A Comparison Study of Four Cervical Disk Arthroplasty Devices Using Finite Element Models

Area of Science:

• Biomechanical engineering
• Spinal surgery
• Medical device analysis

Background:

• Limited comparative studies exist for different artificial cervical disc designs.
• Understanding device-specific biomechanical effects is crucial for optimizing cervical disc arthroplasty (CDA).

Purpose of the Study:

• To compare the biomechanical behavior of four artificial cervical discs (Secure-C, Mobi-C, Prestige LP, Prodisc C).
• To evaluate external (range of motion) and internal (facet force, intradiscal pressure) responses after CDA.
• To determine the influence of device design on cervical spine biomechanics.

Main Methods:

• Utilized validated C2-T1 finite element models to simulate CDAs at C5-C6.
• Compared four specific prosthetic discs: Secure-C, Mobi-C, Prestige LP, and Prodisc C.
• Applied a hybrid loading protocol to assess sagittal moments, index/adjacent level motion, facet forces, and intradiscal pressures.

Main Results:

• All tested artificial discs restored motion at the index level.
• Mobi-C and Secure-C demonstrated higher flexion and extension, respectively.
• Facet forces increased at the index level and decreased at adjacent levels.
• Prestige LP increased intradiscal pressure at adjacent levels, while others decreased it.

Conclusions:

• Secure-C and Mobi-C's translational capabilities may reduce adjacent segment pressures, potentially mitigating degenerative changes.
• Consideration of facet joint integrity is important for selecting artificial cervical discs.
• Device design significantly impacts biomechanical outcomes following cervical disc arthroplasty.