Is L5-S1 posterior spinal instrumented fusion with left-sided laminectomy, complete facetectomy, and foraminotomy, including bone marrow aspirate (CPT 20939), medically indicated for a patient with spondylolisthesis, segmental instability, and symptomatic unremitting low back pain, radiculopathy, or neurogenic claudication?

Medical Necessity Assessment for L5-S1 Posterior Spinal Instrumented Fusion with Bone Marrow Aspirate (CPT 20939)

Primary Recommendation

The L5-S1 posterior spinal instrumented fusion with laminectomy, facetectomy, and foraminotomy is medically indicated for this patient with Grade 1 spondylolisthesis and severe left L5-S1 neuroforaminal stenosis causing L5 radiculopathy, but the addition of bone marrow aspirate (CPT 20939) is NOT medically necessary and should be denied. 1, 2

Justification for Spinal Fusion and Decompression

Criteria Met for Fusion

• Grade 1 anterolisthesis at L5-S1 with severe left-sided neuroforaminal stenosis represents spinal instability that warrants fusion following decompression. 1, 2 The American Association of Neurological Surgeons guidelines recommend fusion as a treatment option in addition to decompression when there is evidence of spinal instability, such as spondylolisthesis of any grade. 1

• The patient has documented L5 radiculopathy in the left L5 dermatomal distribution with numbness, correlating directly with imaging findings of severe left L5-S1 neuroforaminal stenosis and far lateral disc herniation. 2, 3

• Multiple studies demonstrate superior outcomes with decompression plus fusion compared to decompression alone for patients with spondylolisthesis, with 93% patient satisfaction rates and significant improvements in both back and leg pain. 2

• The presence of spondylolisthesis is a well-established risk factor for delayed clinical and radiographic failure after lumbar decompressive procedures, with studies showing up to 73% risk of progressive spondylolisthesis when fusion is not performed. 1

Conservative Management Documentation Gap

Critical Pitfall: The clinical documentation does NOT explicitly state that the patient failed 6 weeks of conservative management as required by CPB 0743. 4 However, the timeline shows:

• Initial presentation 8/19/2025 with 4-year history of symptoms
• Follow-up 11/4/2025 (approximately 11 weeks later) with ongoing symptoms
• Patient has received epidural steroid injections from Dr. Phillips with temporary relief
• Patient taking Tylenol with codeine and Advil for pain management

While the timeline suggests conservative management attempts, explicit documentation stating "failed 6 weeks of conservative therapy including physical therapy, NSAIDs, and epidural injections" is absent. This documentation gap should be addressed, though the clinical scenario clearly indicates appropriate conservative attempts over a 4-year symptomatic period. 3, 5

Rationale for Instrumentation (Pedicle Screws - CPT 22840)

• Pedicle screw fixation improves fusion success rates from 45% to 83% (p=0.0015) compared to non-instrumented fusion in patients with spondylolisthesis. 1, 2

• The American Association of Neurological Surgeons provides evidence supporting pedicle screw fixation in patients with excessive motion at the site of degenerative spondylolisthesis. 1

• The planned extensive decompression (complete facetectomy and foraminotomy) creates risk for iatrogenic instability, making instrumentation appropriate to prevent postoperative progression. 4

Bone Marrow Aspirate (CPT 20939) - NOT MEDICALLY NECESSARY

Explicit Denial Criteria

CPB 0411 explicitly states that bone marrow aspirate is considered experimental, investigational, or unproven as an adjunct to spinal fusion because there is insufficient evidence to support its use for this indication. The policy considers bone marrow aspirate medically necessary ONLY for treatment of bone cysts (unicameral/simple), which does not apply to this patient. 1

Evidence-Based Rationale for Denial

• No guideline from the American Association of Neurological Surgeons, North American Spine Society, or American Academy of Orthopaedic Surgeons recommends bone marrow aspirate as standard of care for spinal fusion procedures. 4, 1, 2

• Standard fusion techniques using autogenous bone graft and/or allograft (CPT 20930) have demonstrated 90% fusion success rates without bone marrow aspirate supplementation. 2

• The addition of bone marrow aspirate does not improve morbidity, mortality, or quality of life outcomes compared to standard fusion techniques with autograft or allograft alone. 1

Alternative Graft Materials That ARE Medically Necessary

• Autogenous bone graft harvested during the laminectomy is appropriate and considered the gold standard for achieving solid arthrodesis. 4, 1

• Allograft (CPT 20930) is medically necessary when used with the fusion procedure, as CPB 0411 considers cadaveric allograft and demineralized bone matrix medically necessary for spinal fusions. 1

• Interbody fusion devices/cages (CPT 22853) are medically necessary when used with allograft or autogenous bone graft in patients meeting criteria for lumbar spinal fusion. 1, 2

Inpatient Level of Care Justification

Inpatient admission is appropriate for L5-S1 posterior instrumented fusion with extensive decompression based on the following criteria:

• The procedure involves multilevel posterior instrumentation (L5-S1 pedicle screws), complete facetectomy, foraminotomy, and laminectomy, which represents major spinal surgery requiring postoperative monitoring. 5

• Extensive decompression with complete facetectomy creates risk for significant epidural bleeding requiring blood pressure management and potential transfusion. 1

• Posterior instrumented fusion procedures typically require 23-hour observation minimum for neurological monitoring, pain control optimization, and mobilization assessment. 4, 5

• The patient's age (53 years) and planned extensive surgical intervention support inpatient admission for safe postoperative recovery. 5

Summary of Approval/Denial Recommendations

APPROVE with Medical Necessity:

• L5-S1 posterior spinal instrumented fusion (CPT 22612,22558)
• L5 laminectomy (CPT 63047)
• Complete facetectomy and foraminotomy
• Pedicle screw instrumentation L5-S1 (CPT 22840)
• Autogenous bone graft from local bone (included in fusion codes)
• Allograft if used (CPT 20930)
• Interbody fusion device/cage if used (CPT 22853)
• Inpatient level of care

DENY - Not Medically Necessary:

• Bone marrow aspirate (CPT 20939) - Explicitly considered experimental/investigational per CPB 0411 with insufficient evidence for use as adjunct to spinal fusion 1

Critical Documentation Requirements for Final Approval

To fully meet CPB 0743 criteria, the following documentation should be explicitly stated in the medical record:

• Specific statement that patient "failed 6 weeks of conservative management including physical therapy, NSAIDs, and epidural steroid injections" (currently implied but not explicitly documented) 3, 5

• Confirmation that symptoms are "unremitting" despite conservative measures (partially documented with ongoing symptoms at 11/4/2025 visit) 2

• Explicit measurement of spondylolisthesis grade on imaging reports (documented as "greater than 2mm" and "Grade 1" but should be consistently stated) 1, 2