**3. Clinical summary**

Worldwide clinical usage of both devices is ongoing. Currently, there have been no reported adverse events due to a material failure, such as device breakage, fatigue failure or an aggressive host immune response leading to a revision surgery to remove the device. Clinical results as measured by validated measures such as Oswestry Disability Index (ODI) and Visual Analog Scale (VAS), along with patient satisfaction, suggest that both devices can relieve the symptoms of their respective degenerative processes (Figures 9, 10). From a biomaterial perspective, no adverse events have occurred as a direct result of these devices not performing as expected. Based upon worldwide clinical success, and the success of a US pilot IDE study, the nucleus replacement device was granted approval by FDA to start a first of its kind IDE pivotal study in the US.

Fig. 9. ODI and VAS scores from the worldwide usage of the cervical arthroplasty device.

chronic inflammatory reaction, with evidence of fibrous connective replacement and infiltration of mononuclear cells. These observations were considered secondary to the surgical procedure and, importantly, occurred at both the control and experimental operative levels. There was no evidence of cellular apoptosis, giant cell reaction or other significant pathological changes. Analysis of the immunohistochemical antibody stains for the local tissues overlying the experimental and control levels were negative in each case. In the histological analyses, there was no detectable wear debris from the device and no evidence of an osteolytic response. There was no evidence of a pro-inflammatory cytokine

Worldwide clinical usage of both devices is ongoing. Currently, there have been no reported adverse events due to a material failure, such as device breakage, fatigue failure or an aggressive host immune response leading to a revision surgery to remove the device. Clinical results as measured by validated measures such as Oswestry Disability Index (ODI) and Visual Analog Scale (VAS), along with patient satisfaction, suggest that both devices can relieve the symptoms of their respective degenerative processes (Figures 9, 10). From a biomaterial perspective, no adverse events have occurred as a direct result of these devices not performing as expected. Based upon worldwide clinical success, and the success of a US pilot IDE study, the nucleus replacement device was granted approval by FDA to start a

Fig. 9. ODI and VAS scores from the worldwide usage of the cervical arthroplasty device.

reaction at any of the experimental or control levels.

first of its kind IDE pivotal study in the US.

**3. Clinical summary** 

Fig. 10. ODI and VAS scores from the US IDE pilot study for the nucleus replacement device.
