Are procedures 64635 and 64636 (nerve injections) medically indicated for a patient with a diagnosis of M47.817 Spondylosis without myelopathy or radiculopathy, lumbosacral region, and a history of prior spinal fusion surgery and other treatments, for the treatment of back pain?

Medical Necessity Assessment for Procedures 64635 and 64636

Procedures 64635 and 64636 (lumbar facet nerve blocks/radiofrequency ablation) are NOT medically indicated for this patient with spondylosis without myelopathy or radiculopathy (M47.817) and prior spinal fusion, as these injection therapies provide only short-term symptomatic relief of less than 2 weeks and are not recommended for long-term treatment of chronic low back pain. 1

Critical Analysis of the Clinical Scenario

Diagnosis Does Not Support Injection Therapy

• The diagnosis M47.817 specifically indicates spondylosis without myelopathy or radiculopathy in the lumbosacral region, which represents degenerative changes without nerve root compression 2
• Facet joint injections are diagnostic and therapeutic procedures intended for facet-mediated pain, which causes only 9-42% of chronic low back pain cases 1
• The patient's post-fusion status suggests the pain may be related to adjacent segment degeneration, hardware issues, or failed back surgery syndrome rather than isolated facet joint pathology 2

Evidence Against Injection Therapies for Chronic Low Back Pain

• Level III evidence demonstrates that epidural steroid injections provide minimal benefit for chronic low back pain without radiculopathy, with relief lasting less than 2 weeks 2, 1
• Facet injections have limited evidence supporting their use beyond short-term diagnostic purposes in patients with chronic axial back pain 2
• Injection therapies (epidural, facet, trigger point) are not recommended as definitive long-term treatment strategies for chronic degenerative low back pain 1

Post-Surgical Context Matters

• In patients with prior spinal fusion and persistent back pain, imaging plays an important role in assessing hardware position and integrity, spinal alignment, fusion status, and postoperative complications including adjacent segment degeneration 2
• The patient requires comprehensive evaluation with MRI (preferred) or CT to identify the actual pain generator, which may include pseudarthrosis, hardware failure, adjacent segment disease, or spinal stenosis 2
• Diagnostic imaging should precede any interventional procedures to ensure appropriate targeting and to rule out structural pathology requiring surgical intervention 2

Alternative Management Pathway

Required Diagnostic Work-Up

• MRI of the lumbar spine without contrast is the preferred initial imaging modality to evaluate post-surgical anatomy, assess fusion integrity, identify adjacent segment degeneration, and visualize soft tissue pathology 2
• Plain radiographs with flexion-extension views may identify instability or hardware complications 2
• If MRI is contraindicated, CT without contrast can assess osseous detail and hardware position 2

Appropriate Conservative Management

• Comprehensive conservative treatment must include formal physical therapy for at least 6 weeks to 3 months, focusing on core strengthening and functional restoration 2, 1
• Trial of neuropathic pain medications (gabapentin, pregabalin) if any radicular component develops 1
• Multimodal pain management with NSAIDs, acetaminophen, and activity modification 2
• Patients should be advised to remain active, as bed rest is less effective than continued activity for low back pain 2

When Injection Therapy Might Be Considered

• Diagnostic facet blocks may be appropriate only if there is clinical suspicion of facet-mediated pain based on specific examination findings (pain with extension and rotation, tenderness over facet joints) 2
• Epidural steroid injections have no role in spondylosis without radiculopathy, as there is no nerve root inflammation to target 2, 1
• Any injection therapy should be performed only after comprehensive imaging has excluded structural pathology requiring surgical correction 2

Critical Pitfalls to Avoid

• Do not perform injection procedures without first obtaining appropriate imaging to identify the pain generator and exclude surgical pathology 2
• Avoid serial injections in patients who fail to demonstrate meaningful functional improvement after the first injection 1
• Do not delay appropriate surgical evaluation in patients with progressive neurological deficits, severe functional impairment, or imaging evidence of significant structural pathology 2
• Recognize that post-fusion patients with persistent pain often have mechanical rather than inflammatory pain sources that will not respond to injection therapy 1

Recommended Course of Action

• Obtain MRI lumbar spine without contrast to evaluate post-surgical anatomy and identify pain generator 2
• Complete comprehensive conservative management including formal physical therapy program for minimum 6 weeks 2, 1
• Refer to spine surgeon for evaluation if imaging reveals adjacent segment disease, pseudarthrosis, hardware complications, or progressive instability 1
• Consider multidisciplinary pain management referral for comprehensive biopsychosocial assessment if conservative measures fail and no surgical pathology is identified 1