What is the appropriate management for a patient with Grade 1 anterolisthesis at C3/C4, disc osteophytes causing indentation over the cal sac, and no neural foramina involvement?

Management of Grade 1 Anterolisthesis C3/C4 with Disc Osteophytes and Thecal Sac Indentation

For Grade 1 cervical anterolisthesis at C3/C4 with disc osteophytes causing thecal sac indentation but no neural foraminal involvement, initial conservative management with cervical immobilization, physical therapy, and close monitoring is the appropriate first-line approach, with MRI being the gold standard for evaluating cord compression and surgical planning if neurological symptoms develop. 1

Initial Assessment and Imaging

MRI of the cervical spine without contrast is the reference standard for evaluating spinal cord compression and should be obtained to assess for myelopathy. 1 The imaging must specifically evaluate:

• Degree of thecal sac indentation and spinal cord compression on T1-weighted sequences 1
• High-intensity signals on T2-weighted MRI indicating cord injury or myelopathy 2
• Space available for cord (SAC) at the listhesis level and adjacent segments 3
• Disc degeneration severity at C3/C4 and adjacent levels 3

CT imaging can supplement MRI to better visualize the bony osteophyte complex and canal dimensions, though it provides inferior soft tissue and cord visualization compared to MRI. 1

Conservative Management Protocol

Cervical immobilization with a rigid cervical collar is recommended to diminish pain and stabilize the affected segment during initial treatment. 1 This approach is appropriate for patients with isolated disc-osteophyte complex without progressive neurological deficit. 1

The conservative regimen should include:

• Cervical collar immobilization for 6-12 weeks 1
• Formal physical therapy focusing on cervical strengthening and range of motion exercises 4
• Anti-inflammatory medications and neuropathic pain agents if radicular symptoms present 4
• Ergonomic modifications to reduce cervical strain 5

Multimodal chiropractic care including cervical manipulation, axial distraction, and isometric stretching may provide symptom relief and has been shown to reduce cervical anterolisthesis over time in select cases. 5 However, manipulation should only be performed by experienced practitioners and avoided if myelopathic signs are present.

Monitoring and Surveillance

Frequent clinical surveillance with neurological examination is essential, potentially with weekly or biweekly MRI initially, to detect any disease progression early. 1 Specific red flags requiring immediate surgical evaluation include:

• Development of myelopathic symptoms (gait instability, hand clumsiness, hyperreflexia) 1
• Progressive motor weakness or sensory deficits 1
• Bowel or bladder dysfunction 1
• Increasing cord compression on serial imaging 2

Flexion-extension radiographs should be obtained to assess for dynamic instability, as cervical mobility at the listhesis level correlates with severity of cord compression. 2 Patients with severe spondylolisthesis demonstrate significantly greater cervical mobility than those with mild displacement. 2

Surgical Indications

Surgical intervention becomes necessary when:

• Acute onset myelopathy with documented cord compression on MRI 1
• Progressive neurological deterioration despite conservative management 1
• Severe cord compression with T2 hyperintensity signal indicating cord injury 2
• Dynamic instability with >3.5mm displacement on flexion-extension views 2

For cervical spondylotic myelopathy with anterolisthesis, anterior cervical decompression and fusion is the preferred surgical approach, as it directly addresses the anterior compression from disc-osteophyte complex. 6 Limited anterior-only fusion at the affected level can provide excellent long-term results while preserving motion at adjacent segments. 6

Critical Considerations

Grade 1 anterolisthesis (displacement <25% of vertebral body width) at C3/C4 has a high incidence in elderly patients with cervical spondylotic myelopathy and tends to cause more intense cord compression than similar grades of retrolisthesis. 2 The C3/C4 level is particularly prone to severe degenerative spondylolisthesis (93% incidence at C3/C4 or C4/5 in severe cases). 2

The absence of neural foraminal involvement does not exclude the possibility of central cord compression or future development of radiculopathy. 3 The cephalad adjacent segment (C2/C3) shows increased translational motion as compensation, which may predispose to adjacent segment disease. 3

Patients without neurological deficit can be managed conservatively even with significant displacement, but require vigilant monitoring as neurological deterioration can occur. 6 The presence of thecal sac indentation without current myelopathy represents a precarious situation requiring close follow-up.

Long-Term Management

If conservative management successfully controls symptoms, monthly maintenance care including monitoring, manipulation of dysfunctional segments, cervical strengthening exercises, and ergonomics coaching can maintain asymptomatic status and potentially reduce listhesis over time. 5 One case demonstrated gradual reduction in cervical retrolisthesis over 13 years with consistent monthly chiropractic maintenance care. 5

Failure of 6 weeks to 3 months of comprehensive conservative therapy in a surgical candidate warrants advanced imaging and surgical consultation. 1, 4 The goal is to identify actionable pathology before irreversible cord injury occurs, as T2 hyperintensity signals on MRI indicate established cord damage with poorer surgical outcomes. 2