1. 2022;25;E15-E26Clinical Effects and Safety of the Use of Methylene Blue for the Treatment of Lumbar Facet Joint Syndrome
   Randomized Controlled Trial
   Xiuqin Yu, MD, Jinyuan Zhang, PhD, Mingxia Wang, MD, Yu Yang, MD, Wei Zhang, MD, Dan Su, MD, Lijun Liao, PhD, Hao Yang, PhD, Hongwei Fang, MD, and Xiangrui Wang, PhD.

BACKGROUND: Lumbar facet joint syndrome (LFJS) has been suggested to be a main source of low back pain. Methylene blue (MB), an inhibitor of nitric oxide synthesis with potential analgesic and anti-inflammatory properties, has been widely applied for a variety of pain-related diseases. However, no studies have been conducted on the treatment of LFJS patients using MB.

OBJECTIVES: The purpose of this study was to evaluate the therapeutic effects of intra-articular injection of MB on LFJS patients.

STUDY DESIGN: A prospective, randomized, controlled clinical trial.

SETTING: Department of pain, Shanghai East Hospital.

METHODS: A total of 120 eligible patients with LFJS were randomly divided into an MB group and a control group. Numeric Rating Scale (NRS), Oswestry Disability Index (ODI), Pittsburgh Sleep Quality Index (PSQI), Patient Health Questionnaire-9 (PHQ-9) were used to evaluate the pre-operation and post-operation states of the patients, and adverse events were recorded. The patients participating in this study were followed up for a period of 6 months.

RESULTS: A total of 104 patients were followed up for the entire 6 months period. The control group included 51 patients, and the MB group included 53 patients. In both groups, the NRS scores, ODI scores, PHQ-9 scores, and PSQI scores decreased at different time points after treatment, compared to baseline. Moreover, the NRS scores were significantly lower than that of the control group at 3 months and 6 months after operation (P < 0.05). The ODI, PSQI, and PHQ-9 scores of the MB group were also respective significantly lower than that of the control group at 3 months and 6 months after operation (P < 0.05). As for the clinical efficacy, the total effective treatment rate of the MB group was significantly higher than that of the control group at 6 months after the procedure (P < 0.05). On the first day after operation, the incidence of hyperglycemia in patients with diabetes in the MB group was significantly lower than that of the control group (P < 0.05).

LIMITATIONS: Firstly, the patients enrolled were recruited from a single center, and the sample size was small. Secondly, the patients were only followed-up for a period of 6 months after treatment. Thirdly, double blinding was not used in the design of this research study.

CONCLUSION: Ultrasound-guided intra-articular MB injection is a safe and effective therapy for patients with LFJS. Intra-articular injection with MB can significantly reduce pain intensity, improve patient lumbar function, pain-related depression and sleep quality, increase total effective rate with no severe adverse side effects.

KEY WORDS: Facet joint syndrome, methylene blue, intra-articular injection, ultrasound guidance