Trial lawyers have been closely watching the Second District of California’s appellate division as they sorted through burden of proof issues on a key evidence question affecting medical opinion testimony. This issue was resolved when it was concluded the underlying trial court erred in excluding defendant's medical experts based on the fact that their opinions did not meet the standard of reasonable medical probability. In doing so, the court concluded that the burden of proof stays with the plaintiff and excluding medical testimony on this basis was a reversible error.
The case, Kline v. Zimmer, Inc., (May 26, 2022, B302544) Cal.App.5th [2022 WL 1679539] was decided by the California Court of Appeal, Second District. The specifics of the decision are detailed below.
Facts of the Case
Kline suffered from osteoarthritis in his right hip and eventually underwent a total hip replacement in 2007. During that surgery, an artificial joint called a Durom Cup was implanted in his body. Zimmer was the manufacturer of the Durom Cup. The first surgery was a failure and Kline was forced to undergo a revision surgery. In the revision surgery, the Durom Cup was replaced with a different device. Kline continued to experience pain after the revision surgery and tried various treatments and physical therapy to alleviate his pain. Eventually, Kline began seeing rheumatologist, Dr. Chabra, who Kline continued to see for over eight years. Kline went on and off steroids for years along with several other drugs; but to no avail. The pain continued and Kline's condition deteriorated. He decided to sue Zimmer and the jury found that the Durom Cup was defective and awarded him $153,317 in economic damages and $9 million in non-economic damages.
A new trial was granted based on Zimmer's contention that the damages were excessive. In the second trial, the jury heard from experts including Dr. Chabra, Kline's orthopedic surgeon, and others. The medical expert testified that Kline's probability of fully recovering if the first surgery had been successful was high, but, after the second surgery, his probability of recovery was low. He opined that the first surgery was the cause of his dire outlook moving forward. Although the second trial resulted in a slightly lower damage amount, Zimmer again moved for a new trial based on:
- The exclusion of testimony on the grounds that it was offered to less than a reasonable medical probability
- The exclusion of certain photographs and video showing Kline engaged in hunting and shooting activities, and
- Excessive damages
The trial court denied Zimmer's motion and appealed. The appellate court reversed the judgment and remanded only on the issue of exclusion of testimony. The issue before the appellate court was whether the lower court correctly excluded the expert medical testimony Zimmer proffered because those opinions were not held to a reasonable medical certainty.
The Purpose For Which Medical Testimony is Offered is Determinative
In a personal injury action, California law requires that "causation must be proven within a reasonable medical probability based upon expert testimony." Jones v. Ortho Pharmaceutical Corp. (1985) 163 Cal. App.3d 396. This "reasonable medical probability" standard is similar to the "more likely than not standard" used by courts in general negligence actions.
Zimmer asserts that the "reasonable medical probability" rule does not apply here because the defense expert's testimony is only offered to challenge whether Kline met his burden of proof on the causation issue. Zimmer was not attempting to introduce an alternate cause, but rather trying to argue that the plaintiff failed to meet his burden of proof in the presentation of his case. In this situation, it argued expert testimony is not subject to the "reasonable medical probability" standard.
To allow a jury to hear a plaintiff's case, however, when it falls short of the minimum showing would allow the jury to find the "requisite degree of certainty where a jury could not." Jones at 403.
The Trial Court Erred in Excluding Defense's Expert Witness Testimony
In any negligence action, those involving medical malpractice or otherwise, a prima facie case, or a showing of the basic elements of the cause of action, must be presented. Espinosa v. Little Co. of Mary Hospital (1995) 31 Cal.App.4th 1304, 1314; Evid. Code §500. In this case, Kline was required to show that the defendant's negligence was more likely than not a substantial factor in causing him damages. Zimmer contends that Kline did not successfully present all of the elements necessary to establish his prima facie case; namely causation. This is the element that Zimmer claimed his expert witness should be able to speak to because that testimony would challenge whether the basic hurdle of establishing the prima facie case was successful.
Even after a plaintiff establishes a prima facie case, the general rule requires that the burden to prove causation remains with the plaintiff. Kline's burden of proof was to bring evidence to show that Zimmer caused his injuries to a reasonable medical probability. Zimmer is permitted to argue that Kline failed in this and present proof to show that Kline failed to satisfy that burden. To accomplish this, Zimmer did not need to show that a different circumstance caused Kline's injuries.
Zimmer is only required to bring evidence that Kline's offer of proof was insufficient to prove that Kline's injuries were more likely than not caused by Zimmer. The court should have allowed Zimmer to offer expert opinions to that effect. The expert opinion Zimmer seeks to present casts doubt on the "accuracy and reliability of the plaintiff's expert. The jury is entitled to consider such evidence in deciding whether the plaintiff's expert is exaggerating his or her opinion." Cahill Bros., Inc. v. Clementina Co. (1962) 208 Cal.App.2d 367, 385.
This reasoning is in line with other state and federal courts nationwide who have also held that the reasonable medical probability standard applies only to the party bearing the burden of proof on the medical issue at the crux of the case. Wilder v. Eberhart (1st Cir. 1992) 977 F.2d 673, 677. The Wilder court also stated that, "inequities would abound if a defendant could not rebut the plaintiff's prima facie case without actually proving an alternative cause." It is paramount that the party without the burden of proof be permitted to introduce alternative causes, or question causation completely.
That being said, the appellate court cautioned that the trial court is not required to approve every expert offered or every opinion offered by a defense expert. The expert opinion will still be required to meet the basic requirements mandated under the law before being heard by a jury. In this case, however, the veracity or qualification of the defense expert is not an issue. Here, the trial court did not allow the defense expert's opinions because their testimony does not reach the level of reasonable medical probability. Given that the defendant does not have to reach this standard, as discussed above, it was a reversible error for the court to categorically exclude this expert opinion evidence and deem the testimony speculative and inadmissible.
Failing to Allow Zimmer's Expert Testimony Requires Reversal
An appellant "seeking reversal based on the erroneous exclusion of evidence must show that a different result was probable if the evidence had been admitted." Karlsson v. Ford Motor Co. (2006) 140 Cal.APp.4th 1202, 1223. Here, the issue of causation was beyond the knowledge of most laypeople. Calling experts to opine and testify as to the subject matter was proper. Evid. Code §801, subd(a). The court erroneously excluded Zimmer's expert testimony, especially when Zimmer had introduced admissible and material testimony that the jury should have been given the opportunity to hear and consider in making its decision. The appellate court here found that this exclusion resulted in a one-sided presentation of the evidence.
Therefore, the trial court's ruling to exclude Zimmer's expert testimony deprived it of a fair trial and constitutes reversible error. The appellate court reversed the ruling and remanded for a new trial.