Is minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) at L2-3 and inpatient level of care medically necessary for a patient with severe back and leg pain, disc bulge with foraminal disc extrusion and significant foraminal stenosis at L2-3, who has failed conservative management including physical therapy (PT) and medication like gabapentin?

Medical Necessity Assessment for MIS TLIF L2-3 and Inpatient Level of Care

The requested minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) at L2-3 is NOT medically necessary because the patient lacks documented spinal instability or spondylolisthesis, which are essential criteria for fusion surgery. 1 The appropriate medically necessary procedure is right-sided L2-3 laminectomy with foraminotomy and discectomy in an ambulatory setting. 1

Critical Deficiencies in Meeting Fusion Criteria

The patient does not meet established criteria for lumbar fusion surgery. The American Association of Neurological Surgeons requires one of the following for fusion to be indicated: documented instability on flexion-extension radiographs, spondylolisthesis of any grade, or conditions where extensive decompression would create iatrogenic instability. 1 None of these conditions are documented in this case.

Missing Essential Documentation

• No flexion-extension radiographs were obtained to assess for dynamic instability, which is a critical prerequisite before considering fusion surgery. 1
• No spondylolisthesis is documented on the MRI report at L2-3 or any other level. 1
• The disc extrusion with foraminal stenosis alone does not constitute an indication for fusion. 2, 1

Decompression Alone Meets Medical Necessity

The patient clearly meets criteria for surgical decompression based on the following:

• Moderate to severe right foraminal stenosis at L2-3 documented on MRI (not mild or mild-to-moderate). 1
• Nerve root compression with the disc extrusion impinging upon the exiting L2 nerve root. 1
• Clinical radiculopathy with 8/10 right-sided pain radiating to the right thigh and diminished sensation along the right anterior thigh. 1
• Failed conservative management including physical therapy (8/26/2025 to 10/30/2025) and gabapentin. 1
• Functional impairment with antalgic gait and two emergency department visits. 1

The Journal of Neurosurgery guidelines recommend laminectomy for individuals with herniated disc and foraminal stenosis graded as moderate to severe when conservative therapy has failed and activities of daily living are limited. 2

Evidence Against Fusion for Isolated Disc Herniation

High-quality randomized controlled trials demonstrate no benefit of fusion over non-operative management for degenerative disc disease without instability. A 2021 BMJ study showed that lumbar spine fusion produces no differences in Oswestry Disability Index scores compared to non-operative management and is associated with increased surgical complications. 1

Fusion should be reserved for specific structural indications. The American Association of Neurological Surgeons explicitly recommends fusion only for cases with documented instability or spondylolisthesis, not for isolated disc herniations with foraminal stenosis. 1 Adding fusion to decompression in the absence of instability exposes patients to higher complication rates (31-40% versus 6-12% for decompression alone) without improving outcomes. 1, 3

Inadequate Conservative Management

The patient's conservative treatment appears incomplete, representing a critical deficiency. 1 Proper conservative management requires:

• Comprehensive physical therapy for at least 6 weeks with documented completion. 1, 3
• Optimization of neuroleptic medications including adequate gabapentin dosing or trial of pregabalin. 1, 3
• Anti-inflammatory therapy with NSAIDs or corticosteroids. 1
• Consideration of selective nerve root block at L2 for both diagnostic and therapeutic purposes. 1, 3

The timeline provided (PT from 8/26/2025 to 10/30/2025) suggests only 9 weeks of therapy, and there is no documentation of epidural steroid injections or selective nerve root blocks being attempted. 1

Inpatient Level of Care Not Justified

Even if fusion were indicated, single-level MIS TLIF procedures can be safely performed in an ambulatory setting. 1 MCG guidelines specify that the appropriate GLOS (geometric length of stay) is ambulatory for single-level procedures without documented instability. 1

Research demonstrates that MIS TLIF results in:

• Significantly less blood loss (averaging 140 mL). 4
• Mean hospital stay of 1.9 days when performed, which can be accomplished in an ambulatory surgery center with 23-hour observation. 4
• Rapid mobilization with narcotic discontinuation at 2-4 weeks postoperatively. 4

The requested inpatient admission is not medically necessary for a single-level procedure in a 47-year-old male without significant comorbidities. 1

Recommended Appropriate Management Pathway

Before any surgical intervention, complete the following conservative management:

1. Formal physical therapy completion with structured program for minimum 6 weeks if not already adequately completed. 1, 3
2. Medication optimization including gabapentin dose escalation to therapeutic levels (up to 3600 mg/day) or trial of pregabalin. 1
3. Anti-inflammatory therapy with scheduled NSAIDs if not contraindicated. 1
4. Selective nerve root block at L2 for both diagnostic confirmation and potential therapeutic benefit. 1, 3

If conservative management fails after comprehensive trial, the medically necessary surgical procedure is:

• Right-sided L2-3 laminectomy with foraminotomy and discectomy performed in an ambulatory setting. 1
• This addresses the documented pathology (foraminal disc extrusion with nerve root impingement) without the added risks and costs of unnecessary fusion. 1

Common Pitfalls to Avoid

The most critical error would be performing fusion without documented instability. This exposes the patient to:

• Higher complication rates (31-40% for fusion versus 6-12% for decompression alone). 1, 3
• Longer operative times and increased blood loss. 3
• No improvement in outcomes compared to decompression alone when instability is absent. 1
• Unnecessary costs without incremental benefit to the patient. 2

Flexion-extension radiographs must be obtained before any consideration of fusion to document or exclude dynamic instability. 1 The absence of this imaging represents incomplete surgical planning.

The presence of multilevel degenerative changes (L1-2, L3-4, L4-5, L5-S1 all show pathology on MRI) does not justify fusion at L2-3 when the symptomatic level can be adequately treated with decompression alone. 1 Treating asymptomatic radiographic findings leads to poor outcomes.