Assessment of leech therapy for knee osteoarthritis: A randomized study

Abstract

Background and purpose Symptomatic treatment of osteoarthritis of the knee with leeches is presently undergoing a renaissance. Previous studies have shown methodical weaknesses. In the present study patients were blinded regarding the treatment, and a control group was included to explore possible differences in various subjective clinical scores and intake of pain medication over time between leech therapy and placebo control.

Patients and methods 113 patients with advanced osteoarthritis of the knee were included. The patients were randomized to a single treatment group, group I (single leech application, n = 38), a double treatment group, group II (double application, n = 35), and a control group (n = 40). The second treatment in group II took place after an interval of 4 weeks. The treatment in the control group was simulated with the help of an “artificial leech”. Results were documented with the KOOS and WOMAC scores and also a visual analog scale (VAS) for pain. Changes in the use of pain medication were monitored over 26 weeks.

Results An improvement in KOOS and WOMAC scores, and also in VAS, was found in all 3 groups following treatment. These improvements were statistically significant for treatment groups I and II during the complete follow-up period. The reduction in individual requirements for pain medication was also statistically significant. The greatest improvement was seen in the group treated twice with the leeches, with a long-term reduction of joint stiffness and improved function in the activities of daily living.

Interpretation Leech therapy can reduce symptoms caused by osteoarthritis. Repeated use of the leeches appears to improve the long-term results. We have not determined whether the positive outcome of the leech therapy is caused by active substances released during the leeching, the placebo effect, or the high expectations placed on this unusual treatment form.

Contributions of authors

SA and US conceived and led the investigation. SS developed the study protocol and guided the statistical analyses. FS and UM performed the initial acquisition of data. CHS, TM, and RMR assisted with the study, in interpretation of results, and drafting of the manuscript. All authors read and approved the final version of the manuscript.

The study was supported by the Deutsche Arthrosehilfe. This did not influence the acquisition or analysis of data presented in this paper.

Supplementary data

A detailed description of the randomization process, the flowchart and evaluation data, the changes over time, and the differences obtained for various parameters over time (expressed as descriptive data and p-values determined with the paired/unpaired Wilcoxon-test for the individual groups) can be found on the Acta Orthopaedica website at www. actaorthop.org, identification number 0801.