Termination of Reimbursement of Arthroscopy in Osteoarthritis of the Knee: Is This Decision Based on Scientific Grounds?

Abstract

Background In Germany, arthroscopy of the knee used to be an accepted procedure in the treatment of osteoarthritis of the knee. However, as of April 1, 2016 reimbursement for this procedure has been discontinued. This was a decision of the Joint Federal Committee (Gemeinsamer Bundesausschuss, G-BA). That decision was based on a report of the German Institute for Quality and Efficiency in Health Care (IQWiG). This report is essentially based on a few studies, three of which have been published in the renowned New England Journal of Medicine. According to the IQWiG, there is "no hint, indication or proof of a benefit of therapeutic arthroscopy" in osteoarthritis of the knee. Since this statement does not coincide with clinical observations commonly made by orthopaedic surgeons, the aim of this analysis was to evaluate the aforementioned studies according to criteria of evidence-based medicine. Material and Methods The three studies on which the IQWiG report is essentially based (Moseley et al. 2002, Kirkley et al. 2008 and Katz et al. 2013), all published in the New England Journal of Medicine, were analyzed according to the standards of evidence-based medicine. Results Although all of the evaluated studies were randomized controlled studies, there were considerable and serious deficiencies. These deficiencies include, among others, sampling bias that affects external validity and selection bias that affects internal validity. While a sham operation was performed in one study, resulting in an ideal blinding of study participants, that study used a non-validated primary outcome measure. That outcome score has not been used in subsequent publications and the algorithm presented for the calculation of the outcome score was incorrect. Although the other studies used validated main outcome measures, patients in those studies were not blinded. A number of further deficiencies were identified as well. Conclusion The studies on which the decision of the Joint Federal Committee is based do have several significant and at times severe methodological deficiencies. For instance, the results of these studies cannot be generalized to all patients suffering from osteoarthritis of the knee, solely on the basis of patient selection. Many of these deficiencies have not been mentioned till now, neither in the literature nor in the final report authored by the IQWiG. Therefore, it seems unlikely that the Joint Federal Committee was aware of these deficiencies when it decided to discontinue reimbursement for arthroscopy in patients with osteoarthritis of the knee. Unfortunately, not all patients suffering from osteoarthritis of the knee respond to conservative therapy. By discontinuing reimbursement for arthroscopy in this patient group, a commonly used treatment option has been withdrawn. The proportion of such patients was 30% after 6 months and 35% after 12 months in one of the studies considered by the IQWiG. It is hence conceivable that the indication for joint replacement surgery could become more generous after the withdrawal of arthroscopy as an alternative treatment option. In summary, it became clear that, given the variety and severity of the deficiencies of the underlying studies, the decision of the Joint Federal Committee could not have been based on scientific criteria. To this extent, it seems appropriate to revive the discussion about the exclusion of arthroscopy from the performance catalogue of the German Health Insurance System.