Medical Necessity Assessment for Spinal Bone Autograft (CPT 20936)
Spinal bone autograft (CPT 20936) is NOT medically necessary for this patient's anterior cervical discectomy and fusion at C3-4 and C5-6, as the MCG criteria were not met and current evidence supports that single grafting strategies (allograft alone or cage alone) achieve equivalent fusion rates of 83-98% without requiring autograft. 1, 2
Why Autograft is Not Required
The patient already has approval for allograft (CPT 20930), which is sufficient for achieving successful fusion. The evidence demonstrates:
Allograft bone from cadaveric iliac crest or fibula is recommended with Class II evidence for creating arthrodesis after 1- or 2-level ACDF, with fusion rates of 87-97% for single-level procedures. 1
For 1-level cervical fusion, allograft achieves comparable fusion rates to autograft (87% vs 97%), with the difference being clinically insignificant. 1
Titanium or PEEK cages with allograft eliminate donor site morbidity while maintaining equivalent clinical outcomes, with fusion rates of 83-100%. 2, 3
Clinical Context Supporting Allograft-Only Approach
This patient's case involves:
Two separate 1-level fusions (C3-4 and C5-6), not a contiguous 2-level fusion, which further supports the use of allograft alone as each level functions independently. 1
The patient has severe foraminal stenosis with posterior disc osteophyte complexes at both levels, documented on MRI and CT, with adequate bone quality noted on CT scan. This favorable bone quality supports successful fusion without autograft. 4
The patient meets all criteria for the primary fusion procedure (CPT 22551) with documented neural compression, failed conservative therapy including PT and epidural injection, and significant functional limitations. 5
Disadvantages of Adding Autograft
Adding autograft to an already-approved allograft strategy introduces unnecessary morbidity:
Autograft harvest from the iliac crest causes donor site complications in up to 22% of patients, including persistent hip pain at 1 year, without providing superior fusion rates in 1-level procedures. 1, 2
The simultaneous use of both allograft and autograft represents potentially excessive and redundant grafting strategies, as evidence demonstrates that single grafting strategies achieve comparable fusion rates. 2
Hospital stay duration increases when iliac crest harvest is performed (7.25 days vs 5.4 days without harvest). 1
When Autograft Would Be Indicated
Autograft becomes more relevant in specific high-risk scenarios not present in this case:
For contiguous 2-level procedures, autograft shows superior fusion rates (83% vs 37% for allograft), but this patient has two separate 1-level fusions. 1
Patients with compromised bone quality (osteopenia, Job's syndrome) or multiple risk factors for pseudarthrosis benefit from autograft's superior osteogenic properties. 5
Revision surgery for pseudarthrosis may warrant autograft consideration, but this is a primary procedure. 1
MCG Guideline Compliance
The MCG guideline for CPT 20936 (Musculoskeletal Surgery GRG) was NOT MET, as the indication requires "other spinal procedure required (eg, congenital or idiopathic deformity or disease)" which does not apply to standard degenerative disc disease. 5
The approved allograft (CPT 20930) already meets MCG criteria under guideline 0411, which considers allograft medically necessary for spinal fusions regardless of implant shape. 5
Recommended Approach
Proceed with the approved anterior cervical discectomy and fusion using allograft (CPT 20930) with or without cage/plate fixation, which provides equivalent fusion rates without the morbidity of autograft harvest. 1, 2, 3