United States Court of Appeals
                         FOR THE EIGHTH CIRCUIT
                                 ___________

                                 No. 06-1638
                                 ___________

HDC Medical, Inc.,                    *
                                      *
            Appellant,                *
                                      * Appeal from the United States
      v.                              * District Court for the
                                      * District of Minnesota.
Minntech Corporation,                 *
                                      *
            Appellee.                 *
                                 ___________

                           Submitted: October 19, 2006
                              Filed: January 25, 2007
                               ___________

Before SMITH, BOWMAN, and COLLOTON, Circuit Judges.
                           ___________

SMITH, Circuit Judge.

      HDC Medical, Inc ("HDC") and Minntech Corporation ("Minntech") are
competitors in a specialized medical-device market. HDC brought suit against
Minntech alleging exclusionary and predatory conduct in violation of the Sherman
Act. The district court1 granted Minntech's motion for summary judgment. HDC
appeals. We affirm.




      1
        The Honorable Ann D. Montgomery, United States District Judge for the
District of Minnesota.
                                    I. Background
       Both HDC and Minntech manufacture dialyzer reprocessing machines.
Minntech manufactures a dialyzer reprocessing machine called "the Renatron," while
HDC produces "the MAKY." Dialyzer reprocessing machines work in conjunction
with dialyzers. Dialyzers, which filter blood waste products, serve as an artificial
kidney in hemodialysis. Dialyzers come in two forms: single-use and multiple-use.
Single-use dialyzers are disposable and can be used only once. Multiple-use dialyzers,
on the other hand, can be used repeatedly if cleaned by a dialyzer-reprocessing
machine. Dialyzer reprocessing machines sanitize multiple-use dialyzers using
chemical mixtures called reprocessing solutions. Minntech produces a reprocessing
solution marketed as Renalin. HDC Medical also produces a reprocessing solution
marketed as Peracidin.

      Beginning in 2000, Minntech began modifying the design of the Renatron.
These modifications, HDC alleges, rendered HDC's reprocessing solution, Peracidin,
incompatible with the Minntech dialyzer reprocessing machines, the Renatron.
Additionally, these modifications, HDC alleges, were accompanied by Minntech
warranty manipulations, slander of the HDC products and tying arrangements
intended to push HDC out of the reprocessing solution market.

      HDC sued Minntech, alleging that Minntech's actions violated the Sherman Act,
15 U.S.C. §§ 1, 2. Minntech successfully moved for summary judgment and the case
was dismissed. The district court dismissed HDC's monopoly claim after determining
no genuine issue of material fact existed regarding Minntech's power in the relevant
market. The district court also dismissed HDC's attempted monopoly claim after
determining that no genuine issue of material fact existed regarding Minntech's
alleged anticompetitive conduct or Minntech's dangerous probability of success.




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                                     II. Discussion
       "We review de novo a grant of summary judgment, considering the facts in the
light most favorable to the nonmoving party. Summary judgment is proper when no
genuine issues of material fact exist and the moving party is entitled to judgment as
a matter of law." Nat'l Am. Ins. Co. v. W & G, Inc., 

, 945 (8th Cir. 2006)
(internal citations omitted). The courts should enter summary judgment on the merits
in antitrust litigation sparingly. Lomar Wholesale Grocery, Inc. v. Dieter's Gourmet
Foods, Inc., 

, 585 (8th Cir. 1987). However, where there has been ample
opportunity for discovery, summary judgment is appropriate in antitrust cases, just as
in any other litigation, upon a showing of an absence of any genuine issue of material
fact. Willmar Poultry Co. v. Morton-Norwich Prods, Inc. 

, 293 (8th Cir.
1975).

                              A. Monopolization Claim
       A prima facie claim of monopolization under the Sherman Act requires a
plaintiff to show that the defendant "possessed monopoly power in the relevant
market" and "willfully acquired or maintained that power." Amerinet, Inc. v. Xerox
Corp., 

, 1490 (8th Cir. 1992). To establish that a defendant possesses
the requisite market power required for monopolization liability, a plaintiff must
establish that the defendant has a dominant market share in a well-defined relevant
market. Morgenstern v. Wilson, 

, 1296 (8th Cir. 1994).

       The relevant product market is a question of fact, which the plaintiff bears the
burden of proving. 

noted, "Antitrust claims often rise or fall on the
definition of the relevant market." Bathke v. Casey's Gen. Stores, Inc., 

,
345 (8th Cir. 1995). The relevant market has two components—a product market and
a geographic market. 

parties dispute only the relevant product market.
The district court found that single-use and multiple-use dialyzers are competitors in
the same market and concluded that Minntech did not possess monopoly power in the



                                         -3-
relevant market. HDC, however, contends that single-use and multiple-use dialyzers
do not compete in the same product market.

       The boundaries of the product market can be determined by the reasonable
interchangeability or cross-elasticity of demand between the product itself and
possible substitutes for it. Brown Shoe Co. v. United States, 

, 325 (1962);
United States v. Archer-Daniels-Midland Co., 

, 246 (8th Cir. 1988) cert.
denied; 

(1989). In other words, the product market can be determined
by analyzing how "consumers will shift from one product to the other in response to
changes in their relative costs." SuperTurf, Inc. v. Monsanto Co., 

, 1278
(8th Cir. 1981). To conduct this inquiry, the courts must weigh several factors
including, industry or public recognition of the products as a separate economic entity,
the product's peculiar characteristics and uses, unique production facilities, distinct
customers, distinct prices, sensitivity to price changes, and specialized vendors. Brown
Shoe 

.

       The district court granted Minntech's motion for summary judgment after
finding that multiple-use dialyzers and single-use dialyzers have identical uses. HDC
does not dispute this finding but argues that the district court ignored case law
suggesting that significant price differences between identical-use products can
establish reasonable interchangeability, and thus support a jury's inference that two
separate product markets exist. We disagree.

       The Supreme Court has repeatedly held that a price differential alone is
insufficient to infer two separate product markets. "[P]rice is only one factor in a
user's choice between one [product] or the other. That there are price differentials
between the two products . . . are relevant matters but not determinative of the product
market issue." United States v. Cont'l Can Co., 

, 455 (1964); see also
Brown Shoe 

. ("It would be unrealistic to accept Brown's



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contention that, for example, men's shoes selling below $8.99 are in a different
product market from those selling above $9.00.")

       HDC maintains that other cases from the Court and this circuit suggest that a
substantial price differential between two products can, alone, justify the inference of
two separate markets. To support this contention, HDC quotes language in United
States v. Aluminum Co. of America, 

(1964), and our holding in Archer-
Daniels-Midland Co. Both cases are distinguishable.

       In Aluminum Co. of America, the Supreme Court found two different product
markets existed for insulated aluminum and insulated copper cable as used in
overhead distribution. Although there were no quality differences between the two
products, copper cable was more expensive. Aluminum Co. of 

. HDC heavily relies upon the Court's statement that "to ignore price in
determining the relevant line of commerce is to ignore the single, most important,
practical factor in the business." 

Court in Aluminum Co. of America used price as only a
supporting factor in its ultimate determination that insulated aluminum and insulated
copper cable were in different product markets. The Court found most persuasive the
fact that insulated aluminum and insulated copper cable had two distinct end uses.
"While the copper conductor does compete with aluminum conductor, each has
developed distinctive end uses-aluminum as an overhead conductor and copper for
underground and indoor wiring, applications in which aluminum's brittleness and
larger size render it impractical. And, as we have seen, the price differential further
sets them apart." 

Thus, the Court in Aluminum Co. of America reminds
lower courts to consider price but also that price alone is not dispositive. Other factors
should also be considered.




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      HDC's reliance upon our holding in Archer-Daniels-Midland Co. is also
misplaced. In that case we created a narrow exception to the general prohibition
against placing great weight on only price differentials to determine the relevant
product market, stating:

      While generally a price differential, even a substantial one, is irrelevant
      for purposes of determining reasonable interchangeability, a large price
      differential as a result of a government price support raising the price of
      one product, but not the other, to an artificially high level is a relevant
      factor. This is true because of the inability of the price supported product
      to constrain the price of the other product. The artificially high price of
      sugar does not constrain the price of HFCS; thus, the competition from
      sugar does not regulate HFCS producers' business behavior. Competition
      between HFCS producers may be necessary to accomplish this goal. The
      price differential between sugar and HFCS, at least as a result of
      government price supports, is sufficient to show that sugar is not
      reasonably interchangeable with HFCS and thus does not belong in the
      same relevant product market with 

.

       Here, HDC does not allege governmental interference with the natural function
of the dialyzer market; therefore, the Archer-Daniels-Midland Co. limited exception
does not apply.

       HDC offered no evidence, other than a substantial price differential, to support
the conclusion that single-use dialyzers are a distinct product market from multi-use
dialyzers. Accordingly, we must affirm the district court's grant of summary judgment
on HDC's monopolization claim, because HDC failed to create a jury question on the
issue of the relevant product market.




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              B. Attempted Monopolization: Anti-competitive Conduct
      "Attempted monopoly claims are aimed at 'the employment of methods, means
and practices which would, if successful, accomplish monopolization, and which,
though falling short, nevertheless approach so close as to create a dangerous
probability of it.'" Gen. Indus. Corp. v. Hartz Mountain Corp., 

, 806–807
(8th Cir. 1987) (quoting American Tobacco Co. v. United States, 

, 785
(1946)).

       To establish an attempted monopolization claim under the Sherman Act, a
plaintiff must prove: "(1) a specific intent by the defendant to control prices or destroy
competition; (2) predatory or anticompetitive conduct undertaken by the defendant
directed to accomplishing the unlawful purpose; and (3) a dangerous probability of
success." 

       The district court found that HDC offered no evidence to support its allegations
of predatory or anti-competitive conduct. The court also found that HDC failed to
offer any evidence supporting the allegation that Minntech's conduct had a dangerous
probability of success. We agree with both conclusions.

      HDC listed several allegedly anticompetitive actions taken by Minntech. We
will address the two principal claims: that Minntech's warranty policy was
implemented to hamper competition and, second, that Minntech altered the design of
two products specifically for the purpose of harming competition.

                            1. The Warranty Allegation
      HDC alleges that Minntech's warranty policy was implemented to hamper
competition. In 1998, Minntech announced that it would not honor a one-year
warranty on its reprocessing machines if any product other than Renalin was used in
the machine. Minntech justified its warranty policy based upon its inability to predict
how its machines would react to another manufacturer's reprocessing solution. In light

                                           -7-
of such uncertainty, Minntech believed that it could not feasibly warrant the
performance of the product. Further, the record indicates that Minntech was willing
to test the effect a competitor's product had on its machines; however, the competitor
would have to pay the cost associated with such tests. The district court determined
that this explanation was a legitimate business justification. We agree.

        We decided a very similar issue in Marts v. Xerox, Inc., 

(8th Cir.
1996). In that case, Xerox announced that it would void the warranty of its
photocopying machine if a consumer used a replacement ink cartridge made by a
different manufacturer. Although Marts was a tying case, we held that this
arrangement did not violate the Sherman Act because "[a]n owner of a new Xerox
copier could forego the benefits of the warranty, buy service from Xerox or an
independent provider, and purchase cartridges from the vendor of its choice. The end
result is the same: customers receive both service and cartridges for their copiers." 

We believe the same logic applies here.

        "Anticompetitive conduct is conduct without legitimate business purpose that
makes sense only because it eliminates competition." Morgan v. Ponder, 

, 1358 (8th Cir. 1989). "When a valid business reason exists for the conduct
alleged to be predatory or anti-competitive, that conduct cannot support the inference
of a [Sherman Act] violation." Midwest Radio Co., Inc. v. Forum Pub. Co., 

, 1297–1298 (8th Cir. 1991); Paschall v. Kan. City Star Co., 

(8th
Cir. 1984). Summary judgment is appropriate when a defendant's business
justification goes unchallenged. Stearns Airport Equip. Co., Inc. v. FMC Corp., 

, 522 (5th Cir. 1999).

       HDC offers no evidence to refute Minntech's legitimate business justification.
Accordingly, we hold that the district court did not err by dismissing this allegation
of anticompetitive conduct.



                                          -8-
                       2. The Product Modification Allegation
       HDC also alleges that Minntech altered the design of two products specifically
for the purpose of harming competition. First, HDC argues that Minntech changed the
Renatron's uptake mechanism solely to prevent the use of competitors' reprocessing
agents. Second, HDC argues that Minntech modified its barcode scanning device
solely to prevent the use of competitors' reprocessing agents.

        In response, Minntech explains that the changes to the uptake valve were made
in order to aid users in properly diluting the reprocessing agent. Both parties agree
proper dilution is essential to ensure patient safety. Patient safety is a valid business
justification. HDC does not offer any evidence to indicate that Minntech's explanation
is false. Also, HDC does not offer any evidence to suggest Minntech's motive was to
engage in anti-competitive conduct.

       The alleged changes in the barcode reader fail for similar reasons. HDC argues
that changes in the Minntech barcode made it difficult for consumers to use HDC's
reprocessing agent in Renatrons. Again, Minntech offered an appropriate business-
related justification for the changes, i.e., to aid consumers in keeping better records
and to comply with necessary government regulations.

      HDC offers no evidence that Minntech engaged in anti-competitive conduct.
Minntech maintains, and we agree, that a rational business justification existed for
each of the allegations of improper conduct. HDC fails to offer any evidence to
discredit these justifications or to suggest that Minntech held an impermissible motive.
Accordingly, we hold that the district court did not err in granting summary judgment
in HDC's attempted monopolization claims.2


      2
        HDC also accuses Minntech of slander and illegal tying products. The district
court rejected these accusations because there was no evidence in the record to support
these allegations. For the reasons expressed by the district court, we agree.

                                          -9-
                          C. Dangerous Probability of Success
       Lastly, the district court determined that HDC failed to prove Minntech's anti-
competitive conduct had a dangerous probability of success. Dangerous probability
of success is "examined by reference to the offender's share of the relevant market."
Alexander v. Nat'l Farmers Org., 

, 1181 (8th Cir. 1982). Dangerous
probability of successes "should be evaluated as of when the alleged anticompetitive
events occurred." Gen. Indus. 

(8th Cir. 1987). HDC argues the
district court used data from the year 2005 rather than data from the time in question
in assessing Minntech's dangerous probability of success. We disagree.

      HDC's allegation is simply not supported by the record. The court's
memorandum opinion and order clearly show that its analysis began with the year
2000—the only year for which HDC provided concrete data. Accordingly, the district
court did not err in concluding that HDC did not prove a dangerous probability of
success.

                                   III. Conclusion
      After a careful review of the considerable record in this case, we conclude that
Minntech was entitled to judgment as a matter of law. HDC failed to show that
genuine issues of material fact exist in either its monopolization or its attempted
monopolization claims. We therefore affirm the judgment of the district court.
                        ______________________________




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