Today’s case, Knudsen v. Ethicon, Inc., 2021 WL 390825 (M.D. Fla. 2021), involves product-liability claims against a surgical-mesh manufacturer. In a short decision, the court dismissed manufacturing-defect and implied-warranty claims as inadequately pleaded under Michigan law. Although not fully developed, the court’s reasons for dismissing the claims exhibit both insight into manufacturing-defect claims and confusion about implied-warranty claims.

The court’s analysis of the manufacturing-defect claims was spot on, starting with its observation that manufacturing-defect claims are “analyzed very differently” than design-defect claims. Knudsen, 2021 WL 390825, at *1 (internal quotation marks omitted). Under Michigan law (like the law of other states), a manufacturing defect exists when “something goes wrong in the manufacturing process and the product is not in its intended condition.” Prentis v. Yale Mfg. Co., 365 N.W.2d 176, 182 (Mich. 1984) (cited by Knudsen, 2021 WL 390825, at *1). Thus, while a purported design defect will necessarily affect all units of a product, a manufacturing defect generally affects only one unit or a subset of units.

This distinction was alluded to in Bryant v. Medtronic, 623 F.3d 1200 (8th Cir. 2010). In that case, which involved a Class III medical device that had received premarket approval from the FDA, the Eighth Circuit affirmed the dismissal of manufacturing-defect claims as expressly preempted by 21 USC 360k(a) because the plaintiffs had failed to allege a violation of the manufacturing requirements imposed on the device through the premarket approval process. Given the plaintiffs’ contention that the manufacturer was liable to “every person” who had received the defibrillator lead at issue rather than liable only to particular individuals who had received specific units, their manufacturing-defect claims were, the court said, “a frontal assault on the FDA’s decision” to approve the device as designed. 623 F.3d at 1207. In other words, although labeled manufacturing-defect claims, they were in fact thinly veiled design-defect claims.

Because a manufacturing defect exists only when the final product “is not in its intended condition” (Prentis, 365 N.W.2d at 182), “[a] claim for a manufacturing defect ‘necessitates examination of the product itself rather than the manufacturer’s conduct.’” Knudsen, 2021 WL 390825, at *1 (quoting Gregory v. Cincinnati Inc., 538 N.W.2d 325, 329 n.10 (Mich. 1995)). That examination entails comparing the unit in question with other units of the same product to determine whether the unit in question deviates from the others. As the Knudsen court put, “[i]n the case of a ‘manufacturing defect,’ the product may be evaluated against the manufacturer’s own production standards, as manifested by that manufacturer’s other like products.” Id. (quoting Prentis, 365 N.W.2d at 182). The Knudsen plaintiff failed to allege any difference between the surgical mesh that he received and other units of surgical mesh manufactured by the defendant and the court granted the defendant’s motion to dismiss the plaintiff’s manufacturing-defect claim “on that basis.” Id. at *2.

Notably, in dismissing the claim, the court implicitly rejected application of the res ipsa loquitur doctrine to injuries allegedly caused by an implantable medical device. Beloved by plaintiffs facing dismissal because they are unable to identify a defect in a product, the doctrine holds that a defect can be presumed when an injury occurs under certain circumstances. While the precise formulation varies from jurisdiction to jurisdiction, in Michigan as elsewhere a plaintiff wishing to invoke the doctrine must establish, among other things, that the injury is “of a kind which ordinarily does not occur in the absence of someone’s negligence” and was “caused by an … instrumentality within the exclusive control of the defendant.” Woodard v. Custer, 702 N.W.2d 522, 525 (Mich. 2005).

Given these prerequisites, the res ipsa loquitur doctrine is never applicable to injuries allegedly caused by implantable medical devices. Leaving aside the fact that medical devices (particularly those with premarket approval) will sometimes fail to perform as intended even when properly manufactured, implantable medical devices never cause injuries while in the exclusive control of the defendant manufacturer. An implantable medical device cannot cause injury until it is implanted. By that point, the device is outside the manufacturer’s exclusive control. At minimum, the device will have been handled by the implanting surgeon during implantation. And, as in Knudsen (where the mesh had been implanted for a decade), the device often will have been in the patient’s body for years before the alleged injury occurs. The “safety and reliability” of an implantable medical device, however, “cannot be guaranteed indefinitely in the extremely hostile environment of the human body, where myriad other factors external to the device are brought to bear.” Walker v. Medtronic, Inc., 670 F.3d 569, 580 (4th Cir. 2012) (internal quotation marks omitted). Accordingly, the res ipsa loquitur doctrine is inapplicable and, as the Knudsen court held, the mere allegation that an implantable medical device malfunctioned “alone is not enough” to state a manufacturing-defect claim. 2021 WL 390825, at *2.

Less satisfying is the court’s analysis of the plaintiff’s implied-warranty claims, even though the court dismissed those claims too. Indeed, the court’s analysis betrays a serious confusion over the source of implied warranties.

In Knudsen, the defendant manufacturer argued that the plaintiff’s implied-warranty claims failed as a matter of state law because the plaintiff “did not provide notice required by the Michigan Uniform Commercial Code (‘UCC’).” 2021 WL 390825, at *2. The court rejected that argument, tentatively accepting the plaintiff’s counter-argument that “the UCC is inapplicable.” Id. Because the plaintiff received the mesh “from a doctor during an operation,” the court characterized him a purchaser of services from the doctor rather than a purchaser of goods from the manufacturer. The UCC, however, applies only to “transactions in goods.” Id. (quoting Mich. Comp. Laws § 440.2314). Thus, having deemed the plaintiff a purchaser of services rather than goods, the court concluded that UCC—and its notice requirement—did not apply and that the plaintiff’s implied-warranty claims were therefore not subject to dismissal for failure to provide notice.

The court’s reasoning rests on an unacknowledged internal contradiction. “[T]he implied warranties of merchantability and fitness for a particular purpose arise through implication by operation of law.” Heritage Resources, Inc. v. Caterpillar Fin. Servs. Corp., 774 N.W.2d 332, 344 (Mich. Ct. App. 2009) (citing Mich. Comp. Laws §§ 440.2314, 440.2315). In particular, those implied warranties—the warranties invoked by the Knudsen plaintiff—arise by operation of the UCC. Cf. id. Therefore, if the UCC is inapplicable to the plaintiff’s warranty claims, as the Knudsen court held, then there is no legal basis for those claims in the first place. The court did not recognize, let alone address, this contradiction.

Although the harm caused by the court’s error is limited in the particular case by its dismissal of the warranty claims on alternative grounds (namely, plaintiff’s failure to adequately allege a defect), the consequences of the court’s erroneous analysis could prove more significant if adopted in other cases.