In the last half of the 20th century, patients who needed surgery for two-level cervical disease almost certainly were treated with anterior cervical discectomy and fusion (ACDF).
The procedure no doubt served those patients well, presumably reducing pain and improving or preventing neurological problems. The tradeoff for a resolution to their neck pain was decreased range of motion. To many, this was a reasonable compromise, because there were exceedingly few alternatives. In the 21st century, patients with cervical disease have an important new option, two-level artificial disc replacement, and there is much reason to believe this will become the new standard of care.