Commentary on an article by Sunny Kim, PhD, et al.: “Increase in Outpatient Knee Arthroscopy in the United States: A Comparison of National Surveys of Ambulatory Surgery, 1996 and 2006”
John Gracy, MD

Kim et al. reviewed the number of knee arthroscopy procedures in the United States in both 1996 and 2006, and the trends from the past to the future, questioning why the rates of arthroscopic procedures have changed and where we are headed. “Where we are headed” could be rephrased: “Are we doing the right thing for our patients?” On the basis of the numbers the authors collated from the Centers for Disease Control and Prevention and the Agency of Health Research and Quality, there is no doubt about the vast increase in outpatient knee arthroscopy in the United States. The important questions are: Is the change real? Why has there been an increase? and Why is the rate of arthroscopic procedures performed in the U.S. more than double the rates in Ontario and England?

There are several underlying issues that make interpreting the numbers difficult, some of which the authors acknowledge. The number of freestanding ambulatory surgery centers has increased and, with reimbursements decreasing, surgeons are more likely to use the ambulatory surgery centers as they may be part owners and thus share in the revenue stream. In addition, my impression of ambulatory surgery centers is that the turnover between cases is faster, allowing more procedures in the same amount of time. The change in the number of procedures done for osteoarthritis is not surprising as Medicare and most insurance companies stopped paying surgeons for arthroscopies in patients with the diagnosis of osteoarthritis in 2004. This development, combined with the inability to use Current Procedural Terminology codes to know what the surgeon actually did, makes the procedural comparisons difficult. Given the change in reimbursement, I am curious about how many diagnoses of meniscal pathology in 2006 would have been coded as osteoarthritis if there had not been such a change. There are two final points. First, the data are a sample, which is interpolated to the numbers used in the study. Second, the survey obtaining inpatient data for 2006 was not done in 1996, so it is unknown how much of a change in the outpatient data is a transfer from inpatient surgical procedures compared with additional arthroscopic cases.

The nearly 50% increase in outpatient knee arthroscopy procedures from 1996 to 2006 is troubling if they are all additional cases (i.e., they are not transferred from inpatient cases in 1996). Even accounting for the population increase, the additional number of arthroscopies is substantial. Most puzzling was the 45% increase in arthroscopy in the female population. The participation of women in both scholastic and nonscholastic sports has changed dramatically in the last forty years, but I have not seen that much of a change in the last ten years. If the authors are correct that half the arthroscopic procedures are done for meniscal tears, we need to be sure that we are actually helping these patients; we need to be able to better define who will benefit from the partial meniscectomy and who will not. However, the increase in arthroscopy in the forty-five to sixty-four-year-old age group is not unexpected. The expectations of middle-aged and elderly individuals with regard to what they can do physically has markedly changed, and the baby boomers are more willing than the previous generations to undergo procedures to continue to look and act young.

The difference between the U.S. and the other countries with regard to the rates of arthroscopic procedures could be due to any number of causes. For example, there are many more magnetic resonance imaging (MRI) machines in the U.S. per capita. As the authors suggested, the practice of defensive medicine (more MRIs) and “doing something” could be contributing factors. Canada and England have substantial governmental budget restraints on how often a procedure can be done. Finally, the societal expectations of what can be done surgically, how quickly a patient can get better, what level of function can be expected at each stage of life, and the so-called quick fix are different not just in different regions of the country from but country to country.


  • * The author did not receive payments or services, either directly or indirectly (i.e., via his institution), from a third party in support of any aspect of this work. Neither the author nor his institution has had any financial relationship, in the thirty-six months prior to submission of this work, with any entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. Also, the author has had no other relationships or has engaged in any other activities that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by the author are always available with the online version of this article at