Background: Multiple clinical trials have shown that arthroscopy for knee osteoarthritis is not efficacious. It is unclear how these studies have affected orthopaedic practice in the USA. Questions/purposes: We questioned whether, in the Veterans Health Administration system, rates of knee arthroscopy in patients with osteoarthritis have changed after publication of the initial clinical trial by Moseley et al. in 2002, and whether rates of arthroplasty within 2 years of arthroscopy have changed during the same period. Methods: Patients 50 years and older with knee osteoarthritis who underwent arthroscopy between 1998 and 2010 were retrospectively identified and an annual arthroscopy rate was calculated from 1998 through 2002 and from 2006 through 2010. Patients who underwent knee arthroplasty within 2 years of arthroscopy during each period were identified, and a 2-year conversion to arthroplasty rate was calculated. Results: Between 1998 and 2002, the annual arthroscopy rate decreased from 4% to 3%. Of these arthroscopies, 4% were converted to arthroplasty within 2 years. Between 2006 and 2010, the annual arthroscopy rate increased from 3% to 4%. Of these arthroscopies, 5% were converted to arthroplasty within 2 years. Conclusions: Rates of arthroscopy in patients with knee osteoarthritis and conversion to arthroplasty within 2 years have not decreased with time. It may be that evidence alone is not sufficient to alter practice patterns or that arthroscopy rates for arthritis for patients in the Veterans Health Administration system were already so low that the results of the initial clinical trial had no substantial effect. Level of Evidence: Level III, Retrospective cohort study.