Willow bark extract (Salicis cortex) for gonarthrosis and coxarthrosis – Results of a cohort study with a control group

Study objectiveThe examination of the effectiveness and tolerance of willow bark extract in patients with gonarthrosis and coxarthrosis compared to conventional therapies.MethodsIn an open, multicentric observational study with reference treatment, 90 patients were treated with a standardised willow bark extract preparation, 41 patients with a standard therapy prescribed by a doctor and 8 patients with a combination of the two. After 3 and finally 6 weeks the effectiveness and tolerance were determined by the doctor (clinical findings, recording of adverse events, global tolerance) and by the patients (WOMAC questions concerning pain and stiffness, questions on general state of health).ResultsA total of 88 patients in the willow bark group and 40 patients in the reference group completed the study. The doctors and patients judged the effectiveness in both groups to be comparable. After 6 weeks the effectiveness of the willow bark extract tended to be assessed as better than in the group undergoing conventional therapy. Also in the subgroup of chronically sick patients (>3 months), after 6 weeks the effectiveness of both forms of treatment was comparable; however, the effect was slower to set in the willow bark group than in the reference group. Doctors and patients assessed the tolerance of the willow bark extract to be better than the conventional therapy. Adverse effects of the drugs did not occur in the willow bark group; one case each of reflux symptoms occurred in the reference group and theConclusionsFor treating mild or fairly severe cases of gonarthrosis and coxarthrosis the effect of willow bark extract is comparable to that of standard therapies, without the corresponding side effects having to be accepted.