Cervical Disc Replacement - Spine

Introduction

In response to clinical concerns and complications related to fusion, ADR has been proposed as a viable alternative method of managing cervical spondylosis.
- interest in and enthusiasm for this technology has increased in recent years.
Pros and cons
- benefit
  - potential to preserve motion
  - pseudoarthrosis not a concern
  - quicker return to routine activities
- risks
  - hardware failure with potential paralysis
  - persistent neck pain from pain originating from facets
Evidence
- A number of randomized controlled trials comparing CDA with ACDF have shown better functional recovery and reduced the risk of re-operations with CDA. Long-term studies are needed.
History
- 1966: Fernström first implanted a stainless steel ball bearing in the cervical spine but reported unacceptable rates of device-related complications.
  - at that time, ACDF was gaining popularity with reports of great clinical success and therefore interest in motion preserving procedures decreased.
- 1980-90s: a renewed interest in cervical ADR resurfaced when lumbar disk arthroplasty gained in popularity use in Europe.
- 2002: first report on modern cervical ADR appeared with the premise that it would decrease or prevent adjacent segment disease by maintaining motion
- 2010 to present
  - several RCT showing superiority to cervical fusion with regard to
    - reoperation rate
    - quicker return to work

Indications

Indications
- single and double level cervical radiculopathy
- single and double level cervical myelopathy
Contraindications
- significant facet degeneration

Preoperative Imaging

Technique

Approach
- anterior approach to cervical spine
Biomechanics
- critical to align center of rotation in both coronal and saggital plane
  - especially important in two level CDA

Complications

Hardware failure
- may have catastrophic consequece in retropulsion into spinal canal