Is spinal bone autograft (20936) and insertion of a biomechanical device (22853) medically necessary for a patient with diffuse cervical spondylosis, multilevel degenerative disc disease, and multifocal foraminal stenosis undergoing C5-C7 anterior cervical discectomy and fusion (ACDF)?

Medical Necessity Determination for C5-C7 ACDF with Spinal Bone Autograft and Biomechanical Devices

Spinal Bone Autograft (CPT 20936): NOT Medically Necessary

The spinal bone autograft harvest is not medically necessary for this C5-C7 ACDF procedure, as the already-approved allograft (CPT 20930) combined with interbody cages achieves equivalent fusion rates of 91-95% for multilevel cervical fusion without the additional donor site morbidity. 1

Evidence-Based Rationale Against Autograft

• The American Association of Neurological Surgeons guidelines establish that autograft bone, allograft bone, or titanium cages with or without autologous graft are all equally recommended options for creating arthrodesis after ACDF (Class II evidence, Strength C recommendation), meaning autograft provides no superior outcome that would justify its additional morbidity 1

• For multilevel ACDF procedures, autograft achieved 100% fusion versus 89.5% with allograft in uninstrumented cases, but when combined with modern interbody devices and anterior plating (already approved as CPT 22846), this difference becomes clinically insignificant 2

• Iliac crest autograft harvest causes persistent hip pain in 22% of patients at 1 year and increases hospital stay duration (7.25 days versus 5.4 days without harvest), representing unnecessary morbidity when equivalent alternatives exist 1, 3

Clinical Context for This Patient

• The patient is a former smoker (nicotine-free since lumbar fusion), which historically reduced fusion rates with allograft, but this smoking effect is no longer relevant given current nicotine-free status 2

• The already-approved allograft morsel (CPT 20930) per CPB 0411 provides adequate bone graft material for fusion when combined with the structural support of interbody cages 1

• Adding autograft harvest represents redundant grafting strategy without evidence of improved outcomes, as single grafting strategies (allograft with cage) achieve fusion rates of 83-100% 3, 4

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Biomechanical Devices/Interbody Cages (CPT 22853 x3): MEDICALLY NECESSARY

The three interbody biomechanical devices (synthetic cages/spacers) are medically necessary for this 2-level C5-C7 ACDF procedure, as they provide immediate structural stability, maintain disc height critical for foraminal decompression in this patient with severe multifocal foraminal stenosis, and achieve 100% fusion rates at 12 months with 97% good-to-excellent clinical outcomes. 1, 4

Evidence Supporting Interbody Device Necessity

• PEEK or titanium cages achieve 100% fusion rates by 6-12 months when supplemented with bone graft (allograft already approved), providing immediate structural stability while maintaining foraminal height for sustained neural decompression 1, 4

• For this patient with severe foraminal stenosis (severe left C3-4, severe right C4-5, mild/moderate C5-6 and C6-7), cages maintain foraminal height better than structural bone grafts alone, which is critical for sustained neural decompression 1

• The American Association of Neurological Surgeons confirms that synthetic spine cages/spacers are medically necessary for cervical fusion in patients meeting CPB 0743 criteria for spinal fusion, which this patient clearly meets with documented severe stenosis, failed 6+ weeks conservative management, radiculopathy, and significant functional impairment (NDI 70%, ODI 64%) 4

Addressing the CPB 0016 Corpectomy Concern

• While CPB 0016 lists cervical corpectomy as one indication for synthetic cages, it also explicitly states that synthetic spine cages/spacers are medically necessary for "cervical fusion for patients who meet criteria in CPB 0743 - Spinal Surgery: Laminectomy and Fusion" 1

• This patient meets ALL criteria in CPB 0743: neural compression symptoms confirmed, advanced imaging showing moderate-to-severe stenosis at multiple levels, failed 6+ weeks conservative therapy including physical therapy, NSAIDs, opioids, muscle relaxers, and steroid injections, and significant ADL limitations 1, 4

• The corpectomy requirement is listed as an alternative indication ("OR"), not a mandatory requirement for all cage use in cervical fusion 4

Multilevel Procedure Considerations

• For 2-level contiguous ACDF (C5-6 and C6-7), interbody devices provide superior maintenance of disc height and segmental lordosis compared to bone graft alone, with final disc height maintained at 6.2mm versus 5.0mm preoperatively 5

• All 25 disc levels in a study of multilevel ACDF with PEEK cages filled with cancellous allograft achieved successful union at 1-year follow-up, with 74% excellent/good clinical outcomes 5

• Third-generation bioactive glass in porous PEEK spacers achieved 100% fusion by 6 months in multilevel instrumented fusions (including 17 two-level, 12 three-level cases), with significant improvements in NDI and VAS pain scores 6

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Summary Algorithm for Medical Necessity

Step 1: Verify Primary Fusion Criteria (CPB 0743)

• ✓ Neural compression symptoms present (bilateral arm weakness, radiculopathy)
• ✓ Advanced imaging confirms moderate-to-severe stenosis
• ✓ Failed 6+ weeks conservative management
• ✓ Significant ADL limitations (NDI 70%, ODI 64%)
• Result: Primary fusion procedures (22551,22552 x2, 22846) are medically necessary

Step 2: Determine Bone Graft Strategy

• Allograft morsel (20930) already approved per CPB 0411
• Autograft (20936) would add donor site morbidity (22% persistent hip pain) without improving fusion rates when combined with cages and plating 1, 3
• Result: Autograft NOT medically necessary

Step 3: Determine Interbody Device Necessity

• Patient meets CPB 0743 fusion criteria, which qualifies for synthetic cages per CPB 0016
• Severe foraminal stenosis requires maintained disc height for sustained decompression
• Cages achieve 100% fusion with allograft fill in multilevel procedures 1, 6, 5
• Result: Interbody devices (22853 x3) ARE medically necessary (Note: 2-level fusion C5-C7 requires only 2 cages, not 3)

Critical Caveat

The request lists three biomechanical devices (22853 x3) for a 2-level fusion (C5-6 and C6-7), which requires only two interbody cages. Verify the actual surgical plan, as the third device code may represent a billing error unless there is an additional level being addressed 1, 5