Sugar-Water Injections Relieve Knee Pain More Than Exercise
Madison, Wisconsin - Injections with a form of sugar known as dextroseprovide significant pain relief and improved knee-related quality of life compared to exercise among people who suffer from knee osteoarthritis.
That’s according to research at the University of Wisconsin School of Medicine and Public Health and published in the Annals of Family Medicine.
The practice known as prolotherapy involves injecting a non-pharmacological solution in painful tendons, ligaments and joints.
Lead author Dr. David Rabago, assistant professor of family medicine at UW, said the study involved 90 people between age 40 and age 76. All had at least three months of knee arthritis pain and had unsuccessfully used other treatments such as physical therapy.
They were divided randomly into three groups: two received blinded injections of either dextrose (sugar) or saline solution. The third group was involved in an exercise program.
Injections with dextrose and saline were done at one, five and nine weeks and if needed, at 13 and 17 weeks.
Participants were contacted by phone after 26 and 52 weeks, and a scoring system was used to rate pain, stiffness, and how the arthritis was affecting normal activities of daily living such as walking up and down stairs or doing household chores.
Rabago said the scores indicated that while participants in all groups made some gains compared to their baseline status, those in the prolotherapy group improved about twice as much as those receiving saline injections or exercise from nine to 52 weeks.
"This suggests there is a biological effect to prolotherapy," he said. "Though the study is of modest size, the data are clear and consistent, showing a robust effect compared to blinded and non-blinded therapies."
Rabago noted that these results do not show that prolotherapy is a cure for osteoarthritis, and that more study of both effects and why it works still need to be investigated.
"We don’t have a detailed understanding about why prolotherapy has a biological effect," he said. "One theory suggests that injected solutions act as a positive irritant and, when injected locally at points of tenderness and pain, stimulate the native healing response. Prolotherapy may work with the person’s own immune response to create a local healing response at the injured tissue."
"The assessment involved overall knee outcomes made up of separate scores for knee pain, stiffness and function,” he added. “Did participants report complete knee recovery? No, but they did report robust improvement in all three knee outcomes by a margin that is clinically relevant."
While prolotherapy rated higher at relieving pain than exercise did, Rabago said patients with knee arthritis should not give up on exercising if they are also using prolotherapy.
"While we have not studied the effect of exercise plus prolotherapy in patients with knee osteoarthritis, prior studies have reported that patients using prolotherapy for other injuries; for example, Achilles tendon inflammation, had positive results when they combined with exercise versus using either exercise or prolotherapy alone," he said. "It’s reasonable to suggest that monitored, progressive at-home exercise or formal physical therapy would be good care."
Rabago said the study will continue for two more years to determine if the participants still feel pain relief beyond 52 weeks.
"The data support a plateau effect between 26 and 52 weeks," he said. "We will follow these patients in a follow-up study to determine whether the positive effect is stable."
Some insurance carriers will cover prolotherapy with prior authorization, but most patients pay for the treatments out-of-pocket. Prolotherapy is not covered under Medicare.
The study was funded by the NIH National Center for Complementary and Alternative Medicine.
Date Published: 05/21/2013