Engineering plays a large role in all surgeries, but particularly so in spine surgery, which is the most complex, most instrumented and riskiest of all orthopedic surgeries. Prof. Dr. Bertagnoli, who was initially trained as a mechanical engineer, has played a significant role in the development of the spinal implants and the instrumentation to implant these devices. Please see some of his 36 patents and copatents. The instrumentation concept has been copied by other manufacturers and he has set the standards for the surgical procedures. Also, the patient should know that Prof. Dr. Bertagnoli is free to implant the best disc for the patient and has no agreement with any manufacturer to exclusively implant their disc.