Is a lumbar arthrodesis (22558) with allograft (20930) medically necessary for a patient with L5-S1 degenerative disc disease (DDD), lumbago, and lumbar radiculopathy, who has tried conservative therapy, including physical therapy (PT) and medications like Ibuprofen and Meloxicam, with temporary relief from injections?

Medical Necessity Assessment for L5-S1 ALIF with Allograft (CPT 22558,20930)

Primary Determination: Not Medically Necessary

Based on the strongest available evidence, the requested L5-S1 ALIF with allograft does not meet medical necessity criteria because the patient has only "mild" stenosis on imaging, which fails to satisfy the requirement for moderate-to-severe stenosis, and has completed only 1 session of formal physical therapy, falling far short of the required 6 weeks of comprehensive conservative management. 1

Critical Deficiencies in Meeting Criteria

Imaging Severity Does Not Meet Threshold

• The insurance policy explicitly requires "moderate, moderate to severe or severe" stenosis—not "mild or mild to moderate"—and the MRI report documents only "mild impression on thecal sac" and "mild bilateral neuroforaminal narrowing" at L5-S1. 1
• The Journal of Neurosurgery guidelines establish that advanced imaging must demonstrate central/lateral recess or foraminal stenosis graded as moderate or greater at the level corresponding with clinical findings before fusion is considered appropriate. 2
• This patient's imaging explicitly states "mild" findings at every level, which categorically fails to meet the established threshold for surgical intervention. 1

Inadequate Conservative Management

• The patient has completed only 1 session of formal physical therapy, which represents less than 2% of the required 6-week minimum conservative treatment period. 1
• The Journal of Neurosurgery guidelines specify that proper conservative treatment requires a comprehensive approach including formal physical therapy for at least 6 weeks before considering surgical intervention, with moderate strength of evidence. 1
• While the patient tried medications (Ibuprofen, Meloxicam, Methocarbamol) and received one epidural steroid injection with 2 weeks of relief, these interventions do not substitute for the mandatory structured physical therapy program. 2, 1
• The fact that one PT session was "not tolerable" does not waive the requirement—alternative approaches such as aquatic therapy, modified programs, or pain-controlled progression should be attempted. 3

Discordance Between Diagnosis and Imaging

Spinal Stenosis Diagnosis Lacks Radiographic Support

• The treatment plan lists "spinal stenosis, lumbar region with neurogenic claudication" as the diagnosis, yet the MRI explicitly documents only "mild" degenerative changes without moderate or severe stenosis. 1
• This represents a critical mismatch between clinical coding and objective imaging findings that undermines the medical necessity determination. 1
• The Journal of Neurosurgery guidelines emphasize that all other reasonable sources of pain must be ruled out, including significant pathology at other spinal levels not part of the surgical request. 2

Modic Changes Alone Do Not Justify Fusion

• While Modic type II changes at L5-S1 indicate vertebral inflammation and advanced degenerative disease, these findings alone do not constitute an indication for fusion without corresponding moderate-to-severe stenosis or documented instability. 1
• Grade B evidence from the Journal of Neurosurgery indicates that epidural steroid injections for inflammatory endplate changes provide limited benefit (55% satisfaction at 3 months without clinically relevant VAS or ODI improvement), but this does not automatically escalate to fusion candidacy. 2

Appropriate Indications for L5-S1 Fusion (Not Met in This Case)

When Fusion Would Be Appropriate

• Lumbar fusion for degenerative disc disease is recommended only when there is documented instability, spondylolisthesis, or when extensive decompression might create instability—none of which are documented in this patient. 2, 1
• The Journal of Neurosurgery provides Grade C evidence that lumbar fusion is not recommended as routine treatment following primary disc excision in patients with isolated herniated lumbar discs causing radiculopathy. 2
• Fusion becomes a treatment option only in patients with herniated discs who have evidence of significant chronic axial back pain AND work as manual laborers, have severe degenerative changes, or have documented instability. 2

Radiculopathy Alone Does Not Mandate Fusion

• For radiculopathy with herniated lumbar disc, good evidence supports that standard discectomy (not fusion) is moderately superior to nonsurgical therapy for improvement in pain and function through 2-3 months. 4
• The International Society for the Advancement of Spine Surgery establishes that discectomy (open, microtubular, or endoscopic) is medically necessary for lumbar disc herniation with radiculopathy after 6 weeks of failed conservative treatment—but this does not require fusion. 5

Allograft Medical Necessity (CPT 20930)

Conditional Approval for Allograft

• The insurance policy states that "cadaveric allograft and demineralized bone matrix are medically necessary for spinal fusions" when allograft materials are 100% bone, regardless of implant shape. 1
• However, since the primary fusion procedure (22558) does not meet medical necessity criteria, the add-on allograft code (20930) is also not medically necessary—the ancillary procedure cannot be approved when the primary procedure is denied. 1

Required Steps Before Reconsideration

Complete Conservative Management Protocol

• The patient must complete a minimum 6-week structured physical therapy program with documented compliance, functional assessments, and objective outcome measures (VAS, ODI scores). 1, 3
• Acute stage management should focus on pain education, individualized physical activity, and directional preference exercises supported with NSAIDs. 3
• If symptoms persist into sub-acute phase (6-12 weeks), add strength training and neurodynamic mobilization, with consideration of repeat transforaminal/epidural injections. 3
• Chronic stage management (>12 weeks) should incorporate spinal manipulative therapy, specific exercises, and function-specific physical training combined with individualized vocational and ergonomic advice. 3

Obtain Updated Imaging if Symptoms Progress

• If the patient completes adequate conservative management and symptoms worsen, repeat MRI should be obtained to document whether stenosis has progressed from "mild" to "moderate or severe" grade. 1
• Flexion-extension radiographs should be obtained to document any dynamic instability or spondylolisthesis that would change the surgical indication. 1

Common Pitfalls to Avoid

• Do not conflate the presence of radiculopathy symptoms with automatic fusion candidacy—radiculopathy from disc herniation typically requires only decompression, not fusion. 2, 5, 4
• Do not accept "PT was not tolerable" as equivalent to completing conservative management—alternative approaches must be documented before this requirement can be considered satisfied. 1
• Do not proceed with fusion based solely on Modic changes or mild degenerative findings without documented moderate-to-severe stenosis or instability. 2, 1
• Recognize that temporary relief from injections (2 weeks in this case) does not indicate failure of conservative management—it suggests the diagnosis may be correct but the treatment timeline has not been adequately pursued. 2