Skip the Surgery for Knee Osteoarthritis
Arthroscopy of the knee joint for osteoarthritis, also called arthrosis or gonarthrosis,has no detectable benefit. That is the conclusion of a final report published by the German Institute for Quality and Efficiency in Health Care (IQWiG) on May 12th 2014. The study included new data in which strengthening exercises under the supervision of a physical therapist were used as comparison therapy. This data did not changethe result of IQWiG’s preliminary report that was published in September 2013.
A release from the institute explains that the benefit of therapeutic arthroscopy with lavage and possible debridement for the treatment of arthrosis of the knee joint is not proven. There was no hint, indication or proof of benefit of therapeutic arthroscopy in comparison with non-active comparator interventions such as sham surgery for any patient-relevant outcome. From the active comparator therapies, only the injection of glucocorticoids into the knee joint produced worse results than arthroscopy for the outcome.
Arthroscopy aims to relieve symptoms
Osteoarthritis of the knee is a chronic progressive disease that often occurs in both knees at the same time. Increasing failure of the joint is associated with changes in the structure of the joint, pain, and loss of flexibility. The condition makes daily tasks such as climbing stairs difficult and can reduce quality of life. The risk factors of gonarthrosis include age, sex, genetic factors and obesity.
Therapeutic arthroscopy of the knee joint is an endoscopic procedure where the knee joint is flushed with saline solution. Sometimes meniscal or cartilage abnormalities are removed or smoothed (debridement). The aim of this procedure is to relieve symptoms like pain and improve flexibility.
Wide variety of treatments
IQWiG compared this treatment with several other interventions, including no treatment, sham treatment ,and active treatments without arthroscopy such as glucocorticoid injections into the knee joint. The effect of these treatments on the daily activities and the quality of life of the people affected was of particular interest. Changes in the severity of symptoms and possible side effects of the treatments were also compared, for example infections after surgery.
Studies were subject to uncertainty
Eleven randomized controlled trials with a total of more than 1000 patients were identified for this research question, but a considerable number of them were subject to uncertainty. For example, in many cases the interventions were not blinded: The patients knew then whether or not they had arthroscopy. Sham arthroscopies can be done, however, in which patients receive a small skin incision on the knee, but no further surgery. This kind of “placebo surgery”, albeit controversial, is particularly informative for the assessment.
No advantage over sham interventions
No benefit of therapeutic arthroscopy in comparison with sham surgery and no treatment could be derived from most study results, and no clear conclusion could be drawn on potential harm from adverse treatment effects. It was already known that invasive treatment methods often have a particularly strong placebo effect. However, the extent of improvement perceived by the patients after placebo arthroscopy in these studies was surprising.
The comparison with active interventions was also sobering. Arthroscopy had a slight advantage only in comparison with glucocorticoid injection into the knee joint: The symptoms were somewhat milder. The study did not provide any information about whether the quality of life of the people affected also improved in comparison with the injection.
Also no benefit in comparison with strengthening exercises
Data from patients who had gonarthrosis with damage of the medial meniscus were used for the comparison of arthroscopic interventions with strengthening exercises under the supervision of a physical therapist. There was no significant effect in the two outcomes “pain” and “global assessment of the symptoms” at any time point of the study. Hence the overall result is the same as in the preliminary report: The benefit of arthroscopy of the knee joint for the treatment of gonarthrosis is not proven.
Process of report production
IQWiG published the preliminary results in the form of the preliminary report in September 2013 and interested parties were invited to submit comments. At the end of the commenting procedure, the preliminary report was revised and sent as a final report to the commissioning agency in May 2014. The written comments submitted were published in a separate document at the same time as the final report. The report was produced in collaboration with external experts.