Treatment information
Understanding your pathway
What is the treatment?
A medial branch block places local anaesthetic near small nerves carrying sensation from the facet joints at the back of the spine. Its main role is often diagnostic or prognostic: it can help assess whether a facet-directed treatment is reasonable. It is different from placing medication inside a facet joint. [1][2][3]
Who may be considered?
A block may be considered when localised spinal pain is thought to involve a facet joint and the result could change management. Symptoms and imaging alone cannot reliably identify every painful joint. Before testing, agree which usual movement or activity will be used to assess the response. [1][2][3]
Assessment, preparation and consent
Before deciding, discuss your diagnosis, previous treatment, medicines and relevant health conditions. Tell the clinician about allergies, infection, blood-thinning medicines, diabetes and possible pregnancy. Do not stop prescribed medicines yourself. Ask what alternatives are available, including not having a procedure, and allow time to consider the benefits, uncertainty and risks that matter to you. [4]
What happens during treatment?
Under imaging guidance, the clinician places small amounts of local anaesthetic near the relevant nerves. The precise anatomy differs between the neck and lower back. A pain and activity record may be requested during the expected anaesthetic period. Follow the clinic's instructions about usual medicines and permitted activities. [1][2][3]
Risks and safety considerations
Soreness, bleeding, infection, allergic reaction and temporary altered sensation can occur. Nearby structures and spinal level influence other risks, which are discussed before consent. Sedation or reduced activity can also make the response harder to interpret, so the plan for assessing the block matters. [1][2][3]
Recovery and when to seek help
Follow the written instructions for transport, supervision, medicines, activity and driving. Recovery depends on the treatment and your health, so a fixed return-to-work date cannot be promised. Ask who to contact outside clinic hours. Seek urgent assessment for fever with worsening pain, new weakness or other unexpected neurological symptoms. Call 000 for breathing difficulty, collapse or another medical emergency. [5][4]
Expected benefit and limitations
Both false-positive and false-negative results are possible. Temporary improvement supports a clinical interpretation; it is not proof of one pain generator. A positive block does not guarantee benefit from radiofrequency ablation. The clinician will interpret the amount, duration and activity-related pattern of change alongside the rest of the assessment. [1][2][3]
Follow-up and rehabilitation
Before treatment, choose a practical goal such as walking, sleep or a daily task. Record changes in that activity, pain and any adverse effects, then discuss them at follow-up. Ask what degree of change would justify further treatment and what would lead to stopping or changing the plan. Rehabilitation and self-management may remain part of care even if symptoms improve. [4][6]
Questions to bring to your appointment
Ask which structure is being targeted, why this approach is being considered and how strong the evidence is for your diagnosis. Clarify costs, the planned review date and any practical help you may need at home. Bring previous reports and your medicine list so the discussion can address your circumstances rather than a generic treatment pathway.
Sources and further reading
Sources support the statements cited above. Overseas guidance may describe different services or eligibility rules. A procedure leaflet explains a technique and its risks; it does not establish that the treatment is effective for every condition.
- Facet joint injections and medial branch block — The Dudley Group NHS Foundation Trust
- Consensus guidelines on interventions for lumbar facet pain — Regional Anesthesia and Pain Medicine
- Low back pain and sciatica: recommendations — NICE
- Procedures in pain medicine clinical care standard — Faculty of Pain Medicine, ANZCA
- Dorsal root ganglion / nerve root block / transforaminal injection — Hull University Teaching Hospitals NHS Trust
- Options for chronic pain management — Healthdirect Australia