Trees v. Ordonez, 311 P.3d 848

This is a medical malpractice case against Dr. Ordonez and Greater Portland Neurosurgical Center over a Synthes plate installed on plaintiff’s cervical spine.
Plaintiff offered Dr. Tencer, a biomechanical engineer (not a physician), as expert on design/installation of the plate; no medical doctor testified to breach of standard of care.
Trial court granted a directed verdict on negligence but denied on causation; Court of Appeals affirmed the directed verdict; Oregon Supreme Court reverses for reasons addressing non-doctor expert admissibility.
Court concludes that expert testimony from a non-physician may establish the standard of care in some cases, and must be evaluated case-by-case on directed-verdict motion.
The court focuses on whether protruding screw heads and plate installation breached the standard of care, and whether causation is proven, ultimately reversing the directed verdict and remanding for proceedings.
The decision remands to circuit court for further proceedings on negligence and causation issues.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Can a non-medical doctor expert establish the standard of care in medical malpractice?	Tencer’s biomechanical expertise suffices.	Only a medical doctor can establish the standard of care.	No strict medical-degree requirement; non-doctor may establish standard of care; case-specific directed verdict analysis required.
Was there sufficient evidence of negligence to submit to the jury?	Dr. Tencer’s testimony showed improper plate/screw installation.	Profound reliance on neurosurgeon standard; insufficient non-physician proof.	Yes, jury could find breach based on screw protrusion and installation per Tencer; directed verdict reversed.
Did causation rise from the evidence of screw protrusion?	Protruding screws likely caused esophageal perforation; causation supported by multiple experts.	Causation too speculative without explicit medical probability.	Evidence supports more likely than not causation; denial of directed verdict on causation affirmed.

Rogers v. Meridian Park Hospital, 307 Or 612 (1989) (medical-malpractice standard of care not limited to doctors in some contexts)
Barrett v. Coast Range Plywood, 294 Or 641 (1983) (medical expert qualification depends on knowledge, not solely degree)
Sheppard v. Firth, 215 Or 268 (1959) (expert admissibility of non-specialist in evidence)
Creasey v. Hogan, 292 Or 154 (1981) (orthopedic and podiatrist standard of care based on cross-disciplinary knowledge)
Sims v. Dixon, 224 Or 45 (1960) (causation proof requires reasonable probability, not mere possibility)
Joshi v. Providence Health System, 342 Or 152 (2006) (medical causation requiring reasonable medical probability)