It’s a typical pain pump story—patient has a minor shoulder injury and gets routine arthroscopic shoulder surgery; patient recovers from surgery okay and starts to feel better, but then within a year patient’s shoulder starts to really hurt. Patient goes back to doctor, and finds out his cartilage is missing. Patient learns that the pain pump used after his surgery was to blame, because it pumped anesthetic into his shoulder joint, which killed the cartilage.
In one case filed in the U.S. District Court for the Southern District of Florida, plaintiff Douglas Kilpatrick lost late last month on summary judgment. The defendant was Breg, which argued that that Kilpatrick did not prove the pump was the cause of the injury. In its Daubert analysis, the court held that the causal link testified to by Kilpatrick’s expert, Dr. Gary Poehling, was excluded under the reliability prong of Federal Rule of Evidence 702.
The court’s ruling reveals that it considered the following as deficiencies in Poehling’s testimony:
None of the articles cited by Poehling were based on controlled, randomized epidemiological studies of human beings (though, such studies would be unethical in this context);
None of the articles explained the process by which bupivicaine (the anesthetic drug) destroyed cartilage;
None of the articles ultimately concludes that general causation exists—that is, that bupivicaine inserted into the shoulder joint can destroy cartilage;
He did not describe the “background risk” of acquiring chondrolysis (background risk is the risk of losing cartilage absent exposure to the pain pump); and
He relies too much on a temporal argument, that the pump must have injured the cartilage, because there were no other possible causes.
Basically, this boils down to one fundamental problem with Dr. Poehling’s testimony—he relied too much on articles that did not “go the distance.” The main article relied on was the Hansen/Beck article, which did not do a rigorous statistical analysis of the conclusion that 63% of patients who received pain pumps lost cartilage. That was the first article to mention an association between the pumps and cartilage loss, so it is not surprising that it was not completely persuasive to the court. Additionally, Poehling couldn’t explain why 37% of patients did not lose cartilage—in his deposition testimony, he just chalked it up to unknown physical differences.
As for the background risk, there are numerous articles that describe the causes of chondrolysis—Poehling should have identified each of them in turn, and discussed their incidence rate. These risks include specific types of infection, age, thermal energy, and specific other chemicals—all of which can be excluded in any decent pain pump case.
Finally, the temporal argument is not firmly rooted in scientific methodology.
These cases are tough in many ways—part of the main problem for Kilpatrick may be that his only causation expert was an orthopedic surgeon—it seems that the Court is looking for more on causation. In this vein, a pharmacologist or cell biologist to testify about how cartilage cells react to anesthetic drugs may have given him the extra push he needed. And, there is much more medical literature out there—the expert really needed to do a full review of the literature, and be able to testify about it. It’s a tough result for Kilpatrick and his lawyers, but these cases are still winnable.