Is cervical artificial disc replacement medically necessary for a 46-year-old female with cervical radiculopathy and prior anterior cervical discectomy and fusion (ACDF) who has failed conservative treatment with medications such as Flexeril (cyclobenzaprine), gabapentin, oxycodone, and prednisone?

Cervical Artificial Disc Replacement is NOT Medically Necessary for This Patient

This patient's request for cervical artificial disc replacement at C4-5 and C5-6 should be denied because she is requesting a hybrid construct (disc replacement adjacent to her existing C6-7 fusion), which is explicitly not FDA-approved, and she had a postoperative infection just 3 months ago that creates unacceptable risk for implant failure. 1

Critical FDA and Safety Contraindications

Hybrid Construct is Not FDA-Approved

• All FDA-approved cervical artificial disc devices (including ProDisc-C, ProDisc-C Vivo, and ProDisc-C SK) are approved only for stand-alone use at levels C3-C7, not for hybrid constructs adjacent to existing fusions. 1
• The patient underwent C6-7 ACDF in June 2025 and is now requesting disc replacement at C4-5 and C5-6, which would create a hybrid construct (artificial disc next to fusion) that lacks FDA approval and long-term outcome data 1
• While some European literature explores expanded indications for cervical disc replacement adjacent to fusion, this remains investigational and is not approved by the FDA for use in the United States 2, 3

Recent Postoperative Infection

• The patient had a confirmed postoperative infection following her C6-7 ACDF in June 2025 requiring 6 weeks of antibiotics, with surgery occurring only 3 months ago. 4
• Recent postoperative infection represents a significant contraindication to artificial disc placement, as it carries an unacceptable risk of recurrent infection and implant failure 4
• Before any surgical intervention can be considered, the patient requires documented proof that the infection is completely resolved with normal inflammatory markers (ESR, CRP) 4

Missing Required Documentation

Segmental Instability Assessment

• Flexion-extension radiographs are an absolute FDA requirement to definitively rule out segmental instability before proceeding with arthroplasty. 4
• While the additional clinical information states "no segmental instability present on imaging done," static MRI cannot adequately assess segmental instability 4
• Dynamic flexion-extension films are mandatory and must be obtained before any consideration of disc replacement 4

Alternative Surgical Approach: ACDF is Appropriate

ACDF Meets Medical Necessity Criteria

• If the infection is proven resolved and instability is ruled out with flexion-extension films, ACDF (not disc replacement) would be the appropriate surgical intervention for this patient. 4
• The patient meets clinical criteria for surgical intervention: 46 years old (under 60), moderate stenosis at C5-6 with moderate left foraminal stenosis, failed 6 weeks of conservative treatment (Flexeril, gabapentin, oxycodone, prednisone), and has significant functional impairment with dropping objects and decreased dexterity 4
• ACDF provides 80-90% success rates for arm pain relief in cervical radiculopathy with moderate to severe foraminal stenosis 4, 5
• The diagnostic injection providing 80% relief confirms that the C5-6 level is the pain generator, supporting surgical intervention at this level 4

Evidence Supporting ACDF Over Disc Replacement in This Context

• ACDF is specifically indicated for patients with moderate to severe foraminal stenosis when conservative management has failed 4
• For 2-level anterior cervical surgery, ACDF with anterior plating provides improved arm pain relief, faster return to activities of daily living, and reduced pseudarthrosis rates compared to ACDF without instrumentation 6
• The addition of anterior cervical plating reduces the repeated operation rate for pseudarthrosis from 4.8% to 0.7% and improves fusion rates from 88% to 94% 6

Required Steps Before Any Surgical Approval

1. Obtain flexion-extension cervical radiographs to definitively rule out segmental instability (absolute FDA requirement for disc replacement consideration) 4

2. Document complete resolution of the postoperative infection with normal inflammatory markers (ESR, CRP) and clinical examination showing no signs of ongoing infection 4

3. If both above criteria are met, proceed with ACDF (not disc replacement) at C4-5 and C5-6 using anterior cervical plating for the 2-level construct 6, 4

Common Pitfalls to Avoid

• Do not approve disc replacement adjacent to existing fusion: This hybrid construct is not FDA-approved and represents off-label use with unknown long-term outcomes 1
• Do not proceed with any implant surgery in the setting of recent infection: The 3-month interval since infected ACDF is insufficient without documented proof of infection resolution 4
• Do not rely on static MRI alone for instability assessment: Dynamic flexion-extension films are mandatory for proper preoperative evaluation 4
• Do not confuse European expanded indications with FDA-approved indications: While some international literature explores hybrid constructs, these remain investigational in the United States 2, 3