Intradiscal ozone therapy for the treatment of low back pain: a review of the literature

Oxygen-ozone therapy is a minimally-invasive technique for the treatment of lumbar disc herniation, with uncertain efficacy and great prejudice mainly due to its use without rational basis or appropriate controls. We try to evaluate the real effectiveness of intradiscal ozone therapy for the treatment of low-back pain, in order to supply further evidence about this promising mini-invasive technique. A comprehensive search of PubMed, Medline, Cochrane, Embase, and Google Scholar databases was performed, covering the period between 1980 and 2015. Various combinations of the following words were used: "ozone", "ozone injection", "intradiscal ozone", "low back pain", "spine". The ozone injection therapy was studied only at intradiscal sites. Peridural, facet joints, sacroiliac joints, juxtaforaminal, and intramuscular paravertebral sites intervention trials were excluded. Furthermore, each study was evaluated for the following variables: study type, type of spine disease, number of patients, injected dose and ozone concentration, follow-up period, clinical outcome at the end of follow-up period and complications. A study was judged positive if the ozone intradiscal injection were clinically effective with statistically significant improvement from baseline (P<0.05). Eight studies involving 4155 patients treated with intradiscal ozone injection were included in the review. All selected studies provided outcome evaluation at 6 months or longer (range: 6-120 months) and all included patients were adults with LBP or sciatica due to lumbar disc herniation treated by the ozone therapy. Pain reduction and functional state were considered as primary outcomes. When reported, Visual Analogue Scale was the most employed pain measurement. Functional state has been evaluated by Os-westry Disability Index or MacNab score. There were no heavy complications in all the evaluated trials. Moreover, five case reports concerning related complications were analysed but not included in the review. Intradiscal ozone injection can be considered as a feasible option for the treatment of herniated disc showing a good safety profile in the majority of treated patients. Nevertheless, our review depicts a huge lack of high-quality evidence on this interesting topic. To date, the use of intradiscal ozone injection therapy as a treatment for LBP cannot be motivated by the best available evidence.