**6. Arthroplasty 2.0**

The first generation of arthroplasty implants replicated conventional orthopedic implants with metal-on-metal articulating surfaces. These types of implants allow rotation, lateral bending, flexion and extension, and in some cases (Prestige-ST) anterolisthesis.

Implants with a polyethylene core have offered more physiologic movement and less concern over metallic deposition and blood levels. These second-generation implants like ProDisc offered a fixed core while the subsequently released Secure-C offered a sliding arthrodesis.

### **Figure 3.**

*The Zimmer Mobi-C was the first arthroplasty device to gain FDA approval in the United States for two-level indications.*

### *Cervical Arthroplasty DOI: http://dx.doi.org/10.5772/intechopen.102964*

Keel base implants like the ProDisc and Secure-C had no additional fixation hardware relaying on press-fit, bony on-growth, and keel anchoring stability. Even within the keel-based implants, the Secure-C introduced a shorter, wider keel which required even less exposure in a cranial-caudal direction.

The Nuvasive PCM disc allowed similar translation while also incorporating an arrow-shaped row of teeth as the primary fixation modality. When Mobi-C was released, the mindset was to perform as little endplate preparation as needed. Mobi-C went a step further to offer a circumferentially mobile center of rotation and obtained FDA approval as a two-level implant in 2013 (**Figure 3**).

While Mobi-C provided even more range of motion, concerns arose regarding hypermobility [38, 39] of the joint and the inability to adequately visualize the mobile core. With a mobile core, there was now a superior and inferior articulating surface to be concerned with, especially in sheer force loading.
