Expert witness essentials for orthopaedic surgeons at all career stages

The AAOS Expert Witness Course offers in-depth training to enhance clinical and legal skills

Expert medical witnesses fulfill a critical public service by offering credible, objective, and evidence-based opinions that assist in the fair and informed resolution of legal disputes. Their expertise is particularly valuable in contexts such as utilization reviews, workers’ compensation claims, personal injury litigation, and disability determinations, where complex medical issues must be interpreted and clearly explained to non-medical audiences.

Unlike fact witnesses, who recount direct experiences or observations, expert medical witnesses are called upon to interpret clinical findings, explain standards of care, assess causation, and evaluate functional outcomes. Their opinions are grounded in years of medical education, clinical experience, and familiarity with current best practices. In this capacity, they serve not as advocates for either party, but as impartial educators to the court, helping judges, juries, and administrative bodies understand the medical facts essential to reaching just conclusions.

This role is widely recognized as indispensable to the legal process, particularly in ensuring that decisions are based on accurate, scientifically sound information. By bridging the gap between medicine and law, expert medical witnesses help uphold the integrity of the justice system and support equitable outcomes for all parties involved.

Differences between fact and expert medical witnesses
Fact witnesses — often treating physicians — testify to firsthand observations made during clinical care. Their role is limited to describing what they personally saw, heard, or did and is grounded in their direct involvement with the individual. They do not provide opinions outside the scope of treatment.

In contrast, expert medical witnesses are retained specifically to provide independent, informed opinions based on their specialized knowledge, clinical experience, and evidence-based analysis. Their role includes interpreting medical facts, assessing causation, evaluating adherence to clinical standards, and projecting likely outcomes. Unlike fact witnesses, experts assist the court by clarifying complex medical issues in a manner that is objective and accessible to non-clinical audiences.

The distinction between fact and expert witnesses is foundational to the legal process. Fact witnesses establish the clinical narrative, and expert witnesses provide critical interpretation within the broader framework of medical science, supporting informed and equitable legal outcomes.

In U.S. courts, the admissibility of expert testimony is primarily governed by two legal standards: the Frye and Daubert standards. These frameworks determine whether an expert’s opinion can be presented to the court, focusing on the scientific validity and relevance of the testimony.

The Frye standard, originating from Frye v. United States, 293 F. 1013 (D.C. Cir. 1923), requires that the scientific principle or technique underlying the expert’s opinion be “generally accepted” within the relevant scientific community. This approach emphasizes consensus among experts and institutions as a gatekeeping mechanism. Although the Frye standard is still used in a minority of states, it has been criticized for being too restrictive and slow to accommodate emerging scientific methodologies.

In contrast, the Daubert standard, established by the U.S. Supreme Court in Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993), is the prevailing framework in federal courts and has been adopted by most state jurisdictions. Under Daubert, the trial judge assumes the role of “gatekeeper,” tasked with ensuring that expert testimony is both relevant to the legal issue at hand and reliable from a scientific standpoint.

The Daubert standard outlines several nonexclusive criteria for evaluating reliability:

Testability: whether the theory or technique can be and has been empirically tested
Peer review and publication: whether the work has been subject to scrutiny and validation by the scientific community
Known or potential error rate: the frequency and likelihood of error associated with the method
Standards and controls: whether the methodology follows established standards or protocols.
General acceptance: the extent of acceptance in the relevant community (although not dispositive)

The Daubert framework reflects a shift from focusing solely on general acceptance to a broader, more flexible assessment of scientific rigor. It encourages the court to evaluate not just whether the expert is qualified, but whether the reasoning and methods underlying the opinion are scientifically valid and properly applied to the facts of the case.

These standards have profound implications for expert medical witnesses, who must ensure that their methodologies are not only grounded in current scientific practice but also clearly articulated and defensible under legal scrutiny. Whether under Frye or Daubert, the goal remains the same: to prevent unreliable or unscientific expert opinions from misleading the court and to support the integrity of the judicial process.

Qualification for an expert medical witness
The American Medical Association (AMA) Code of Medical Ethics emphasizes that expert testimony must be impartial, scientifically grounded, and clinically accurate. This ethical mandate affirms the expert’s responsibility to serve the interests of justice rather than those of any party involved. Testimony must be honest, transparent about its limitations, and aligned with accepted standards of medical practice.

An expert witness should hold appropriate board certification, possess relevant clinical experience, and ideally have a record of scholarly contributions. Physicians must limit their testimony to areas within their expertise and disclose any potential conflicts of interest, as outlined in the AAOS Standards of Professionalism.

Beyond credentials, impartiality is essential. Experts must avoid becoming perceived as “hired guns.” Ethical pitfalls — such as selectively reviewing records, charging unreasonable fees, or having unsubstantiated changes in opinion — can severely undermine both credibility and the integrity of their testimony.

Physicians who serve as expert witnesses have a professional obligation to provide clear, ethical, and unbiased medical opinions. By following established standards — such as those outlined by AMA and AAOS — they support fair adjudication and help maintain public confidence in the legal system. Effective expert testimony relies on thorough preparation, objective analysis, and credible presentation.

Structured education as well as adherence to professional guidelines not only fulfill legal and ethical responsibilities but also help to strengthen the integrity of both medical practice and judicial proceedings.

Recognizing the importance of ongoing education, the Annual AAOS Workers’ Compensation and Musculoskeletal Injuries Course offers physicians valuable insights into the intersection of orthopaedics and legal processes. Additionally, the AAOS Expert Witness Course is specifically designed to bridge clinical expertise with legal application. These programs provide in-depth training on documentation, legal standards, deposition techniques, courtroom testimony, and ethical considerations — critical components for developing the skills and professionalism that define an effective expert witness.

J. Mark Melhorn, MD, FAAOS, is an associate clinical professor in the Department of Orthopaedic Surgery at the University of Kansas School of Medicine in Wichita.

George B. Holmes Jr., MD, FAAOS, is an associate professor emeritus and director emeritus of the Section of Foot and Ankle and director emeritus of the Foot and Ankle Fellowship at Rush University Medical Center in Chicago.

References

American Medical Association Code of Medical Ethics. Medical Testimony. Accessed May 21, 2025. https://code-medical-ethics.ama-assn.org/ethics-opinions/medical-testimony
Standards of Professionalism: Orthopaedic Expert Opinion and Testimony. Updated May 12, 2010. Accessed May 21, 2025. https://www.aaos.org/globalassets/about/meet-the-aaos/sop-orthopaedic_expert_opinion_and_testimony_5-12-2010.pdf
Frye v. United States, 293 F. 1013, D.C. Cir. 1923.
Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579, 1993.

Advance your medicolegal expertise with two premier AAOS courses

J. Mark Melhorn, MD, FAAOS, serves as course director for the 27th Annual AAOS Workers’ Compensation and Musculoskeletal Injuries Course, alongside George B. Holmes Jr., MD, FAAOS, course codirector for the Expert Witness Course. Together, these two educational offerings provide a unique opportunity for physicians to enhance their clinical, legal, and communication skills in occupational and forensic medicine.

Annual AAOS Workers’ Compensation and Musculoskeletal Injuries Course
Presented by AAOS and the International Academy of Independent Medical Evaluators, this livestreamed virtual event will take place on Nov. 7 and 8, 2025, with an optional half-day Expert Witness Course on Nov. 6. The course features:

Expert-led lectures and interactive panel discussions
New faculty and updated content on causation, diagnosis, and treatment of occupational injuries
Practical strategies for:
- Causation analysis
- Report writing and documentation
- Utilization review and treatment authorization
- Navigating medical liability
- Deposition preparation and testimony skills
- Communicating effectively with patients, attorneys, and claims administrators

Whether you are new to workers’ compensation or an experienced evaluator, this course offers practical tools to improve your evaluations and outcomes.

Half-Day Expert Witness Course
This focused session is ideal for those interested in expanding or refining their expert witness practice. Topics include:

Business considerations for individual versus group expert witness practices
Insurance and risk management (including malpractice and errors and omissions coverage)
Marketing, professional networking, and organizational affiliations
Deposition and testimony strategies: staying calm, credible, and clear
Integrating artificial intelligence tools to streamline record review and reporting
Common pitfalls and how to maintain professional boundaries and credibility

Register now to secure your place and benefit from this integrated educational experience that combines clinical knowledge with legal insights and practical business strategies.