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A Systematic Review and Meta-Analysis of Medical Leech Therapy for Osteoarthritis of the Knee

Lauche, Romy PhD; Cramer, Holger PhD; Langhorst, Jost MD; Dobos, Gustav MD

Clinical Journal of Pain:
doi: 10.1097/AJP.0b013e31828440ce
Original Articles

Objectives: Osteoarthritis of the knee is a common chronic disease among older adults. Therapeutic approaches mainly consist of physiotherapy or pharmacological therapy, but these approaches are limited over time by their cost and/or side effects. This paper presents a systematic review and meta-analysis of the effectiveness of medical leech therapy for osteoarthritis of the knee.

Methods: The PubMed/MEDLINE, Cochrane Library, EMBASE, Scopus, and CAMBASE databases were screened in August 2012 to identify randomized (RCTs) and nonrandomized controlled clinical trials (CCTs) comparing leech therapy to control conditions. Main outcome measures were pain, functional impairment, and joint stiffness. For each outcome, standardized mean differences (SMD) and 95% confidence intervals were calculated.

Results: Three RCTs and 1 CCT were found, in which a total of 237 patients with osteoarthritis were included. Three trials had a low risk of bias. There was strong overall evidence for immediate (SMD=−1.05; P<0.01) and short-term pain reduction (SMD=−1.00; P<0.01), immediate improvement in patients’ physical function (SMD=−0.72; P<0.01), and both immediate (SMD=−0.88; P=0.04) and long-term improvement in their joint stiffness (SMD=−0.62; P<0.01). Moderate evidence was found for leech therapy’s short-term effects on physical function (SMD=−0.46; P<0.01) and long-term effects on pain (SMD=−0.45; P<0.01). Leech therapy was not associated with any serious adverse events.

Discussion: This systematic review found moderate to strong evidence for the reduction of pain, functional impairment, and joint stiffness after medical leech therapy in patients with osteoarthritis of the knee. Given the low number of reported adverse events, leech therapy may be a useful approach in treating this condition. Further high-quality RCTs are required for the conclusive judgment of its effectiveness and safety.

Author Information

Department of Internal and Integrative Medicine, Kliniken Essen-Mitte, Faculty of Medicine, University of Duisburg-Essen, Essen, Germany

They were not, however, involved in the extraction or analysis of the reviewed data or the risk of bias assessment.

R.L. was responsible for conceiving and designing the review, performing the literature search, extracting and analyzing the data, conducting the risk of bias assessment, and drafting the manuscript. H.C. was responsible for conceiving and designing the review, performing the literature search, extracting and analyzing the data, conducting the risk of bias assessment, and critically revising the manuscript. J.L. and G.D. participated in conceiving and designing the study, reviewing trials, as well as critically revising the manuscript; it is important to note that 2 authors (J.L. and G.D.) were involved in the reviewed trials. All authors approved the final version of the manuscript.

The authors declare no conflict of interest. Supported by a grant from the Rut- and Klaus-Bahlsen-Foundation, Hannover, Germany. This funding source had no influence on the review’s planning, organization, management, or publication.

Reprints: Romy Lauche, PhD, Kliniken Essen-Mitte, Klinik für Naturheilkunde und Integrative Medizin, Am Deimelsberg 34a, 45276 Essen, Germany (e-mail:

Received August 1, 2012

Accepted December 20, 2012

© 2014 by Lippincott Williams & Wilkins