Lumbar Medial Branch Blocks & Facet Joint Injections
The facet joints are small paired joints on the back of the spine that provide stability and allow controlled motion. Like any joint, they can become arthritic, inflamed, and painful — a condition called lumbar facet syndrome or facet-mediated pain.
Lumbar medial branch blocks and facet joint injections are the two main tools for diagnosing and treating this type of back pain.
Medial Branch Blocks vs. Facet Joint Injections
Lumbar Medial Branch Blocks (MBBs): Local anesthetic is injected adjacent to the medial branch nerves — the tiny nerves that carry pain signals from each facet joint. MBBs are primarily diagnostic: if your back pain significantly decreases after the block, it confirms the facet joints as the pain source. Two positive MBB procedures (on separate occasions) are typically required before proceeding to radiofrequency ablation for long-lasting relief.
Facet Joint Injections: Steroid and local anesthetic are injected directly into the facet joint capsule under fluoroscopic guidance. These provide both diagnostic information (if pain improves) and therapeutic relief (the steroid reduces joint inflammation). Relief from facet injections typically lasts 1–6 months.
Signs of Facet-Mediated Pain
- Low back pain that worsens with bending backward (extension) or twisting
- Pain that radiates into the buttocks or upper thigh, but not below the knee
- Morning stiffness that improves with movement
- Tenderness directly over the facet joints on physical examination
- MRI or X-ray showing facet joint arthritis or degeneration
The Procedure
Both procedures are performed under fluoroscopic guidance. You lie face-down; the target joints or nerves are identified under X-ray and precisely targeted with a needle under 5 mm in length in most cases. The injections are well-tolerated; most patients describe pressure rather than pain.
Path to Long-Lasting Relief
Medial branch blocks → Positive response confirmed × 2 → Radiofrequency ablation → 12–18 months of relief
This stepwise approach is the evidence-based pathway for facet-mediated pain and is covered by Medicare and most commercial insurance when properly documented.
Contact Us
Call 516-492-3100 to discuss whether your back pain may be coming from the facet joints and whether a medial branch block is the right diagnostic step.