## Facts

- Karen L. Ralston previously received extensive radiation and surgical treatment for cancer in her left femur, leaving the bone significantly weakened.
- In April 1996, she fractured her lower left femur and knee area after tripping.
- Her surgeon, Dr. William Bohn, implanted Smith & Nephew’s femoral “MultiHole Nail” to stabilize the fracture and permit healing.
- About six months later, Ralston twisted her leg at work; the MultiHole Nail was found broken and a new fracture was discovered.
- Dr. Bohn removed the broken nail, performed a bone graft, and implanted a longer titanium intramedullary nail extending to the hip.
- Ralston continued to have serious left-leg problems and later underwent additional procedures, including a knee replacement by Dr. Kimberly Templeton.
- By summary judgment, Ralston narrowed her case to a failure-to-warn theory, asserting the manufacturer should have warned Dr. Bohn about a more durable “five-hole nail” alternative that allegedly would have been better for her condition.
- Ralston initially designated Dr. Christopher Ramsey as an expert, but her counsel agreed to strike him and attempted to substitute Dr. Templeton.
- The district court excluded Dr. Templeton’s opinions under Federal Rule of Evidence 702 and Daubert and then granted summary judgment for Smith & Nephew due to lack of admissible expert evidence.

## Issues

1. Whether the district court abused its discretion under Federal Rule of Evidence 702 and Daubert by excluding Dr. Templeton’s expert testimony on warning adequacy and causation.
2. Whether, after exclusion of Dr. Templeton’s testimony, summary judgment was proper on the remaining failure-to-warn claim for lack of evidence on essential elements.

## Decision

- The Tenth Circuit affirmed.
- The district court did not abuse its discretion in excluding Dr. Templeton’s expert opinions as unqualified and unreliable under Rule 702 and Daubert.
- Without admissible expert testimony on warning adequacy and causation, Ralston could not raise a genuine dispute of material fact on her failure-to-warn claim, so summary judgment for the manufacturer was appropriate.

## Legal Principles

- Trial courts have a gatekeeping duty under Rule 702 and Daubert to ensure expert testimony is both qualified (fit to the specific subject) and reliable (supported by an adequate methodological basis).
- A medical degree and general specialty do not automatically qualify a physician to offer expert opinions on specialized medical-device design, performance, or manufacturer warnings; the proponent must show subject-matter expertise tied to the opinions offered.
- In complex medical-device failure-to-warn cases, expert testimony is ordinarily required to establish (1) inadequacy of warnings to the treating physician and (2) causation, including whether a different warning would have changed treatment decisions and avoided injury.
- When essential elements require expert proof and the plaintiff lacks admissible expert evidence, summary judgment is proper.

## Conclusion

The court upheld the exclusion of the plaintiff’s substituted orthopedic expert because her opinions on intramedullary nail warnings and causation lacked specialized qualification and a reliable basis, and it affirmed summary judgment because the remaining failure-to-warn theory could not be proven without admissible expert testimony.


Ralston v. Smith & Nephew Richards, Inc., 275 F.3d 965 (10th Cir. 2001)