Mongeon v. Ethicon, Inc., 456 F.Supp.3d 298

Background

Plaintiff Sheila Mongeon underwent implantation of an Ethicon TVT‑S mid‑urethral sling in February 2009 to treat stress urinary incontinence; she later experienced mesh erosion and had the device removed.
Plaintiff sued in the MDL on multiple theories (negligence, various strict liability claims, fraud, warranty, consumer protection, etc.). Defendants moved for summary judgment on many counts and partial summary judgment on negligence and gross negligence (Counts I and XIV).
Central factual dispute: whether Dr. C. Scott Koenig informed Plaintiff pre‑operatively about risks of mesh erosion, chronic pain, and dyspareunia, and whether Ethicon’s Instructions for Use omitted those risks.
Dr. Koenig testified he stood by his 2009 recommendation, believed he had adequately disclosed risks, but also admitted he did not view erosion/dyspareunia as significant and would have disclosed risks listed in the Instructions for Use; he said he would not have used TVT‑S had he known about worse reported outcomes.
Court applied Massachusetts law and the learned intermediary framework for failure‑to‑warn medical device cases, using the burden‑shifting approach from Liu v. Boehringer.
Court granted summary judgment to Defendants on many counts (II, III, IV, V, VI, VII, VIII, IX, X, XIII, XV) but denied summary judgment on negligence (Count I), breach of implied warranty (Count XII, failure‑to‑warn theory), and gross negligence (Count XIV), leaving those for trial.

Issues

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Ethicon can be liable for negligence/failure to warn under the learned intermediary rule	Mongeon: Ethicon failed to warn prescribing physician of non‑obvious risks (mesh erosion, dyspareunia); she would have declined surgery if warned	Ethicon: Learned intermediary rule applies; physicians would not have heeded additional warnings, so no causation	Court: Applied burden‑shifting; presumption that physician would heed warning arises, defendants rebutted, but plaintiff raised triable issues of causation — Counts I and XIV survive
Whether Dr. Koenig’s testimony defeats causation	Ethicon: Dr. Koenig’s statement that he’d still recommend TVT‑S rebuts presumption	Mongeon: Koenig also said he’d have disclosed IFU risks and would not have used TVT‑S if aware of worse outcomes; raises credibility issues	Court: Credibility and other evidence permit a reasonable juror to find causation; summary judgment denied on causation issue
Breach of implied warranty based on failure to warn	Mongeon: Implied warranty of merchantability includes failure to warn; omission caused her injury	Ethicon: No causal link between omission and injury	Held: Genuine dispute on causation; summary judgment denied as to Count XII
Disposition of other pleaded claims (strict liability, fraud, negligent infliction, unjust enrichment, etc.)	Mongeon: (did not oppose dismissal of several claims)	Ethicon: moved for summary judgment on many counts	Held: Summary judgment granted to defendants on Counts II, III, IV, V, VI, VII, VIII, IX, X, XIII, and XV

Key Cases Cited

Laaperi v. Sears, Roebuck & Co., 787 F.2d 726 (1st Cir. 1986) (manufacturer duty to warn users of product hazards)
Knowlton v. Deseret Med., Inc., 930 F.2d 116 (1st Cir. 1991) (learned intermediary doctrine in medical‑product cases)
Garside v. Osco Drug, Inc., 976 F.2d 77 (1st Cir. 1992) (presumption that physician would heed adequate warning)
Liu v. Boehringer Ingelheim Pharm., Inc., 230 F. Supp. 3d 3 (D. Mass. 2017) (burden‑shifting framework for learned intermediary failure‑to‑warn claims)
MacDonald v. Ortho Pharm. Corp., 394 Mass. 131 (Mass. 1985) (declining learned intermediary rule for oral contraceptives; discussed as distinguishable)
Back v. Wickes Corp., 375 Mass. 633 (Mass. 1978) (implied warranty of merchantability and strict liability principles)
Haglund v. Philip Morris, Inc., 446 Mass. 741 (Mass. 2006) (warranty liability may be premised on design defect or failure to warn)