Objectives. To assess the efficacy of a prolotherapy injection and exercise protocol in the treatment of chronic nonspecific low back pain.
Design. Randomized controlled trial with two-by-two factorial design, triple-blinded for injection status, and single-blinded for exercise status.
Setting. General practice.
Participants. One hundred ten participants with nonspecific low-back pain of average 14 years duration were randomized to have repeated prolotherapy (20% glucose/0.2% lignocaine) or normal saline injections into tender lumbo-pelvic ligaments and randomized to perform either flexion/extension exercises or normal activity over 6 months.
Main outcome measures : Pain intensity (VAS) and disability scores (Roland-Morris) at 2.5, 4, 6, 12, and 24 months.
Results. Follow-up was achieved in 96% at 12 months and 80% at 2 years. Ligament injections, with exercises and with normal activity, resulted in significant and sustained reductions in pain and disability throughout the trial, but no attributable effect was found for prolotherapy injections over saline injections or for exercises over normal activity. At 12 months, the proportions achieving more than 50% reduction in pain from baseline by injection group were glucose-lignocaine: 0.46 versus saline: 0.36. By activity group these proportions were exercise: 0.41 versus normal activity: 0.39. Corresponding proportions for >50% reduction in disability were glucose-lignocaine: 0.42 versus saline 0.36 and exercise: 0.36 versus normal activity: 0.38. There were no between group differences in any of the above measures.
Conclusions. In chronic nonspecific 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.
Prolotherapy is a treatment for chronic nonspecific low-back pain that involves a protocol of ligament injections, exercises, and vitamin and mineral supplements. It is based on the premise that back pain results from weakened ligaments and that these ligaments can be strengthened by the injection into them of irritant proliferant solutions. 12,17,14,20 These solutions variously contain phenol, glycerine, or hypertonic glucose, mixed with local anesthetic, and aim to induce inflammation and deposition of collagen fibers in the weak ligaments. There is limited histologic evidence of thickening of sacroiliac ligaments in association with a reduction in low-back pain scores and increased lumbar range of motion using all these solutions combined. 14 The supplementary regimen of exercises and oral vitamins and minerals ostensibly promote collagen growth to induce optimal strengthening of the treated ligaments.
The anecdotal and experimental evidence are contradictory. Testimonies to the effectiveness of prolotherapy include one from the former Surgeon General of the United States, C. Everett Koop, MD, 16 “. . .I have been a patient who has benefited from prolotherapy. Having been so remarkably relieved of my chronic disabling back pain, I began to use it on some of my patients.” The few controlled trials of prolotherapy have provided mixed results. One trial reported negative results. 4 In another, the results were borderline-positive. 15 The one trial with clearly positive results was confounded by the use of co-interventions such as spinal manipulation and injection of tender gluteal muscles with corticosteroid. 19 The efficacy of prolotherapy injections and the associated exercise program for low-back pain, therefore, has not been established.
Phenol has been a classic constituent of proliferant solutions, and at concentrations of 1.2% has been promoted as safe. 19 Many practitioners prefer to use an alternative solution of hypertonic glucose and lignocaine only, 7 although there is no histologic or clinical trial evidence of its efficacy. The present trial was undertaken to assess the efficacy and safety of glucose/lignocaine prolotherapy injections and exercises in a randomized, controlled trial. The null hypothesis was that prolotherapy injections and exercises would be no more effective than the control treatment.