Is medical necessity met for facet joint injections (codes 64635 and 64636) in a patient with spondylosis without myelopathy or radiculopathy (M47.816) and spondylolisthesis (M43.16) in the lumbar region?

Medical Necessity Assessment for CPT 64635 and 64636

Medical necessity is NOT met for facet joint injections (CPT 64635 and 64636) in this patient because the diagnosis explicitly states "spondylosis WITHOUT myelopathy or radiculopathy," and facet joint injections require the absence of radiculopathy as a fundamental criterion—this patient's diagnoses do not establish facet-mediated pain as the pain generator. 1

Critical Exclusion Criteria

The American College of Neurosurgery explicitly states that facet joint injections are not medically necessary for patients with radiculopathy, as guidelines specifically indicate these are "insufficient evidence or unproven for neck and back pain with untreated radiculopathy." 2 While this patient's diagnosis states "without radiculopathy," this alone does not establish medical necessity—additional specific criteria must be met.

Required Criteria for Medical Necessity (Not Met in This Case)

The American College of Neurosurgery requires ALL of the following conditions to be satisfied before facet joint injections are considered medically necessary: 1

• Symptoms suggestive of facet joint syndrome must be present - Not documented in the predetermination request
• Facet-mediated pain must be confirmed by provocative testing - No evidence of diagnostic blocks performed
• No other obvious cause of pain on imaging studies - Spondylolisthesis (M43.16) represents an alternative structural pain generator
• Pain must limit daily activities - Not documented
• Pain must persist for more than 3 months - Not documented
• Conservative treatment must have failed for at least 6 weeks - No documentation of failed conservative care
• Consideration of radiofrequency facet neurolysis as potential follow-up - Not mentioned

Diagnostic Inadequacy

The diagnosis codes provided (M47.816 and M43.16) describe structural pathology but do not establish facet joints as the pain generator. 1 The American College of Neurosurgery notes that facet joints are not the primary source of back pain in the majority of patients, with only 4% of patients achieving significant relief with controlled diagnostic facet blocks. 1

No physical or radiographic findings consistently correlate with facet pain, making diagnostic facet blocks using the double-injection technique with an improvement threshold of 80% or greater the most reliable means of establishing this diagnosis. 1 This patient has no documentation of diagnostic blocks.

Evidence Against Therapeutic Efficacy

Moderate evidence indicates that facet joint injections with steroids are no more effective than placebo injections for relief of pain and disability. 1, 2 Research shows that only 7.7% of patients selected for facet injection based on clinical criteria achieve complete relief. 1

Alternative Pain Generators to Consider

The presence of spondylolisthesis (M43.16) suggests alternative pain mechanisms: 1

• Discogenic pain - Spondylolisthesis is frequently associated with disc pathology
• Mechanical instability pain - The listhesis itself may be the primary pain generator
• Nerve root compression - Even "without radiculopathy" on the diagnosis, subclinical nerve involvement may exist

Proper Diagnostic Pathway

If facet-mediated pain is truly suspected, the appropriate pathway requires: 1

1. Controlled comparative local anesthetic blocks (double-injection technique) with ≥80% pain relief threshold
2. If positive diagnostic blocks, proceed to radiofrequency ablation of medial branch nerves (the gold standard treatment), NOT repeated intraarticular injections 1
3. Medial branch blocks show better evidence for both diagnostic accuracy and therapeutic efficacy (average 15 weeks pain relief per injection) compared to intraarticular facet injections 1

Procedural Requirements If Criteria Were Met

Should this patient eventually meet criteria, mandatory requirements include: 1

• Fluoroscopic or CT guidance is required for all facet joint interventions (Level I evidence)
• Therapeutic facet joint intra-articular injections should only be done in the context of special arrangements for clinical governance, clinical audit, or research 3

Documentation Deficiencies

The predetermination request lacks: 1

• Duration of symptoms
• Failed conservative treatments (physical therapy, medications, activity modification)
• Functional limitations
• Results of any diagnostic injections
• Imaging findings beyond the diagnosis codes
• Clinical examination findings suggestive of facet-mediated pain

Without this documentation, medical necessity cannot be established regardless of the diagnosis codes provided.