Is it acceptable to perform three levels of left cervical Medial Branch Blocks (MBBs) in a single patient?

Cervical Medial Branch Blocks: Number of Levels

Performing three levels of left cervical medial branch blocks in a single session exceeds the evidence-based standard and should not be approved; limit to two levels (maximum 8 injections) per session as supported by current clinical practice guidelines. 1

Guideline-Based Limitations

The 2023 PM&R synthesis of clinical practice guidelines on interventional pain management establishes clear parameters for medial branch blocks:

• Maximum of 2 levels per treatment session is the standard recommendation across high-quality clinical practice guidelines 1
• This translates to up to 8 individual injections when performed bilaterally (4 medial branches per level) 1
• The request for 3 levels of unilateral cervical MBBs would require 6 injections, which falls within the total injection count but violates the 2-level maximum 1

Evidence Supporting Two-Level Limitation

High-quality guidelines emphasize that radiofrequency ablation (the therapeutic endpoint after diagnostic MBBs) should only be performed after positive response to medial branch blocks, with specific attention to:

• Dual diagnostic blocks with ≥80% pain relief are required before progression to radiofrequency neurotomy 1
• The strongly-supported recommendation states confirmatory diagnostic facet nerve blocks are essential 1
• Limiting the number of levels tested improves diagnostic specificity and reduces false-positive rates 2, 3

Clinical Rationale for Level Restriction

Research demonstrates important considerations for limiting injection levels:

• Volume-dependent dispersion patterns show that even 0.50 mL injections spread to unintended targets, decreasing diagnostic specificity 2
• Performing 3 levels simultaneously increases the risk of overlapping anesthetic spread, compromising the diagnostic value of the procedure 2
• Studies show that only 25% of patients progress from initial MBB to radiofrequency neurotomy when proper selection criteria are applied, indicating the importance of precise diagnostic testing 4

Recommended Approach

Approve a maximum of 2 levels of left cervical MBBs per session:

• If 3 levels require evaluation, stage the procedures into two separate sessions 1
• First session: Test the 2 most clinically suspected levels based on examination findings
• Second session (if needed): Test the third level only if the first two levels showed inadequate response
• This approach maintains diagnostic accuracy while adhering to evidence-based practice standards 1, 4

Common Pitfalls to Avoid

• Do not approve multi-level blocks beyond 2 levels as this increases false-positive rates and reduces the predictive value for subsequent radiofrequency ablation success 2, 3, 4
• Excessive levels tested simultaneously make it impossible to determine which specific level is the pain generator 2
• The 62% progression rate from second diagnostic block to radiofrequency neurotomy demonstrates that proper patient selection through limited-level testing is clinically meaningful 4