P42. Facet fluid is indicative of cervical degenerative spondylolisthesis. - Heard, Jeremy C.; Lee, Yunsoo; Lambrechts, Mark; Wiafe, Bright M.; Kern, Nate; Goodman, Perry; Canseco, Jose; Hilibrand, Alan; Vaccaro, Alexander; Kepler, Christopher; Schroeder, Gregory (Spine Journal, 2023)