In re Zimmer, Nexgen Knee Implant Prods. Liab. Ltd., 884 F.3d 746

Theodore Joas received a Zimmer NexGen Flex total knee implant in Wisconsin (2008) and developed tibial-component aseptic loosening requiring revision surgery (2012).
Joas sued Zimmer alleging defective design, manufacture, and failure-to-warn; his case was transferred to an MDL in N.D. Illinois and designated a bellwether.
The district court excluded Joas's causation expert (Dr. Fetto) under Daubert, leaving no expert to link implant defect to Joas’s injury and undermining design/manufacture claims.
Joas limited his appeal to the inadequate-warning claim, arguing Zimmer failed to warn (1) him directly and (2) his surgeon (Dr. Larson) about using two bags of cement rather than one (based on Zimmer expert Dr. Dearborn’s testimony).
The district court granted summary judgment: it applied the learned-intermediary doctrine (foreclosing direct-to-patient warnings) and held Joas lacked causation because Dr. Larson did not read Zimmer’s packaging and there was no presumption he would have heeded an improved warning.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Zimmer owed Joas a duty to warn the patient directly (vs. learned-intermediary)	Joas: Zimmer should have warned patients directly about early failure risk	Zimmer: Duty satisfied by warning the prescribing surgeon; learned-intermediary applies	Court predicted WI Supreme Court would adopt learned-intermediary; claim against direct warning barred
Whether Joas has evidence that an adequate patient warning would have changed outcome (causation)	Joas: He would have chosen a different implant if warned of early failure	Zimmer: Surgeon chose implant; Joas did not select implant and cannot show he would have avoided injury	Summary judgment: Joas lacks causation as to patient-warning theory
Whether Zimmer had a duty to instruct the surgeon about specific cement quantity	Joas: Zimmer should have warned surgeons to use two bags of cement	Zimmer: Surgical technique (cement amount) is guided by surgeon training, not manufacturer instructions	Court: No evidence manufacturer had duty to dictate cement amount; expert testimony supports Zimmer’s position
Whether a heeding presumption should apply to the surgeon who admitted he did not read warnings	Joas: Court should apply presumption that surgeon would have read/heed an adequate warning	Zimmer: Wisconsin law requires proof that the relevant actor would have heeded a different warning; no presumption	Court declined to adopt heeding presumption here; summary judgment affirmed for lack of causation

Daubert v. Merrell Dow Pharm., 509 U.S. 579 (1993) (expert testimony must be reliable and relevant under Rule 702)
Rodas v. Seidlin, 656 F.3d 610 (7th Cir. 2011) (federal courts must predict state supreme court law when unresolved)
ADT Sec. Servs., Inc. v. Lisle-Woodridge Fire Prot. Dist., 672 F.3d 492 (7th Cir. 2012) (follow intermediate appellate decisions unless convincing reason not to)
Pisciotta v. Old Nat'l Bancorp, 499 F.3d 629 (7th Cir. 2007) (consult other jurisdictions when state law is unsettled)
Centocor, Inc. v. Hamilton, 372 S.W.3d 140 (Tex. 2012) (survey noting many states adopt learned-intermediary doctrine)
Kurer v. Parke, Davis & Co., 272 Wis.2d 390, 679 N.W.2d 867 (Wis. Ct. App. 2004) (plaintiff must show that a proper warning would have altered behavior and avoided injury)
Tanner v. Shoupe, 228 Wis.2d 357, 596 N.W.2d 805 (Wis. Ct. App. 1999) (heeding presumption may apply for prior users who would likely have read/ heeded a warning)
State v. Kandutsch, 336 Wis.2d 478, 799 N.W.2d 865 (Wis. 2011) (specialized medical issues require expert testimony)