                  United States Court of Appeals
                              For the Eighth Circuit
                          ___________________________

                                  No. 12-3130
                          ___________________________

                   Carol Mack; Aaron Mack, wife and husband

                        lllllllllllllllllllll Plaintiffs - Appellants

                                             v.

    Stryker Corporation, a Michigan corporation; Stryker Sales Corporation, a
                             Michigan corporation

                      lllllllllllllllllllll Defendants - Appellees
                                       ____________

                     Appeal from United States District Court
                    for the District of Minnesota - Minneapolis
                                   ____________

                             Submitted: October 24, 2013
                                Filed: May 12, 2014
                                   ____________

Before BYE, SMITH, and BENTON, Circuit Judges.
                           ____________

SMITH, Circuit Judge.

      Carol Mack underwent shoulder surgery in 2002. The surgeon inserted a pain
pump designed to infuse anesthetic into Mack's shoulder to mitigate her pain while
she recovered from surgery. Following surgery, Mack developed a painful shoulder
condition known as chondrolysis. Mack, along with her husband, sued Stryker
Corporation and Stryker Sales Corporation (collectively, "Stryker"), the manufacturer
and seller of the pain pump. Mack alleged negligence and strict products liability for
design defect and failure to warn. Her husband asserted a claim for loss of consortium.
The district court1 granted Stryker's motion for summary judgment. On appeal, Mack
contends that the district court misapplied the summary judgment standard by
construing the facts in a light more favorable to Stryker. Furthermore, Mack contends
that "[t]he district court . . . disregarded admissible expert testimony and instead relied
upon the court's own inexpert interpretation of technical evidence and its relevance to
conclude that there was no evidence that Stryker should have known of the risk to
cartilage posed by its pain pump." We affirm.

                                      I. Background
       Mack underwent arthroscopic shoulder surgery on August 1, 2002, to alleviate
persistent pain in her left shoulder. Near the surgery's conclusion, the surgeon inserted
a pain pump that Stryker had manufactured, marketed, and sold to him. The pump
consisted of a pumping mechanism and anesthetic reservoir attached to a catheter. The
pain pump was designed to deliver a set dosage of an anesthetic, in this case
bupivacaine, at regular intervals into a patient's surgically repaired shoulder for
approximately two days to assist in the patient's recovery from surgery. Specifically,
the pump was designed to inject bupivacaine directly into the glenohumeral joint
space of the patient's shoulder. Stryker marketed its pain pumps for this use.

       The glenohumeral joint consists of a ball (humeral head) and socket (the
glenoid). During shoulder movement, the ball glides (articulates) against the socket.
A layer of articular cartilage acts as a cushion by covering the ball and socket, thus
preventing painful bone-on-bone contact during shoulder movement. Articular
cartilage is found only in enclosed joint spaces like the glenohumeral joint. Articular
cartilage is somewhat unique in that synovial fluid, not blood, nourishes the cartilage


      1
      The Honorable Paul A. Magnuson, United States District Judge for the District
of Minnesota.

                                           -2-
cells. When these cartilage cells no longer receive nourishment from synovial fluid,
they die. Eventually, the cartilage matrix comprised of these dead cells dissipates until
no cartilage remains. When no cartilage remains, shoulder movement is accompanied
by painful bone-on-bone contact where the ball and socket interact without the
protective cushion. Chondrolysis is the painful medical condition whereby an
individual loses articular cartilage in a joint.

      Following her surgery, Mack began to experience additional shoulder pain. She
began receiving additional treatment and therapy on the shoulder in 2003. By January
2004, Mack was diagnosed with chondrolysis. Mack underwent several additional
shoulder surgeries to combat chondrolysis's effects.

        Mack brought this diversity suit against Stryker on July 13, 2010. Mack
asserted several theories of recovery, including negligence and strict products liability
based on a design defect and failure to warn.2 The district court granted Stryker's
motion for summary judgment. Mack v. Stryker Corp., 893 F. Supp. 2d 976, 978 (D.
Minn. 2012). The district court reasoned that, based on the medical literature existing
at the time of Mack's surgery in 2002, it was not reasonably foreseeable to Stryker that
the use of its pain pump in an articular joint would lead to joint damage. Id. at 987. In
fact, the medical community was unaware of any link between pain pumps and
chondrolysis until at least 2007.3 Id. The district court noted that it was "troubled by
the hindsight and speculation necessary to find in favor of Mack." Id. The district


      2
        Mack also asserted causes of action for fraud, negligent misrepresentation, and
breach of warranties. Mack abandoned these causes of action prior to the district
court's summary judgment determination.
      3
       Other courts have determined that the medical community did not find a
specific link between intra-articular use of pain pumps and chondrolysis until 2005.
See Rodriguez v. Stryker Corp., 680 F.3d 568, 570–71 (6th Cir. 2012). We need not
determine the specific date of the medical community's discovery because the parties
agree that it was years after Mack's surgery in 2002.

                                          -3-
court added that "[t]he law does not obligate Stryker to be a pioneer, particularly when
existing literature did not objectively forewarn of injury," id. at 987 (citation omitted),
and "[i]t would be nothing short of rank speculation to suggest that any testing Stryker
may have undertaken prior to 2002 would necessarily have revealed the causal
connection that is still arguably unsettled today," id. at 988 (citation omitted).

                                    II. Discussion
       Mack contends on appeal that the district court erred by failing to recognize the
extent of the medical community's knowledge of the risks associated with intra-
articular pain pumps at the time of Mack's surgery. Mack also disputes the effect of
the Food and Drug Administration's (FDA) failure to clear intra-articular pain pumps
for postoperative use.

      "We review de novo a district court's grant of summary judgment." Rester v.
Stephens Media, LLC, 739 F.3d 1127, 1130 (8th Cir. 2014) (citation omitted).
Summary judgment is appropriate "if the movant shows that there is no genuine
dispute as to any material fact and the movant is entitled to judgment as a matter of
law." Fed. R. Civ. P. 56(a). "We view the facts in the light most favorable to the
nonmoving party and give that party the benefit of all reasonable inferences that can
be drawn from the record." Spencer v. Jackson Cnty. Mo., 738 F.3d 907, 911 (8th Cir.
2013) (quotation, alteration, and citation omitted). The parties agree that Minnesota
substantive law applies.

       In Minnesota, a plaintiff who asserts a strict products liability claim must
demonstrate "that (1) the product was in fact in a defective condition, unreasonably
dangerous for its intended use; (2) such defect existed when the product left
defendant's control; and (3) the defect was the proximate cause of the injury
sustained." Lee v. Crookston Coca-Cola Bottling Co., 188 N.W.2d 426, 432 (Minn.
1971). To recover on a negligence theory, the plaintiff must show "(1) the existence
of a duty of care; (2) a breach of that duty; (3) an injury; and (4) the breach of the duty

                                           -4-
being the proximate cause of the injury." Schafer v. JLC Food Sys., Inc., 695 N.W.2d
570, 573 (Minn. 2005). The Supreme Court of Minnesota has stated that, in the design
defect context, there is little or no distinction between strict liability and negligence.
See Lee, 188 N.W.2d at 432 ("While in conventional tort terms no proof of negligence
is necessary [in a strict products liability action], in many cases proof of a defect may
simply be a substitute word for negligence."); see also Piotrowski v. Southworth
Prods. Corp., 15 F.3d 748, 751 (8th Cir. 1994) ("Where design defect cases are
involved, Minnesota merges the theories of strict liability and negligence.") (citation
omitted).

      The Supreme Court of Minnesota has explained:

            A manufacturer is obligated to exercise that degree of care in his
      plan or design so as to avoid any unreasonable risk of harm to anyone
      who is likely to be exposed to the danger when the product is used in the
      manner for which the product was intended, as well as an unintended yet
      reasonably foreseeable use.

            What constitutes "reasonable care" will, of course, vary with the
      surrounding circumstances and will involve a balancing of the likelihood
      of harm, and the gravity of harm if it happens, against the burden of the
      precaution which would be effective to avoid the harm.

Bilotta v. Kelley Co., Inc., 346 N.W.2d 616, 621 (Minn. 1984) (quotations, alteration,
and citations omitted).

       Drug and medical device manufacturers have "the duty to exercise ordinary and
reasonable care not to expose the potential consumer to an unreasonable risk of harm
from the use of its products." O'Hare v. Merck & Co., 381 F.2d 286, 291 (8th Cir.
1967) (adjudicating a negligence claim under Minnesota law). They have a duty to test
and investigate their products based upon the foreseeable risk of harm to potential
users in light of current medical knowledge and discoveries. Id. Manufacturers are

                                           -5-
held to the skill of an expert in the field that their products enter, and they are
obligated to keep informed of medical knowledge and discoveries in that field. Id.
Thus, "[t]he manufacturer is held accountable as an expert in its field only for those
dangers of which it has knowledge or those which it could discover through the
exercise of reasonable care." Id. (footnote omitted).

       However, drug manufacturers are not insurers of the products that they sell. Id.
at 290–91. Consequently, no liability attaches where the harmful effects of a product
are those that no human skill or foresight could have predicted. Id. at 291. "The
manufacturer's duty to warn users of the potential danger inherent in its product is
commensurate with its actual knowledge of the risk involved to those users or the
knowledge constructively imparted to it by available scientific or other medical data."
Id.

       According to Minnesota law, therefore, the foreseeability of potential harm
determines the existence and extent of the manufacturer's duty to warn. See id.; see
also Whiteford by Whiteford v. Yamaha Motor Corp., U.S.A., 582 N.W.2d 916, 918
(Minn. 1998) ("In Minnesota, it is well settled that a manufacturer has a duty to
protect users of its products from foreseeable dangers. But if the danger is not
foreseeable, there is no duty.") (footnotes omitted). "In determining whether a danger
is foreseeable, courts look at whether the specific danger was objectively reasonable
to expect, not simply whether it was within the realm of any conceivable possibility."
Whiteford, 582 N.W.2d at 918 (footnote omitted).

       Finally, the Supreme Court of Minnesota has acknowledged that
"[f]oreseeability of injury is a threshold issue related to duty that is ordinarily
'properly decided by the court prior to submitting the case to the jury.'" Domagala v.
Rolland, 805 N.W.2d 14, 27 (Minn. 2011) (quoting Alholm v. Wilt, 394 N.W.2d 488,
491 n.5 (Minn. 1986)). The court submits the issue of foreseeability to the jury only
"in close cases." Domagala, 805 N.W.2d at 27. Minnesota's foreseeability test "look[s]

                                         -6-
to the defendant's conduct and ask[s] whether it was objectively reasonable to expect
the specific danger causing the plaintiff's injury." Id. (citation omitted). However,
"[t]he test is not whether the precise nature and manner of the plaintiff's injury was
foreseeable, but whether the possibility of an accident was clear to the person of
ordinary prudence." Id. (quotation and citations omitted).

                                  A. Medical Literature
       To establish that the use of pain pumps in articular joints presented a
foreseeable risk of harm at the time of Mack's surgery, Mack provided the expert
testimony of Dr. Stephen Trippel, an orthopedic surgeon who specializes in the study
of articular cartilage. In his declaration, Dr. Trippel opined that "[l]ong before 2000,
existing medical and scientific knowledge of the anatomy and physiology of joint
spaces and intra-articular cartilage indicated that continuous exposure to foreign
[s]olutions could be harmful to the articular cartilage." He further stated:

             Prior to 2000, what was known by medical science about joints
      and the fragility of cartilage would have put a careful and prudent and
      reasonable medical device maker on notice that continuous infusion of
      commonly used anesthetics over a period of two to three days into a joint
      space would likely risk injury to the cartilage. There was enough
      information available, even before studies investigating the effect of
      irrigation solutions and local anesthetics on articular cartilage, to raise
      serious concern that there would likely be a problem if the articular
      cartilage were continually exposed to these substances for two to three
      days.

       Stryker moved to exclude Dr. Trippel's testimony, arguing that his "opinion
[that] Stryker was on notice that continuous infusion of local anesthetics into the intra-
articular space was likely unsafe is unreliable because his own reliance literature does
not support his opinion." In granting Stryker's motion for summary judgment, the
district court denied as moot Stryker's motion to exclude Dr. Trippel's testimony. The
district court agreed with Stryker that the medical literature at the time of Mack's

                                           -7-
surgery "d[id] not support the conclusion that in 2002 Stryker should have known that
its pain pump could ca[u]se cartilage damage." Mack, 893 F. Supp. 2d at 987.
Consequently, we must determine whether the district court correctly concluded that
the existing medical literature in 2002 was insufficient to allow Stryker to foresee the
risk of articular cartilage damage from the use of its pain pumps for infusion of intra-
articular anesthetics.

       To support his opinion, Dr. Trippel relied on 12 medical articles that were
published prior to Mack's surgery. The first article detailed a study whereby the
researcher injected substances into rabbit joints to determine the effects of joint
injections. See J. Albert Key, The Production of Chronic Arthritis by the Injection of
Weak Acids, Alkalies, Distilled Water, and Salt Solution into Joints, 15 J. Bone &
Joint Surgery 67, 84 (1933). After explaining the study's experimental design, Dr.
Trippel relayed the researcher's findings "that in all cases, that is for all of the[]
solutions, even the regular saline, the injections led to the rabbits getting arthritis in
their knees." Furthermore, the severity of the arthritis correlated with the number of
injections into the joint. Dr. Trippel extrapolated these conclusions to device
manufacturers by noting that "[a]ny manufacturer reading this study would know that
continuous injection into a joint for two to three days could risk harm to the cartilage."

       The second article that Dr. Trippel relied upon for his opinion was similar to the
Key article in that researchers determined that saline solution harmed cartilage. See
Brian F. Reagan et al., Irrigating Solutions for Arthroscopy, A Metabolic Study, 65 J.
Bone & Joint Surgery 629 (1983). Dr. Trippel explained the researchers' findings "that
normal saline concentrations when given for one, two, five and eight hours was
inhibitory to cartilage health." Dr. Trippel also stated that "[t]he time-and-dose
response addressed in this article showed that the longer the cartilage was exposed to
the saline, the worse the effect on the cartilage cells could be."




                                           -8-
       Dr. Trippel also relied on an article whereby researchers studied the effect of
inundating articular cartilage from pigs and dogs with bupivacaine for up to two
hours. See Roberta Nole et al., Bupivacaine and Saline Effects on Articular Cartilage,
1 Arthroscopy 123, 126 (1985). Dr. Trippel noted that the researchers found that
bupivicaine inhibited cartilage cells; however, articular cartilage cells recovered from
a maximum two-hour exposure within three days. The fourth article upon which Dr.
Trippel relied was a literature review whereby the authors stated that, based on the
Nole article, little was known about the long-term effects of the acute inhibition of
articular cartilage cells. See John P. Fulkerson & Thomas F. Winters, Jr., Articular
Cartilage Response to Arthroscopic Surgery: A Review of Current Knowledge, 2
Arthroscopy 184 (1986). The Fulkerson article contained no new findings.

       Dr. Trippel also relied on an article detailing a study wherein researchers
repeatedly injected rabbit joints with saline solutions and determined that repeated
injections of saline over four weeks inhibited the synthesis of a vital protein used to
generate cartilage cells. See J. Neidel et al., Intra-articular Injections and Articular
Cartilage Metabolism: An Experimental Study in Rabbits, 111 Archives of
Orthopaedic and Trauma Surgery 237 (1992). The study concluded that prolonged
exposure to the saline solution prevented the cartilage from ever recovering.

       The sixth study upon which Dr. Trippel relied showed how cartilage exposure
to various solutions, none of which were anesthetics, over periods of two, four, and
twenty hours demonstrated a "softening effect" upon the cartilage, indicating cartilage
damage. See J.S. Jurvelin et al., Effects of Different Irrigation Liquids and Times on
Articular Cartilage: An Experimental, Biomechanical Study, 10 Arthroscopy 667
(1994). Next, Dr. Trippel relied on a study in which researchers immersed the knee
joints of rats into various solutions to determine the effect of these solutions on
articular cartilage. See S.K. Bulstra et al., The Effect In Vitro of Irrigating Solutions
on Intact Rat Articular Cartilage, 76–B Journal of Bone & Joint Surgery 468 (1994).



                                          -9-
Dr. Trippel averred that the study demonstrates that a variety of substances harm
articular cartilage upon contact.

        The eighth article upon which Dr. Trippel relied involved the testing of
morphine (a different anesthetic) on human articular cartilage. See John W. Jaureguito
et al., The Effects of Morphine on Human Articular Cartilage of the Knee: An In Vitro
Study, 18 Arthroscopy 631 (2002). The researchers in this article used saline solutions,
saline solutions mixed with different concentrations of morphine, and combinations
of morphine and bupivacaine.

       The ninth and tenth articles upon which Dr. Trippel relied contained case
reports regarding patients who lost cartilage in their shoulders following surgery. See
Y. Shibata et al., Chondrolysis of the Glenohumeral Joint Following a Color Test
Using Gentian Violet, 25 International Orthopedics 401 (2001); Kazuya Tamai et al.,
Chondrolysis of the Shoulder Following a "Color Test"—Assisted Rotator Cuff
Repair—A Report of 2 Cases, 68 Acta Orthopaedica Scandinavica 401 (1997). The
cartilage loss resulted from direct injection of gentian violet (a dye) into the
glenohumeral joint.

       The penultimate article upon which Dr. Trippel relied detailed six reports where
patients' knees were accidentally irrigated with chlorhexidine 1% in aqueous solution
during arthroscopy. See C.M. Douw et al., Clinical and Pathological Changes in the
Knee After Accidental Chlorhexidine Irrigation During Arthroscopy. Case Reports
and Review of the Literature, 80–B The Journal of Bone and Joint Surgery 437
(1998). All six patients developed chondrolysis in the knee. Similarly, the last article
upon which Dr. Trippel relied described three patients who developed chondrolysis
after receiving 0.02% aqueous chlorhexidine solution during arthroscopic knee
surgery. See A.L. Van Huyssteen & D.J. Bracey, Chlorhexidine and Chondrolysis in
the Knee, 81–B Journal of Joint and Bone Surgery 995 (1999). Dr. Trippel used this



                                         -10-
study to demonstrate that joint exposure to low concentrations of chlorhexidine can
cause extensive damage to articular cartilage.

       Mack contends that the district court "failed to understand and analyze the
literature" that supported Dr. Trippel's conclusion that pain pump manufacturers like
Stryker should have known about potential risks inherent in continuously infusing any
type of solution into articular joints. Stryker responds by noting that even Dr. Trippel
admitted that the medical community had not drawn a connection between continuous
infusion of a local anesthetic into an intra-articular joint and chondrolysis until 2005
or 2007. The question thus becomes whether the 12 articles support Dr. Trippel's
opinions such that a jury should determine whether a device manufacturer could
reasonably foresee that continuous infusion of bupivacaine into Mack's glenohumeral
joint would harm her articular cartilage, notwithstanding that the medical community
did not discern chondrolysis specifically as a risk until years after Mack's surgery.

       We agree with the district court that the 12 articles underpinning Dr. Trippel's
opinions do not support his conclusions. As the district court recognized, most of the
articles that Dr. Trippel cites do not involve the study of the effects of continuous
infusion of bupivacaine or other anesthetics in articular joints. See Mack, 893 F. Supp.
2d at 986. The Key, Reagan, Jurvelin, Bulstra, and Neidel articles involve the
injection of saline solutions rather than anesthetics, so the manufacturer of a device
designed to infuse anesthetics into the articular joint would have no reason to
conclude that anesthetic infusion could harm the joint based on these articles. See id.
The same problem arises with the Tamai and Shibata articles (gentian dye) and the
Douw and Van Huyssteen articles (antiseptic chlorhexidine). See id.

       The remaining articles, which involved the study of anesthetics, also fail to alert
reasonable manufacturers like Stryker to the dangers of continuous infusion of
bupivacaine into articular joints. For example, the conclusions of the Nole article
directly conflict with Dr. Trippel's opinions. The Nole article would not alert a

                                          -11-
reasonable medical device manufacturer like Stryker of the risk of its pain pumps. The
district court explained that Nole concluded that "b[u]p[i]vacaine itself seems to be
fairly well tolerated by articular cartilage, but the saline solution in which it is
prepared is transiently inhibitory of the uptake of sulfates in articular cartilage." Mack,
893 F. Supp. 2d at 986 (quoting Nole, supra, at 126). Furthermore, "Nole also
concluded that there was '[no] immediate need to stop the use of intraarticular
bupivacaine.'" Id. (alteration in original) (quoting Nole, supra, at 126). Finally, the
district court stated that "Nole further reported that affected cells recovered after three
days, thereby suggesting that any impact was fleeting and reversible." Id. (citing Nole,
supra, at 126). Consequently, even careful study of the Nole article would fail to alert
pain pump manufacturers of the dangers that Dr. Trippel asserts.

       The Jaureguito article contains similar assurances, for it stated that solutions
containing bupivacaine and morphine had no "'deleterious effect' on human articular
cartilage." Id. (quoting Jaureguito, supra, at 635). As the district court noted, the
Jaureguito article was also distinguishable because it involved older patients with
advanced osteoarthritis. Id. at 982. Thus, the Jaureguito article also fails to alert
Stryker to a foreseeable risk of harm to articular cartilage.4

       Furthermore, the articles that Dr. Trippel identifies fail to capture the full
context of the relevant medical knowledge at the time of Mack's surgery. First,
surgeons have used "pain pumps to provide anesthetics to post-operative joints for
years." Rodriguez, 680 F.3d at 570. Second, Stryker provides several articles that
recognize the safety and effectiveness of placing pain pumps in articular joints. See,
e.g., Barber et al., The Effectiveness of an Anesthetic Continuous–Infusion Device on


      4
        Additionally, the Jaureguito study was published only one month before
Mack's surgery. Id. at 986 n.9. Because we conclude that it would not have provided
Stryker with notice of potential harm, we need not decide whether publication of an
article one month before a patient's surgery gives a medical device manufacturer
enough time to read, understand, and adapt to the article's findings.

                                           -12-
Postoperative Pain Control, 18 Arthroscopy 76 (2002); Narinder Rawal et al.,
Postoperative Patient-Controlled Local Anesthetic Administration at Home, 86
Anesthesia & Analgesia 86 (1997). In one study, researchers set out "to examine the
effectiveness of an intra-articular pain catheter for controlling postoperative pain
following arthroscopic" surgery. Ken Yamaguchi et al., Postoperative Pain Control
Following Arthroscopic Release of Adhesive Capsulitis: A Short-Term Retrospective
Review Study of the Use of an Intra-Articular Pain Catheter, 18 The Journal of
Arthroscopic and Related Surgery 359, 360 (2002). The researchers studied 20
patients who received continuous infusion of bupivacaine in their articular joints. Id.
at 361–62. Out of 20 patients, only one patient experienced any complication from use
of the pain pump—a temporary complication unrelated to chondrolysis. Id. at 363.
The article concluded that "[t]he results of this study suggest that delivery of
bupivacaine through an indwelling intra-articular pain catheter can be a highly
effective means of achieving pain control following arthroscopic" surgery, especially
where "[t]here were no direct complications with this method, including no
infections." Id. at 364.

       Our decision today is consistent with the Sixth Circuit's decision in Rodriguez.
Like the district court here, the Rodriguez court considered Dr. Trippel's opinions and
the bases for them, which included the same 12 articles that Dr. Trippel presented in
the present case. Id. at 570–71.5 The Rodriguez court adopted the reasoning of the
district court from which Rodriguez appealed, which stated:

      While the pre-2004 medical articles raise the general notion that health
      of (usually animal) cartilage could be weakened by prolonged exposure
      to certain "foreign elements," it is a bridge way too far to say that
      Stryker—in the context in which infusion pumps were broadly used and
      medically accepted without reservation—should have, prior to marketing


      5
      In fact, Dr. Trippel relied on a thirteenth study in Rodriguez because Rodriguez
underwent shoulder surgery in 2004.

                                         -13-
      the pain pump, culled through seven decades of literature, found the
      sporadic articles raising this concern, ignored all the authority/evidence
      to the contrary, and then independently concluded that its pain pump
      could cause chondrolysis, particularly where no one in the medical
      community connected the destruction of cartilage to the use of pain
      pumps until after the plaintiff's surgery.

Id. at 573. We agree.6 The 12 articles that Dr. Trippel submits do not warn against the
continuous infusion of bupivacaine in articular joints. Furthermore, other articles
trumpeted the use of bupivacaine-injecting pain pumps into articular spaces. See, e.g.,
Yamaguchi, supra, at 364. Mack fails to show that any "specific danger was
objectively reasonable to expect"; therefore, we hold that Mack has demonstrated
merely that articular cartilage damage "was within the realm of any conceivable
possibility." See Whiteford, 582 N.W.2d at 918. "[N]o developed human skill or
foresight" could have led a medical device manufacturer to select Dr. Trippel's
articles, read them between the lines, ignore their conclusions, and ignore the plethora
of other articles that recommended to the contrary. See O'Hare, 381 F.2d at 291
(quotation and citation omitted). Consequently, we conclude that Stryker could not
have foreseen the potential for articular cartilage damage as the result of the surgical
implementation of its pain pump based on the medical community's knowledge in



      6
        A separate panel of the Sixth Circuit decided a similar case to Rodriguez less
than three months later, and it reversed a district court's decision to grant summary
judgment to a pain pump manufacturer without acknowledging Rodriguez. See
Krumpelbeck v. Breg, Inc., 491 F. App'x 713 (6th Cir. 2012) (unpublished).
Krumpelbeck and Rodriguez directly conflict. We decline to consider Krumpelbeck
because it is not the law of this circuit and likely not the law of the Sixth Circuit due
to Rodriguez's prior publication. See Rutherford v. Columbia Gas, 575 F.3d 616, 619
(6th Cir. 2009) ("A published prior panel decision remains controlling authority unless
an inconsistent decision of the United States Supreme Court requires modification of
the decision or this Court sitting en banc overrules the prior decision." (quotation and
citation omitted)). Additionally, we do not find it persuasive.

                                          -14-
2002. Stryker, as a matter of law, had no duty to protect or warn Mack of the harm
that Stryker's pain pumps may inflict. See Domagala, 805 N.W.2d at 27.

                                    B. FDA Denial
       Stryker and its predecessors in interest sought FDA approval for the use of pain
pumps in the late 1990s. Typically, a company has two avenues by which to obtain
FDA approval. See Medtronic, Inc. v. Lohr, 518 U.S. 470, 477–79 (1996). First, the
company could pursue the more rigorous premarket approval (PMA) process whereby
the FDA scrupulously evaluates the device's safety and effectiveness. See id. at 477.
To avoid the costly, time-consuming PMA process, device manufacturers can seek
clearance by providing "premarket notification" to the FDA. Id. at 478. Known as the
"§ 510(k)"7 process, the FDA would then approve a device if the manufacturer
demonstrates that a "substantially similar" product is currently in use for that purpose.
See id. at 478–79.

        Stryker obtained § 510(k) clearance for its pain pump for "intraoperative" use;
the parties agree that "intraoperative use" generally means a location on the body
where surgery is performed. However, Stryker twice sought § 510(k) clearance for use
of its pain pump in articular spaces, yet the FDA denied § 510(k) clearance on both
occasions. These denials occurred before Mack's surgery. The FDA denied clearance
because of the lack of a "substantially similar" predicate device. As the district court
noted, Mack does not contend that the FDA denials alone subject Stryker to liability.
Mack, 893 F. Supp. 2d at 985. Furthermore, Mack presents no evidence that the FDA
denied Stryker's applications because of safety concerns or that Stryker violated any
FDA regulation. Id. at 985–86. Mack contended before the district court that the FDA
denials should have prompted Stryker to conduct safety tests on its pain pumps. Id.
at 986. The district court rejected Mack's argument, stating that "[i]t would be illogical


      7
       The "510(k)" process is named after the section number given to this process
in the Medical Device Amendments of 1976.

                                          -15-
to conclude that the FDA denial, which was not based on safety concern, and did not
raise a safety concern within Stryker, triggered to duty to undertake safety testing or
to warn of safety concerns." Mack, 893 F. Supp. 2d at 986.

       On appeal, Mack avers that "the FDA denials told Stryker [ ] that it was not
permitted to market pain pumps for intra-articular use because nobody had proven that
such use was safe." Additionally, Mack contends that a denial of clearance based on
the lack of a predicate device implicates safety because "a predicate device is a device
that has been shown to be safe and effective for the intended use."

       The Supreme Court has already rejected such arguments. See Medtronic, 518
U.S. at 492–93. The Medtronic Court explained that, pursuant to the § 510(k) process,
medical device manufacturers must demonstrate that their devices are substantially
equivalent to devices that were on the market before Congress passed the Medical
Device Amendments of 1976. Id. at 477–78. Congress enacted this exception because
several pre-1976 devices were grandfathered into the market such that they need not
obtain PMA approval. Id. Thus, the § 510(k) exception exists to prevent these
manufacturers from monopolizing the market while new devices cleared PMA and to
ensure that improvements to existing devices could be introduced into the market
quickly. Id. at 478. Because § 510(k) allows more recent devices to be grandfathered
into the market without undergoing the PMA process, § 510(k) is concerned with
"equivalence, not safety." Id. at 493 (citation omitted). The § 510(k) process protects
the public little. Id. Post Medtronic, § 510(k) rejections typically do not alert device
manufacturers that their products are unsafe.

       Medtronic applies here. The FDA denials did not indicate to Stryker that use
of its pain pumps in intra-articular spaces was unsafe or could result in foreseeable
harm.




                                         -16-
                                  III. Conclusion
       Therefore, we affirm the district court's decision to grant summary judgment
to Stryker.

BYE, Circuit Judge, dissenting.

      I believe Carol Mack is entitled to have a jury determine whether the use of pain
pumps in articular joints presented a foreseeable risk of harm at the time of her August
2002 shoulder surgery. I therefore respectfully dissent.

       As the court acknowledges, the issue of foreseeability under Minnesota law is
reserved for the jury's determination in "close cases." Ante at 6 (quoting Domagala
v. Rolland, 805 N.W.2d 14, 27 (Minn. 2011)). In Huggins v. Stryker Corp., 932 F.
Supp. 2d 972 (D. Minn. 2013), a federal district court addressed a similar claim
involving a February 2002 surgery date and determined "a jury could reasonably find
by a preponderance of the evidence that Stryker should have known the risks of intra-
articular pain pump use [in February 2002]." Id. at 990. In denying Stryker's motion
for summary judgment, the court noted that Minnesota requires the issue of
foreseeability to be submitted to the jury in "close cases." Id. at 986.

       Significantly, the medical literature at issue in Huggins is essentially the same
medical literature at issue in this case. See id. at 978-79 & n.4 (involving ten of the
same twelve published studies dating between 1933 and 1999 which were relied upon
by Mack's experts). The district court indicated cases "across the country" have
addressed whether pain pump manufacturers such as Stryker knew or should have
known intra-articular pain pump use could cause cartilage damage based on the
existing medical literature, and noted the courts "have confronted this issue with
inconsistent results." Id. at 986-87 (citing cases where summary judgment has been
both granted and denied). In addition to Huggins, summary judgment has been denied
in several cases involving surgery dates comparable to Mack's August 2002 surgery.

                                         -17-
See Hackett v. Breg, Inc., Civ. No. 10-1437, 2011 WL 4550186, at *1 (D. Colo. Oct.
3, 2011) (involving an April 3, 2002, surgery date); Creech v. Stryker Corp., No.
2:07CV22 DAK, 2012 WL 33360 at *1 (D. Utah Jan. 6, 2012) (involving six surgeries
between February 2003 and July 2004); Kildow v. Breg, Inc., 796 F. Supp. 2d 1295,
1298 (D. Or. 2011) (involving surgeries in July 2003 and March 2004).8 Huggins also
noted "multiple juries have found that the risks were foreseeable" when the jury was
allowed to consider the issue. See Huggins, 932 F. Supp. 2d at 987 (citing the final
judgment in Hackett, and Beale v. I-Flow Corp., No. 0801-01554 (Ore. Cir. Ct.
Multnomah Cnty. Dist. Jan. 22, 2010)).

       Given the inconsistent decisions reached on the issue of foreseeability by both
reasonable judges and reasonable jurors, I fail to see how we can conclude Mack's
claim on foreseeability is anything but a "close case." Minnesota law thus allows her
to have a jury decide her claim. I therefore disagree with our decision to affirm the
grant of summary judgment in favor of Stryker. I would reverse the district court and
remand this "close case" for a jury trial.
                        ______________________________




      8
      The slight difference in surgery dates is immaterial where the majority of the
medical literature at issue was published by 1999.

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