Solid radiographic fusion with a nonconstrained device 5 years after cervical arthroplasty

Area of Science:

• Spine surgery
• Orthopedic surgery
• Biomedical engineering

Background:

• Cervical disc arthroplasty (CDA) is an increasingly popular alternative to anterior cervical discectomy and fusion for treating cervical disc herniation.
• Spontaneous fusion after CDA is rare, with previous reports involving semiconstrained devices.

Observation:

• A 56-year-old male with C-7 radiculopathy underwent CDA using the DISCOVER Artificial Cervical Disc (non-constrained).
• At 60 months post-surgery, radiographic imaging revealed complete fusion at the C6-7 level with bridging bone and no motion.
• The patient reported significant improvement in pain and functional scores (VAS, NDI, SF-36).

Findings:

• This is the first reported case of spontaneous radiographic fusion occurring with a non-constrained cervical prosthesis.
• The fusion was an unintended radiographic outcome but did not negatively impact the patient's clinical results.

Implications:

• This finding suggests that even non-constrained cervical prostheses may lead to fusion in some patients.
• Further research is needed to understand the mechanisms and prevalence of fusion with non-constrained CDA devices.
• Excellent clinical outcomes can be achieved despite radiographic fusion following CDA.