Is removal of posterior hardware medically indicated for a patient with prior Anterior Cervical Discectomy and Fusion (ACDF) at C4-5 and C5-7, and posterior C3-6 fusion, considering nonunion of anterior cervical spine fusion and pseudarthrosis after fusion or arthrodesis, and meeting Medical Coverage Guidelines (MCG) criteria?

Removal of Posterior Hardware is NOT Medically Indicated

In this patient with documented anterior cervical pseudarthrosis following ACDF at C4-5 and C5-7, the posterior C3-6 fusion hardware should be retained, not removed, as the posterior instrumentation is the primary stabilizing construct preventing further instability and neurological deterioration. 1

Critical Clinical Context

This patient presents with a complex scenario requiring careful analysis:

• Prior failed anterior fusion (ACDF at C4-5 and C5-7) with documented nonunion/pseudarthrosis 2
• Salvage posterior fusion (C3-6) was performed to address the anterior failure 2
• The posterior hardware is currently the only stable construct maintaining cervical alignment and preventing progressive deformity 1

Why Hardware Removal is Contraindicated

The Posterior Fusion is the Definitive Treatment

Posterior fusion with instrumentation is the established salvage procedure for anterior cervical pseudarthrosis, achieving 100% fusion rates in multiple studies. 3, 4 The evidence strongly supports:

• Posterior lateral mass screw/rod fixation achieves solid fusion in all patients (100%) with symptomatic anterior pseudarthrosis 3
• A consecutive series of 33 patients treated with posterior fusion for anterior pseudarthrosis demonstrated 100% fusion rate at average 46-month follow-up 4
• Posterior fusion provides superior stability compared to anterior revision, with only 2% nonunion rate versus 44% with anterior revision 2

Removing Hardware Would Destabilize the Spine

The posterior instrumentation serves critical functions that cannot be abandoned:

• Maintains cervical alignment and prevents progressive kyphotic deformity 1
• Provides the only stable construct given the documented anterior column failure 1
• Prevents neurological deterioration that would result from recurrent instability 1

The Appropriate Clinical Pathway

If Patient is Symptomatic Despite Posterior Fusion

The evidence-based approach for persistent symptoms after posterior fusion for pseudarthrosis is:

1. Confirm posterior fusion status using flexion-extension radiographs or CT imaging 3, 4
2. Consider 18F-NaF PET/CT if conventional imaging is equivocal, as intragraft uptake has 100% sensitivity for detecting pseudarthrosis 5
3. If posterior pseudarthrosis is confirmed, revision posterior fusion with augmented fixation is indicated—not hardware removal 3
4. If posterior fusion is solid, investigate alternative pain generators including adjacent segment disease 5, 4

If Anterior Pseudarthrosis Persists

When anterior nonunion persists despite solid posterior fusion:

• Combined anterior-posterior approach may be necessary to restore anterior column support 1
• Anterior revision with plating can be performed while maintaining posterior instrumentation 1
• The posterior hardware provides essential stability during anterior revision and should remain in place 1

Common Clinical Pitfalls to Avoid

Misinterpreting "Hardware Removal" Criteria

Standard MCG criteria for hardware removal typically apply to:

• Healed fractures where hardware served temporary stabilization purpose
• Symptomatic hardware causing pain in otherwise stable, fused spines
• Infected hardware requiring removal with simultaneous revision

These criteria do NOT apply to this patient, where the posterior hardware is the definitive treatment for anterior pseudarthrosis, not a temporary measure 1, 3, 4.

Underestimating Pseudarthrosis Complexity

Patients with anterior cervical pseudarthrosis represent a high-risk population:

• Even after achieving solid posterior fusion, 28% continue to report moderate to severe pain 4
• The underlying pseudarthrosis indicates compromised healing capacity requiring robust stabilization 1
• Removing the only stable construct would likely result in recurrent instability and symptom progression 1

Expected Outcomes with Hardware Retention

With the posterior instrumentation maintained:

• 100% fusion rate can be expected based on multiple case series 3, 4
• Significant symptom improvement occurs in the majority of patients, though 28% may have persistent moderate-severe pain despite solid fusion 4
• 72% patient satisfaction rate is achievable with posterior fusion for anterior pseudarthrosis 4
• Prevention of progressive deformity and neurological deterioration 1

Alternative Considerations

If there are specific concerns about the posterior hardware (infection, prominent hardware causing soft tissue irritation, documented hardware failure), these should be addressed through:

• Revision posterior instrumentation rather than simple removal 3
• Treatment of infection with staged removal and reimplantation if necessary
• Hardware exchange for symptomatic prominent instrumentation while maintaining spinal stability

Simple hardware removal without revision stabilization is not a medically sound option in this clinical scenario. 1, 3, 4