Background and Need for Innovation

Cervical total disc replacement (TDR) aims to address degenerative disc disease in the neck by replacing the damaged disc with an artificial one while preserving motion at the treated level. Traditional designs, often employing metal-on-metal or metal-on-plastic ball-and-socket articulations, have demonstrated effectiveness in maintaining motion and reducing the need for secondary surgeries compared to anterior cervical discectomy and fusion (ACDF). However, these articulated devices lack the shock-absorbing viscoelastic properties of a healthy disc and may lead to excessive stress on adjacent spinal structures, potentially resulting in facet degeneration and device-related complications.

Viscoelastic One-Piece Implant: The Freedom® Cervical Disc

A new approach using a one-piece viscoelastic cervical disc, the Freedom® Cervical Disc (FCD), was clinically evaluated in a two-year European post-market study. The FCD is designed to mimic the natural biomechanics of the cervical spine by offering viscoelasticity (shock absorption), six degrees of motion, and stable yet flexible load-sharing between vertebrae. This one-piece design consists of a bonded elastomeric core and titanium endplates, implanted via an anterior cervical approach.

Study Methods

Thirty-nine patients with single or two-level degenerative disc disease at C3–C7 levels participated in the study, conducted at five European surgical centers. All participants had failed conservative management and underwent implantation of the FCD. Clinical outcomes were measured by improvement in neck disability index (NDI), visual analog scale (VAS) pain scores (neck and arm), neurological function (sensory, motor, reflex), complications, and patient satisfaction over a two-year follow-up.

Clinical Outcomes

• Significant improvements in all outcome measures were observed within six weeks, and these benefits continued through 24 months.

• Mean NDI scores improved from 48% preoperatively to just 4% at two years, reflecting dramatically reduced disability.

• VAS pain scores for neck, left arm, and right arm dropped substantially; neck pain intensity, for example, declined from 63 mm preoperatively to 15 mm at two years.

• Neurological deficits were reduced notably: preoperative sensory, reflex, and motor deficits were present in 62%, 21%, and 38% of patients respectively, improving to 17%, 6%, and 3% at two years.

• Patient satisfaction was high, with 83% stating they would “definitely” choose the same treatment again and another 11% saying they would “probably” opt for it.

Safety and Surgical Details

There were no device-related adverse events or implant removals during the study. Most procedures were completed in about 90 minutes with minimal blood loss, and patients typically stayed in the hospital for five days. The majority of surgeries were single-level implantations at the C5–C6 and C6–C7 segments.

Discussion and Future Considerations

The FCD’s viscoelastic one-piece design is unique among cervical TDRs and aims to better replicate the natural function of the disc. Initial results demonstrate that the device provides excellent pain relief, restores function, and improves neurological status with very high patient satisfaction over two years. The FCD compares favorably with both other TDRs and fusion techniques based on outcome measurements like NDI and VAS.

However, the authors stress the need for longer-term studies to confirm whether this implant truly optimizes spinal biomechanics and reduces adjacent segment degeneration over time.

Conclusion

The one-piece viscoelastic Freedom® Cervical Disc demonstrates strong clinical outcomes with sustained pain reduction, improved function, and high patient satisfaction at two years post-surgery. This study suggests that viscoelastic TDRs may offer promising advantages in the management of degenerative cervical disc disease, but ongoing research and extended follow-up are necessary to validate these results over the long term.

Access Full Research Here: https://www.kicventures.com/_files/ugd/bd3076_a68be4db70144fdfa1e258de20c8767c.pdf