What Are Medial Branch Blocks (Diagnostic Blocks)?
The zygapophysial joints are small joints between the bones that make up the spine.
These “z- joints” may become a cause of chronic back pain. The only way to determine if these joints are the cause of your pain is to numb or “block” the nerves-called the medial branches – that send pain signals from the joints.
If the medial branch block (MBB) eliminates your pain, then the joint is determined to be the cause of your pain. If your pain is not stopped by the block, then causes other than the z-joint may need to be considered.
The medial branch block (MBB) is a diagnostic test just like a chest x-ray, NOT a treatment. Therefore, you should not expect lasting pain relief from the medial branch block (MBB).