Facet Joint Syndrome

Chronic musculoskeletal pain of non-specific origin affects approximately 30% of the global population. Beyond its prevalence, it represents a serious health and socioeconomic problem. It is considered the leading cause of years lived with disability and is characterized by persistent functional limitation, deterioration of quality of life, and poorer mental health, with a high comorbidity of depression, anxiety, and sleep disorders, as well as a greater risk of suicidal ideation and behavior. From a socioeconomic perspective, chronic pain entails an impact of up to USD 635 billion annually just in United States (USA). In fact, spinal pain alone represents the condition with the highest direct costs (around USD 134.5 billion in USA) and additional indirect costs due to absenteeism and presenteeism, which impair productivity and work performance. These figures are expected to be substantially higher when considered at a global scale. One of the main aggravating factors of this condition is that in up to 90% of patients experiencing pain there is no identifiable anatomopathological substrate that reliably explains the symptoms (non-specific pain). Radiological findings are extremely common in asymptomatic populations, and making diagnostic or therapeutic decisions based on such findings, promotes overdiagnosis and low-value clinical cascades. It is estimated that up to 50% of imaging requests and 60% of spinal surgeries6 are unnecessary or unjustified. For this reason, Clinical Practice Guidelines recommend prioritizing interventional diagnostic techniques based on functional criteria over the interpretation of radiological findings, as they allow for more sensitive and specific identification of nociceptive sources (with a recommendation grade I-II). In this context, the motivation of the project is to study PENS as a non-pharmacological, safe, and transferable alternative to nerve blocks, reducing the risk of complications associated with the use of local anesthetics/corticosteroids and large-gauge needles. According to recent systematic reviews and meta-analyses confirming immediate analgesic responses, PENS could be a feasible alternative that maintains functional diagnostic and therapeutic value with a generally mild adverse-event profile and lower cost.

This is a prospective, randomized, two-arm, phase II study. The purpose of this study is: * To evaluate and compare the efficacy and safety of magnetic resonance-guided focused ultrasound (MRgFUS) and radiofrequency ablation (RFA) for treatment of facet-joint osteoarthritis low back pain. * Determining the effect of the MRgFUS System and RFA for improving functional disabilities and in reducing pain resulting from facet-joint osteoarthritis low back pain. Efficacy will be determined by the level of pain relief (as measured by the Numerical Rating Scale, NRS), decrease in analgesics/opiate, improved quality of life (as measured by the Oswestry Disability Questionnaire, ODQ, and core outcome measures index questionnaire, COMI), pain interference with function (as measured by the Brief Pain Inventory-Interference scale, BPI-QoL), general health status (as measured by the EQ5D), physical exam, X-ray and MRI studies from baseline up to 12-Months post- MRgFUS and radiofrequency treatment. * Evaluate incidence and severity of adverse events associated with the MRgFUS system and RFA used for the treatment of pain resulting from facet-joint osteoarthritis low back pain.