The MOVE-C Cervical Artificial Disc - Design, Materials, Mechanical Safety.

Area of Science:

• Biomaterials Science
• Orthopedic Biomechanics
• Spinal Surgery Devices

Background:

• Cervical disc prostheses are vital for treating degenerative disc disease.
• Existing designs include ball-and-socket or flexible core types, with articulating surfaces often being metal-on-metal or metal-on-UHMWPE, lacking axial damping.
• The MOVE-C prosthesis integrates an articulating surface with a flexible core to address these limitations.

Purpose of the Study:

• To evaluate the mechanical safety and performance of the novel MOVE-C cervical disc prosthesis.
• To provide crucial data on the implant's ability to combine articulating surfaces with a flexible core.

Main Methods:

• The MOVE-C prosthesis features TiAl6V4 cranial and caudal plates, with the cranial plate TiNbN coated and the caudal plate containing a polycarbonate-urethane (PCU) core.
• Mechanical safety was assessed using standard (ISO 18192-1, ASTM F2364) and non-standard tests, focusing on wear and creep.
• Wear rate and creep-relaxation behavior were specifically analyzed to understand implant performance.

Main Results:

• The PCU wear rate was measured at a maximum of 1.54 mg per million cycles, falling within the reported range for UHMWPE in other cervical prostheses.
• Creep-relaxation tests indicated physiological behavior, showing some deformation but no structural failure.
• These results demonstrate the mechanical integrity and acceptable wear characteristics of the MOVE-C design.

Conclusions:

• The MOVE-C cervical disc prosthesis exhibits mechanical safety comparable to existing devices on the market.
• The use of PCU, with potentially less bioactive wear particles than cross-linked UHMWPE, may lead to reduced wear-related in vivo failures.
• Further clinical studies are necessary to confirm these potential long-term benefits and in vivo performance.