Prolotherapy is a treatment that aims to strengthen weakened ligaments that are believed to be a common cause of chronic musculoskeletal pain. It involves the repeated injection of tender ligaments with an irritant solution that purportedly stimulates inflammation and subsequent strengthening of these ligaments. This then leads to a reduction in pain and disability. The prolotherapy protocol used for chronic low back pain in general practice in Australia uses a solution of 20% glucose and 0.2% lignocaine and is supplemented by flexion/extension exercises and vitamin and mineral tablets. This thesis reports on a randomised controlled trial designed to assess the efficacy, safety, costs and predictors of outcome of the glucose/lignocaine and exercise components of this prolotherapy protocol.
One hundred and ten participants with non-specific low back pain of average 14 years duration were randomised to have repeated prolotherapy or normal saline injections into tender Jumbo-pelvic ligaments and also to perform either flexion/extension exercises or normal activity over six months. A blinded assessment of pain intensity (VAS) and disability scores (Roland-Morris) was made at 10 weeks, and four, six, 12 and 24 months.
Follow-up was achieved in 96% of participants at 12 months and in 80% at 24 months. Ligament injections, with or without exercises, resulted in significant and sustained reductions in pain and disability throughout the 24 months of the trial, but no attributable effect was found for glucose/lignocaine solutions over saline solution nor for exercises over normal activity. The key summary results were the proportions at 12 months achieving >50% reduction in pain from baseline. By injection group, these were glucose-lignocaine, 0.46 versus saline, 0.36, and by activity group, these were exercise, 0.41 versus normal activity, 0.39. Corresponding proportions for >50% reduction in disability were glucose-lignocaine, 0.42 versus saline, 0.34; and exercise, 0.36 versus normal activity, 0.38. There were no between group differences in any of the above measures at 12 months or at 24 months. There was a high incidence of minor side effects with the prolotherapy protocol but no long-term sequelae attributable to this treatment.
Predictors of a poorer response included smoking, high anxiety and depression levels and previous use of over four different treatments.
The savings in the costs of back pain to the cohort as a whole were 13 times the costs of the treatment. At 12 months, hours lost from paid work due to back pain decreased from 9.3% to 1.9% of usual paid hours and hours lost from unpaid work decreased from 29.8% to 14.3% of usual unpaid hours. There was no increase in the number employed.
The results suggest that in chronic non-specific low back pain, significant and sustained reductions in pain and disability occur with ligament injections, irrespective of the solution injected or the concurrent use of exercises. The results cast doubt on the purported mechanisms of action of prolotherapy. Its role in practice is where less invasive therapies have failed and the patient has been fully informed of the potential benefits and risks of prolotherapy.