Reading the recent order in Morritt v. Stryker Corp., 1:07-cv-02319, 2013 U.S. Dist. LEXIS 136843 (E.D.N.Y. Aug 12, 2013) (Report and Recommendation adopted Sept. 23, 2013), reminds us of walking down a long corridor with numerous open doors, each leading to a jury trial on the merits of the plaintiffs’ medical device product liability claims. The case is blog-worthy because the district court closed every door, and provided along the way careful and useful discussion of the limits on treating physicians as experts, the limits on "differential diagnoses" to prove causation, and the limits on a plaintiff’s ability to amend pleadings after the defendant has moved for summary judgment. Where the plaintiffs in Morritt had dug themselves into a hole—owing we suspect to the weakness of their claims to begin with—the district court refused to throw them a lifeline, and justifiably so.

The husband and wife plaintiffs in Morritt alleged product liability claims related to a knee prosthesis used to treat the wife. However, before plaintiffs filed their complaint, they knew that the wife had hip problems as well, but they omitted those allegations from the complaint. The defendants eventually moved for summary judgment on the knee-related claims, which the court granted on the plaintiffs’ design defect claim, but denied on their manufacturing defect claim. Id. at **1-5.

This is where it gets interesting. The plaintiffs had opposed summary judgment with a declaration from the treating surgeon, which stated that premature polyethylene wear caused the knee injury and that "a manufacturing, material, or design defect caused the tibial insert in [the plaintiff’s] knee to fail." Id. at **8-9. The court considered the opinion over defendant’s objections, but remarked that the defendant was "free to make a motion in limine challenging [the surgeon’s] testimony. Id. at *5. To complicate matters, while the defendant’s motion was pending, the wife passed away. Id. at *3.

Thus, with the landscape changed and their "expert" in the crosshairs, the plaintiffs moved to amend the complaint to (1) add a wrongful death claim (although it is not at all evident from the order whether the wife’s death even arguably had anything to do with the defendant or its product) and (2) to add the previously omitted claims related to the wife’s hip. Id. at *6. The defendant, for its part, accepted the court’s suggestion and moved to exclude the treating surgeon’s opinions. Id. at *5.

In a nutshell, the defendant won and the plaintiffs lost. The court first addressed the defendant’s motion in limine, and although the surgeon was qualified to opine on his observation of the tibial insert and his medical diagnosis, the court ruled that he was not qualified to opinion on the source of the polyethylene wear. According to the court, that would be an "expert opinion on [ ] entirely different field[s] or discipline[s]’ from his medical background." Id. at *14. Door number one closed.

The court went further. The treating surgeon had relied on a "differential diagnosis" to determine that a product defect caused the injury. Don’t get us started on the bastardization of "differential diagnoses" to form opinions on causation in litigation. Doctors perform differential diagnoses to diagnose disease in their patients so they can eliminate possibilities and prescribe the most effective treatment. They do not use differential diagnoses in the regular course of clinical practice to determine substantial factor causation, which is a litigation-driven concept. The Morritt court rejected the surgeon’s differential diagnosis, because "he failed to employ a reliable scientific methodology." Id. at *16. He just looked at the explanted device before concluding that a "defect" caused it to fail. That does not sound very scientific to us, and did it not to the court either, which faulted the doctor for failing to perform any further examination or testing. The court further faulted the doctor for relying on information learned outside his treatment of the wife. Id. at *21. Door number two closed.

The court’s order rejecting the treating surgeon’s opinions on product defect and causation cascaded into the other pending motion—the plaintiffs’ motion to amend to add the husband’s wrong death claim and hip-related claims. To start with, the court was quick to deny leave to amend to add claims related to alleged hip injuries. After all, the plaintiffs knew about the hip injuries even before they filed their first complaint, and there was no explanation why they waited more than four years to allege hip-related facts. An amendment to add new claims related to a different injury also would require additional discovery and motion practice after discovery was already closed. The hip claims therefore stayed off the table. Id. at **24-27. Another door closed.

Finally, the court denied leave to add a wrongful death claim on behalf of the surviving husband on the basis that it would be futile and prejudicial. Most notably, in ruling that a wrongful death claim would be futile, the court went outside the pleadings and applied a summary judgment standard to conclude that the proposed wrongful death claim would fail as a matter of law. As it turns out, that’s a rule: When a plaintiff requests leave to amend after a motion for summary judgment has been filed, the court can deny the amendment as futile when the evidence in support of the new claim creates no triable issue of fact and the defendant would be entitled to judgment as a matter of law, even if the proposed amended complaint would state a valid claim on its face. Id. at *29. It’s a good rule too, because why should a plaintiff be allowed to change the stakes after a defendant has relied on the claims pleaded and evidence adduced to file a dispositive motion? The answer is that such a bait and switch should not be allowed, and especially not where the proposed amendment lacks all merit.

In the end, because the court had already held that the treating surgeon could not testify regarding product defect and causation, plaintiffs had no evidence to link the plaintiff’s death to any fault on the defendant’s part. The court noted that "the parties have had ample opportunity to develop and explore the factual foundation supporting the existence of a manufacturing defect." Id. at *30. True, the court had previously denied summary judgment on the manufacturing defect claim, but "the instant motions demand that the Court revisit the issue of causation, which was at the heart of the summary judgment decision." Id. at **30-31. We get the sense that the Court felt it had already given the plaintiffs too much leeway, and regretted it. The court’s parting shot was to note the disruption that an amendment would cause to the defendant’s litigation strategy, observing that allowing the amendment would place the defendant at "a tactical disadvantage: it has developed a litigation strategy based on a defined universe of evidence, and advanced that strategy by filing a motion for summary judgment." Id. at **34-35. Door number four closed, or maybe slammed is the better word.

The late wife’s estate was left with the wife’s manufacturing defect claims, which had previously survived summary judgment. But the defendant in Morritt has requested leave to file another motion for summary judgment on the basis that plaintiffs have no admissible expert opinions to support their manufacturing defect claim. Given this order, we think we hear the hinges turning on the plaintiffs’ last available door.