Medical Necessity Determination: Repeat Diagnostic Nerve Blocks for Chronic Shoulder Pain
Direct Answer
Repeat diagnostic axillary and suprascapular nerve blocks are NOT medically necessary in this case, as the patient has already achieved 80% pain relief with the first diagnostic block, which is sufficient to proceed directly to radiofrequency ablation without requiring a second confirmatory block. 1
Rationale and Clinical Decision Framework
Key Clinical Facts Supporting This Decision
The patient already demonstrated 80% pain relief with increased functional capacity after the first diagnostic nerve block, which exceeds the typical threshold (≥50%) required to proceed with definitive treatment 1
High-quality guidelines explicitly state that repeat diagnostic blocks are not required before radiofrequency ablation when initial diagnostic blocks are positive - specifically, one high-quality guideline noted that "repeat RFA can be useful without needing repeat MBBs [medial branch blocks]" 2
The Aetna CPB criteria cited in this case do not establish medical necessity for repeat confirmatory blocks - the criteria state that axillary nerve blocks for chronic shoulder pain and suprascapular nerve blocks for chronic upper extremity pain have "NOT MET" the established effectiveness criteria 1
Analysis of the Aetna CPB Criteria
What the Guidelines Actually Support
Peripheral nerve blocks (64450) are supported only as part of a comprehensive pain management program for chronic pain - this criterion was listed as "MET" 1
Axillary nerve block (64417) for chronic shoulder pain is explicitly listed as "NOT MET" in the Aetna criteria, indicating insufficient evidence for effectiveness 1
Suprascapular nerve block (64418) for chronic upper extremity pain is also listed as "NOT MET" 1
Critical Interpretation
The fact that the patient already received one diagnostic block that was "previously certified by PR" (physician reviewer) and achieved 80% relief means the diagnostic phase is complete. Requesting a second "confirmatory" block contradicts the evidence-based approach where a single positive diagnostic block is sufficient to proceed with radiofrequency ablation. 2
Evidence-Based Approach to Shoulder Pain Management
What IS Medically Necessary for This Patient
Interscalene brachial plexus block is the first-choice regional analgesic technique for shoulder surgery pain management, not isolated axillary and suprascapular blocks 1, 2
If the patient is proceeding to repeat shoulder surgery, continuous interscalene block is preferred over single-shot blocks due to longer duration of analgesia and reduced rebound pain 1, 2
Combined axillary and suprascapular nerve blocks are recommended as alternatives only when interscalene block is contraindicated 1, 2
The Diagnostic-to-Treatment Pathway
For radiofrequency procedures targeting chronic pain, guidelines support performing RF after a positive response to diagnostic blocks - but they do not require multiple confirmatory blocks 2
The patient's 80% pain relief with functional improvement (ability to perform lifting activities) constitutes a positive diagnostic response that justifies proceeding to definitive treatment 1
Clinical Pitfalls and Concerns
Why Repeat Blocks Are Not Indicated
There is no established evidence that repeat diagnostic nerve blocks improve outcomes or change treatment decisions when the first block is clearly positive 2
The CPB explicitly states "the effectiveness of these approaches has not been established" for axillary and suprascapular nerve blocks in chronic shoulder pain 1
Repeating diagnostic blocks in this scenario represents unnecessary procedural burden, cost, and potential complications without clinical benefit 1
The Real Clinical Question
The patient has advanced glenohumeral degenerative changes with bone-on-bone changes documented on imaging, has failed conservative treatment for 12+ months, and is attempting to avoid repeat shoulder surgery 1. The question should not be whether to perform repeat diagnostic blocks, but rather:
Is radiofrequency ablation appropriate for this degree of structural pathology? The evidence for RFA in advanced glenohumeral arthritis is limited 2
Should the patient proceed directly to surgical intervention given the severity of degenerative changes and failure of conservative measures? 1
Recommended Clinical Pathway
If Proceeding with Surgery
Utilize continuous interscalene block as the primary regional anesthetic technique for perioperative pain management 1, 2
Add IV dexamethasone to increase analgesic duration and decrease supplemental analgesia requirements 1, 3
Implement multimodal analgesia with paracetamol and NSAIDs/COX-2 inhibitors started pre-operatively 1, 3
If Attempting Non-Surgical Management
A single positive diagnostic block (already completed) is sufficient to proceed with radiofrequency ablation if that is the chosen treatment path 2
However, the evidence for RFA effectiveness in advanced glenohumeral arthritis is weak, and the Aetna CPB criteria reflect this lack of established effectiveness 2, 1
Final Determination
The request for repeat diagnostic/confirmatory nerve blocks should be DENIED based on:
Lack of medical necessity - the first diagnostic block already provided sufficient information (80% relief) 1
Absence of supporting evidence - guidelines do not require repeat confirmatory blocks before RFA 2
Explicit CPB criteria stating these blocks have not met effectiveness standards for chronic shoulder pain 1
The underlying clinical scenario (advanced degenerative changes with bone-on-bone arthritis) suggests these patients may be better served by definitive surgical intervention rather than temporizing nerve blocks 1