If you find yourself gingerly maneuvering up and down stairs and in and out of chairs because your knees are so painful and stiff, your doctor may have diagnosed osteoarthritis, the “wear and tear” type of arthritis. Exercise helps alleviate the stiffness but can be too uncomfortable for some sufferers…and painkilling drugs provide only temporary relief while carrying a risk for potentially serious side effects. The good news: There’s promising new evidence that an alternative treatment requiring just a few visits to a doctor’s office can ease symptoms for a year or more. It makes use of a substance you normally wouldn’t consider to be therapeutic—sugar!

The treatment involves injecting a solution into and around painful joints. Called prolotherapy, the technique has been around for at least 75 years. However, it isn’t broadly accepted because there haven’t been many high-quality studies demonstrating its effectiveness and clarifying which type of solution works best. With the recent publication of a study from the University of Wisconsin School of Medicine, that may be about to change…


The study included 90 adults with osteoarthritis of the knee and moderate-to-severe pain that had lasted for at least three months and had not responded well to other treatments. At the start of the study, all participants completed questionnaires that assessed, using a 100-point scale, the severity of their arthritis in terms of pain, stiffness and loss of function.

Next, participants were randomly assigned to one of three groups. One group was instructed in knee exercises and encouraged to practice them at home, gradually working their way up over the course of 20 weeks until they were doing the exercises three times during the day, five days per week.

Participants in groups two and three received prolotherapy sessions at weeks one, five and nine…and at weeks 13 and 17 if the participant and his/her physician thought the additional treatment would be helpful. Group two received injections of a saline (salt) solution…group three received injections of a dextrose (sugar) solution. Each session included up to 15 injections. Because this was a “blinded” experiment, neither the participants nor the doctor giving the injections knew which type of solution was being used on any given patient.

At several points during the treatment and a year after the start of the study, participants again filled out the symptom questionnaires to score their pain, stiffness and function.

Results: The dextrose prolotherapy group had the best improvement by a significant margin. Nine weeks into the study, after the third round of prolotherapy, the dextrose group’s symptom score had improved by 13.9 points, on average. In comparison, the saline prolotherapy group had improved by 6.8 points…and the exercise group improved by an average of just 2.5 points.

Even more encouraging was the fact that the relief seemed to be long-lasting. Though the final injections were given at week nine, 13 or 17 (depending on the patient), at week 52 the dextrose prolotherapy group still reported an average improvement of 15.3 points compared with their pretreatment symptom scores. This degree of improvement on the 100-point scale has been determined to be “clinically robust” in prior studies, the researchers said. In comparison, the saline prolotherapy group wound up with an average improvement of just 7.6 points, while the exercise group ended up with an 8.2-point improvement.

How it works: No one knows exactly how prolotherapy helps or why the sugar solution would work better than the salt solution. The basic theory, though, is that the injections provoke minor, temporary inflammation, causing the body to send more blood and nutrients to the area and thus promoting a healing response.


Although the anesthetic lidocaine was used to minimize the discomfort of the injections, participants reported short-term mild-to-moderate pain as the shots were given. No other adverse side effects were noted. The temporary discomfort seemed to be worth it, though—among participants who received dextrose prolotherapy, 91% said that they would recommend the treatment to other people with knee arthritis.

The procedure also can hurt the wallet—because most insurance providers do not cover prolotherapy, considering it to be experimental. If paying out-of pocket, you can expect dextrose prolotherapy to cost from about $150 to $500 per session, depending on the provider and location. Still, you may consider that money well-spent if it brings significant relief from pain and allows you to once again participate in everyday activities and favorite pastimes.

Prolotherapy should be administered by a physician (an MD, ND or DO) trained in the procedure. Ask your primary care doctor for a referral, or check the provider locator of the American Association of Orthopaedic Medicine, then call the doctor you are considering to find out whether he uses dextrose solution. You may be advised to temporarily reduce or discontinue anti-inflammatory drugs (aspirin, ibuprofen, naproxen) while undergoing prolotherapy—but acetaminophen is OK if it’s otherwise safe for you. If you take blood thinners or other drugs, tell the doctor because extra precautions may be warranted.