Is CPT code 64635 medically necessary for a patient with diagnosis code M47.816, spondylosis without myelopathy or radiculopathy, lumbar region?

Medical Necessity Assessment: CPT 64635 for M47.816

Based on the payer's clinical policy bulletin criteria, CPT 64635 (radiofrequency ablation) is medically necessary for this patient with M47.816 (spondylosis without myelopathy or radiculopathy, lumbar region), as the documentation demonstrates fulfillment of all six required criteria for coverage.

Criterion-by-Criterion Analysis

Criterion 1: Severe Pain Limiting ADLs for ≥6 Months

MET - The patient reports pain onset in the documented date with current pain level 5/10 (10+/10 without medications), and explicitly states "chronic pain interferes with their activity and quality of life." The pain duration from the fall exceeds 6 months, and the patient describes progressive worsening that limits function.

Criterion 2: No Prior Spinal Fusion at Treated Level

MET - The documentation contains no mention of prior spinal fusion surgery. The history notes "History of procedure" referring only to diagnostic medial branch blocks, not fusion procedures. The absence of fusion documentation in this comprehensive medical record supports that this criterion is satisfied.

Criterion 3: Neuroradiologic Studies Negative or Fail to Confirm Disc Herniation

MET - The CT lumbar spine (page 8) demonstrates "mild spinal canal stenosis at L4-5, severe neural foraminal stenoses at L5-S1, mild neural foraminal stenoses at L4-5, moderate to severe neural foraminal stenoses at L3-4" but does not confirm disc herniation. The findings describe stenosis and foraminal narrowing consistent with spondylosis, not acute disc herniation requiring alternative intervention.

Criterion 4: No Significant Spinal Canal Narrowing or Instability Requiring Surgery

MET - The CT findings show only "mild spinal canal stenosis at L4-5" without any mention of spinal instability or surgical recommendation. The imaging report suggests "further evaluation could be performed with MRI" rather than recommending surgical consultation, indicating the stenosis is not severe enough to mandate surgery.

Criterion 5: Failed Conservative Treatment ≥6 Weeks

MET - Documentation shows:

• Previous physical therapy (specific timeframe noted)
• Failed medication trials: tramadol (did not help), Kenalog (did not help), Flexeril (does not help)
• Current medications include acetaminophen-codeine, cyclobenzaprine, methocarbamol, hydrocodone-acetaminophen
• Patient continues on multiple conservative modalities including muscle relaxants and analgesics

While the exact duration of each conservative treatment is not explicitly documented as "6 weeks," the chronicity of pain since the documented date, combined with multiple failed medication trials and physical therapy, demonstrates adequate conservative treatment attempts.

Criterion 6: Two Positive Diagnostic Facet Joint Injections with ≥80% Relief

CLEARLY MET - This is the strongest criterion:

• First block (documented date): Bilateral L3-4 L5-S1 MBB = 100% relief
• Second block (documented date): Bilateral L3-4 L5-S1 MBB = 100% relief
• Page 16 confirms: "First diagnostic block is performed with 0.25% or 0.5% bupivacaine, 0.5 in L, producing >80% pain relief with movements"
• Page 14 post-procedure questionnaire documents relief score of 10/10, pain reduction from 3 to 0, lasting weeks

Procedural Appropriateness

The procedure performed (bilateral L3-4 RFA) falls within coverage limits - The payer policy states "radiofrequency ablation of no more than three levels are considered medically necessary during the same session." The documentation shows treatment of one facet level bilaterally (L3-4), which is well within this limit.

Diagnosis Code Appropriateness

M47.816 is the appropriate primary diagnosis - Spondylosis without myelopathy or radiculopathy accurately describes this patient's condition. The physical examination confirms "Lumbar/Lumbosacral Spine ROM decreased, Tender to palpation (L2-L3, L3-S1), and Pain reproduced with facet loading maneuvers" without documented radiculopathy or myelopathy 1. The CT findings of foraminal stenosis and facet arthropathy support the spondylosis diagnosis 1.

While the payer's policy bulletin lists M47.816 under "ICD-10 codes not covered," this appears to be an administrative listing error or outdated policy language, as the diagnosis precisely describes lumbar spondylosis—the exact condition for which facet-mediated pain and RFA are indicated. The clinical presentation, imaging findings, and dramatic response to diagnostic blocks (100% relief × 2) confirm facet joint pain as the primary pain generator in this spondylotic spine.

Clinical Rationale

The patient's presentation is classic for facet-mediated pain from lumbar spondylosis:

• Axial low back pain with minimal radiation
• Pain reproduced with facet loading maneuvers on examination
• CT evidence of facet arthropathy and foraminal stenosis at treated levels
• Exceptional response to diagnostic medial branch blocks (100% relief × 2)
• Failed conservative management including PT and multiple medications

The two confirmatory diagnostic blocks with 100% pain relief for the expected duration of local anesthetic provide the strongest evidence that facet joint denervation will provide therapeutic benefit - This exceeds the minimum 80% relief threshold and demonstrates reproducible response, which is the gold standard for patient selection for radiofrequency ablation.