Is transection of bilateral S1, S2, and S3 spinal lateral branch nerves under direct visualization (endoscopic neurectomies) medically necessary for a patient with chronic, refractory posterior sacroiliac joint complex pain?

Medical Necessity Determination: NOT MEDICALLY NECESSARY

Bilateral S1, S2, S3 endoscopic neurectomy (CPT 64772 x6 and 64999) is NOT medically necessary for this patient because CPT 64772 is explicitly listed as "not covered" and "unproven because of insufficient evidence" for chronic low back pain treatment, and the patient has not completed the evidence-based treatment algorithm that requires radiofrequency ablation before considering more invasive surgical options. 1

Primary Rationale for Non-Certification

Explicit Coverage Exclusion

• CPT 64772 (transection or avulsion of spinal nerve, extradural) is specifically designated as "not covered" in the Clinical Policy Bulletin for spinal surgery. 1
• Direct visual rhizotomy (extradural transection) lacks adequate evidence supporting its effectiveness for sacroiliac joint pain and is classified as unproven. 1
• The use of CPT 64999 (unlisted procedure) indicates this is not a standardized or well-established procedure in clinical practice, raising significant concerns about its evidence base. 2

Inadequate Diagnostic Confirmation

• The patient requires positive response to at least two separate diagnostic sacral lateral branch blocks with ≥50% pain relief to confirm the SI joint as the pain generator. 2
• The documentation shows conflicting results: one report states 80-90% relief from sacral lateral branch blocks, while another indicates only 30% relief with bilateral L5-S1 TFESI. 2
• The patient's diagnosis of "spondylosis without myelopathy or radiculopathy, lumbar region" does not align with isolated SIJ pain and suggests multiple potential pain generators. 1
• MRI findings reveal L5-S1 pathology with moderate bilateral neural foraminal stenosis, L3-4 anterolisthesis with pars defects, and facet arthropathy—all of which could contribute to the patient's symptoms. 1, 2

Failure to Complete Evidence-Based Treatment Algorithm

The American Society of Anesthesiologists recommends a stepwise approach that must be followed before considering surgical neurectomy: 3, 1

1. Conservative management (completed: physical therapy, medications, activity modification) 3, 4

2. Diagnostic intraarticular SIJ injections (partially completed: bilateral diagnostic SIJ injection on 10/07/2025 provided "great amount of relief") 3

3. Therapeutic intraarticular corticosteroid injections (NOT adequately completed: patient reports only 1-2 months relief from steroid injections, but guidelines recommend repeat therapeutic injections if ≥50% relief for ≥2 months) 3, 4

4. Radiofrequency ablation of sacral lateral branches (NOT attempted: this is the established therapeutic intervention with moderate evidence for pain relief from the posterior sacroiliac joint complex) 1, 5, 6

5. Only after documented failure of multiple RFA attempts would more invasive surgical options be reconsidered 1

Evidence-Based Next Steps

Immediate Recommendation: Cooled Radiofrequency Ablation

• Proceeding with cooled radiofrequency ablation of bilateral S1, S2, S3 lateral branches is the evidence-based next step given the reported 80-90% relief from diagnostic blocks. 1, 5, 6
• Cooled radiofrequency ablation has the strongest evidence among RFA techniques for treating chronic sacroiliac joint pain. 4, 6
• The American Society of Anesthesiologists recommends conventional or thermal radiofrequency ablation of medial branch nerves when previous diagnostic/therapeutic injections provided temporary relief. 4
• Intra-articular sacroiliac joint infiltrations with local anesthetic and corticosteroids hold the highest evidence rating (1 B+), and if these fail or produce only short-term effects, cooled radiofrequency treatment of the lateral branches of S1 to S3 (S4) is recommended (2 B+). 5

Additional Diagnostic Considerations

• The negative medial branch blocks at L4-5 and L5-S1 suggest facet joints are not the primary pain source, but the L3-4 anterolisthesis with pars defects has not been adequately addressed. 1
• The patient has documented L5-S1 pathology with moderate bilateral foraminal stenosis that could contribute to symptoms, meaning the SI joint may not be the sole pain generator. 2
• At least 3 of 5 positive provocative physical examination tests are required to confirm SI joint as the pain generator (sensitivity 94%, specificity 78%). 3, 4
• The patient's exam shows multiple positive tests (FADIR, Patrick's/FABER, thigh thrust, ASIS distraction all positive bilaterally), which supports SIJ as a pain generator, but does not exclude other sources. 3

Risk-Benefit Analysis

Risks of Proposed Procedure

• The risks of this extensive surgical procedure outweigh any potential benefits given the lack of established efficacy and inadequate diagnostic confirmation. 2
• Sacroiliac joint injections are generally safe, but risks include pain, vasovagal reaction, facial flushing/sweating, and transient sciatic nerve block with associated fall risk. 3
• The proposed endoscopic neurectomy carries surgical risks including nerve injury, bleeding, infection, and potential for worsening pain without established benefit. 2

Benefits of Evidence-Based Alternative (RFA)

• Radiofrequency ablation is minimally invasive with established safety profile and moderate evidence for efficacy. 5, 6
• RFA allows for repeat procedures if needed, whereas surgical neurectomy is irreversible. 6
• Current evidence suggests that sacral lateral branch radiofrequency ablation can provide relief for posterior sacroiliac joint complex pain. 6

Common Pitfalls to Avoid

Premature Escalation to Surgery

• Skipping radiofrequency ablation and proceeding directly to surgical neurectomy violates established treatment algorithms and denies the patient a proven, less invasive option. 1
• The patient's desire for "permanent solutions" and concern about "short-term relief" does not justify bypassing evidence-based intermediate steps. 1

Incomplete Diagnostic Workup

• Multiple pain generators are present (L3-4 anterolisthesis, L5-S1 pathology, SIJ dysfunction), and surgical neurectomy of only the SIJ innervation may leave other sources untreated. 1, 2
• The conflicting diagnostic block results (80-90% vs 30% relief) require clarification before proceeding with any ablative or surgical procedure. 2

Misalignment of Diagnosis and Procedure

• The primary diagnosis listed is "spondylosis without myelopathy or radiculopathy, lumbar region," which does not support isolated SIJ pathology as the indication for the requested procedure. 1

Criteria Summary

CRITERIA NOT MET:

• CPT 64772 explicitly listed as "not covered" and "unproven" 1
• Evidence-based treatment algorithm incomplete (RFA not attempted) 1, 5
• Diagnostic confirmation inadequate (conflicting block results, multiple pain generators) 2
• Procedure lacks standardization (unlisted CPT 64999 required) 2

RECOMMENDED PATHWAY:

1. Clarify diagnostic block results with repeat confirmatory blocks if needed 2
2. Proceed with cooled radiofrequency ablation of bilateral S1, S2, S3 lateral branches 1, 4, 5
3. Address L3-4 anterolisthesis if symptoms persist after SIJ treatment 1
4. Consider surgical options only after documented failure of multiple RFA attempts 1