal fixation is determining how to

secure the fixation device to the spine without damaging the spinal cord. Methods of

fixation have developed which utilize wires that extend through the spinal canal and hold

a rod against the lamina,1 or that utilize pedicular screws which extend into the pedicle2

1
The “lamina” is part of the neural arch of a vertebra extending from the
pedicle to the median line.
2
The “pedicle” is the basal part of each side of the neural arch of a vertebra
connecting the laminae with the centrum.

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and secure a plate which extends across vertebral segments. The system taught in

U.S. Patent No. 4,805,602 (“the ’602 patent”), which is also assigned to Cross Medical

and is part of the case against Medtronic but not involved in this appeal, exemplifies the

advantages of both methods. The screw and rod system of the ’602 patent provides a

rigidity which is intermediate between wired implant and plate systems. Several screw

and rod systems are known in the art. Those which feature an anchor secured to the

bone by a separate screw are termed “polyaxial.” Polyaxial screws have a capability of

pivoting in the anchor. Devices in which the anchor and the bone screw form a unitary

body are deemed “monoaxial.” Monoaxial screws have no ability to pivot relative to the

anchor.

Cross Medical’s ’555 patent discloses a device, an embodiment of which is

illustrated in Figures 1, 2, and 3 below:

The ’555 device allows a surgeon to place a series of bone screws 21, each

carrying an anchor seat 23, into the bones of a patient. A stabilization rod 18 thereafter

may be positioned in the channels 51, 52 of the anchor seats. The ’555 device allows

05-1043 3
surgeons to secure the rod to the anchor seats with top-tightening nuts 27. By

connecting the rod in this fashion to the anchors on adjacent spinal bones, the position

of the patient’s spine may be fixed as desired by the surgeon.

On February 4, 2003, Cross Medical filed suit alleging that certain of Medtronic’s

polyaxial screws—MAS, Vertex, M8, Sextant, M10, Legacy 4.5, and Legacy 5.5—

infringe the ’555 patent and U.S. Patent No. 5,466,237 (“the ’237 patent”). The accused

devices employ a “set screw,” which features external threads to mate with the receiver

member’s internal threads, to hold the rod in the receiver member. The accused

devices also include a “crown member” that lies between the rod and the bone screw.

An illustration of the accused device follows, with explanatory text added.

Medtronic denied infringement and counterclaimed seeking a declaratory

judgment of non-infringement and invalidity. Subsequent to the initial pleading,

responses and amended pleadings added claims and counterclaims relating to several

additional patents, including the ’602 patent. The district court resolved several issues

through summary adjudication. Of importance to this appeal, the district court

05-1043 4
separately entertained motions for partial summary judgment of infringement and

validity of claim 5 of the ’555 patent.

Claim 5 recites:

A fixation device for the posterior stabilization of one or more bone
segments of the spine, comprising:

at least two anchors and an elongated stabilizer comprising a rod
having a diameter and a longitudinal axis, said anchors each
comprising anchoring means which secure said anchors to said bone
segment and an anchor seat means which has a lower bone interface
operatively joined to said bone segment and an anchor seat portion
spaced apart from said bone interface including a channel to receive
said rod; and

securing means which cooperate with each of said anchor seat portions
spaced apart from said bone interface and exterior to the bone relative
to said elongated rod, said seat means including a vertical axis and first
threads which extend in the direction of said vertical axis toward said
lower bone interface to a depth below the diameter of the rod when it is
in the rod receiving channel, and said securing means including second
threads which cooperate with the first threads of the seat means to
cause said rod to bear against said channel through the application of
substantially equal compressive forces by said securing means in the
direction of the vertical axis and applied on either side along said
longitudinal axis of said channel.

’555 patent, col. 8, ll. 33-57 (emphases added).

On May 29, 2004, the district court construed the “operatively joined,” “securing

means,” and “bear against said channel” limitations of claim 5 of the ’555 patent. Based

on these constructions, the court granted Cross Medical’s motion for partial summary

judgment of infringement, and denied Medtronic’s cross-motion for partial summary

judgment of non-infringement. On August 19, 2004, the district court additionally

construed the “anchor seat means” and “anchoring means” limitations of claim 5 of the

’555 patent. The court then denied Medtronic’s motion for partial summary judgment

that claim 5 was anticipated, obvious, and indefinite, and granted Cross Medical’s

05-1043 5
cross-motion for partial summary judgment that claim 5 was neither anticipated,

obvious, nor indefinite.

On September 28, 2004, with proceedings still on-going with respect to the ’555

patent and other patents-in-suit, the district court granted Cross Medical’s motion for a

permanent injunction to preclude Medtronic’s infringement of claim 5 of the ’555 patent.

The district court presumed irreparable harm because Cross Medical had prevailed on

the merits at the summary judgment stage. Medtronic argued that there could be no

harm because it withdrew all of the asserted infringing devices from the market;

however, the district court found that some of the infringing products remained available

and that Medtronic had the capacity to bring infringing product back to market. On

October 4, 2004, the district court stayed the injunction for 90 days to allow Medtronic

time to appeal.

On October 13, 2004, Medtronic appealed from the order granting the injunction,

asserting jurisdiction under 28 U.S.C. § 1292(a)(1), (c)(1). Medtronic asks this court to

review the district court’s claim construction rulings, reverse or vacate the district court’s

partial summary judgment orders on infringement, indefiniteness, anticipation, and

obviousness with respect to claim 5 of the ’555 patent, and vacate the permanent

injunction. On November 19, 2004, Cross Medical filed a motion to dismiss this appeal

for lack of jurisdiction.

05-1043 6
 II. DISCUSSION

A. Jurisdiction

“Whether this court has jurisdiction over an appeal taken from a district court

judgment is a question of law which we address in the first instance.” Pause Tech. LLC

v. TiVo Inc., 401 F.3d 1290, 1292 (Fed. Cir. 2005). Section 1292(a)(1) provides that the

court of appeals has jurisdiction over appeals from interlocutory orders “granting,

continuing, modifying, refusing or dissolving injunctions, or refusing to dissolve or

modify injunctions.” 28 U.S.C. § 1292(a)(1) (2000). Section 1292(c)(1) provides this

court exclusive jurisdiction over an appeal of an interlocutory order granting an

injunction if we would otherwise have jurisdiction under § 1295. Id. § 1292(c)(1).

Medtronic appeals from an order permanently enjoining Medtronic from infringing the

’555 patent. On its face, the order falls within the scope of § 1292(a)(1), (c)(1).

Cross Medical argues that under Woodard v. Sage Products, Inc., 818 F.2d 841

(Fed. Cir. 1987) (en banc), this court does not possess jurisdiction because the

injunction is one in form but not substance. Cross Medical asserts that the injunction is

not coercive because it enjoins Medtronic from engaging in activities it had abandoned

before the injunction issued. Cross Medical asserts that Medtronic simply should have

sought a stay of the injunction pending appeal under Federal Rule of Appellate

Procedure 8(a). Alternatively, Cross Medical argues that even if the court has

jurisdiction to review the order, it has no jurisdiction to reverse or vacate the partial

summary judgment rulings because no final judgment on the ’555 patent has been

entered, and the orders were not certified for appeal.

05-1043 7
 Medtronic counters that the order falls under § 1292(a)(1), (c)(1). Medtronic

asserts that Sage Products is inapposite and that no case has denied jurisdiction in an

appeal from the grant of an injunction. Medtronic states that Cross Medical argued

below that the injunction was necessary to prevent irreparable harm, that Medtronic

pulled products from the market to avoid a willfulness finding, that the district court

entered the injunction with full knowledge of Medtronic’s actions, and that it would be

unfair to deny Medtronic its statutory right of appeal.

Cross Medical’s reliance on Sage Products is misplaced. In Sage Products,

plaintiff’s amended complaint included a prayer for injunctive relief, and the issue was

whether plaintiff could lodge an appeal under § 1292(a)(1) from an order granting

defendant’s motion for summary judgment of non-infringement. 818 F.2d at 843-44.

There was no order specifically denying injunctive relief. Id. Instead, plaintiff argued

that the adverse summary judgment ruling had the effect of denying injunctive relief. Id.

at 844. This court sitting en banc considered the impact of the Supreme Court’s then

recent decision in Carson v. American Brands, Inc., 450 U.S. 79 (1981). We explained

that Carson “instructed that an interlocutory appeal under section 1292(a)(1) requires

(a) that the order be injunctive in nature, (b) that it cause a serious, if not irreparable,

consequence, and (c) that the order can be effectively challenged only by immediate

appeal.” Sage Products, 818 F.2d at 849. We held that Woodard failed to establish

that the order met the Carson requirements. Id. at 855.

However, in reporting on how other courts interpreted Carson, we criticized the

Seventh Circuit for applying “the Carson requirements to an order explicitly granting an

injunction,” observing that “the Supreme Court in Carson expressly limited its holding to

05-1043 8
orders that have ‘the practical effect of refusing an injunction.’” Id. at 850 n.6 (quoting

Carson, 450 U.S. at 84). We explained that “as a rule of general applicability to orders

deemed to deny injunctions, the Carson rule is workable and sensibly balances the

statutory provisions of sections 1291 and 1292(a)(1) in light of their respective

purposes.” Id. at 853. The Supreme Court subsequently confirmed our reading of

Carson as applying only to orders that have “the practical effect of granting or denying

injunctions.” Gulfstream Aerospace Corp. v. Mayacamas Corp., 485 U.S. 271, 287-88

(1988) (“Section 1292(a)(1) will, of course, continue to provide appellate jurisdiction

over orders that grant or deny injunctions and orders that have the practical effect of

granting or denying injunctions and have ‘“serious, perhaps irreparable, consequence.”’”

(quoting Carson, 450 U.S. at 84 (quoting Baltimore Contractors, Inc. v. Bodinger, 348

U.S. 176, 181 (1955)))); see also 19 James Wm. Moore et al., Moore’s Federal Practice

¶ 203.10[2][a], at 12 (3d ed. 2005) (“Moore’s”) (“While the statute clearly applies to

orders that formally grant injunctive relief, it also authorizes interlocutory appeals from

orders that have the practical effect of granting an injunction.”). Therefore, “if the district

court’s order expressly grants an injunction, the order is appealable under § 1292(a)(1),

without regard to whether the appellant is able to demonstrate serious or irreparable

consequences.” Moore’s ¶ 203.10[2][a], at 14.

In this case, the district court entered an order expressly enjoining Medtronic

from infringing claim 5 of the ’555 patent. Thus, Carson is inapplicable. See PIN/NIP,

Inc. v. Platte Chem. Co., 304 F.3d 1235, 1242 (Fed. Cir. 2002) (finding jurisdiction

without referring to the Carson test because “[t]he district court’s grant of a permanent

injunction . . . [brought the] appeal squarely within the confines of § 1292(a)(1)”). On

05-1043 9
appeal from the district court’s grant of the injunction, we have jurisdiction under 28

U.S.C. § 1292(a)(1).

Moreover, we may review the underlying partial summary judgment orders

because they are inseparably connected to the merits of the permanent injunction. See

id. at 1242-48 (reviewing a summary judgment ruling that a claim was not anticipated by

the prior art where jurisdiction was based on § 1292(a)(1), (c)(1)); Katz v. Lear Siegler,

Inc., 909 F.2d 1459, 1461 (Fed. Cir. 1990) (reviewing propriety of joinder of counter-

defendant on appeal from injunction); Moore’s ¶ 203.10[7][b], at 45-47 (“[An

interlocutory appeal under § 1292(a)(1)] enable[s] the circuit court to review other orders

that are inseparably or very closely connected with the merits of the injunctive

order . . . .”). The district court presumed irreparable harm based on Cross Medical’s

success on the merits, which manifested itself in the summary judgment orders

concerning claim 5. Because Cross Medical’s success on the merits turns on the

propriety of the summary judgment rulings, our review of the grant of the permanent

injunction requires that we rule on the summary judgment orders. See Mendenhall v.

Barber-Green Co., 26 F.3d 1573, 1581 n.12 (Fed. Cir. 1994) (noting “that an

interlocutory appeal from a permanent injunction, to the extent that it considers

questions of validity and infringement . . . is identical in substance to an appeal brought

under § 1292(c)(2)”). The cases cited by Cross Medical are not germane.

For these reasons, Cross Medical’s motion to dismiss the appeal for lack of

jurisdiction is denied.

05-1043 10
 B. Standard of Review

“We review the grant of a permanent injunction for an abuse of discretion which

requires plenary review of the correctness of . . . rulings on matters of law.” Stratos

Mobile Networks USA, LLC v. United States, 213 F.3d 1375, 1379 (Fed. Cir. 2000)

(internal quotations omitted). We review the grant of a motion for summary judgment de

novo. Id. However, we review the denial of a motion for summary judgment for abuse

of discretion. Gart v. Logitech, Inc., 254 F.3d 1334, 1338 (Fed. Cir. 2001). Summary

judgment should only be granted “if the pleadings, depositions, answers to

interrogatories, and admissions on file, together with the affidavits, if any, show that

there is no genuine issue as to any material fact and that the moving party is entitled to

a judgment as a matter of law.” Fed. R. Civ. P. 56(c). In applying this standard, “[t]he

evidence of the non-movant is to be believed, and all justifiable inferences are to be

drawn in [the non-movant’s] favor.” Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 255

(1986). “The fact that both the parties have moved for summary judgment does not

mean that the court must grant summary judgment to one party or the other. . . . Cross-

motions are no more than a claim by each party that it alone is entitled to summary

judgment, and the court must evaluate each motion on its own merits, taking care in

each instance to view the evidence in favor of the nonmoving party.” Bubble Room, Inc.

v. United States, 159 F.3d 553, 561 (Fed. Cir. 1998) (internal citation omitted); accord

Gart, 254 F.3d at 1338-39.

Claim construction is a question of law reviewed de novo. See Phillips v. AWH

Corp., 415 F.3d 1303, 1328 (Fed. Cir. 2005) (en banc). Determination of infringement is

a factual question. Bai v. L & L Wings, Inc., 160 F.3d 1350, 1353 (Fed. Cir. 1998).

05-1043 11
“Indefiniteness, . . . like claim construction, is a question of law that we review de novo.”

Atmel Corp. v. Info. Storage Devices, 198 F.3d 1374, 1378 (Fed. Cir. 1999).

Anticipation is a question of fact. Advanced Display Sys., Inc. v. Kent State Univ., 212

F.3d 1272, 1281 (Fed. Cir. 2000). “Obviousness is a question of law based on

underlying facts.” Group One Ltd. v. Hallmark Cards, Inc., 407 F.3d 1297, 1303 (Fed.

Cir. 2005).

C. Claim Construction

In the course of its rulings on partial summary judgment for both infringement and

validity, the district court construed the “anchoring means,” “anchor seat means,”

“operatively joined,” “securing means,” and “bear against said channel” limitations of

claim 5. Medtronic challenges each construction.

1. “anchors each comprising anchoring means . . . and anchor seat means”

In the district court, the parties disputed whether either the “anchoring means”

limitation or “anchor seat means” limitation imposed a requirement that the bone screws

be polyaxial. The district court did not construe each limitation separately. Instead, the

district court referred to its prior ruling in Cross Medical Products, Inc. v. DePuy

AcroMed, Inc., No. SA CV 00-876-GLT(ANx), (C.D. Cal. Jan. 9, 2003), and explained

that both the “anchoring means” and “anchor seat means” limitations were in § 112, ¶ 6

form and “must be construed by referring to the specification.” Invalidity Opinion at 3-4.

The district court held that “although the claim language itself does not indicate whether

the screws are polyaxial or monoaxial, the specifications and the drawings establish that

the claims are limited to polyaxial screws.” Id. at 3.

05-1043 12
 Medtronic asserts that although the preferred embodiment describes a polyaxial

screw, there is no basis to read this feature into claim 5 because neither “anchoring

means” nor “anchor seat means” are § 112, ¶ 6 limitations. Medtronic argues that even

if these are § 112, ¶ 6 limitations, a monoaxial screw is an alternative embodiment and,

thus, should be considered corresponding structure, citing Micro Chemical, Inc. v. Great

Plains Chemical Co., 194 F.3d 1250 (Fed. Cir. 1999). Medtronic also relies on the

doctrine of claim differentiation, arguing that the recitation in claim 1 of a polyaxial screw

limitation implies that claim 5 does not possess that limitation. Finally, Medtronic adds

that Cross Medical is estopped from denying that claim 5 covers monoaxial screws

because Cross Medical marked its monoaxial screws with the ’555 patent number.

Cross Medical counters that both “anchoring means” and “anchor seat means”

are § 112, ¶ 6 limitations and their corresponding structure is a polyaxial screw. Cross

Medical argues that claim differentiation must give way to a proper § 112, ¶ 6 analysis

and that the court should not consider “marking estoppel” in construing claim 5 because

marking is extrinsic evidence. Cross Medical adds that claims should be construed to

preserve their validity.

The limitations at issue are contained in the following text of claim 5:

said anchors each compris[e] anchoring means which secure said
anchors to said bone segment and an anchor seat means which has a
lower bone interface operatively joined to said bone segment and an
anchor seat portion spaced apart from said bone interface including a
channel to receive said rod. . . .

05-1043 13
 . . . said seat means including a vertical axis and first threads which
extend in the direction of said vertical axis toward said lower bone
interface to a depth below the diameter of the rod when it is in the rod
receiving channel . . . .

’555 patent, col. 8, ll. 36-43, 46-51 (emphases added).

a. “anchoring means”

The limitation recites the word “means,” which gives rise to the presumption that

§ 112, ¶ 6 applies. See Rodime PLC v. Seagate Tech., Inc., 174 F.3d 1294, 1302 (Fed.

Cir. 1999). The claimed function of the “anchoring means” is to “secure said anchors to

said bone segment.” ’555 patent, col. 8, ll. 38-39. No structure is recited in the claim to

perform this function. See id., ll. 35-56. Thus, § 112, ¶ 6 applies and the “claim shall be

construed to cover the corresponding structure . . . described in the specification and

equivalents thereof.” 35 U.S.C. § 112, ¶ 6 (2000); Al-Site Corp. v. VSI Int’l, Inc., 174

F.3d 1308, 1320 (Fed. Cir. 1999).

The specification discloses only one embodiment. That embodiment contains a

screw which carries a separate anchor such that “when the screw 21 engages the

anchor seat 23, a limited ball-and-socket joint is formed which permits freedom of

movement between the rod support 23 and the screw 21.” ’555 patent, col. 5, ll. 4-47.

The specification unambiguously states that a feature of the “present invention” is that

“[e]ach anchor seat is secured by a cancellous screw which cooperates through a

sloped bore in the anchor seat so as to provide a limited ball and socket motion.” Id.,

col. 1, l. 65–col. 2, l. 21. It continues:

The present invention utilizes a rod and vertebral anchors which
holds [sic] the rod in position. Each anchor is secured to the vertebrae by
a transpedicular screw member.
....

05-1043 14
 . . . [T]he present design utilizes two implant sets on either side of
the spinous processes. Each implant set includes a . . . rod . . . .
Generally, an implant set is used on each side of the spinous
process . . . . The rod is held in position by a stainless steel vertebral
anchor which captures the rods. The anchor has a seat member which is
secured to the vertebrae by a stainless steel transpedicular screw. The
screw is separate from the anchor seat and thus provides for limited
motion between the anchor seat and the vertebrae.

Id., col. 3, ll. 26-67 (emphasis added). The patent discloses no other structure for

securing the anchor to the bone. The patent states that the polyaxial design “acts as a

‘shock-absorber’ to prevent direct transfer of load from the rod to the bone-screw

interface prior to achieving bony fusion, thereby decreasing the chance of failure.” Id.,

ll. 63-67. Thus, the district court was correct both in linking the recited function to the

structure disclosed in the specification and in concluding that the corresponding

structure was polyaxial. Medtronic argues that even if the limitation is a means-plus-

function limitation linked to the disclosed polyaxial structure, the claim nonetheless

should be construed to include alternative structures like monoaxial screws. However,

because there is only one embodiment described in the specification to secure the

anchor to the bone—a polyaxial screw and anchor structure—there is no basis on which

to extend the limitation to cover alternative, non-disclosed structure not shown to be

structurally equivalent. See 35 U.S.C. § 112, ¶ 6; Al-Site, 174 F.3d at 1320.

We reject the parties’ remaining arguments. First, although the doctrine of claim

differentiation suggests that claim 5 should be broader than claim 1, any presumption

that the claims differ with respect to this feature may be overcome by a contrary

construction mandated by the application of § 112, ¶ 6. See Laitram Corp. v. Rexnord,

Inc., 939 F.2d 1533, 1538 (Fed. Cir. 1991) (holding that the doctrine of claim

differentiation yields to an interpretation mandated by § 112, ¶ 6). Second, Medtronic’s

05-1043 15
assertion that “marking estoppel” applies is incorrect. Even if Cross Medical marked

monoaxial screws with the ’555 patent number, such evidence conflicts with the intrinsic

record and has no bearing on our construction. See Phillips, 415 F.3d at 1318 (“[A]

court should discount [extrinsic evidence] that is clearly at odds with the claim

construction mandated by the claims themselves, the written description, and the

prosecution history, in other words, with the written record of the patent.” (internal

quotation omitted)); cf. SmithKline Diagnostics v. Helena Labs. Corp., 859 F.2d 878,

890-91 (Fed. Cir. 1988) (holding that an accused infringer’s mis-marking of a product

could not convert by estoppel an admittedly non-infringing product into an infringing

product). Finally, Cross Medical’s argument that we should consider the validity of

claim 5 in construing the limitation misses the mark. Because the other claim

construction tools unambiguously resolve the claim construction dispute, considering

validity would be improper. Phillips, 415 F.3d at 1327 (“[W]e have limited the maxim [of

construing a claim to preserve its validity] to cases in which ‘the court concludes, after

applying all the available tools of claim construction, that the claim is still ambiguous.’”).

b. “anchor seat means”

While the limitation recites the word “means,” thus giving rise to the presumption

that § 112, ¶ 6 applies, see Rodime, 174 F.3d at 1302, the claim language is sufficiently

structural as to take the limitation out of the ambit of § 112, ¶ 6. Thus, the district court

erred in treating “anchor seat means” as a means-plus-function limitation; however, that

error is harmless with respect to the conclusion that the claim covers polyaxial

structures, based on the district court’s correct construction of the “anchoring means”

limitation, discussed supra.

05-1043 16
 2. “operatively joined”

The district court construed “lower bone interface operatively joined to said bone

segment” to mean “connect[ed] during a surgical procedure.” Infringement Opinion at 5.

The district court interpreted “connect” to mean “in contact.” See id. & n.2. The district

court reasoned that because the claim involves a surgical procedure, “operatively”

means “involving surgical operations.” Id. The district court explained that construing

“operatively” to mean “to produce an appropriate effect” would improperly import a

limitation from the specification. Id. at 4-5.

Medtronic argues that the “bone interface” language surrounding the phrase

“operatively joined” requires that there be contact between the bone segment and the

anchor seat. Medtronic asserts that “operatively” means to produce an effect and that

effect is micro-motion, which Medtronic describes as “limited motion” between the

anchor and the bone. Medtronic argues that it would be inconsistent to construe claim 5

to require a polyaxial screw which enables polyaxial movement, but not to require a

micro-motion effect. Medtronic adds that the district court’s construction renders

“operatively” superfluous because the only way to attach the screw to bone is via

surgery.

Cross Medical counters that the “bone interface” is the portion of the anchor seat

that comes into contact with the bone when there is contact, but that “bone interface”

does not require contact. Cross Medical argues that the district court correctly

construed “operatively” to mean “surgically.” Cross Medical asserts that even if we

construe “operatively” to mean “effectively,” the effect is posterior stabilization, not

05-1043 17
micro-motion. Cross Medical adds that “polyaxial” and “micro-motion” are not

synonymous.

The claim recites an “anchor seat means which has a lower bone interface

operatively joined to said bone segment.” ’555 patent, col. 8, ll. 39-42. The claim does

not state explicitly whether the “bone interface” and the “bone segment” must be in

contact. However, we may refer to the dictionary to begin understanding the ordinary

meaning of these claim terms, “so long as the dictionary definition does not contradict

any definition found in or ascertained by a reading of the patent documents.” Phillips,

415 F.3d at 1322-23 (internal quotations omitted). “[B]one” modifies “interface,”

indicating that the anchor seat has a “lower” portion that may share a “common

boundary” with “bone.” See Webster’s Third New Int’l Dictionary 1178 (2002) (defining

“interface”). The term “joined” describes the relationship between the “bone interface”

and the “bone segment.” Use of the word “joined” indicates that the “interface” and the

“bone” must be brought together or connected to form a single unit, a whole, or a

continuity, and thus that the interface and the bone are in contact. See id. at 1218

(defining “join”).

The written description confirms that the interface must contact the bone. The

screw is separate from the anchor seat, which prevents the direct transfer of load from

the rod to the “bone-screw interface,” and decreases the chance of failure of the “bone-

screw interface.” Id., col. 3, ll. 19-22, ll. 64-67. This use of the term “interface” is

consistent with its meaning a “common boundary” between two parts. Moreover, the

patent refers to the “anchor” as being held, ’555 patent, Abstract, or “secured” to the

bone, id., col. 3, ll. 59-60, and to the point of attachment as a “fusion bed,” id., col. 7,

05-1043 18
l. 15. These references suggest contact between the anchor seat and the bone.

Furthermore, to adjust the height of the anchor posterior to the bone, the patent teaches

the addition of washers that are the same diameter as the anchor seat. Id., col. 5, ll. 50-

57. The washers co-act with the anchor seat to function as the bone interface while

elevating the seat. If contact with bone were not contemplated, then there would be

little need to add washers to elevate the seat. The drawings show contact between the

anchor and bone, which is consistent with the description. Id., Figures 3, 14, 17-20.

Because the ordinary meaning of “interface” and “joined,” as reflected in dictionary

definitions and in the overall context of the intrinsic record, leads to the conclusion that a

person of ordinary skill in the art would have understood these terms to require “contact”

between the interface and the bone, the district court’s construction in this regard was

correct. It would be improper to construe “joined” more broadly to mean “connected”

without requiring contact.

As to “operatively,” the term is often used descriptively in patent drafting to mean

“effectively” in describing the functional relationship between claimed components.

See, e.g., Innova/Pure Water, Inc. v. Safari Water Filtration Sys., Inc., 381 F.3d 1111,

1118 (Fed. Cir. 2004) (“[Operatively connected] is a general descriptive term frequently

used in patent drafting to reflect a functional relationship between claimed

components.”). Here, the preamble of the claim recites that the invention is operative

when it effects posterior stabilization of one or more bone segments of the spine. ’555

patent, col. 8, ll. 33-34; see Innova, 381 F.3d at 1118 (declining to decide whether

preamble was an affirmative limitation, but recognizing that preamble recited the

intended use corresponding to “operatively”). The body of the claim is consistent as it

05-1043 19
calls for anchors and a stabilizer rod, and provides detail on how these structures

interrelate to stabilize the bone segment. See ’555 patent, col. 8, ll. 35-57; Innova, 381

F.3d at 1118-19 (looking to the body of the claim to understand the purpose). Although

the written description does not define “operatively,” it consistently describes the

purpose of the device to be for posterior stabilization. See ’555 patent, col. 1, ll. 9-12

(“This invention relates generally to an apparatus for immobilization of the spine, and

more particularly, to an apparatus for posterior internal fixation of the spine . . . .”);

Innova, 381 F.3d at 1118-19 (looking to the written description to understand the

purpose). It discusses disadvantages of prior art spinal fixation methods and

apparatuses, ’555 patent, col. 1, ll. 13-64; col. 2, l. 36–col. 3, l. 25, details how the

invention’s features provide an advantageous fixation system, id., col. 3, l. 26–col. 6, l.

44, and provides a method of spinal fixation therapy for use with the device, id., col. 6, l.

45–col. 7, l. 50. Therefore, from the context of the written description, it is clear that one

of ordinary skill in the art would have understood “operatively” to mean effective to

produce posterior stabilization. The district court erred in construing “operatively” to

mean “surgically.” Because the only way a “fixation device” can provide “posterior

stabilization” is through a surgical procedure, construing “operatively” to mean

“surgically” renders the word superfluous, as used in the claim.

For all of these reasons, we modify the district court’s claim construction and

conclude that, in claim 5, the “lower bone interface [is] operatively joined to said bone

segment” when the interface and the bone segment are connected and in contact such

that the device is effective to perform posterior stabilization.

05-1043 20
 3. “securing means”

The district court considered the “securing means” limitation to be in § 112, ¶ 6

form, and described its function as “appl[ying] a force to the rod, which compresses the

rod against the anchor seats and secures the rod in place.” Infringement Opinion at 6.

The district court explained that compression must be applied on “either side”—either

inside or outside—of the rod-receiving channel. Id. at 7. The district court identified the

corresponding structure as an “outer nut.” Id. at 6.

Medtronic argues that the district court’s interpretation of the function of the

“securing means” somehow ignores the claim language: “through the application of

substantially equal compressive forces . . . applied on either side along said longitudinal

axis of said channel.” ’555 patent, col. 8, ll. 54-57 (emphasis added). Medtronic asserts

that this language mandates that forces be applied along the longitudinal axis of the rod

on “either side” of the channel and not on “either side” of the vertical axis. Medtronic

interprets “either side” of the channel to be on the “outside” of the channel. Although

Medtronic does not dispute that the corresponding structure is an external nut,

Medtronic argues that the written description and prosecution history show a disavowal

of equivalents to an external nut.

Cross Medical responds that the district court did not ignore the “either side”

limitation, and that, in any event, “either side” can mean that the forces are applied

“inside” the channel. Cross Medical provides the illustration that standing on “either

side” of the room would connote standing inside the room. Cross Medical adds that the

specification and prosecution history do not evince a disavowal, and that claim

differentiation doctrine supports structural equivalents.

05-1043 21
 The claim requires:

at least two anchors and an elongated stabilizer comprising a rod having a
diameter and a longitudinal axis . . . .

securing means which cooperate with each of said anchor seat
portions . . . said securing means including second threads which
cooperate with the first threads of the seat means to cause said rod to
bear against said channel through the application of substantially equal
compressive forces by said securing means in the direction of the vertical
axis and applied on either side along said longitudinal axis of said channel.

’555 patent, col. 8, ll. 36-37, 44-57.

We agree with the parties that the limitation is in § 112, ¶ 6 format. See Rodime,

174 F.3d at 1302 (noting that a concession by the parties that the claim is in § 112, ¶ 6

form does not relieve the court of its duty to examine whether § 112, ¶ 6 applies). The

claim recites “securing means,” which gives rise to the presumption that § 112, ¶ 6

applies. See id. The function is “to cause said rod to bear against said channel through

the application of substantially equal compressive forces by said securing means in the

direction of the vertical axis and applied on either side along said longitudinal axis of

said channel.” ’555 patent, col. 8, ll. 53-57.

“[E]ither side” does not refer to “either side” of the rod on the vertical axis of the

channel perpendicular to the rod, because that interpretation would render the “in the

direction of the vertical axis” language redundant. The “and” in the phrase “in the

direction of the vertical axis and applied on either side” makes that clear. Therefore, the

function is to cause the rod to bear against the rod-receiving channel by applying a

compressive force in the direction of the vertical axis while ensuring that substantially

equal forces are applied along the longitudinal axis of the rod on opposite sides—either

inside or outside—of the rod-receiving channel.

05-1043 22
 We must now determine whether the claim recites structure to carry out that

function. The claim states that the “securing means . . . cooperate with each of said

anchor seat portions,” id., ll. 44-45, in that the “securing means include[s] second

threads which cooperate with the first threads of the seat means to cause [the desired

function],” id., ll. 51-57. Although it is the operation of the threads that causes the rod to

bear against the channel by applying a compressive force in the direction of the vertical

axis, a naked incantation of threads alone does not ensure that substantially equal

forces are applied along the longitudinal axis of the rod on opposite sides of the rod-

receiving channel. Because there is insufficient structure recited for performing the

specified function, § 112, ¶ 6 applies. Thus, we construe the claim “to cover the

corresponding structure . . . described in the specification and equivalents thereof.”

The structure for performing the recited function is described as follows:

The nut 27 includes internal threads 83 which engage the external
threaded area 76 on the anchor seat. The nut 27 is a hex nut which can
be tightened relative to the seat 25.
As the nut 27 is rotated about the anchor seat 25, it cooperates with
the top side of the flange 46,47 to tighten the clamp 25 in relation to the
rod support 23. The rod 18 is grasped in the tunnel 84 formed between
the rod-receiving channel 54 of the anchor seat 23 and the arch 72 of the
cap 25.
The threads 76 on the anchor seat 23 extend downwardly on the
seat below the top of the cylindrical surface of the rod 18 as is shown in
FIG. 2 and the nut 27 has a relatively constant diameter through the bore
as is shown in FIGS. 2 and 4. Accordingly, the nut 27 can be screwed
directly onto the anchor seat 23 to compressively hold the rod without the
cap 25.

‘555 patent, col. 6, ll. 9-24. Figures 5 and 7 depict the rod 18 in the channel created by

the anchor seat 23, with the nut 27 securing the rod in place. Thus, the structure that

corresponds to the claimed function is a nut with internal threads cooperating with the

05-1043 23
external threads of the anchor seat (an “external nut”). The claim covers that structure

and equivalents thereof.

We are not persuaded by Medtronic’s argument that the written description

shows a disavowal of equivalents. Although we need not decide that there can never

be a disavowal of § 112, ¶ 6 equivalents, “§ 112-6 was written precisely to avoid a

holding that a means-plus-function limitation must be read as covering only the means

disclosed in the specification.” D.M.I., Inc. v. Deere & Co., 755 F.2d 1570, 1574 (Fed.

Cir. 1985). In this case, the inventors were merely describing the structure that

performs the claimed function.

Nor are we persuaded that the prosecution history shows a disavowal. In an

August 4, 1994 Office Action (“Office Action”), the Examiner rejected the apparatus

claims, in part, under § 112, ¶ 1, because “[t]he specification fail[ed] to provide an

enabling description of the embodiment of the action device excluding the cap/cap

means,” and because “language directed toward the ‘securing means’ cooperating with

the seat means through application of compressive forces by the securing means” failed

to have support in the specification. Office Action at 4. Subsequent to that rejection, an

interview was held with the Examiner and the Examiner Interview Summary referred to

“securing means” as “i.e., the nut.” In addition, Remarks in the April 27, 1995

Amendment (“Amendment”) stated that Applicant amended the claims “to define the

anchor seat means having a channel and threads which cooperate with the securing

means (i.e., the nut) so as to capture the stabilizer between the channel and the

securing means.” Amendment at 4. However, Applicant did not add language in claim

5 that limited securing means to a nut. The statements referring to “securing means” as

05-1043 24
“i.e., the nut” simply help to provide the requisite linkage between the function recited in

the claim and the “corresponding” structure. See Default Proof Credit Card Sys., Inc. v.

Home Depot U.S.A., Inc., 412 F.3d 1291, 1298 (Fed. Cir. 2005) (“A structure disclosed

in the specification qualifies as “corresponding” structure only if the specification or

prosecution history clearly links or associates that structure to the function recited in the

claim.”). Applicant did not disclaim all structural equivalents.

Therefore, the district court correctly construed the “securing means” limitation to

refer to the external nut described in the written description. Under § 112, ¶ 6, the claim

also covers equivalents thereof.

4. “bear against said channel”

The parties dispute whether the language of claim 5 reciting that the

“rod . . . bear[s] against said channel” precludes the presence of any intervening

structure between the rod and the channel. The district court held that “[t]here is

nothing in the [language of claim 5] which excludes an anchor channel composed of

more than one component part.” Infringement Opinion at 8. Medtronic argues that the

district court’s construction is erroneous, and that by placing a separable crown member

over the anchor seat, Medtronic has prevented the rod from “bear[ing] against [the]

channel” as a matter of law. Medtronic asserts that the anchor seat must form the

channel and the crown is not part of the anchor seat. Cross Medical responds that

claim 5 does not require that the channel of the anchor seat be a unitary component

and thus does not preclude a finding that the crown is part of the anchor seat.

The dispute reduces to whether the “channel” must be formed in a unitary

structure. The claim requires that the anchor seat means have “an anchor seat portion

05-1043 25
spaced apart from said bone interface including a channel to receive said rod,” ’555

patent, col. 8, ll. 41-42, and that the “securing means . . . cause[s] said rod to bear

against said channel,” id., ll. 51-54. The claim does not state that the anchor seat

portion forming the channel is unitary. Although the sole embodiment described in the

specification depicts a unitary structure, id., col. 5, ll. 20-21, the mere depiction of a

structural claim feature as unitary in an embodiment, without more, does not mandate

that the structural limitation be unitary. See CCS Fitness, Inc. v. Brunswick Corp., 288

F.3d 1359, 1367 (Fed. Cir. 2002) (holding that “member” encompassed a multi-

component structure where the preferred embodiment showed a single-component

structure, but the specification did not otherwise require a certain number of

components). There is nothing in the written description or prosecution history that

limits the channel to being formed in a single-component structure. Thus, the district

court correctly concluded that the “bear against said channel” language of claim 5 does

not exclude an “anchor seat portion” composed of multiple components.

D. Infringement

The district court ruled as a matter of law that the accused devices met the

“operatively joined,” “securing means,” and “bear against said channel” limitations, that

Medtronic was a direct infringer, and that alternatively, Medtronic either contributed to

infringement or induced infringement. Infringement Opinion at 4-9. Medtronic appeals.

05-1043 26
 1. “operatively joined”

The district court held that the accused devices met the “operatively joined”

limitation as a matter of law because “‘the accused device, to be infringing, need only be

capable of operating in the [infringing] mode . . . actual [infringing] operation in the

accused device is not required.’” Id. at 5-6 (quoting Intel Corp. v. U.S. Int’l Trade

Comm’n, 946 F.2d 821, 832 (Fed. Cir. 1991)). The district court cited Hilgraeve Corp. v.

Symantec Corp., 265 F.3d 1336, 1343 (Fed. Cir. 2001), for the proposition that “an

accused device may be found to infringe if it is reasonably capable of satisfying the

claim limitations, even though it may also be capable of non-infringing modes of

operation.” Infringement Opinion at 5. The court explained that Medtronic’s devices

“are capable of operative joinder to the bone segment, and are sometimes used in this

way.” Id. at 5-6. In response to Medtronic’s argument that it could not directly infringe

because it did not perform surgery, the district court held that “under 35 U.S.C. § 271

Defendants can be liable for inducing the infringement or for selling a device which

constitutes part of the invention.” Id. at 8.

Medtronic argues that it does not itself make an anchor seat which contacts bone

and it does not perform surgery. Medtronic asserts that Intel and Hilgraeve are

inapposite and that it cannot be a direct infringer simply because its accused devices

are capable of being made into infringing devices by surgeons. Medtronic adds that it

does not induce or contribute to infringement because there is no evidence of

physicians bringing the receiver member into contact with the bone segment to make

the claimed apparatus; because Medtronic does not design the receiver member to

05-1043 27
contact the bone segment; and because Medtronic instructs surgeons not to place the

device into contact with the bone.

Cross Medical counters that to directly infringe, Medtronic need only make

devices that are capable of being converted into infringing devices, citing Intel,

Hilgraeve, and Bell Com. Research Inc. v. Vitalink Com. Corp., 55 F.3d 615 (Fed. Cir.

1995). Cross Medical asserts that Medtronic’s argument that it does not directly infringe

because it does not perform surgery is as superficial as the non-infringement argument

concerning the “Commissioner.com” product in Fantasy Sports Props., Inc. v.

SportsLine.com, Inc., 287 F.3d 1108 (Fed. Cir. 2002), and therefore must fail.

Furthermore, Cross Medical argues that Medtronic’s representatives are present in the

operating room and thus that Medtronic performs surgery. Alternatively, Cross Medical

argues that Medtronic induces infringement because it sells devices to surgeons,

designs its anchors to function when in contact with bone, and intends that surgeons

bring the anchor seat into contact with bone; and because surgeons actually bring the

anchor seat into contact with bone. Cross Medical asserts that Medtronic is a

contributory infringer because it has not proven that there are substantial non-infringing

uses.

“[W]hoever without authorization makes, uses, offers to sell, or sells any patented

invention, within the United States or imports into the United States any patented

invention during the term of the patent therefor [directly] infringes the patent.” 35 U.S.C.

§ 271(a) (2000). To prove direct infringement, the plaintiff must establish by a

preponderance of the evidence that one or more claims of the patent read on the

accused device literally or under the doctrine of equivalents. Advanced Cardiovascular

05-1043 28
Sys., Inc. v. SciMed Life Sys., Inc., 261 F.3d 1329, 1336 (Fed. Cir. 2001). “Literal

infringement requires that each and every limitation set forth in a claim appear in an

accused product.” Franks Casing Crew & Rental Tools, Inc. v. Weatherford Int’l, Inc.,

389 F.3d 1370, 1378 (Fed. Cir. 2004) (internal citation omitted). Claim 5 of the ’555

patent is an apparatus claim. See ’555 patent, col. 8, ll. 34-57. We held in Part II.C.2

supra that the “operatively joined” limitation requires that “the interface and the bone

segment are connected and in contact such that the device is effective to perform

posterior stabilization.”

In support of its argument that Medtronic directly infringes, Cross Medical cites

evidence that Medtronic’s representatives appear in the operating room, identify

instruments used by surgeons, and thus in effect “join” the anchor seat to the bone.

Cross Medical argues that the situation is analogous to those in which courts have

found a party to directly infringe a method claim when a step of the claim is performed

at the direction of, but not by, that party. See, e.g., Shields v. Halliburton Co., 493 F.

Supp. 1376, 1389 (W.D. La. 1980). However, if anyone makes the claimed apparatus,

it is the surgeons, who are, as far as we can tell, not agents of Medtronic. Because

Medtronic does not itself make an apparatus with the “interface” portion in contact with

bone, Medtronic does not directly infringe.

Nor does Intel support a finding of direct infringement. The claim at issue in Intel

called for a “programmable selection means” and thus required only that an accused

device be capable of operating in the enumerated mode. 946 F.2d at 832; see Fantasy

Sports, 287 F.3d at 1117-18; High Tech Med. Instrumentation Inc. v. New Image Indus.,

Inc., 49 F.3d 1551, 1555-56 (Fed. Cir. 1995). Here, the claim does not require that the

05-1043 29
interface be merely “capable” of contacting bone; the claim has a structural limitation

that the anchor seat be in contact with bone. See Fantasy Sports, 287 F.3d at 1117-18

(stressing the “programmable” language of the claim at issue in Intel and holding that

Intel “does not stand for the proposition . . . that infringement may be based upon a

finding that an accused product is merely capable of being modified in a manner that

infringes the claims of a patent”); High Tech, 49 F.3d at 1555-56 (distinguishing Intel

based on the permissive language of the claim at issue). Cross Medical would

distinguish High Tech by asserting that the device in that case had to be physically

altered to become infringing, while Medtronic’s device need not be altered. However,

Cross Medical again fails to recognize that the limitation—the anchor seat being in

contact with bone—is absent until the screw and anchor are put in place during surgery.

Bell Communications and Hilgraeve are also inapposite. In Bell

Communications, plaintiff asserted that defendant’s product embodied a claimed

method, but the district court granted summary judgment of non-infringement reasoning

that the product had non-infringing modes of operation. 55 F.3d at 618-19. In

Hilgraeve, plaintiff asserted that defendant sold software that, when in operation,

infringed plaintiff’s method claim, but the district court granted summary judgment of

non-infringement based on rationale similar to that in Bell Communications. See

Hilgraeve, 265 F.3d at 1339-40. In both cases on appeal, this court held that the district

court had erred by overlooking the rule that “an accused product that sometimes, but

not always, embodies a claimed method nonetheless infringes.” Bell, 55 F.3d at 622-

23; accord Hilgraeve, 265 F.3d at 1343 (“[S]o too the sale of a device may induce

infringement of a method claim even if the accused device is capable of non-infringing

05-1043 30
modes of operation in unusual circumstances.”). However, a rule that governs

infringement of a method claim may not always govern infringement of an apparatus

claim. See, e.g., NTP, Inc. v. Research in Motion, Ltd., 418 F.3d 1282, 1317-18 (Fed.

Cir. 2005) (distinguishing between method claims and apparatus claims for the purpose

of determining infringement under section 271(a)). To infringe an apparatus claim, the

device must meet all of the structural limitations. See Hewlett-Packard Co. v. Bausch &

Lomb, Inc., 909 F.2d 1464, 1468 (Fed. Cir. 1990) (“[A]pparatus claims cover what a

device is, not what a device does.”); In re Michlin, 256 F.2d 317, 320 (C.C.P.A. 1958)

(“It is well settled that patentability of apparatus claims must depend upon structural

limitations and not upon statements of function.”). In this case, claim 5 is an apparatus

claim which contains the structural limitation that the anchor seat contact bone. Cross

Medical has not proven that Medtronic makes an apparatus with an anchor seat in

contact with bone.

Cross Medical’s reliance on Fantasy Sports is also misplaced. In Fantasy

Sports, the apparatus claim called for “[a] computer for playing football.” 287 F.3d at

1111. The district court found that the accused “Commissioner.com” product did not

infringe because it was a “modifiable software tool,” not a computer for playing football.

See id. at 1118. We disagreed, holding that Sportsline directly infringed by making or

using the apparatus because no reasonable juror could find that the

“Commissioner.com” product was not software installed on a computer. See id. at

1118-19. Cross Medical argues that the theory that Medtronic does not directly infringe

because it does not itself contact the anchor seat to the bone is as superficial as

Sportsline’s theory that its product was software but not a computer. However, unlike in

05-1043 31
Fantasy Sports, in this case, no reasonable juror could find that the accused infringer

itself makes or uses the entire claimed apparatus. The anchor seat of the device does

not contact bone until the surgeon implants it.

Because Medtronic is not a direct infringer, we next consider whether Medtronic

induces or contributes to infringement. Under § 271(b), “[w]hoever actively induces

infringement of a patent shall be liable as an infringer.” 35 U.S.C. § 271(b). “‘In order to

succeed on a claim of inducement, the patentee must show, first that there has been

direct infringement,’ and ‘second, that the alleged infringer knowingly induced

infringement and possessed specific intent to encourage another’s infringement.’”

MEMC Elec. Materials, Inc. v. Mitsubishi Materials Silicon Corp., 420 F.3d 1369, 1378

(Fed Cir. 2005) (quoting Minn. Mining & Mfg. Co. v. Chemque, Inc., 303 F.3d 1294,

1304-05 (Fed. Cir. 2002)). Under § 271(c), “[w]hoever offers to sell or sells within the

United States . . . a component of a patented machine, manufacture, combination or

composition . . . constituting a material part of the invention, knowing the same to be

especially made or especially adapted for use in an infringement of such patent, and not

a staple article or commodity of commerce suitable for substantial noninfringing use,

shall be liable as a contributory infringer.” 35 U.S.C. § 271(b). In order to succeed on a

claim of contributory infringement, in addition to proving an act of direct infringement,

plaintiff must show that defendant “knew that the combination for which its components

were especially made was both patented and infringing” and that defendant’s

components have “no substantial non-infringing uses.” Golden Blount, Inc. v. Robert H.

Peterson Co., 365 F.3d 1054, 1061 (Fed. Cir. 2004) (internal quotations omitted).

05-1043 32
 As to the predicate act of direct infringement, we conclude that there is a genuine

issue of material fact as to whether surgeons infringe by making the claimed apparatus.

The only evidence that Cross Medical cites suggesting that the anchor seat contacts

bone is the statement of Medtronic’s employee, Michael Sherman, during his January

29, 2004 deposition:

Q. How far down do you screw the screw initially?
A. Well, it depends. Because if you screw these screws all the way
down, they stop rotating. And the rotating around the ball is a feature of
the screw. So you lose some of your ability to rotate, or your freedom.
Because the reason these screws have multiple angles is to make
it easier to assemble the system in the patient. So if you screw these
things down super-tight, you may have – you know, you’ve eliminated the
multiaxial capability of the screw.
So the surgeon in his judgment gets it down, and I like to tell them,
as far as they feel comfortable doing and still have some rotation.
Because the further in the instrumentation is into the patient, the lower –
the closer the instrumentation is to the loads, and thus the lower the
bending moments are on the instrumentation and the less likelihood of
metal failure.
Q. In practice, in some instances the screw is screwed down such that
the receiver touches the bone; is that right?
A. I’m sure some surgeons do that. And it can touch the bone and still
move a little because the bone is elastic. And the tissue right on top of the
bone isn’t necessarily bone. It’s periosteum. It’s deformable.

Medtronic counters with an April 22, 2004, declaration from Kevin Foley, M.D., a board

certified neurosurgeon, who has performed over 500 operations using Medtronic’s

allegedly infringing products. Dr. Foley states, in pertinent part, that:

[i]n all of the surgeries I perform using Medtronic Products, I try to
minimize or avoid contact of any part of the receiver member to the
patient’s spinal anatomy to ease the eventual implantation of the rod. I do
not count on any type of direct connection between the receiver member
and the patient’s spine to impart any stability to the spine or to the implant
construct. . . .
When implanting the Medtronic Products in a patient’s spine, any
contact between the receiver member and any portion of the patient’s
anatomy is incidental to the surgery and not intended to impart any
stability to the spine. In fact, when I instruct other spine surgeons in how

05-1043 33
 to implant the Medtronic Products, I tell them that if they tighten down on
the bone screw enough to bring the receiver member into engagement
with the spine, they should back off the bone screw by one-quarter to one-
half turn so as to better enable alignment of the receiver members with the
rod.

Thus, Sherman—who is not testifying that he witnessed contact—speculates that

some surgeons may bring the receiver member into contact with bone. Dr. Foley

confirms that from time to time, “incidental to the surgery,” the receiver member comes

into contact with bone. However, Dr. Foley also suggests that he “tr[ies] to minimize or

avoid contact” and instructs others to “back off the bone screw by one quarter to one-

half turn” “if they tighten down on the bone screw enough to bring the receiver member

into engagement with the spine.”

On the one hand, drawing inferences in favor of Medtronic, a reasonable juror

could conclude that the apparatus is not made because, more likely than not, there is no

contact between the receiver member and the bone. On the other hand, drawing

inferences in favor of Cross Medical, a reasonable juror could conclude that the

apparatus is made by surgeons. Sherman’s statements suggest that the device is

capable of posterior stabilization when the receiver member contacts bone, and the

statements of both Sherman and Dr. Foley suggest that there may be some contact

between the receiver member and the spine. We leave it to the fact finder to decide

whether surgeons directly infringe.

As to inducement, there is a genuine issue of material fact both as to whether

Medtronic “knowingly induced infringement” and as to whether Medtronic “possessed

specific intent to encourage [the surgeons’] infringement.” On the one hand, in the

record are Medtronic’s “Field Bulletins” instructing surgeons that the proper technique

05-1043 34
for installation of the Medtronic device is with the receiver member not in contact with

the bone. Medtronic asserts that these materials, together with Dr. Foley’s statement,

show that it had no knowledge that the surgeons made the claimed apparatus and that

it had no specific intent to encourage infringement. On the other hand, Cross Medical

points to Sherman’s statements—that he would instruct surgeons to screw the receiver

member down “as far as they feel comfortable doing and still have some rotation” and

that “[the receiver member] can touch the bone and still move a little because the bone

is elastic”—as evidence that Medtronic anticipated that surgeons would contact bone

and intended that the device function when in contact with bone. Drawing inferences in

favor of Medtronic, a reasonable juror could find that Medtronic did not know that

surgeons make the claimed apparatus and, moreover, did not specifically intend for

surgeons to contact bone with the anchor seat. Drawing inferences in favor of Cross

Medical, a reasonable juror could find that Medtronic designed its device to function

when the anchor seat contacted bone, anticipated that surgeons would contact the

anchor seat to bone, and thus intended for the surgeon to make or use the apparatus as

claimed.

As to contributory infringement, there is a genuine issue of material fact as to

whether there are substantial non-infringing uses of Medtronic’s devices, specifically,

uses of the devices with no receiver member-to-bone contact. Drawing inferences in

favor of Medtronic, a reasonable juror could conclude, based on Dr. Foley’s statements,

that a substantial number of surgeries occur in which the claimed apparatus is not made

or used, as surgeons are able to avoid contact between the seat and bone. Drawing

inferences in favor of Cross Medical, a reasonable juror might also conclude that in

05-1043 35
almost every surgery, the claimed apparatus is made or used, as some contact between

the receiver member and the bone is incidental.

Therefore, the district court erred in ruling both that there were no genuine issues

of material fact as to infringement and that Medtronic infringed as a matter of law.

2. “securing means”

The district court ruled that Medtronic’s “set screw” is equivalent to the external

nut as a matter of law because it performs compression in “substantially the same way”

to achieve “substantially the same result” as the “external nut.” Infringement Opinion at

6. The district court cited testimony that the set screw has opposite points of contact on

the rod 180 degrees apart, noted that the screw is intended to be coaxial with the

anchor means, and explained that “[a]lthough Plaintiff does not provide tests showing

the magnitude of the force on either side, everything before the Court supports the

conclusion the forces are substantially equal.” Id. at 7. The district court added that

“[d]efendants submit[ed] no evidence to show the forces are not equal.” Id. The district

court reasoned: “[v]iewing the devices themselves and the testimony, it appears

Defendants’ inner screw meets the limitation applying substantially equal compressive

forces on either side of the channel.” Id.

Medtronic argues that a set screw is not equivalent to an external nut as a matter

of law, citing Chiuminatta Concrete Concepts Inc. v. Cardinal Industries, Inc., 145 F.3d

1303 (Fed. Cir. 1998). Medtronic notes that the ’555 patent’s express reference to the

use of a set screw to attach a cross-link to the rod, but lack of a reference to a set screw

to lock the rod to the anchor seat, is compelling evidence of non-equivalents. In

addition, Medtronic asserts that set screws and external nuts are not interchangeable

05-1043 36
because set screws apply a “splaying” force to the side walls of the anchor seat while

external nuts do not; an external nut applies compressive forces to the rod in a way that

bows or bends the rod upwardly in the anchor seat channel while the set screw

minimizes this type of load on the rod; and bowing creates a problem in Medtronic’s

devices. Medtronic adds that Dr. Puno, an inventor of the ’555 patent, testified that a

set screw and an external nut were not interchangeable. Medtronic portrays as

unsupported the views of Dr. Villarraga, Cross Medical’s expert, who opined that the set

screw and external nut are interchangeable. Medtronic argues that Cross Medical has

offered no evidence that the set screw applies “substantially equal compressive forces”

to the rod; and asserts that Michael Sherman offered convincing testimony that they do

not. Medtronic asserts that at the least, there is a genuine issue of material fact as to

whether the set screw is an equivalent.

Cross Medical argues that a set screw and external nut perform the function of

compression in substantially the same way—applying a downward force on a rod

achieved by engaging threads of the receiver—to achieve the identical result—securing

the rod in the channel; and that Chiuminatta is distinguishable. Cross Medical cites

evidence that the set screw applies force to opposite sides of the channel. Cross

Medical asserts that, because the compression being applied from the set screw to the

rod would be through absolutely equal forces applied on either side of the channel

absent machining imperfections and patient physiology, if one were to account for these

factors, the forces would be substantially equal. Cross Medical argues that “splaying”

and “bowing” do not affect equivalents and that Dr. Villarraga’s opinion on

interchangeability is properly based on her knowledge of mechanical engineering and

05-1043 37
her examination of the devices. Cross Medical asserts that Dr. Puno’s testimony on

interchangeability is irrelevant. Cross Medical argues that Medtronic admitted in U.S.

Patent No. 6,660,004 (“the ’004 patent”) that the set screw and external nut were

interchangeable. Cross Medical additionally asserts that because Medtronic argued

that a set screw and external nut are equivalent to invalidate claims of another patent,

Medtronic is estopped from asserting that they are not equivalent.

“‘Literal infringement of a § 112, ¶ 6 limitation requires that the relevant structure

in the accused device perform the identical function recited in the claim and be identical

or equivalent to the corresponding structure in the specification.’” Frank’s Casing, 389

F.3d at 1378 (quoting Odetics, Inc. v. Storage Tech. Corp., 185 F.3d 1259, 1267 (Fed.

Cir. 1999)). “Because structural equivalents under § 112, ¶ 6 are included within literal

infringement of means-plus-function claims, ‘the court must compare the accused

structure with the disclosed structure, and must find equivalent structure as well as

identity of claimed function for the structure.’” Id. (quoting Pennwalt Corp. v. Durand-

Wayland, Inc., 833 F.2d 931, 934 (Fed. Cir. 1987) (en banc) (emphasis omitted)). “This

inquiry for equivalent structure under § 112, ¶ 6 examines whether ‘the assertedly

equivalent structure performs the claimed function in substantially the same way to

achieve substantially the same result . . . .’” Id. (quoting Odetics, 185 F.3d at 1267).

At the outset, we conclude that Medtronic is not estopped from challenging

interchangeability. In this case, Medtronic argued that a set screw and external nut are

functionally equivalent for purposes of invalidating claim 10 of the ’237 patent.

However, that argument has no bearing on Medtronic’s challenge to the

interchangeability of a set screw and an external nut with respect to claim 5 of the ’555

05-1043 38
patent because the functions of the “securing means” in claim 5 of the ’555 patent and

claim 10 of the ’237 patent are different. Claim 10 does not require the application of

substantially equal compressive forces to the rod on either side of the channel. See

’237 patent, col. 4, ll. 42-58, ll. 61-63; col. 5, ll. 14-22. Because the positions are not

entirely inconsistent, judicial estoppel does not apply. See Interactive Gift Express, Inc.

v. Compuserve Inc., 256 F.3d 1323, 1345 (Fed. Cir. 2001) (“[A] party will be judicially

estopped from asserting a position on appeal that is directly opposed to a position that

the party successfully urged at trial.” (internal citations omitted)).

As to the merits, the claimed function has two parts: (1) causing the rod to bear

against the channel by applying a compressive force in the direction of the vertical axis;

and (2) ensuring that substantially equal forces are applied along the longitudinal axis of

the rod on opposite sides—either inside or outside—of the rod-receiving channel.

There is no dispute that the set screw applies a compressive force in the direction of the

vertical axis. However, there is a genuine issue of material fact as to whether the set

screw applies substantially equal forces on opposite sides of the channel, and thus

whether there is identity of function.

On the one hand, Cross Medical cites testimony stating that the v-ring on the

bottom of the internal set screws creates two points of contact when the set screws are

compressed against the rod; that the two points of contact between the set screw and

the rod are 180 degrees apart, separated by the drive in the set screw; and that the set

screw is intended to be co-axial with the receiver (but because of manufacturing

tolerances is not co-axial). (Sherman Dep. of Jan. 29, 2004, at 137-41; Sherman Dep.

of Jan. 30, 2004, at 283-84.) On the other hand, Medtronic cites testimony stating that

05-1043 39
Sherman did not know if the load on the points of contact on either side of the v-ring

were equal; that when the implant is functioning in a patient, the screw takes on

additional load from the rod; and that anytime the screw is loaded, load will increase on

one side of the plug such that forces on the two sides would be unequal. (Id. at 365-

66.) Sherman further testified that he did not know if forces would be equal before the

screw and anchor seat were implanted, because manufacturing tolerances might impact

the forces. (Id. at 366-67.) Drawing inferences in favor of Medtronic, a reasonable juror

could find that the forces are not substantially equal on each side of the channel

because of manufacturing tolerances and the additional load placed on the screw by the

rod when implanted. Crediting Cross Medical’s evidence, a reasonable juror could draw

an inference based on Sherman’s testimony that the forces applied to the rod on either

side of the channel are substantially equal.

Moreover, there is a genuine issue of material fact as to whether the set screw

accomplishes the claimed function in substantially the same way as the external nut.

Medtronic has cited the testimony of Dr. Puno stating that he considered using a set

screw in 1990 to hold the rod in place but decided against the set screw because of

splaying concerns. (Puno Dep. of April 9, 2004, at 32, l. 10-36, l. 24.) Dr. Puno stated

that having the side walls of the anchor seat spread apart when the screw was

tightened down would be “a bad thing” and “could end up loosening the connection on

the rod.” (Id. at 35, ll. 7-14.) Although Dr. Puno testified that he thought a set screw

and external nut were interchangeable, he qualified his statement when confronted with

prior deposition testimony to the opposite effect. (Id. at 37, l. 3–41, l. 23.) Dr. Villarraga

stated that the structures were interchangeable because they both could compress a

05-1043 40
rod into a channel, and because other polyaxial devices utilized set screws. (Villarraga

Decl. of April 12, 2004, at 2.) However, Dr. Villarraga neither explained with any

specificity why one of ordinary skill in the art at the time the ’555 patent issued would

believe the structures to be interchangeable, nor did she refer to any testing. (See id.)

Drawing inferences in favor of Medtronic, a reasonable juror could find that the set

screw does not compress the rod in substantially the same way based on Dr. Puno’s

testimony about the potential for splaying and his conscious decision to avoid the set-

screw design. Drawing inferences in favor of Cross Medical, a reasonable juror could

find that the set screw compresses the rod in substantially the same way because both

employ threads as a compression mechanism, and some statements of Drs. Puno and

Villarraga support a finding of interchangeability.

We thus disagree with Medtronic that the equivalents question should be

removed from the trier of fact under Chiuminatta. In that case, we held that no

reasonable juror could conclude that the differences between “soft round wheels” and a

“skid plate” were insubstantial. Chiuminatta, 145 F.3d at 1310. One of the many

reasons that we found no equivalents as a matter of law was that the patent at issue

discussed the use of wheels for another function, but never disclosed that wheels could

perform the same function as the skid plate. Id. In this case, although Medtronic may

argue that the fact finder should draw an inference of no interchangeability based on the

inventors’ explicit reference to set screws to form a cross-link, see ’555 patent, col. 6, ll.

25-44, and their failure to explicitly recognize set screws as a means for securing the

anchor to the bone, we must draw inferences in favor of Cross Medical in evaluating

05-1043 41
Medtronic’s cross-motion for summary judgment. As discussed supra, we believe that

the issue of interchangeability should be left for the trier of fact.

We also reject the other arguments that both sides make in attempting to prevail

on equivalents as a matter of law. First, we reject Cross Medical’s argument that the

’004 patent serves as an admission on interchangeability. Even though the ’004 patent,

which is assigned to an entity related to Medtronic, suggests that an “internally-threaded

nut” is interchangeable with “a set screw or internal plug,” ’004 patent, col. 8, ll. 10-32,

that patent issued in 2003 and is irrelevant to known interchangeability in 1995, when

the ’555 patent issued. See Al-Site, 174 F.3d at 1320 (“[A] structural equivalent under

§ 112 must have been available at the time of the issuance of the claim.”). Second, we

reject Medtronic’s contentions that the lack of “bowing” with the set screw and the

evidence that the external nut does not function to cause “bowing” in Medtronic’s device

are relevant to interchangeability. Even if the external nut causes “bowing” in

Medtronic’s device, it is immaterial to the equivalents analysis because “prevention of

bowing” is not a limitation of claim 5. See Micro Chem., 194 F.3d at 1258 (cautioning

against adopting a function different from that explicitly recited in the claim).

Furthermore, although Medtronic argues that the external nut may not work well in

Medtronic’s products, any impact this might have on the interchangeability analysis is

undercut by a lack of evidentiary support.

In summary, we conclude that there is a genuine issue of material fact with

respect to whether a set screw is equivalent to an external nut. Thus, the district court

erred in deciding equivalents as a matter of law.

05-1043 42
 3. “bear against said channel”

Relying on its holding that the channel of the anchor seat could comprise more

than one component, the district court ruled that, even if the crown is free-floating and

not physically joined to the anchor seat because there is no lock between the crown and

the screw, Medtronic’s devices met the “bear against said channel” limitation as a

matter of law. Infringement Opinion at 7-8. The district court considered evidence that

the crown member is physically joined to the anchor seat because it cannot be removed

without breaking the screw. Id. The district court analogized the crown in Medtronic’s

devices to a “pressure disk”—which was physically between the rod and the anchor

seat—that the district court previously had held met the “bear against the channel”

limitation in Cross Medical Products, Inc. v. DePuy Acromed, Inc., No. SA CV 00-876-

GLT (ANx), (C.D. Cal. Feb. 11, 2002). Infringement Opinion at 7.

Medtronic argues that even if the anchor seat can be comprised of multiple

components, as a matter of fact, the crown member in its accused devices is not part of

the channel formed by the anchor seat and, thus, the rod does not bear against the

channel as recited in the claim. Medtronic asserts that the crown is free floating and not

physically or otherwise joined to the receiver; that the crown is either screwed or slid

into the receiver; and that the crown is retained either by a snap ring or by interrupting

the threads on the receiver after the crown is screwed into the receiver. Medtronic adds

that the presence of the crown between the rod and the bone screw causes the receiver

member to become rigidly locked to the screw, which serves a different function than a

channel absent a crown member.

05-1043 43
 Cross Medical counters that there is nothing to preclude a finding that the crown

is part of the anchor seat. Cross Medical argues that the crown member is part of the

channel formed by the anchor seat because the crown is assembled into the device

before it is sold, and cannot be removed without damaging the device. Cross Medical

asserts that the crown is physically joined to the receiver, and adds that any difference

in function is irrelevant because claim 5 has no functional limitation.

There is a genuine issue of material fact as to whether the “bear against [the]

channel” limitation is met by the accused products. Sherman testified that in one

product, “the crown member is threaded and screws down into the receiver member

until it passes the threads of the receiver member and then floats freely until locked

down by the rod.” (Sherman Decl. of April 23, 2004, at 3.) Sherman stated that in other

products, “the crown member is maintained in the receiver member by a snap ring that

is designed to allow the crown ‘member’ to float or move freely within a limited range”

before being locked down by the rod. (Id.) Sherman added that the rod touches only

the crown member in each of Medtronic’s products. (Id. at 3-4.) Viewing this evidence

in the light most favorable to Medtronic, a reasonable juror could conclude that the rod

bears only against the crown member, which is separate from the channel in the anchor

seat, and thus the rod does not “bear against” the channel of the anchor seat.

However, a reasonable juror could also find that the crown member is a part of

the channel, and thus that the rod bears against the channel. Cross Medical cites to

evidence that the screw, crown, snap ring, and receiver are assembled as one unit

before the implant arrives to the surgeon. (Sherman Dep. of Jan. 29, 2004, at 123.)

Cross Medical also cites evidence that the snap ring, which holds the crown member

05-1043 44
loosely in place, is damaged if the implant is disassembled. (Id. at 247.) And we agree

with Cross Medical that the function served by the crown member is irrelevant to finding

that this structural limitation is met. See Amstar Corp. v. Envirotech Corp., 730 F.2d

1476, 1482 (Fed. Cir. 1984) (“[M]odifications by mere addition of elements of

function . . . cannot negate infringement . . . .”).

Because there is a genuine issue of material fact as to whether the “bear against

[the] channel” limitation is met, the district court erred in ruling that the accused devices

met this limitation as a matter of law.

E. Invalidity

The district court granted Cross Medical’s cross-motion for partial summary

judgment on all invalidity defenses raised by Medtronic with respect to claim 5 of the

’555 patent, including indefiniteness, anticipation, and obviousness. Medtronic appeals

each of these rulings.

1. Indefiniteness

As noted in Part II.C.3 supra, Medtronic argued that the district court erroneously

interpreted the function of the “securing means” to require that equal forces be applied

along the longitudinal axis of the channel on “either side” of the vertical axis. Medtronic

asserted that the district court’s interpretation would leave “said longitudinal axis”

without a sufficient antecedent basis and render claim 5 indefinite. We construed the

function of the “securing means” limitation as “to cause the rod to bear against the rod-

receiving channel by applying a compressive force in the direction of the vertical axis,

while ensuring that substantially equal forces are applied along the longitudinal axis of

the rod on opposite sides—either inside or outside—of the rod-receiving channel.” We

05-1043 45
agreed with Medtronic that the antecedent basis for “said longitudinal axis” was by

implication the longitudinal axis of the rod. See Slimfold Mfg. Co. v. Kinkead Indus.,

Inc., 810 F.2d 1113, 1116 (Fed. Cir. 1987) (noting that an antecedent basis can be

present by implication). Because the “said longitudinal axis” limitation is not lacking in

antecedent basis, we conclude that the district court did not err in granting Cross

Medical’s motion for summary judgment that claim 5 is not indefinite.

2. Anticipation

The district court held that claim 5 was not anticipated as a matter of law

because claim 5 covers only polyaxial screws and the two prior art references asserted

to be anticipating—U.S. Patent No. 4,763,644 to Webb (“the ’644 patent”) and the

“Bryd-Transpedicular Spinal Fixator”—disclose only monoaxial screws. Invalidity

Opinion at 5. Medtronic’s arguments on anticipation turn entirely upon whether claim 5

covers monoaxial screws. Because we determined in Part II.C.1 supra that claim 5

does not cover monoaxial screws, we conclude that the district court did not err in

granting Cross Medical’s motion for partial summary judgment that claim 5 is not

anticipated.

3. Obviousness

In the district court, Medtronic contended that claim 5 was obvious in view of the

’602 patent, the ’644 patent, and the Byrd device. Invalidity Opinion at 6. The parties

agreed that the ’602 and ’644 patents were prior art, but the district court held that

because Dr. Puno, an inventor on the ’555 patent, also invented the closure mechanism

of the Bryd device, the Bryd device was not prior art. Id. at 6. Focusing on the ’602 and

’644 patents, the district court explained that the ’602 patent and the ’555 patent are

05-1043 46
both polyaxial spinal implant devices. Id. The district court noted that “[t]he only major

difference between the ’602 patent and the ’555 is the ’602 device is tightened from the

bottom and the ’555 is a top-loading nut,” but that “[t]he ’644 patent covers a top-loading

monoaxial spinal implant device.” Id. at 7. However, the district court held that there

was no motivation to combine the ’602 and ’644 references, relying on its prior ruling in

Cross Medical Products, Inc. v. DePuy AcroMed, Inc., No. SA CV 00-876-GLT(ANx)

(C.D. Cal. Jan. 9, 2003).

In AcroMed, the defendant had argued that “the top-loading nut would have been

obvious in light of the problem to be solved, i.e., surgeons having difficulty tightening the

bottom-loading nuts during implantation.” Invalidity Opinion at 7. The district court

“found AcroMed failed to show motivation to combine because ‘the problem was not

discovered by looking at the prior art or the patent itself. . . . It was only discovered

when doctors tried to use the product.” Id. The court cited In re Sponnoble, 405 F.2d

578, 585 (C.C.P.A. 1969), for the proposition that “‘a patentable invention may lie in the

discovery of the source of a problem even though the remedy may be obvious once the

source of the problem is identified.’” Invalidity Opinion at 7.

The district court found that Medtronic offered no evidence that the problem was

disclosed in the prior art. Id. The district court noted that “Defendants cite only the ’555

patent to describe the problem the ’555 patent sought to fix.” Id. The district court

explained that “[a]lthough Defendants argue the clinical investigators identified the

problem with the bottom-loading nut, the investigators’ letters are not prior art.” Id. The

district court acknowledged that “motivation to combine need not be explicit in the prior

art; ‘it can be implicit in the knowledge of one of skill in the art,’” id. (quoting Nat’l Steel

05-1043 47
Car, Ltd. v. Canadian Pac. Ry., Ltd., 357 F.3d 1319, 1337 (Fed. Cir. 2004)), but

reasoned that “[t]his rule does not change the result in this case because it does not

relate to identification of the problem,” id. at 7. The district court then denied

Medtronic’s motion for summary judgment on obviousness and granted Cross Medical’s

cross motion. Id. at 7-8.

Medtronic argues that it presented sufficient evidence that the bottom-tightening-

nut problem was known to those of ordinary skill in the art and that this provides a

motivation to combine the ’644 and ’602 references. Medtronic cites communications

from clinical investigators as evidence of recognition of the problem by those of ordinary

skill in the art, and argues that the district court’s analysis and adoption of the reasoning

in Sponnoble were in error. In addition, Medtronic cites: (a) the ’644 patent as evidence

that bottom-tightening devices then available were problematic to assemble in situ; (b)

U.S. Patent No. 5,261,913 (“the ’913 patent”) as evidence that it was within the

knowledge of one of ordinary skill to use a top-tightening nut; and (c) the ’555 patent as

evidence that prior art polyaxial screws designed with bottom-tightening nuts were

awkward.3 Medtronic argues that even if the ’913 patent does not qualify as prior art, it

3
In a footnote in its opening brief, Medtronic asserts that the district court
erroneously resolved a fact question as to whether Dr. Puno was an inventor of the Bryd
device but never requests relief or provides record cites for its assertions. Medtronic
makes no other reference to the Bryd device with respect to obviousness in its opening
brief. In its response brief, Medtronic asserts that even if Dr. Puno is a joint inventor of
the Bryd device, there is a different set of joint inventors on the Bryd device—Drs. Puno
and Bryd—than on the ’555 patent—Dr. Puno and Mellinger. Medtronic argues that the
two sets of inventors are separate legal entities under In re Kaplan, 789 F.2d 1574,
1575 (Fed. Cir. 1986), and that the Bryd device may be prior art under §§ 102(f) and
103. Medtronic adds that even if the Bryd device is confidential, it evidences knowledge
of those of ordinary skill.
Medtronic has not properly raised the inventorship issue in its opening brief to
warrant relief from this court. See Fuji Photo Film Co. v. Jazz Photo Corp., 394 F.3d

05-1043 48
evidences knowledge of one of ordinary skill in the art. Medtronic asserts that, at the

least, this evidence is enough to create a genuine issue of material fact on motivation to

combine.

Cross Medical counters that Dr. Puno was one of the clinical investigators who

recognized the problem with the ’602 device, that Dr. Puno discovered the problem as

part of his inventive process, and thus that the clinical investigators’ recognition of the

problem is not evidence of a motivation to combine. Cross Medical argues that the ’644

patent does not itself provide reason to apply its teachings to modify the ’602 device

because it discusses prior art assembly problems related to use of a locking nut and

threaded rod to hold the screw. Cross Medical argues that the ’602 device did not use a

threaded rod with a locking nut, and thus the inventors did not confront the same

problem as confronted by the inventors of the ’644 device. Cross Medical asserts that

the ’913 patent cannot evidence knowledge of ordinary skill in the art at the time of the

invention because the application that matured into the ’913 patent was filed two

months after the invention date of the ’555 patent, and that application was not

published for 18 months. Cross Medical cites differences between the ’602 and ’555

patents in addition to the bottom-tightening nut, and asserts that Medtronic submitted no

evidence explaining how the particular structural elements of the ’602 device could be

modified to achieve the structure disclosed in claim 5 as a whole. Cross Medical argues

that Medtronic failed to discuss “trade-offs” to the use of the top-tightening device, and

neglected to discuss secondary considerations.

1368, 1375 n.4 (Fed. Cir. 2005) (holding that this court will not address arguments that
are not properly raised in the opening brief). Nor will this court consider Medtronic’s
new arguments raised for the first time in its reply brief. Id.

05-1043 49
 “A claimed invention is unpatentable if the differences between it and the prior art

are such that the subject matter as a whole would have been obvious at the time the

invention was made to a person having ordinary skill in the art.” In re Kotzab, 217 F.3d

1365, 1369 (Fed. Cir. 2000); see 35 U.S.C. § 103. An invention may be a combination

of old elements disclosed in multiple prior art references. Kotzab, 217 F.3d at 1369. In

determining whether a combination of old elements is non-obvious, the court must

assess whether, in fact, an artisan of ordinary skill in the art at the time of invention, with

no knowledge of the claimed invention, would have some motivation to combine the

teachings of one reference with the teachings of another reference. See In re Fulton,

391 F.3d 1195, 1200-02 (Fed. Cir. 2004). Motivation to combine references “may come

explicitly from statements in the prior art, the knowledge of one of ordinary skill in the

art, or, in some cases the nature of the problem to be solved.” Kotzab, 217 F.3d at

1370. “The test for an implicit teaching is what the combined references, knowledge of

one of ordinary skill in the art, and the nature of the problem to be solved as a whole

would have suggested to those of ordinary skill in the art.” Id.

The sole issue before us is whether the district court erred in ruling that there is

no genuine issue of material fact as to whether the subject matter as a whole would

have been obvious to one of ordinary skill in the art at the time of the invention based on

the absence of any evidence of a motivation to combine the ’602 and ’644 references.

We conclude that a genuine issue of material fact exists with respect to motivation to

combine. Cross Medical designated the screw disclosed in the ’602 patent as the “PWB

I” and performed a pilot study testing its use in humans. A paper, entitled “The Puno-

Winter-Bird (PWB) Spinal System for Transpedicular Fixation of the Lumbar Spine,”

05-1043 50
recounted that surgeons participating in the pilot study found the implant design

“tedious,” and that it was “technically difficult to position the wrench when the nut was

tightened, since it required that the nut be advanced from under the rod.” The paper

explained that “[a]lthough [the PWB I] provided satisfactory fixation of the rod, the

design was not ‘user friendly.’” The paper noted that “[a] design improvement was in

order and led to the development of the PWB II.” Other evidence in the record confirms

that surgeons in the pilot study recognized the problem and requested changes. The

surgeons who participated in the pilot included investigators other than inventors of the

’555 patent.

From this evidence, a reasonable juror could conclude that at the time of the

invention, one of ordinary skill in the art could have been motivated to modify the PWB I

in light of the problem to be solved. Giving credit to Medtronic’s evidence, the clinical

investigators recognized the bottom-tightening problem with the ’602 device and

proposed changes. The problem was within the general knowledge of those of ordinary

skill in the art, and thus provided sufficient motivation to navigate the prior art in the

spinal implant field in search of a teaching on how one might modify the ’602 device

away from a bottom-tightening assembly.

The district court erred in discounting the clinical investigators’ recognition of the

problem. “It has long been the law that the motivation to combine need not be found in

prior art references, but equally can be found ‘in the knowledge generally available to

one of ordinary skill in the art.’” Nat’l Steel, 357 F.3d at 1337 (quoting In re Jones, 958

F.2d 347, 351 (Fed. Cir. 1992)). Evidence of a motivation to combine references need

not be in the form of prior art. See id. at 1338-39. Evidence that a person of ordinary

05-1043 51
skill in the art recognized the same problem to be solved as the inventor and suggested

a solution is, at the least, probative of a person of ordinary skill in the art’s willingness to

search the prior art in the same field for a suggestion on how to solve that problem.

See Pro-Mold & Tool Co. v. Great Lakes Plastics, Inc., 75 F.3d 1568, 1573 (Fed. Cir.

1996) (Motivation to combine “may also come from the nature of a problem to be

solved, leading inventors to look to references relating to possible solutions to that

problem.” (citing Application of Rinehart, 531 F.2d 1048, 1054 (C.C.P.A. 1976))); In re

Huang, 100 F.3d 135, 139 n.5 (Fed Cir. 1996) (stating that problem well-known to a

person of ordinary skill in the art would have directed that person of ordinary skill to the

reference teaching the missing elements); see also, e.g., In re Gartside, 203 F.3d 1305,

1320-21 (Fed. Cir. 2000) (recognizing that motivation to combine can come from the

nature of the problem to be solved); In re Rouffet, 149 F.3d 1350, 1355 (Fed. Cir. 1998)

(same). To the extent that the district court determined that the only investigators who

recognized the problem of the bottom-tightening assembly were inventors on the ’555

patent, that conclusion has no basis in the record.

Furthermore, the district court’s reliance on Sponnoble is misplaced. In that

case, those of ordinary skill in the art of packaging pharmaceutical products recognized

a moisture-transfer problem with “structure[s] for temporarily isolating a compartment

containing a solid pharmaceutical product from a compartment containing an aqueous

solution.” Sponnoble, 405 F.2d at 585. The industry believed that moisture was

transmitted around the plug separating the two compartments. Id. at 586. Sponnoble

discovered that moisture traveled through the plug and remedied that problem with a

solution available in the prior art. Id. Our predecessor court held that the invention was

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non-obvious because one of ordinary skill in the art would not have chosen the solution

without recognizing the true cause of the problem, and “the cause of the problem [was]

not suggested by the prior art.” Id. In this case, however, the problem was known to

the clinical investigators at the time of the invention, and thus, unlike Sponnoble, the

problem was within the general knowledge of one of ordinary skill in the art. See Nat’l

Steel, 357 F.3d at 1338 (“Something that has already been rendered obvious to a

newcomer in the field is probative of what would be obvious to someone who has been

around for a longer period of time.”). If the problem is within the knowledge of one of

ordinary skill in the art, then it is irrelevant that the prior art does not disclose the

problem. See id. at 1337-39.

Moreover, we conclude—after drawing inferences in favor of Medtronic—that the

’644 patent itself may have provided sufficient motivation for one of ordinary skill to have

considered its teachings and altered the ’602 device. The ’644 invention was an

improvement over prior art spinal implant devices which used a threaded rod with

locking nuts. In characterizing the prior art, the patent states that “[t]he need to thread

the nut along the rod results in the device being rather slow to assemble and can result

in damage to soft tissue if carried out in situ.” ’644 patent, col. 2, ll. 10-12. The solution

was, in part, a top-tightening nut. See id., col. 3, ll. 16-23; id., Figure 2. Thus, the ’644

patent discusses a problem posed by the assembly of certain spinal stabilization

devices in situ and a solution. Confronted with the implantation problem of the ’602

device, one of ordinary skill might have found the problem solved by the ’644 patent

sufficiently analogous to have been motivated to apply its teachings. In turn, we reject

Cross Medical’s contention that the ’644 device cannot provide the requisite motivation

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because the problem it addressed may have differed slightly from the problem

encountered by surgeons using the ’602 device. One of ordinary skill in the art need not

see the identical problem addressed in a prior art reference to be motivated to apply its

teachings. See In re Oetiker, 977 F.2d 1443, 1448 (Fed. Cir. 1992) (Nies, C.J.,

concurring) (“Such suggestion or motivation to combine prior art teachings can derive

solely from the existence of a teaching, which one of ordinary skill in the art would be

presumed to know, and the use of that teaching to solve the same or similar problem

which it addresses.” (citing In re Wood, 599 F.2d 1032, 1037 (C.C.P.A. 1979))

(emphasis added)); cf. In re Dillon, 919 F.2d 688, 694 (Fed. Cir. 1990) (en banc) (“‘[A

reference is not from a non-analogous art if] the reference is reasonably pertinent to the

particular problem with which the inventor was involved.’” (quoting In re Deminski, 796

F.2d 436, 442 (Fed. Cir. 1986) (quoting in turn from Wood, 599 F.2d at 1036))).

As to the other evidence cited by Medtronic, the ’555 patent suggests that the

inventor recognized the problem of bottom-tightening. However, the patent does not

provide evidence that the problem was within the knowledge of those of ordinary skill in

the art at the time of the invention; or that the problem was disclosed in the prior art.

The ’913 patent is also of limited relevance because it issued after the invention date.

See Mahurkar v. C.R. Bard, Inc., 79 F.3d 1572, 1576-77 (Fed. Cir. 1996).

Thus, we conclude that, because there are genuine issues of material fact on the

underlying facts related to obviousness, the grant of summary judgment was in error.

III. CONCLUSION

We conclude that we have jurisdiction over this appeal. We affirm the district

court’s construction of the “anchoring means,” “securing means,” and “bear against said

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channel” limitations, but modify the district court’s construction of the “operatively joined”

and the “anchor seat means” limitations. Because we find genuine issues of material

fact regarding infringement, we reverse the grant of Cross Medical’s motion for partial

summary judgment of infringement and find no abuse of discretion in the denial of

Medtronic’s cross-motion for partial summary judgment of non-infringement. We also

reverse the grant of Cross Medical’s motion for partial summary judgment that claim 5 is

not obvious but affirm the grant of that motion as to indefiniteness and anticipation. We

further conclude that the district court did not abuse its discretion in denying Medtronic’s

cross-motion for summary judgment as to these invalidity issues. As a result, we vacate

the permanent injunction. We remand for further proceedings consistent with this

opinion.

AFFIRMED-IN-PART, REVERSED-IN-PART, VACATED-IN-PART, AND REMANDED.

COSTS

Costs to Medtronic.

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