Effect of Intradiscal Methylene Blue Injection for the Chronic Discogenic Low Back Pain: One Year Prospective Follow-up Study

OBJECTIVE: To evaluate the efficacy of intradiscal methylene blue (MB) injection in patients with chronic discogenic low back pain. METHOD: Twenty patients with discogenic low back pain (4 males, 16 females; mean age 45.6 years) refractory to conservative management were recruited. All subjects underwent MB injection in target lumbar intervertebral discs confirmed by provocative discography. The clinical outcome was assessed by visual analog scale (VAS) and Oswestry disability index (ODI) at baseline and 1, 3, 6 and 12 months after treatment. Successful outcome was described as minimum of 2 points reduction in pain intensity compared with the baseline. RESULTS: VAS and ODI significantly decreased after one injection. The average VAS and ODI were reduced significantly from 5.1 and 38.0 at baseline to 3.2 and 27.4 at 3 months after injection (p<0.05). However, the mean score of VAS at 12 month follow-up was 4.5 and we could not observe any difference between 12 months after injection and pretreatment. Eleven of twenty patients (55%) reported successful outcomes after intradiscal MB injection at 3 month follow up and the average VAS was reduced by 3.3+/-1.1 (p<0.05). At the time of 12 month follow up, pain had relapsed in 6 patients who have had satisfactory effect at 3 month follow up. Successful outcome was maintained in only 5 patients (20%) for 1 year. CONCLUSION: The intradiscal MB injection is a short-term effective minimally invasive treatment indicated for discogenic back pain but it may lose its effectiveness long-term.

ANTIVIRAL TESTS OF METHYLENE BLUE INJECTION ON VZV IN VITRO / 药物分析学报

Methylene blue injection has a stronger direct inactivation on VZV in vitro. When the injection was diluted from 1:16 to 1:128, which was obvious (P＜0.01 and P＜0.05). The MIC was 1:222, the IC50 was 1:135 and IC90 was 1:77. The results of microcellculture method showed when the injection was diluted from 1:16 to 1:64, it also effectively inhibited the proliferation of VZV in WISH continuous cell-lines (P＜0.01 and P＜0.05). The MIC was 1:95, the IC50 was 1:45 and the IC90 was 1:21.