High-intensity focused ultrasound (HIFU) is an emerging technology that allows for the targeted thermal ablation of deep tissues in a non-invasive manner, by concentrating acoustic energy on the target nerve, whilst preserving adjacent structures. Recently, open clinical studies have confirmed the feasibility, safety and efficacy of HIFU in patients with lumbar facet syndrome, with clinical response rates similar to those of RFA and no significant complications.

This observational, prospective, non-interventional study aims to evaluate the clinical efficacy of lumbar medial branch ablation using this technique at 1, 3 and 6 months, as well as to assess patient satisfaction with the procedure. Only clinical data from patients undergoing the procedure in routine clinical practice will be collected.

Inclusion Criteria:

• Over 18 years of age.
• Signed informed consent for data collection.
• Mechanical low back pain with a positive diagnostic block (>30% pain reduction) of the lumbar medial ramus with local anaesthetic.

Exclusion Criteria:

• Presence of pain with mixed characteristics or suspected multiple aetiology of the low back pain (e.g. sacroiliac joint involvement).
• Active systemic infection.
• Pregnancy.
• History of spinal surgery at the level of treatment.
• Presence of tumours, metastatic disease or osteoporosis in the treatment area.
• Pacemaker or implantable generator carriers.
• Coagulation disorders or thrombocytopenia.
• Vertebral fracture or compression at the treatment level.
• Medical condition contraindicating sedation or the treatment position.

Patients with mechanical low back pain without any other associated clinical features (neuropathic pain characteristics or significant suspicion of pain in other anatomical regions that may be causing the low back pain) who undergo lumbar medial branch ablation using the HIFU technique.