Prolotherapy — A Neglected Treatment for Knee Osteoarthritis?
Abstract & Commentary
By Joseph E. Scherger, MD, MPH
Vice President, Primary Care, Eisenhower Medical Center; Clinical Professor, Keck School of Medicine, University of Southern California, Los Angeles
Dr. Scherger reports no financial relationships relevant to this field of study.
Synopsis: The injection of a dextrose solution in and around the knee (prolotherapy) is an alternative treatment for the pain of knee osteoarthritis. A randomized, controlled trial shows that prolotherapy is effective for long-term control of knee pain and improvement in knee function.
Source: Rabago D, et al. Dextrose prolotherapy for knee osteoarthritis: A randomized controlled trial. Ann Fam Med 2013; 11:229-237.
Injection therapy in a painful knee with osteoarthritis is commonly done, usually with a corticosteroid or hyaluronic acid. Corticosteroids have side effects that limit their use and hyaluronic acid solutions are expensive. An alternative therapy using concentrated dextrose solutions has been available through a limited number of practitioners for at least 75 years. This treatment was called sclerotherapy based on a belief that scar tissue was being formed,1 but has been changed to prolotherapy with the belief that ligamentous and other tissue proliferates as a result of the irritant nature of the injection.2 The actual mechanism of action of prolotherapy is not known.
Prior to this study, the quality of the research on prolotherapy has been weak, although the results have been positive.3 This randomized, controlled trial at the University of Wisconsin may be the first rigorous, double-blinded study of prolotherapy. Ninety patients with osteoarthritis knee pain were randomized to a three-arm study of receiving prolotherapy, saline solutions, or a home exercise program. The injections included both extra-
articular and intra-articular sites of the affected knee(s) at 1, 5, and 9 weeks with optional additional sessions at 13 and 17 weeks. Improvement scores were obtained using the Western Ontario McMaster University Osteoarthritis Index (WOMAC)4 and the knee pain scale (KPS).5 Pain and function analysis was done at baseline and at 5, 9, 12, 24, and 52 weeks.
All three groups showed improvement over the 52- week study period with the saline and exercise groups showing similar modest changes. The prolotherapy group showed substantially greater improvement (P < 0.05), with 50% of the patients having improvement at 52 weeks over a minimal change scale. The procedure was well tolerated with no reported side effects.
COMMENTARY
Recently, a patient with painful osteoarthritis of the knee asked me what I thought of prolotherapy. I had no idea what she was talking about. She told me there was a practitioner in a nearby city that offered this treatment and that a friend recommended it after having good results. My reading showed that prolotherapy was injecting concentrated dextrose solutions in and around the knee and that the mechanism of action was not known, but the dextrose caused irritation that might lead to pain relief. This method has been around for a long time but no rigorous studies have been done. I was skeptical and steered my patient away from such an alternative therapy and toward more conventional methods that usually lead to surgery.
This rigorous study by a respected university team showing good results impresses me. It seems there is an inexpensive and easy-to-administer alternative for treating the pain of osteoarthritis of the knee and possibly other joints. Training in using prolotherapy is available and it is a simple outpatient procedure taking about 15 minutes to administer. A series of treatment sessions is required. The side effects are minimal and the risks are very low. Prolotherapy is a cost-effective alternative treatment for osteoarthritis that should be further studied. Today, I would not steer my patients away from it, and may consider having our group take up this therapy.
References
1. Schultz L. A treatment for subluxation of the temporomandibular joint. JAMA 1937;109:1032-1035.
2. Hackett GS, et al. Ligament and tendon relaxation treated by prolotherapy. 5th ed. Oak Park, IL: Gustav A. Hemwall; 1993.
3. Rebago D, et al. A systemic review of prolotherapy for chronic musculoskeletal pain. Clin J Sport Med 2005; 15:376-380.
4. Bellamy N, et al. Validation study of WOMAC: A health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip or knee.
J Rheumatol 1988;15:1833-1840.
5. Rejeski WJ, et al. The evaluation of pain in patients with knee osteoarthritis: The knee pain scale. J Rheumatol 1995;22:1124-1129.
