Grant Of Summary Judgment Reversed Because Trial Court Erred In Not Admitting Plaintiff’s Causation Testimony.

Plaintiff was treated with the drug Zometa for several months after a diagnosis of breast cancer and chemotherapy. She was thereafter treated for osteonecrosis of the jaw by two oral specialists. Following the dental treatment, plaintiff brought an action against the manufacturer of Zometa, and in that pursuit offered the testimony of an expert on the causal link between the treatment she received and her jaw condition. In ruling on defendant’s motion for summary judgment, the district court, after finding plaintiff’s expert testimony on causation to be irrelevant and unreliable, excluded the expert’s causation testimony, and granted the motion.  The Ninth Circuit reversed and remanded, stating: “[W]e have consistently recognized the difficulties in establishing certainty in the medical sciences;” and, “Given the difficulties in establishing a medical cause and effect relationship, ‘causation can be proved even when we don’t know precisely how the damage occurred, if there is sufficiently compelling proof that the agent must have caused the damage somehow.” (Messick v. Novartis Pharmaceuticals Corporation (Ninth Cir.; April 4, 2014) 747 F.3d 1193.)