Interventional Procedures
Medial Branch Blocks
A precise diagnostic block of the small nerves carrying pain from a facet joint, used to plan longer-lasting treatment.
Time in the office
The block itself takes about 15 minutes, but plan on roughly an hour in total, since you will be asked to stay nearby or note your pain levels for several hours afterward while the anesthetic is active.
When relief starts
If the block is positive, relief begins almost immediately and typically lasts two to four hours, matching the working time of the anesthetic used, after which pain is expected to return.
What it is
Each facet joint receives sensation from two small medial branch nerves. Numbing those nerves temporarily interrupts pain signals from that joint.
A medial branch block is primarily a diagnostic test. If your pain drops substantially while the anesthetic is working, that joint is confirmed as the source.
This confirmation is what makes radiofrequency ablation predictable rather than a trial and error.
What to expect, step by step
The procedure takes about 15 minutes and is performed under fluoroscopic guidance.
Very small volumes of anesthetic are used, so the block stays specific to the target nerves.
You will be asked to record your pain levels over the hours following the block — this record determines the next step.
Recovery
You may resume normal activity the same day.
Deliberately test your usual painful movements during the numbing window to give an accurate report.
Pain returns as the anesthetic wears off; that is expected and does not mean the test failed.
Typical results
A positive block means significant temporary relief in the expected time frame.
Two positive blocks generally qualify a patient for radiofrequency ablation.
A negative block is also useful — it redirects the search to the true pain generator.
Risks and considerations
Serious complications are uncommon, but no procedure is risk-free and you deserve the honest version before you consent.
- Temporary numbness or weakness in nearby muscles for a few hours
- Small risk of bruising or soreness at the needle sites
- Rare infection or allergic reaction to the anesthetic
- A false positive or false negative result, which is why two separate blocks are usually required
- No lasting therapeutic effect on its own, since this is primarily a diagnostic test
Common questions
Why do I need two blocks instead of one?
What should I do during the numb window?
Does a negative block mean nothing is wrong?
Is sedation used for this procedure?
Conditions this treats
Medial Branch Blocks is most often recommended for the conditions below, once the source of pain has been confirmed.
- Spinal Facet SyndromePain arising from the small paired joints at the back of the spine, often worse with extension, twisting and standing.
- Neck InjuriesWhiplash, strain and facet injury of the cervical spine following collisions, falls and sports impacts.
- Auto Accident InjuriesPost-collision neck, back and joint pain, including whiplash and delayed-onset symptoms.
- Chronic HeadachesFrequent headaches including cervicogenic and occipital neuralgia patterns arising from the neck.
Related treatments
- Epidural Steroid InjectionsAnti-inflammatory medication delivered precisely around an irritated spinal nerve root to relieve radiating arm or leg pain.
- Facet Joint InjectionsSteroid and anesthetic placed inside an arthritic facet joint to confirm the pain source and calm inflammation.
- Radiofrequency AblationRadio waves used to interrupt pain signals from confirmed facet or sacroiliac nerves, often giving relief for a year or more.
- Sacroiliac Joint InjectionsImage-guided injection into the SI joint to confirm and treat one-sided low back and buttock pain.
Ready to get a real diagnosis?
Most patients are seen within two weeks. Call our office or send a request and our staff will help you choose the most convenient location.