Table 2.

International classification of disease procedure codes used to identify patients who underwent lumbar spinal fusion surgery^a

ICD-9-CM code	Description
81.05	Dorsal and dorsolumbar fusion, posterior technique
81.06	Lumbar and lumbosacral fusion, anterior technique
81.07	Lumbar and lumbosacral fusion, lateral transverse process technique
81.08	Lumbar and lumbosacral fusion, posterior technique
81.35	Refusion of dorsal and dorsolumbar spine, posterior technique
81.36	Refusion of lumbar and lumbosacral spine, anterior technique
81.37	Refusion of lumbar and lumbosacral spine, lateral transverse process technique
81.38	Refusion of lumbar and lumbosacral spine, posterior technique
81.62	Fusion or refusion of two to three vertebrae
81.63	Fusion or refusion of four to eight vertebrae
81.64	Fusion or refusion of nine or more vertebrae

Note:

^aThe following code algorithms were used: (81.62 AND [81.05 OR 81.06 OR 81.07 OR 81.08 OR 81.35 OR 81.36 OR 81.37 OR 81.38]) or ([81.62 OR 81.63 OR 81.64] AND [81.05 OR 81.07 OR 81.35 OR 81.37]).