Difficulty scores estimated by the Rasch analysis.
| Procedure | Description | Difficulty Score |
| Transforaminal lumbar interbody fusion | Transforaminal lumbar interbody fusion; 1 interspace (CPT Code 22630)—with posterior nonsegmental instrumentation (CPT Code 22840)—with insertion of interbody device (CPT Code 22853)—with placement of spine autograft (CPT Codes 20936) | –0.385 |
| Posterior/posterolateral arthrodesis 1 levela | Posterior/posterolateral arthrodesis; lumbar; 1 interspace (CPT Code 22612)—with placement of posterior nonsegmental instrumentation (CPT Code 22840)—with placement of spine autograft (CPT Code 20937) | –1.266 |
| Posterior arthrodesis for spinal deformity up to 6 vertebral segments | Posterior arthrodesis for spinal deformity up to 6 vertebral segments (CPT Code 22800)—with posterior segmental instrumentation (CPT Code 22842)—with placement of spine autograft (CPT Code 20937) | 0.128 |
| Posterior arthrodesis for spinal deformity 7–12 vertebral segments | Posterior arthrodesis for spinal deformity 7–12 vertebral segments (CPT Code 22802)—with posterior segmental instrumentation (CPT Code 22843)—with spine autograft (CPT Code 20937) | 1.099 |
| Posterior osteotomy | Posterior osteotomy of the lumbar spine (CPT Code 22214)—with laminectomy and spinal cord decompression, lumbar (CPT Code 63047)—with placement of posterior nonsegmental instrumentation (CPT Code 22840) | –0.385 |
| Laminectomy | Laminectomy and spinal cord decompression, lumbar (CPT Code 63047) | –1.266 |
| Interlaminar stabilization device without fusion | Insertion of interlaminar stabilization device without fusion, with open decompression, lumbar, single level (CPT Code 22867) | –1.099 |
| Posterior/posterolateral arthrodesis 2 levelsb | Posterolateral arthrodesis; lumbar; 1 interspace (CPT Code 22612) with posterolateral arthrodesis; lumbar, additional interspace (CPT Code 22614)—with posterior segmental instrumentation (CPT Code 22842)—with placement of spine autograft (CPT Code 20937) | –0.653 |
| Posterior vertebral joint arthroplasty | Posterior vertebral joint(s) arthroplasty (eg, facet joint[s] replacement), including facetectomy, laminectomy, foraminotomy, and vertebral column fixation, injection of bone cement, when performed, including fluoroscopy, single level, lumbar spine (CPT Code 0202T) | 0c |
↵a Stabilizing/fusing 2 vertebrae to stop the motion at 1 segment or interspace. For example, a L4-L5 fusion is a 1-level spinal fusion.
↵b Stabilizing/fusing 3 vertebrae to stop the motion at 2 segments or interspaces. For example, a L3-L5 fusion is a 2-level spinal fusion.
↵c Assigned for comparative purposes.