Is lumbar laminectomy and fusion surgery medically indicated for a patient with lumbar spinal stenosis L4-5 and degenerative spondylolisthesis, who has not responded to conservative management and has significant low back pain radiating to the right leg, interfering with activities of daily living (ADLs) and work activities?

Lumbar Laminectomy and Fusion is Medically Indicated for This Patient

Yes, lumbar laminectomy and fusion at L4-5 is medically indicated for this patient with lumbar spinal stenosis, degenerative spondylolisthesis, and radicular pain that has failed conservative management including epidural steroid injection. 1, 2

Evidence Supporting Fusion in Stenosis with Degenerative Spondylolisthesis

The presence of degenerative spondylolisthesis at L4-5 fundamentally changes the surgical approach from decompression alone to decompression plus fusion:

• Class II medical evidence demonstrates that 96% of patients with stenosis and degenerative spondylolisthesis treated with decompression plus fusion reported excellent or good outcomes, compared to only 44% with decompression alone. 3, 2

• Multiple studies provide Class III evidence showing that patients undergoing decompression and fusion for stenosis with spondylolisthesis report statistically significantly less back pain (p=0.01) and leg pain (p=0.002) compared to decompression alone. 1

• The American Association of Neurological Surgeons recommends fusion as a treatment option in addition to decompression when there is evidence of spinal instability, and any degree of spondylolisthesis constitutes documented instability. 1, 2

Conservative Management Requirements Met

This patient has completed appropriate conservative treatment before surgical consideration:

• The patient underwent transforaminal epidural steroid injection at L4-5 with temporary relief, demonstrating failed conservative management. 1

• Pain interfering with activities of daily living and work activities represents significant functional impairment despite conservative measures. 1

• The American Association of Neurological Surgeons guidelines require failure of comprehensive conservative management for at least 3-6 months before considering fusion, which this patient has satisfied. 1

Why Decompression Alone is Insufficient

Performing decompression without fusion in the setting of degenerative spondylolisthesis carries substantial risk:

• Preoperative spondylolisthesis is a documented risk factor for 5-year clinical and radiographic failure after decompression alone, with up to 73% risk of progressive slippage. 2

• Extensive decompression without fusion can lead to iatrogenic instability in approximately 38% of cases. 2

• Studies show that patients with spondylolisthesis who undergo decompression alone have higher rates of poor outcomes due to progression of spinal deformity. 2

Instrumentation Considerations

While the evidence supports fusion in this clinical scenario, the role of pedicle screw instrumentation requires nuanced consideration:

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

• Class III evidence supports pedicle screw fixation in patients with excessive motion or kyphosis associated with spondylolisthesis. 3

• However, pedicle screw fixation does not improve functional outcomes following posterolateral fusion in all patients with stenosis and spondylolisthesis—it primarily improves fusion rates. 3

Critical Distinction from Stenosis Without Spondylolisthesis

This case must be distinguished from isolated stenosis without instability, where decompression alone is the recommended treatment:

• Decompression alone is the recommended treatment for lumbar spinal stenosis with neurogenic claudication without evidence of instability. 2

• In the absence of deformity or instability, lumbar fusion has not been shown to improve outcomes in patients with isolated stenosis. 2

• However, this patient has documented degenerative spondylolisthesis at L4-5, which represents biomechanical instability and changes the treatment algorithm entirely. 1, 2

Ambulatory vs Inpatient Setting

The MCG criteria indicating ambulatory level of care may require reconsideration:

• Single-level instrumented fusion procedures have higher complication rates (31-40%) compared to decompression alone (6-12%), which may warrant inpatient monitoring depending on patient comorbidities. 1

• However, many single-level TLIF procedures are now safely performed in ambulatory settings with appropriate patient selection and postoperative monitoring protocols. 1

Common Pitfalls to Avoid

• Do not perform decompression alone in the setting of degenerative spondylolisthesis, as this creates unacceptable risk of progressive instability and need for revision surgery. 2

• Do not add fusion to decompression for isolated stenosis without documented instability, as this increases operative time, blood loss, and surgical risk without proven benefit. 2

• Ensure adequate conservative management is documented, including formal physical therapy (not just home exercises), medication trials, and epidural steroid injections. 1

• Verify that imaging findings correlate with clinical symptoms—the stenosis and spondylolisthesis at L4-5 must correspond to the right leg radicular pain pattern. 1, 2