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Listen to your gut.  Follow your instincts.  Trust your intuition.  Great advice in many situations.  Like deciding whether to buy skinny jeans or whether to buy your forever home.  Or, when things seem “off” or feel “dangerous.”  Or, when your body is trying to tell you something about your health.  These are all times to investigate your feelings about a situation and allow your “gut” or “sense” to be your guide (or at least a back seat driver you don’t ignore).  A general sense, feeling, or impression, however, does not get the job done when you are the medical causation expert in a complex medical device case.  As the court in Hobus v. Howmedica Osteonics Corporation, 2023 WL 6850144 (D. Ore. Oct. 17, 2023) told plaintiff when it dismissed his case. 

Plaintiff suffered from back problems nearly his whole life that were exacerbated by a car accident in 2014 that led to spinal fusion surgery in 2016 during which his surgeon chose to implant an expandable interbody fusion cage device manufactured by the defendant.  Plaintiff alleged that the collapse of the cage caused him to have to undergo revision surgery and caused him to suffer chronic pain.  Plaintiff submitted three expert reports – a medical causation report from his implanting surgeon, a design defect report from a biomedical engineer, and a damages report.  Defendant moved to exclude all three and for summary judgment.  The motion on the damages expert was denied which was of no consequence because the court excluded the medical causation expert in his entirety and the bulk of the engineering opinion. 

Because plaintiff’s medical causation expert was his treating surgeon, the court took its time detailing the surgeon’s opinions in the treating records.  Opinions such as:  plaintiff’s MRI shows no cord compression or nerve root impingement and “there is nothing there to account for his [pain];” or based on further MRIs the surgeon saw “no obvious problems there or explanation as to why [plaintiff] was having symptoms.”  Most importantly, when device failure was identified, his surgeon noted that plaintiff had achieved a “solid fusion” and therefore the failure was “of questionable significance,” there was still no neural impingement, and there was a “low” likelihood that revision surgery would alleviate plaintiff’s pain.  Id. at *2-3. 

Flash forward to becoming plaintiff’s expert, and the surgeon’s new opinion was that the collapse of the cage was an “important contributing factor” to and “major cause” of plaintiff’s injuries.  Id. at *5.  Plaintiff’s expert report provided “little detail” regarding how he reached this new conclusion.  And when asked at deposition what his methodology was, the best he could say was “it’s just my sense.”  His “gut says he might have done better.”  Confirming he used no methodology, he said “I just have my instincts as a clinician.”  Id. at *5-6.  So, it was no stretch for the court to conclude that plaintiff’s expert “utilized no generally accepted methodology in arriving at his medical conclusions.”  Id. at *6.  Clinical experience can be a basis for reliable expert testimony, but only where the clinician has “extensive experience” with the issue on which he is opining.  Here, plaintiff’s expert had only one patient who experienced a cage collapse – plaintiff.  Id.  The court found it “difficult” to call that sufficient experience on which to base his opinion.                

Plaintiff also tried to argue that his surgeon relied on his own medical records to reach his conclusions.  As pointed out above, that’s a stretch too.  But more importantly, the court stated the general principle that

Although medical records may, in some circumstances, support a clinician’s overall conclusion, they do not independently verify the methodology that the clinician used. That is, while a medical record may be the basis of an expert’s findings, it offers no explanation for the validity of the expert’s methods.

Id.  At most, the surgeon’s records demonstrated a “consistent uncertainty” as to whether the cage collapse was a possible cause of plaintiff’s injuries. 

Finally, plaintiff’s expert failed to address “the numerous possible factors causing plaintiff’s pain.”  Id. at *8.  He deemed the cage collapse was a significant causative factor of plaintiff’s pain without considering the impact of other factors affecting pain.  “[A]n expert opinion that wholly fails to consider alternative causes cannot be a reliably based opinion.”  Id.  Taken together, the court had more than enough reasons to exclude plaintiff’s medical causation expert.

Plaintiff’s design defect expert did not fare much better.  She concluded that to be safe, defendant’s cage needed to withstand a force of 2,000 N.  But beyond that, the court could not conclude that she reliably applied that opinion to the facts of the case.  She looked at six clinical failure reports but conducted no inquiry as to why the devices failed in those cases – she had no information on those patients’ ages, weights, activity levels, etc. to know the amount of force placed on those devices.  She “assumed” those failures were due to a design defect.  Do assumptions ever really work out in any context?  Id. at *11.

Plaintiff’s expert did not test the model of cage that was used in plaintiff’s surgery.  In other words, the expert did not determine whether the device could withstand 2,000 N before opining it was defective for failing to meet that standard.  The company testing that the expert did rely on was about “breakage” not device collapse and the expert offered no explanation for her “leap” from breakage to collapse making her opinion “wholly speculative.”  Id. at *12.  Not only did the expert not test the model, she did not test the actual device used in plaintiff’s surgery.  She could have but decided not to because of the cost.  Failing to take this step that would have provided an objective basis for her opinion, “deeply undermines the reliability” of her conclusion.  Id.  

The design expert also offered an opinion on feasible alternative design.  She offered two—the first was not an alternative design and the second was not feasible.  First, she suggested alternative designs that were not expandable.  But that is a significant design feature of defendant’s product that provides utility not available in static cages.  Id. at *14.  So, as we have pointed out in other cases a different product is simply a different product, not an alternative design of the product at issue.  Second, plaintiff’s expert testified about ways the expandable cage could be improved but had not performed any analysis to determine if any of her ideas were feasible.  So, she could not testify on alternative design.

Finally, perhaps realizing where things were headed with his medical causation expert, plaintiff tried to sneak in medical causation through his biomedical engineer.  But rendering opinions as to the specific cause of plaintiff’s injuries goes well beyond her engineering expertise.  Her engineering experience and training may allow her to make general findings regarding what injuries may occur from a cage collapse, but offering opinions that connect the cage collapse to plaintiff’s specific injuries crosses into medical causation on which this expert was not qualified to opine.

In the end, it was the exclusion of plaintiff’s medical causation expert that led the court of award summary judgment for the defendant.  Oregon law requires expert testimony where causation involves complex medical questions. Without a causation expert, plaintiff could not meet his burden of proof which is just a tad more onerous than gut feelings and basic instincts.