M6-C Overview

The M6 artificial cervical disc offers an innovative option for artificial cervical disc replacement because of its unique design which is based on a natural disc’s qualities.

Engineered to replicate your own disc, the M6 is the only artificial disc that incorporates an artificial nucleus (made from polycarbonate urethane) and a woven fiber annulus (made from polyethylene). The M6 artificial nucleus and annulus are designed to provide the same motion characteristics of a natural disc.

Together, the M6’s artificial nucleus and annulus provide compressive capabilities along with a controlled range of natural motion in all 6 degrees of freedom along each vertebra. This “natural” motion is designed to provide the freedom to move your neck naturally.

The M6 has two titanium outer plates with keels for anchoring the disc into the bone of the vertebral body. These outer plates are coated with a titanium plasma spray that promotes bone growth into the metal plates, providing long term fixation and stability of the disc in the bone.

Artificial Disc Components

Artificial Nucleus

  • Viscoelastic polymer designed to simulate native nucleus
  • Allows physiologic axial compression
  • Retained between endplates & fiber annulus matrix
  • Designed to enable physiologic Center Of Rotation
Artificial Annulus

  • Ultra High Molecular Polyethylene (UHWMPE) fiber material
  • Intended to simulate native annulus & its performance
  • Designed to provide controlled physiologic motion in all planes and axes
  • Robust fiber matrix with multiple layers similar to native annulus
Sheath

  • Designed to minimize tissue in-growth & debris migration
  • Allows for full range of motion
Fixation

  • Titanium endplates with tri-keel design
  • Titanium Plasma Spray (TPS) coated endplate
  • Low profile keel height (2mm)

Quality of Motion

Quality of Motion assesses how well the motion of an implanted functional spine unit approximates the motion of a healthy one over the entire range of motion, not just its endpoints. Through biomechanical testing, a load vs. angular displacement curve (“kinematic signature”) is generated that allows assessment of the Quality of Motion parameters.

Biomechanical testing with the M6-L artificial lumbar disc has demonstrated equivalent Quality of Motion compared to the healthy disc. The innovative artificial fiber annulus and nucleus construct of the M6-L is the critical component in replicating this physiologic motion, as it is designed to provide the necessary restraint and control needed throughout the spine’s natural range of motion.

C5-C6 Flexion-Extension Load-Displacement Curves

Biomechanical results showing the M6 cervical disc (orange) maintained total ROM (13.5) vs. the intact disc (13.3) with excellent Quality of Motion. The “kinematic signatures” of the intact disc (grey) and M6 cervical disc are nearly identical.

Patwardhan et al. Musculoskeletal Biomechanics Laboratory, Edward Hines Jr. VA Hospital, Hines, Illinois, USA

* This behavior is expected based on a limited cadaver study on the bench, not in-vivo results.