A disc replacement in the lumbar spine is no small matter. These replacements have two problems. One is longevity. We really do not know how long a well functioning lumbar disc replacement will last. At your age of 18, this disc has to last at least 70 years which is asking a lot from a metal/plastic bearing surface. More likely than not, this disc will eventually wear out and fixing a worn lumbar artificial disc is the reason I do not replace lumbar discs with artificial ones.
The other problem is the function of the artificial disc in the first place. The placement requires an anterior approach to the spine with its own set of potential complications. If the disc malfunctions, the surgical options are limited.
I do not know your disorder but I for one would not be the surgeon you would want to see as I do not look favorably on lumbar artificial discs (cervical artificial discs are another story). See the section on the website regarding lumbar artificial discs.