Is hybrid surgery with total disc replacement at C4-5 and Anterior Cervical Discectomy and Fusion (ACDF) at C5-6 medically indicated for a patient with cord compression and severe symptoms, given a history of conservative treatments and diagnostic testing showing large focal disc herniation and significant compression of the spinal cord?

Hybrid Surgery with Total Disc Replacement at C4-5 and ACDF at C5-6 is Medically Indicated

For this patient with severe cord compression symptoms, documented large focal disc herniation causing significant spinal cord compression, and failed conservative treatments, the proposed hybrid surgery combining total disc replacement at C4-5 and ACDF at C5-6 is medically indicated and represents an appropriate surgical strategy for multilevel cervical degenerative disc disease. 1

Evidence Supporting Hybrid Surgery for Multilevel Disease

The hybrid surgical approach combining cervical arthroplasty and fusion in a single-stage procedure has demonstrated safety and efficacy in patients with symptomatic multilevel cervical degenerative disc disease with predominant anterior myeloradicular compression 1. This technique aims to restore or maintain motion where appropriate while favoring bony fusion when indicated by degenerative changes 1.

Key clinical outcomes from hybrid surgery studies:

• In 24 patients with multilevel disease (mean age 46.7 years), all but one patient demonstrated significant clinical improvement on neurological examination, Nurick scale, NDI, and SF-36 measures 1
• Follow-up ranging 12-40 months (mean 23.8 months) showed functioning disc prostheses with total range of motion 3-15 degrees and successful fusion through cages 1
• No patients required revision surgery for persisting or recurring symptoms, procedure-related complications, or device dislocations 1
• Multilevel cervical arthroplasty with disc replacement is a safe and effective alternative to fusion for management of cervical radiculopathy and myelopathy 2

Surgical Indications Are Met

This patient meets established criteria for anterior cervical decompression:

• Severe symptoms with cord compression: The presence of large focal disc herniation with significant spinal cord compression causing severe symptoms represents a clear indication for surgical intervention 3
• Failed conservative management: The patient has undergone conservative treatments without adequate relief, meeting the requirement for surgical consideration 4
• Appropriate imaging confirmation: Diagnostic testing has confirmed the anatomic pathology correlating with clinical symptoms 3

Anterior cervical decompression provides rapid relief (within 3-4 months) of arm/neck pain, weakness, and sensory loss compared to continued conservative treatment, with success rates of 80-90% for arm pain relief 4. Long-term improvements in motor function, sensation, and pain are maintained over 12 months following anterior decompression 4.

Rationale for Hybrid Construct Selection

The combination of total disc replacement at C4-5 and ACDF at C5-6 is strategically sound:

• Hybrid constructs (TDR-ACDF combinations) are established treatment options for multilevel cervical disease, avoiding the need for multilevel fusion while maintaining range of motion at appropriate levels 2, 5
• By using ACDF combined with arthroplasty, surgeons can avoid multilevel fusion and maintain range of motion at preserved disc levels 5
• The technique allows tailored treatment: fusion where degenerative changes are severe (C5-6) and motion preservation where appropriate (C4-5) 1

For two-level disease, anterior cervical plating reduces pseudarthrosis risk from 4.8% to 0.7% and improves fusion rates from 72% to 91% 4. The use of anterior cervical plating in ACDF provides improved arm pain relief, faster return to activities of daily living, and reduced pseudarthrosis rates 6.

Critical Consideration: Osteoporosis Status

The unknown osteoporosis status requires immediate preoperative assessment:

• Bone quality directly impacts implant stability and fusion success rates
• Osteoporosis may contraindicate certain implant types or require modified surgical technique
• Preoperative DEXA scanning or CT-based bone density assessment should be obtained before finalizing the surgical plan

Spinal cord atrophy (transverse area < 45 mm²) may predict poor surgical outcome, and patients should be informed of this prognostic factor 3. Multilevel T2 hyperintensity, T1 focal hypointensity combined with T2 focal hyperintensity, and spinal cord atrophy each convey a poor prognosis 3.

Preoperative Requirements

Before proceeding, ensure the following are documented:

• Flexion-extension cervical radiographs to definitively rule out segmental instability, as static MRI cannot adequately assess this 6
• Bone density assessment given unknown osteoporosis status
• Detailed MRI review for prognostic indicators: multilevel T2 hyperintensity, T1 hypointensity with T2 hyperintensity at the same level, or cord atrophy 3
• Confirmation that clinical symptoms correlate with imaging findings at both surgical levels 4

Expected Outcomes and Realistic Expectations

Patients should be counseled on anticipated results:

• Motor function recovery occurs in 92.9% of patients, with long-term improvements maintained over 12 months 4
• Strength improvements are maintained over 12 months but may not achieve 100% return to baseline 4
• The complication rate for ACDF is approximately 5%, with good or better outcomes in 99% of patients using Odom's criteria 4
• Anterior cervical decompression demonstrates long-term improvement in motor function including wrist extension, elbow extension, and shoulder abduction 4

Common Pitfalls to Avoid

Critical considerations for surgical success:

• Avoid premature intervention: While this patient has failed conservative management, ensure adequate documentation of the duration and types of conservative therapies attempted 4
• Prevent anatomic mismatch: Confirm that symptoms correlate with cervical pathology at both proposed surgical levels, not alternative sources 4
• Minimize intraoperative tissue trauma: Achieving postoperative interbody stability and avoiding soft tissue traction helps prevent heterotopic ossification formation after disc arthroplasty 7
• Monitor for adjacent segment disease: Long-term follow-up is essential, as adjacent level degeneration can occur after both fusion and arthroplasty 2

The proposed hybrid surgery represents evidence-based treatment for this patient's multilevel cervical pathology with severe cord compression, provided preoperative bone density assessment is completed and all clinical findings correlate with the planned surgical levels.