## Facts

- Peggy Trees underwent cervical spine fusion surgery performed by neurosurgeon Julio A. Ordonez, M.D.
- Ordonez implanted a cervical stabilization plate (with screws) to secure the fused vertebrae.
- Trees later experienced serious complications requiring additional surgeries and resulting in permanent disabilities.
- Trees alleged Ordonez negligently failed to properly place and secure the plate and screws, causing injury, including damage to soft tissue and the esophagus.
- To prove negligence, Trees offered expert testimony from Dr. Tencer, a biomechanical/biomedical engineer with experience in orthopedic medical devices and familiarity with the specific plate system used.
- Tencer testified about the manufacturer’s instructions, the device’s mechanical design, the risks of screws not being fully seated, and what a reasonably careful surgeon should do when using the device.
- The circuit court concluded there was sufficient evidence of causation but granted defendants a directed verdict on standard of care and breach, reasoning Trees lacked physician expert testimony on those elements.
- The Oregon Court of Appeals affirmed, concluding Trees failed to connect device mechanics to the surgeon’s standard of care.

## Issues

1. In a medical negligence action, must the plaintiff present standard-of-care and breach testimony from a medical doctor, or may a qualified non-physician expert testify to those elements when the alleged negligence concerns a medical device’s use?
2. Viewing the evidence most favorably to the plaintiff, did the record contain evidence sufficient to submit standard of care and breach to the jury, making a directed verdict improper?

## Decision

- The Oregon Supreme Court reversed the Court of Appeals and the circuit court and remanded for further proceedings.
- The court held Trees was not categorically required to present expert testimony from a medical doctor to establish the standard of care and breach.
- The court concluded Trees introduced sufficient expert evidence from a biomechanical engineer to create a jury question on at least one aspect of her negligence claim regarding the plate and screw placement.

## Legal Principles

- In medical negligence cases, expert testimony is generally required when the applicable standard of care is beyond a lay jury’s common knowledge.
- Oregon law does not impose a profession-based rule requiring that standard-of-care and breach testimony always come from a physician; the controlling question is whether the expert is qualified by knowledge, skill, experience, training, or education to assist the trier of fact on the specific matter at issue.
- When alleged negligence involves device-specific, mechanical questions (including compliance with manufacturer instructions and the mechanical consequences of implantation choices), a non-physician expert with relevant specialized expertise may provide admissible testimony on standard of care and breach.
- On review of a directed verdict, the court asks whether there is any evidence in the record supporting the challenged element, viewing the evidence in the light most favorable to the nonmoving party.

## Conclusion

The Oregon Supreme Court held that a medical malpractice plaintiff is not required to use a physician expert to prove standard of care and breach where a qualified biomechanical engineer’s device-focused testimony provides evidence from which a reasonable jury could find negligence, and it reversed the directed verdict and remanded.


Trees v. Ordonez, 311 P.3d 848 (Or. 2013)