What is the recommended treatment for a patient with Grade I spondylolisthesis, bilateral L5 pars defects, and multilevel discogenic nerve root impingement?

Treatment for Grade I Spondylolisthesis with Bilateral L5 Pars Defects and Multilevel Nerve Root Impingement

This patient requires initial conservative management for 3-6 months, and if symptoms persist with functional impairment, surgical decompression with posterolateral fusion is recommended, particularly given the multilevel nerve root impingement, bilateral L5 pars defects with marrow edema, and two-level spondylolisthesis. 1

Initial Conservative Management (3-6 Months Required)

Conservative treatment must be attempted first and should include:

• Structured physical therapy with flexion-based exercises focusing on core strengthening, hamstring stretching, and spine range of motion for at least 6 weeks 1, 2
• Neuroleptic medications (gabapentin or pregabalin) initiated early for the documented radicular symptoms affecting multiple nerve roots (right L3, bilateral L4, bilateral L5, bilateral S1) 1
• NSAIDs as first-line anti-inflammatory therapy 1
• Epidural steroid injections given the presence of nerve root contact and impingement documented on MRI 1
• Activity modification with restriction of offending activities that exacerbate symptoms 2

Important Caveat About Conservative Management

While conservative management can be effective for isolated spondylolysis or Grade I spondylolisthesis (96% achieving minimal disability scores in one study), this patient's presentation is more complex with multilevel discogenic nerve root impingement at four levels and bilateral pars defects with marrow edema, suggesting active instability 2. The marrow edema at the L5 pars defects indicates ongoing stress and potential progression 3.

Diagnostic Imaging Requirements Before Surgery

• Upright radiographs with flexion-extension views are essential to document segmental motion and instability at both L4-5 and L5-S1 levels 1
• Consider CT scan to definitively assess for L4 pars defects, as the MRI report indicates difficulty determining their presence 1

Surgical Indications

Surgery should be considered if ANY of the following occur:

• Failure of comprehensive conservative management for 3-6 months 1, 4
• Persistent disabling radicular symptoms causing unacceptable functional impairment that correlates with the multilevel imaging findings 1
• Progressive neurological deficits 1

Evidence Supporting Surgery in This Context

The preponderance of evidence favors decompression with fusion for patients with spondylolisthesis and stenosis, particularly when extensive decompression is required 5. This patient has multilevel nerve root impingement requiring decompression at L3-4, L4-5, and L5-S1, which increases the risk of iatrogenic instability if fusion is not performed 5.

In a 10-year prospective study, surgical treatment showed considerably better outcomes than conservative management for patients with symptomatic stenosis, with four-fifths achieving excellent or fair results 4. Importantly, patients who failed conservative treatment and underwent delayed surgery (median 3.5 months) achieved outcomes essentially similar to those who had initial surgery 4.

Recommended Surgical Approach

Posterolateral fusion (PLF) following decompression at L4-5 and L5-S1 is the standard approach 1. Alternative consideration includes transforaminal lumbar interbody fusion (TLIF), which provides high fusion rates and allows simultaneous decompression through a unilateral approach 1.

Instrumentation Considerations

While pedicle screw fixation does not routinely improve functional outcomes in all patients with spondylolisthesis, it significantly increases fusion rates (83% vs 45% without instrumentation) 5. Given this patient has:

• Two-level spondylolisthesis (L4-5 and L5-S1)
• Bilateral L5 pars defects with marrow edema
• Severe facet arthropathy at both levels
• Multilevel decompression requirements

Pedicle screw instrumentation should be strongly considered to maximize fusion success and prevent progression 5.

Extent of Fusion

The fusion should address both unstable levels (L4-5 and L5-S1) given the Grade I spondylolisthesis at both levels and the need for multilevel decompression 5. The L3-4 level, while showing disc bulge with nerve root impingement, does not demonstrate spondylolisthesis and may be adequately treated with decompression alone if included in the surgical plan 6.

Critical Pitfalls to Avoid

• Do not perform extensive bilateral decompression without fusion in the setting of spondylolisthesis, as this creates iatrogenic instability and poor outcomes 5, 6
• Assess and optimize psychosocial factors including mood, expectations, and "yellow flags" before surgery, as these significantly impact surgical outcomes 1
• Address modifiable risk factors such as smoking, depression, and chronic pain syndrome before surgical intervention 7
• Unilateral microdecompression without fusion is only appropriate for patients with unilateral symptoms, minimal back pain, and no greater than 25% spondylolisthesis—this patient does not meet these criteria with bilateral symptoms and multilevel involvement 6

Monitoring During Conservative Treatment

• Reassess at 6 weeks and 3 months using validated outcome measures (Oswestry Disability Index, Visual Analog Scale) 7
• Monitor for progressive neurological deficits or cauda equina symptoms requiring urgent surgical intervention 8
• Document functional impairment objectively to support surgical decision-making if conservative treatment fails 1