### UNITED STATES COURT OF APPEALS Tenth Circuit Byron White United States Courthouse

1823 Stout Street Denver, Colorado 80294 (303) 844-3157 Patrick J. Fisher, Jr. Elisabeth A. Shumaker Clerk Chief Deputy Clerk June 10, 1997

TO: All recipients of the captioned opinion
RE: 95-1085, 95-1104, 95-1123, Oja v. Howmedica, Inc. April 16, 1997
Please be advised of the following correction to the captioned decision: Due to a formatting error, the section headings are incorrectly labeled. The Arabic numbers should be Roman numerals. A corrected version of the opinion is attached for your convenience. Very truly yours, Patrick Fisher, Clerk

Susie Tidwell Deputy Clerk encl.

## F I L E D United States Court of Appeals Tenth Circuit 

### APR 16 1997 

### PATRICK FISHER Clerk PUBLISH
UNITED STATES COURT OF APPEALS

TENTH CIRCUIT

MAUREEN G. OJA,

Plaintiff - Appellee/ Cross - Appellant,

v. HOWMEDICA, INC., a Delaware corporation, Defendant - Appellant/

Cross - Appellee.

-------------------------- PRODUCT LIABILITY ADVISORY COUNCIL, INC.; HEALTH INDUSTRY MANUFACTURERS ASSOCIATION; ASSOCIATION OF TRIAL LAWYERS OF AMERICA,

Amici Curiae. No. 95-1085, 95-1104, 95-1123

APPEAL FROM THE UNITED STATES DISTRICT COURT

FOR THE DISTRICT OF COLORADO

(D. Ct. No. 93-C-858)
Malcolm E. Wheeler, Parcel, Mauro, Hultin & Spaanst ra, Denver, Colorado, appearing for Defendant-Appellant/Cross-Appellee.- 2 -

Elizabeth C. Moran, Pryor, Johnson, Montoya, Carney& Karr, Englewood, Colorado (Peter W. Pryor, Pryor, Johnson, Montoya, Carney & Karr, Englewood, Colorado, and Thomas L. Roberts, Roberts & Zboyan, Denver, Colorado, with her on the briefs), appearing for Plaintiff-Appelle/Cro ss-Appellant. Robert N. Weiner and Steve J. Boom, Arnold & Porter , Washington, DC, and Hugh Young, Jr., Product Liability Advisory Council , Inc., Reston, Virginia, for amicus curiae Product Liability Advisory Council, I nc. Bruce N. Kuhlik and Jennifer A. Johnson, Covington & Burling, Washington, DC, and Donnellda Rice, Health Industry Manufacturers A ssociation, Washington, DC, for amicus curiae Health Industry Manufacturers Association. Pamela A. Liapakis, President, Association of Trial Lawyers of America, Washington, DC and Jeffrey Robert White, Washington , DC, for amicus curiae Association of Trial Lawyers of America.

Before TACHA, BRISCOE, and MURPHY, Circuit Judges.

TACHA, Circuit Judge.

Maureen Oja brought a products liability action aga inst Howmedica, Inc., the manufacturer of a prothestic hip replacement sy stem, asserting three claims relevant to this appeal: (1) negligence, (2) negli gent failure to warn, and (3) strict liability. At the close of the plaintiff’s case, t he district court granted Howmedica’s motion for a directed verdict on Oja’s strict liability manufacturing defect claim. The court, however, permitted Oja to proceed with her strict liability claims based on design and warning defect s.- 3 -

The jury returned a general verdict for Howmedica o n the negligence and remaining strict liability claims. The jury, howev er, found for Oja on her negligent failure to warn claim. The jury awarded Oja $896,921 in compensatory and $896,921 in punitive damages. The district cou rt reduced the damage award to $448,460.50 and $612,535.96, respectively, and awarded Oja prejudgment interest from the date the action accrued. On appeal, Howmedica argues that: (1) the Medica l Device Amendments of 1976 (“MDA”) preempts Oja’s negligent failure to warn claim; (2) the jury’s finding of negligent failure to warn is inconsistent with its verdict for Howmedica on the strict liability and negligence claims; (3) the district court erred in submitting both a “negligence” and “negligent failu re to warn” claim to the jury without properly instructing the jury about the ele ments and burdens of proof on each claim; and (4) punitive damages cannot be awar ded as a matter of law because the evidence was insufficient to show that Howmedica acted wantonly or recklessly. In her cross-appeal, Oja raises two issues. Oja ar gues that the district court erred in (1) dismissing her strict liability claim based on a manufacturing defect and (2) awarding her prejudgment interest from the date that her action “accrued” as defined by the relevant statute of limitations r ather than the date of her injury.- 4 -

We exercise jurisdiction pursuant to 28 U.S.C. § 12 91. For the reasons set forth below, we affirm the district court’s ruling that the MDA does not preempt Oja’s negligent failure to warn claim. We reverse and remand for a new trial, however, because we conclude that the jury’s findin g of negligent failure to warn is irreconcilably inconsistent with its verdict forHowmedica on the strict liability claim. We also reverse the district court’s order granting a directed verdict for Howmedica on the strict liability manufacturing def ect claim. Because we remand for a new trial, we do not address the remai ning issues on appeal.

BACKGROUND The Porous-Coated Anatomic One-Piece Acetabular Component hip (“PCA hip”) consists of three components: (1) a metal st em that is inserted into the central canal of the patient’s large upper leg bone , (2) a cup that is inserted into the patient’s hip socket, and (3) a rounded metal f emoral head that is rigidly attached to the top of the metal stem and is fitted into the cup. The cup is composed of an outer metal shell and an inner polye thylene liner. The liner attaches to the metal shell by an integral staking peg projecting from the back of the liner through a hole in the metal shell. An “a nti-rotation lug” prevents the liner from rotating in the metal shell. Unless the liner is prevented from rotating,- 5 -

the liner will wear and shed microscopic debris. S uch debris may cause a patient to suffer from severe bone dissolution or “osteolys is.” On July 2, 1984, Oja underwent surgery to replace h er existing artificial hip with a PCA hip. Her orthopedic surgeon, Dr. McElhi nney, implanted the PCA hip without using cement because he had concluded that Oja’s existing bone structure provided little area for cement fixation. By early 1992, Oja began experiencing severe pain i n her hip in the area of her PCA hip implant. Dr. Richard Evans, an orthope dic surgeon, recommended immediate surgery. On July 29, 1992, he removed th e PCA hip. The surgery revealed that the staking peg was missing, that the polyethylene liner had completely disengaged from the metal cup, and that debris had spread into Oja’s hip joint. Moreover, osteolysis had left large def ects in Oja’s hip, especially in the area of the hole in the cup. On April 21, 1993 , Oja filed this products liability suit against Howmedica.- 6 - DISCUSSION
I. P REEMPTION OF O JA ’ S N EGLIGENT F AILURE TO W ARN C LAIM a. Overview of the Medical Device Amendments1 Prior to trial, Howmedica moved for summary judgment, claiming that allof Oja’s

state law claims were preempted by the MDA. The district court denied Howmedica’s motion and its motion for reconsideration. At the close of the evidence, Howmedica moved for a directed verdict on allof Oja’s state law claims based on MDA preemption. The district court denied the motion. After the jury returned its verdict, Howmedica renewed its motion for judgment as a matter of law, arguing onlythat the MDA preempted Oja’s negligent failure to warn claim. The district court denied the motion. On appeal, Howmedica again argues only that the MDA preempts Oja’s negligent failure to warn claim. Thus, we do not address whether the MDA preempts any of Oja’s other state law claims. SeeState Farm Fire & Cas. Co. v. Mhoon , 31 F.3d 979, 984 n.7 (10th Cir. 1994) (holding that the failure to raise an issue in the opening brief waives the issue). - 7 - Howmedica argues that the MDA preempts Oja’s neglig ent failure to warn claim. 1 Because Congress’s intent is the “ultimate touchs tone” in every preemption case, see Retail Clerks Int’l Ass’n v. Schermerhorn , 375 U.S. 96, 103 (1963), we begin our preemption analysis by outlini ng the purposes and statutory framework of the MDA. In 1976, Congress enacted the MDA “to provide for the safety and effectiveness of medical devices intended for human use.” Pub. L. No. 94-295, 90 Stat. 539, 539 (1976) (preamble). The MDA class ifies medical devices into three categories (classes I, II and III) based on the amount of risk they pose to the public. Class I devices are subject only to “gener al controls” because they pose little threat to public heath and safety. 21 U.S.C . § 360c(a)(1)(A). Class II devices are subject to special controls because “ge neral controls by themselves are insufficient to provide reasonable assurance of the safety and effectiveness of- 8 -

the device.” 21 U.S.C. § 360c(a)(1)(B). Class III devices are subject to the most stringent MDA controls because they present “a pote ntial unreasonable risk of illness or injury.” 21 U.S.C. § 360c(a)(1)(C). The MDA automatically classifies a device as a clas s III device unless the device fits within one of three exceptions listed. First, a device placed in commercial distribution prior to May 28, 1976, avoi ds class III status through a grandfathering provision. 21 U.S.C. § 360c(f)(1)(A )(I)(I). Second, a post-1976 device may escape classification as a class III dev ice if the FDA has reclassified the device as a class I or II device. 21 U.S.C. § 360c(f)(1)(A)(I)(II); 21 U.S.C. § 360c(f)(1)(B). Finally, a device may avoid class III device status if it is “substantially equivalent” to a grandfathered devic e or a post-1976 device that the FDA has classified as a class I or II device. 21 U .S.C. § 360c(f)(1)(A)(ii). Manufacturers intending to market any new medical d evice must submit a premarket notification to the FDA. 21 U.S.C. § 360 (k). In addition to the premarket notification (also known as the “§ 510(k) process”), Class III devices must undergo a comprehensive premarket approval (“P MA”) process before marketing. 21 U.S.C. § 360e. The purpose of the P MA is to provide the FDA with “reasonable assurance” that the device is safe and effective. 21 U.S.C. § 360e(d)(2).- 9 -

While the MDA contemplates that most Class III devi ces will reach the market only through the PMA process, a manufacturermay obtain market approval through any of three alternative processes . First, the MDA contains a grandfathering provision which allows pre-1976 devi ces to remain on the market without FDA approval until the FDA completes the PMA. 21 U.S.C. § 360e(b)(1)(A); 21 C.F.R. § 814.1(c)(1). Second, the MDA contains an investigational device exemption (“IDE”) for new de vices under clinical investigation to determine their safety or effectiv eness. See 21 U.S.C. § 360j(g). In order to foster the development of useful device s, IDE procedures allow manufacturers to begin limited marketing of new dev ices without undergoing the rigorous PMA process. 21 U.S.C. § 360j(g)(1). Fi nally, a Class III device may reach the market without undergoing the PMA procedu res if the FDA determines, on the basis of the § 510 process, that the device is “substantially equivalent” to a device already on the market. 21 U.S.C. § 360e(b)( 1)(B). b. Regulation of the PCA Hip Under the MDA On April 25, 1983, Howmedica filed a premarket noti fication submission with the FDA, seeking permission to market the PCA hip under the § 510(k) process. The application included sample labels, adescription of the intended use, a description of the product (dimensions, mate rials, processing, and sterilization procedures), photographs of the compo nents, engineering drawings,2 Oja underwent her PCA hip surgery on July 2, 1984, when Howmedica’s IDE

application was pending. Thus, at the time of Oja’s surgery, Howmedica had not yet received an IDE for cementless use. This distinguishes our case from Martin v. Telectronics Pacing Sys., Inc. , 105 F.3d 1090 (6th Cir. 1997) and Becker v. Richards Med. Co. , 937 F. Supp. 181 (N.D.N.Y. 1996). - 10 - and a description of test results. During the nextfew months, the FDA requested that Howmedica submit additional testing informatio n and certification that the PCA hip would be used only with cement. Howmedica complied with each of these requests. On August 10, 1983, the FDA granted Howmedica permi ssion to market the PCA hip for use with bone cement pursuant to the § 510(k) process “subject to the general controls provision of the Federal Food, Dru g & Cosmetic Act.” The FDA also imposed several specific limitations on Howmed ica: (1) the PCA hip could not be labeled or promoted for non-cemented use, (2 ) the PCA hip could only be used with low-viscosity cement, and (3) fixation of the PCA hip without cement would be considered an investigational procedure re quiring an IDE. On October 18, 1983, Howmedica submitted an IDE app lication in order to conduct a clinical study of the PCA hip when used w ithout cement. 2 Over the course of the next year, Howmedica submitted animal studies, comparative control groups, and other information to the FDA. On December 12, 1984, the FDA authorized Howmedica to conduct the clinical in vestigation. After that date,- 11 -

the PCA could be used without cement in an experime ntal context, with a patient’s full informed consent. On September 4, 1987, the FDA issued its final rule classifying the PCA hip as a class II medical device when used with cem ent. 52 Fed. Reg. 33686, 33707 (codified at 21 C.F.R. § 888.350). At that t ime, the FDA had determined that classification as a class III device was “not necessary to provide reasonable assurance of the safety and effectiveness of the de vice.” 21 C.F.R. § 860.93. On October 26, 1989, following the clinical investi gation of the PCA hip, Howmedica filed a request for a PMA to market the P CA hip when used without cement. The FDA issued a conditional approval lett er on April 2, 1991. The FDA conditioned final approval upon: (1) deleting one word from the proposed labeling, (2) providing an update of the clinical d atabase, and (3) complying with future requirements, such as the summation of long- term survivorship data. In 1991, the FDA inspected and cited Howmedica for several regulatory violations, including the failure to report information that the PCA hip had caused serious injury in patients. In response, Howmedicainformed the FDA that it would “voluntarily” issue a “Dear Doctor” letter to surgeons using the device, instructing them on the proper surgical techniques to avoid damage to the polyethylene liner of the cup. The FDA indicated t hat it had “no adverse comments” about the content of the letter.3 In a five to four decision, the Court held that the MDA did not preempt any of the

plaintiffs’ common law claims. Justice Stevens authored the plurality opinion, which Justices Kennedy, Souter, and Ginsburg joined in its entirety. Justice Breyer, who concurred in the judgment, joined in Parts I, II, III, V, and VII of the plurality opinion. Thus, only those five sections constitute the opinion of the Court. - 12 - On February 21, 1992, the FDA reclassified the PCA hip when used without cement from a class III device to a class I I device. See 58 Fed. Reg. 3227 (Jan. 8, 1993). Howmedica therefore invoked the § 510(k) process (rather than the more rigorous PMA) to obtain authorization to m arket the PCA hip without cement. On June 10, 1992, the FDA granted Howmedic a permission to market the PCA hip when used without cement under the premarke t notification procedure. On January 8, 1993, the FDA published its final rul e classifying the PCA hip as a class II medical device when used without cement. 58 Fed. Reg. 3227, 3228 (codified at 21 C.F.R. § 888.358) c. MDA Preemption Analysis in Medtronic, Inc. v. Lohr In Medtronic, Inc. v. Lohr , 116 S. Ct. 2240 (1996), the Supreme Court addressed whether the MDA’s general labeling regulations preempted a state law negligent failure to warn claim for injuries suffer ed by the recipient of a pacemaker, a class III device. 3 Id. at 2256-58. The regulations require manufacturers of every medical device, with a few l imited exceptions, to label the device with “information for use, . . . any relevan t hazards, contraindications, side effects, and precautions.” 21 C.F.R. § 801.109(c).- 13 -

The Court began its preemption analysis by looking to the text of the MDA’s preemption provision (21 U.S.C. § 360k) and the FDA’s regulation interpreting that provision (21 C.F.R. § 808.1(d)): § 360k State and local requirements respecting devi ces (a) General Rule Except as provided in subsection (b) of this sectio n, no State or political subdivision of a State may establish or c ontinue in effect with respect to a device intended for human use anyrequirement-- (1) which is different from, or in addition to, anyrequirement applicable under this chapter to the device, and (2) which relates to the safety or effectiveness of the device or to any other matter included in a requirement applicable t o the device under this chapter. § 808.1 Scope (d) State or local requirements are preempted only when the Food and Drug Administration has established specific co unterpart regulations or there are other specific requirement s applicable to a particular device under the Act, thereby making any existing divergent state or local requirements applicable to the device different from or in addition to, the specific Food and Drug Administration requirements. Medtronic , 116 S. Ct. at 2256-58. The Court concluded that the statute and regulation evinced “an overarching concern that pre -emption occurs only where a particular state requirement threatens to interfere with a particular federal interest.” Id. at 2257. Based on the MDA’s statutory language and the FDA’s regulation, the Court developed a two-prong inquiry to determine th e preemptive scope of the MDA. Id. First, a federal requirement must be “applicable to the device” in4Prior to the Supreme Court’s decision in Medtronic , Howmedica argued that

several FDA “requirements” would preempt Oja’s negligent failure to warn claim. The Supreme Court rejected most of these grounds in Medtronic . Accordingly, in - 14 - question. Id. at 2257 (quoting 21 U.S.C. § 360k). In other word s, a federal requirement will preempt state law only if “specifi c” to a “particular device.” Id

. (quoting 21 C.F.R. § 808.1(d)). Second, a state re quirement must be “with respect to” a medical device and must be “differentfrom, or in addition to” a federal requirement. Id. (quoting 21 U.S.C. § 360k). Accordingly, “[s]tate regulations of ‘general applicability’ are not pree mpted except where they have ‘the effect of establishing a substantive requireme nt of a specific device.’” Id. (quoting 21 C.F.R. § 808.1(d)(1)). Applying the two-prong test, the Court concluded th at the MDA’s labeling regulations did not preempt the plaintiffs’ neglige nt failure to warn claim. First, the Court found no preemption because the federal l abeling regulations reflected “important but entirely generic concerns about devi ce regulation generally.” Id. at 2558. Second, the Court concluded that the negl igent failure to warn claim also escaped preemption because its “generality leaves [it] outside the category of requirements that § 360k envisioned to be ‘with res pect to’ specific devices.” Id. d. Application of Medtronic In its supplemental brief, Howmedica argues that th e FDA imposed two warning requirements sufficient to preempt Oja’s ne gligent failure to warn claim. 4Howmedica’s supplemental brief filed after Medtronic , Howmedica limited its

preemption argument to the only viable grounds remaining, namely the FDA’s dealings with Howmedica in 1983 and 1991. Thus, we address only these grounds. - 15 - Howmedica points to the FDA’s regulation of the PCAhip in 1983 and in 1991. With respect to Howmedica’s dealings with the FDA i n 1983, Howmedica alleges: In 1983, when first deciding whether to allow Howme dica to begin marketing the PCA hip, the FDA four times required Howmedica to submit more testing, information, and certification s . . . and then required Howmedica to add, to all labeling and prom otional materials for that specific device, specific warning statemen ts that the device be used only with bone cement, not cementless . . . . The warnings specifically required by the FDA did not include any of the warnings that Oja asked the jury to impose under Colorado to rt law. Applt. Supp. Brief at 4 (citations omitted). Under the Medtronic two-pronged preemption test, we must first determi ne whether the FDA imposed any specific federal warnin g requirement applicable to the PCA hip in its 1983 dealings with Howmedica. T he record indicates that the FDA imposed only one labeling requirement on Howmed ica: the FDA stated that Howmedica could not label or promote the PCA hip fo r non-cemented use. This mandate constitutes a specific federal requirement applicable to the PCA hip, but that does not end our preemption inquiry. Like the failure to warn claim at issue in Medtronic , the general state common law requirements imposedby Oja’s negligent failure to warn claim were not specifical ly developed “with respect to” medical devices. Medtronic , 116. S. Ct. at 2258. Instead, Oja’s negligent fa ilure- 16 -

to warn claim is predicated upon a general duty app licable to every manufacturer “to inform users and purchasers of potentially dang erous items of the risks involved in their use.” Id. Moreover, Howmedica’s general duty to warn users of potential dangers in this case does not have “the e ffect of establishing a substantive requirement for a specific device.” Id

. at 2257. Thus, the standard of care governing Oja’s negligent failure to warn clai m is not the type of devicespecific requirement that would threaten the MDA’s federal interests. See id. at 2258. Accordingly, we find no preemption based on Howmedica’s dealings with the FDA in 1983. Similarly, we find no preemption based on the FDA’s regulation of the PCA hip in 1991. Howmedica alleges: In 1991 the FDA specifically scrutinized Howmedica’ s internal documents regarding reported problems with the PCA hip, reexamined Howmedica’s medical device reports perta ining to the PCA hip (including reports relied on by Oja at tria l as evidence of the need for additional warnings), reexamined Howme dica’s labeling and warning materials, and imposed device-specific requirements for specific additional labeling and warnings. The war nings required by the FDA did not include any of the warnings that Oj a asked the jury to require under Colorado tort law. . . . Applt. Supp. Brief at 3-4 (citations omitted). Fir st, we note that any FDA requirement imposed in 1991 would have no preemptiv e effect as to Howmedica’s pre-1991 post-sale duty to warn. Second, the recor d is not clear that the 1991 “voluntary” Dear Doctor letter even constituted an MDA “requirement” at all.- 17 -

We need not resolve this question, however, because assuming arguendo that the warnings contained in the letter were specific fede ral requirements, we find no preemption under the second prong of the analysis e mployed in Medtronic . As with the 1983 claims, the duties imposed by Oja’s n egligent failure to warn claim do not constitute positive enactments of state law sufficient to constitute a state requirement developed “with respect to” a medical d evice. The Court in Medtronic made clear that the general duty to warn of forese eable dangers is “not the kind[] of requirement[] that Congress and the F DA feared would impede the ability of federal regulators to implement and enfo rce specific federal requirements.” Medtronic , 116 S. Ct. at 2258. Accordingly, we affirm the district court’s ruling that the MDA does not preempt Oja’s negligent failure to warn claim.
II. I NCONSISTENT J URY V ERDICTS a. Waiver Howmedica next contends that we should vacate the j udgment entered on the jury verdict in favor of Oja on her negligent f ailure to warn claim because it is irreconcilably inconsistent with the jury verdict i n favor of Howmedica on Oja’s strict liability claims. As a preliminary matter, we must determine whether we may review this issue. A party’s failure to objectto a general jury verdict on the ground of inconsistency before the jury is discharg ed constitutes waiver, unless- 18 -

the verdict is inconsistent on its face such that e ntry of judgment upon the verdict is plain error. Hinds v. General Motors Corp. , 988 F.2d 1039, 1047 (10th Cir. 1993) (citing Diamond Shamrock Corp. v. Zinke & Tru mbo, Ltd. , 791 F.2d 1416, 1424 (10th Cir. 1986)). In this case, the parties do not dispute that the v erdict forms required the jury to return a general verdict. The jury reached a verdict at 5:00 pm on the night before Thanksgiving. The court then read the verdict, polled the jury, entered judgment, and excused the jurors. Howmedic a relies on Jarvis v. Commercial Union Assurance Cos ., 823 F.2d 392, 393 (10th Cir. 1987), to support its position that under these circumstances , Howmedica had no “meaningful opportunity” to object to the verdict a nd therefore its failure to object should not constitute waiver. In Jarvis , the jury returned a verdict and special interrogatory answers that the trial judge recognized as arguably inconsistent. Id. at 394. In open court, the judge asked the jury t o review its verdict and answers to determine if the jury markedthe forms as intended. Id. After further deliberations, the jury sent the judg e a note stating that the forms were correctly marked and that “if there is a confl ict with the Special Interrogatory form and the Verdict Forms, we will n eed a description of this conflict.” Id. at 395. The court informed the parties of the jury’s note and explained:- 19 -

I wanted to inquire if there was an inconsistency i n the jury’s mind. They are saying that there is none, so I am going t o bring them in and publish the verdict. Id. at 394. Accordingly, the judge read the verdict, polled the jury, entered judgment, and discharged the jury. Id. We held that “it would be a perverse default of justice to say that under the circumstan ces present here, counsel had waived the right to correct an onerous inconsistenc y in the jury’s resolution of his client’s case only because he did not raise an obje ction.” Id. at 396. We find Howmedica’s reliance on Jarvis misplaced. In Jarvis , “the court summarily declared the conflict resolved and procee ded with entry of the verdict.” Id. Under such circumstances, an objection to the ver dict as inconsistent would have been frivolous in light of the trial court’s d isposition of the issue. In contrast to Jarvis , the trial court in this case did not raise and de cide the issue sua sponte before discharging the jury. Instead, the record indicates that Howmedica had the opportunity to object to any inconsistencie s in the verdict prior to the jury’s discharge or immediately thereafter. In fac t, Howmedica’s counsel objected to at least one aspect of the verdict befo re leaving the courtroom. The attorney stated: “I think there are some problems with the verdict in that there are -- seems to me the punitive damages are above the c ompensatory.” Howmedica could have made similar objection to the verdict be ing inconsistent or complained that the trial court discharged the jury before How medica could make such an- 20 -

objection. Howmedica did not do this. Under such circumstances, we hold that Howmedica has waived its right to object to the ver dict unless it is “inconsistent on its face such that entry of judgment upon the ve rdict is plain error.” Hinds , 988 F.2d at 1047. b. Facial Inconsistency “A verdict that resolves separate and distinct caus es of action in favor of both parties is not inconsistent on its face.” Har ris Mkt. Research v. Marshall Mktg. & Communications, Inc. , 948 F.2d 1518, 1522 (10th Cir. 1991). In contrast, when “several causes of action are identi cal and defended on the same ground, a verdict for the plaintiff on one cause of action and for the defendant on another is inconsistent.” Diamond Shamrock Corp. , 791 F.2d at 1425. To determine whether the verdicts in this case are irreconcilably inconsistent, we must examine the relationship betw een strict liability and negligence under Colorado law. In Fibreboard Corp. v. Fenton , 845 P.2d 1168, 1174 (Colo. 1993) (en banc), the Supreme Court of C olorado stated: Under a negligence theory a plaintiff is required t o prove that a manufacturer’s failure to warn of a risk fell belowan acceptable standard of care. Under a strict liability theory, however, the focus of the inquiry is whether the defendant failed to w arn of particular risks that were known or knowable in light of the g enerally recognized and prevailing scientific and technical knowledge available at the time of manufacture and distributi on.- 21 -

Despite the theoretical differences noted in Fibreb oard Corp. , we have recognized that Colorado has not drawn a “rigid distinction be tween negligence and strict liability failure to warn concepts.” Romero v. Int ernational Harvester Co. , 979 F.2d 1444, 1452 (10th Cir. 1992). For example, as with all tort claims, the plaintiff must prove the elements of causation and damages. More importantly, “[o]ne critical area of overlap is that, ‘[r]egardl ess of whether a product liability action is grounded in negligence or strict liability, a plaintiff must prove that the product was defective.’” Perlmutter v. United Stat es Gypsum Co. , 54 F.3d 659, 663 (10th Cir. 1995) (quoting Mile High Concrete, I nc. v. Matz , 842 P.2d 198, 205 (Colo. 1992)). Under either theory, the produc t must have been defective at the time of sale. See Perlmutter v. United States Gypsum Co. , 4 F.3d 864, 869 (10th Cir. 1993) (holding that in a negligence clai m, there is “no post-sale duty to warn or remedy when the product was non-defective u nder standards existing at the time of manufacture”); Fibreboard Corp. , 845 P.2d at 1175 (stating that “[i]n [strict liability] failure-to-warn cases, a productis not defective and unreasonably dangerous if a particular risk is not known or know able in light of the generally recognized and prevailing scientific and technical knowledge available at the time of manufacture and distribution”). In this case, the elements of defectiveness and cau sation were common to all of Oja’s claims. The record on appeal reveals that these two elements were5 The jury instruction regarding Oja’s negligent failure to warn claim stated: If a product manufacturer knows, or in the exercise of reasonable care should know, that use of the product may be harmful or injurious to a user, and such risk of harm or injury is not obvious to a reasonable surgeon, then the manufacturer must use reasonable care to warn the surgeon of the risk of harm or injury if, and to the extent, and in the manner, a reasonably careful person would warn under the same or similar circumstances. The duty to warn may extend beyond the time of sale of a product where a danger concerning the product becomes known to the manufacturer subsequent to the sale and delivery of the product, even though it was not known at the time of the sale. A manufacturer has no duty to warn surgeons regarding its product after the product is sold unless you find that the product was defective and unreasonably dangerous as originally designed and sold. Where dangerous defects in design come to the manufacturer’s attention after the device has been sold, the manufacturer has a duty to either remedy such defects, or, if such a complete remedy is not feasible, to give physicians adequate warnings and instructions concerning methods for minimizing danger and injury. Failure to do so is negligence. A manufacturer has no duty to warn surgeons using a product about a newly developed safety device if the product was not defective under standards existing at the time the product was manufactured. Whether or not the PCA hip was defective as originally sold should be determined by the standard set forth in these instructions of the plaintiff’s claim for sale of a defective product. Here, too, if the defendant had a duty to warn, it would be a duty to warn members of the medical profession, including the plaintiff’s surgeons.

- 22 - essentially the only elements disputed at trial. T o find for Oja on her negligent failure to warn claim, the jury had to find that th e PCA hip was defective at the time of sale and caused her injuries. 5 To find for Howmedica on Oja’s strict liability claim, the jury had to find that the PCA hip was either not defective at6 With respect to the strict liability for failure to warn claim, the jury instructions

stated in relevant part: For the plaintiff, Ms. Oja, to recover from the defendant, Howmedica, on her claim for sale of a defective product, you must find that all of the following facts have been proved by a preponderance of the evidence: (1) The PCA hip was defective and, because of one or more defects, it was unreasonably dangerous to a person who might reasonably be expected to use it or be affected by it; (2) The PCA hip was defective at the time it was sold by the defendant or left its control; (3) Plaintiff incurred injuries, damages or losses; and (4) The defect in the PCA hip was a cause of the plaintiff’s injuries, damages or losses.

- 23 - the time of sale or did not cause her injuries. 6 Given these parameters, we hold that the verdict for Oja on her negligent failure t o warn claim and the verdict for Howmedica on Oja’s strict liability failure to warnclaim were facially inconsistent. Accordingly, we vacate the judgment of the district court and order a new trial.
III. D IRECTED V ERDICT ON T HE M ANUFACTURING D EFECT C LAIM In her cross-appeal, Oja argues that the district c ourt erred in directing a verdict for Howmedica on Oja’s manufacturing defectclaim. The district court concluded that Oja had failed to present any eviden ce to support a jury finding that the PCA hip contained a manufacturing defect. Instead, the court found that Oja had presented evidence sufficient only to permi t a jury to find that the PCA hip suffered from a design defect.- 24 -

We review the district court’s grant of a directed verdict de novo, applying the same standard used by the district court. Knig ht v. Snap-on Tools Corp. , 3 F.3d 1398, 1401 (10th Cir. 1993). “A directed verd ict is appropriate only if the evidence, viewed in the light most favorable to the nonmoving party, ‘points but one way and is susceptible to no reasonable inferen ces supporting’ the nonmoving party.” Id. (internal citations omitted). “However, a mere sc intilla of evidence is insufficient to create a jury question.” Honce v. Vigil , 1 F.3d 1085, 1088 (10th Cir. 1993). Although federal law dictates whether a directed verdict is appropriate, in a diversity action we examine the e vidence in terms of the underlying burden of proof as dictated by state law . Mason v. Texaco, Inc. , 948 F.2d 1546, 1554 (10th Cir. 1991). In Hiigel v. General Motors Corp. , 544 P.2d 983, 988 (Colo. 1975), the Supreme Court of Colorado expressly adopted the doc trine of strict liability in tort for selling a product in a “defective conditio n unreasonably dangerous to the user or consumer” as stated in section 402A of the Restatement (Second) of Torts. To avoid a directed verdict in a strict liability a ction brought under Colorado law, a plaintiff must offer proof of each element set fo rth in section 402A sufficient to create an issue of fact. Belle Bonfils Mem’l Blood Bank v. Hansen , 665 P.2d 118, 125 n.12 (Colo. 1983). In particular, a plain tiff must offer sufficient evidence that the product at issue was in a “defect ive condition unreasonably- 25 -

dangerous” at the time the product was sold to the plaintiff. White v. Caterpillar,
Inc. , 867 P.2d 100, 104-05 (Colo. Ct. App. 1993). A cl aim of defect can be premised on a manufacturing, design, or warning def ect. Id. at 105. “The question in manufacturing defect cases is whether the product as produced conformed with the manufacturer’s specifications.” Camacho v. Honda Motor
Co. , 741 P.2d 1240,1247 (Colo. 1987). A defect in man ufacturing usually occurs because of insufficient quality control. See, e.g. , L EWIS B ASS , P RODUCTS L IABILITY : D ESIGN AND M ANUFACTURING D EFECTS , § 4.07, at 57 (1986). Under Colorado law, a plaintiff may prove a manufac turing defect by direct or circumstantial evidence. See Union Ins. Co. v. RCA Corp. , 724 P.2d 80, 82-83 (Colo. Ct. App. 1986). In this case, the staking p eg was completely missing when Dr. Evans removed Oja’s PCA hip. Under such condit ions, direct proof of a defect in the staking peg was impossible. See id. at 83. Accordingly, Oja relied exclusively on circumstantial evidence to support h er manufacturing defect claim. Oja’s surgeon testified that he made only a visua l check for improper staking before implanting the PCA hip. Her expert concluded that although the surgeon saw no noticeable defect in the device, the PCA hip could still have suffered from an internal manufacturing defect in t he staking peg. To support her claim, Oja introduced evidence that Howmedica recei ved at least two product experience reports (“PERs”) describing instances inwhich surgeons discovered a- 26 -

staking problem only after implanting the PCA hip and performing a trial reduction. In addition to those two PERs, Oja submitted six other PERs describing inadequate staking in PCA hips manufactured near th e time Howmedica manufactured Oja’s PCA hip. In particular, Howmedi ca received a PER on February 1, 1984, that stated: Nature of Complaint [By Surgeon]: Please replace to my stock-- no charge--while dislocating the hip during a trial reduction in surgery the plastic core came out of metal backing. Results of Evaluation [By Howmedica Employee]: The assembly staking on above part was inadequate. We have esta blished a push test & careful visual inspection (100%) on PCA acet abular cup assemblies which should preclude such failures. Similarly, Howmedica received a PER on August 27, 1 984, that stated: Nature of Complaint [By Surgeon]: Customer complains that the HDP is not close enough in the metal part. Results of Evaluation [By Howmedica Employee]: As received the fit of the insert to the cup was excellent but the stake holding the components together was poor. This part was of very early production (Oct. 1983) and the staking process stil l required improvement. The process has been improved and we have also added a “push test” to the stake to assure adequate assembly. Finally, Oja submitted evidence indicating that How medica rejected one of the PCA hips from the same lot as Oja’s PCA hip bec ause of a staking problem. The remaining devices in her lot underwent a “tight ness of plastic insert to cup VISUAL” test. Howmedica did not, however, conduct any other performance- 27 -

tests on the lot of PCA hips containing her hip. Oja claims the absence of adequate inspection and testing procedures increase d the likelihood that her PCA hip suffered from a manufacturing defect. We have carefully reviewed the record and conclude that Oja presented sufficient evidence from which a jury could reasonably conclude that Oja’s PCA hip suffered from a manufacturing defect. The stak ing peg in Oja’s PCA hip was completely missing. Within a year of the device’s manufacture, Howmedica sent a number of other PCA hips to surgeons that did not“conform to [Howmedica’s] specifications” because of inadequate staking. See Camacho , 741 P.2d at 1247. The PERs strongly suggest that problems with inadeq uate staking were not infrequent during early production of the PCA hip. More importantly, the PERs indicate that the problems could have been caused b y inadequate testing and inspection in the manufacturing process, in additio n to inadequate design. Under such circumstances, we hold that a jury could reaso nably conclude that Oja’s PCA hip suffered from a manufacturing defect.

CONCLUSION We AFFIRM the district court’s order finding that the MDA does not preempt Oja’s negligent failure to warn claim. We VACATE the judgment entered on the jury’s verdict and REMAND for a new trial because we hold that- 28 -

the jury’s verdict for Howmedica on the strict liab ility failure to warn claim but against Howmedica on the negligent failure to warn claim are irreconcilably inconsistent. We also REVERSE the directed verdictfor Howmedica on Oja’s strict liability manufacturing defect claim. Becau se we remand for a new trial, we do not address the remaining issues presented on ap peal.