## Facts

- Janice Sides underwent a lumbar laminectomy with spinal fusion on June 17, 2003, at St. Anthony’s Medical Center.
- After surgery, she developed a surgical-site infection involving *E. coli*.
- Sides and her husband sued the hospital, the operating surgeon, and related entities for medical malpractice.
- Plaintiffs pleaded negligence under a res ipsa loquitur theory, alleging the infection was the type of event that ordinarily does not occur absent negligence and that defendants had control of the operative environment and superior access to information.
- Plaintiffs sought to use medical expert testimony to establish that the infection and circumstances supported an inference of negligence.

## Issues

1. In a medical malpractice case pleaded under res ipsa loquitur, may a plaintiff introduce expert medical testimony to show the injury is of a kind that ordinarily does not occur absent negligence?

## Decision

- The Missouri Supreme Court reversed the dismissal and remanded.
- The court held that expert testimony may be used to support the res ipsa inference in medical malpractice cases.
- The court rejected the view that prior precedent categorically barred expert testimony in res ipsa medical malpractice cases.
- To the extent lower-court decisions read Hasemeier to prohibit expert testimony in such cases, those decisions were overruled.
- The court adopted Restatement (Second) of Torts § 328D comment d, permitting res ipsa when expert opinion supplies the foundation that the injury ordinarily would not occur without negligence.

## Legal Principles

- In medical malpractice actions, expert testimony is generally required to establish negligence and the applicable standard of care, except in limited situations where lay experience permits an inference of negligence without medical expertise.
- Pleading res ipsa loquitur does not excuse the general requirement of expert testimony in medical malpractice cases.
- Expert testimony may be used to establish the predicates for res ipsa loquitur, including that:
  - the event is of a kind that ordinarily does not occur in the absence of negligence;
  - the cause was within the defendant’s control; and
  - the injury was not due to the plaintiff’s voluntary action or contribution.
- Res ipsa loquitur may be submitted in complex medical cases when expert evidence supports that the injury would not ordinarily occur absent negligence.

## Conclusion

The court reinstated the malpractice action, holding that plaintiffs may use expert medical testimony to establish the foundational elements for a res ipsa loquitur inference and rejecting prior interpretations that treated precedent as barring expert support for res ipsa in medical malpractice cases.


Sides v. St. Anthony's Med. Ctr., 258 S.W.3d 811 (Mo. 2008)