According to the AAOS 2010 report on Orthopaedic Practice in the United States, most orthopaedic surgeons in private practice have four major sources of income—private payers, Medicare, self pay, and workers’ compensation. For the practitioners who responded to the survey, workers’ compensation accounted for between 11 percent and 15 percent of their total compensation.

To retain—or increase—workers’ compensation as a significant payer source, orthopaedic surgeons need to stay up-to-date on issues surrounding the impact of injury on a patient’s ability to work. Take, for example, the question of whether favoring the injured limb results in overuse of the opposite uninjured limb. If it does, the patient may be able to claim a work-compensable condition in the originally uninjured opposite limb.

But the answer depends on multiple factors. Causation questions require a complete understanding of epidemiology, the medical condition in question, and the legal jurisdiction requesting the opinion—exactly the kind of material covered in the AAOS-sponsored course, “Occupational Orthopaedics & Workers’ Compensation: A Multidisciplinary Perspective,” which will be held this year in San Antonio, Texas, Nov. 2–4.

Causation questions
One section of the course will deal with how to approach causation issues, such as the question posed above. According to The Guides to the Evaluation of Disease and Injury Causation (American Medical Association [AMA] Press, 2008), the National Institute for Occupational Safety and Health and the (NIOSH) and the American College of Occupational and Environmental Medicine (ACOEM) have outlined the following six-step process to determine the work-relatedness of a disease:

1. Identify evidence of disease.
2. Review and assess the available epidemiologic evidence for a causal relationship.
3. Obtain and assess the evidence of exposure.
4. Consider other relevant factors.
5. Judge the validity.
6. Form conclusions about the work-relatedness of the disease in the person undergoing
   evaluation.

For example, the patient claims, “My right meniscus tear caused my left hip osteoarthritis (OA).” Using the NIOSH/ACOEM process, the orthopaedist would approach the problem in the following way:

• Identify evidence of disease—The history, physical examination, and radiographs confirm the left hip OA. They also show, however, that the patient has mild OA of the right hip, and the amount of OA appears similar in both hips.
• Review and assess the available epidemiologic evidence for a causal relationship—This requires a review of the literature, which can be done quickly. In preparing this article, for example, I found two articles indicating that no hard data support the belief that ‘favouring’ one leg adversely affects the other.
• Obtain and assess the evidence of exposure—The orthopaedist might want to ask about the patient’s job activities, previous trauma or injury, previous surgery, and previous workers’ compensation claims, among other issues.
• Consider other relevant factors—These might include age, body build, injuries to other joints, family history, history of injury, mechanism of injury, which activities increase or decrease symptoms, and previous treatments. Epidemiology cannot be separated from the specific individual. A 45-year-old male carpenter with a body mass index (BMI) of 36, a history of knee problems and a family history of OA, who smokes, drinks a couple of six-packs per week, and had a fall within the past year, landing on the left hip, has a very different situation than a 60-year-old female bus driver, with a BMI of 28, who has never smoked and had no history of knee problems until a skiing accident 2 years earlier that resulted in an arthroscopic partial medial meniscectomy and decreased range of motion in the right knee and left hip.
• Judge the validity—What are the key factors in the case? They might include age, BMI, fracture history, and previous trauma.
• Form conclusions about the work-relatedness of the disease in the person undergoing evaluation—Is this enough science and supporting information to provide an opinion? What more information is needed?

Other examples
In addition to addressing causation questions, the course faculty will also examine issues such as whether whole body vibration causes back pain (Daniel M. Spengler, MD); whether the medical literature is trustworthy (Eugene J. Carragee, MD); and how to complete AMA Impairment Guides.

The course is designed to provide fresh perspectives on treatment options, patient care management, and strategies for handling both nonmedical and medical issues associated with workers’ compensation. For those physicians interested in additional education regarding legal issues, a half-day linked course—“AAOS Expert Witness: Solving the Legal Quagmire—Methods and Insight”—will be held on Nov. 1. For more information, visit www.aaos.org/courses

J. Mark Melhorn, MD, is the course director for “AAOS Occupational Orthopaedics & Workers’ Compensation Course: A Multidisciplinary Perspective” and the “AAOS Expert Witness: Solving the Legal Quagmire—Methods and Insight” courses.