Table 3.

Difficulty Scores Estimated by the Rasch Analysis.

CPT® Code	Description	Difficulty Score
22015	Incision and drainage, open, of deep abscess (subfascial), posterior spine; lumbar, sacral, or lumbosacral	-1.55808
22554	Arthrodesis, anterior interbody technique, including minimal discectomy to prepare interspace (other than for decompression); cervical below C2	0.00000
27280	Arthrodesis, sacroiliac joint (including obtaining graft), open	0.65616
62287	Decompression procedure, percutaneous, of nucleus pulposus of intervertebral disc, any method utilizing needle based technique to remove disc material under fluoroscopic imaging or other form of indirect visualization, with the use of an endoscope, with discography and/or epidural injection(s) at the treated level(s), when performed, single or multiple levels, lumbar	-1.55808
62292	Incision and drainage, open, of deep abscess (subfascial), posterior spine; lumbar, sacral, or lumbosacral	-1.94415
63030	Laminotomy (hemilaminectomy), with decompression of nerve root(s), including partial facetectomy, foraminotomy and/or excision of herniated intervertebral disc; 1 interspace, lumbar	-1.19898
63620	Stereotactic radiosurgery (particle beam, gamma ray, or linear accelerator), 1 spinal lesion	-0.69098
63655	Laminectomy for implantation of neurostimulator electrodes, plate/paddle, epidural	-0.44980
63662	Removal of spinal neurostimulator electrode plate/pad-dle(s) placed via laminotomy or laminectomy, including fluoroscopy, when performed	-1.23454
63663	Revision including replacement, when performed, of spinal neurostimulator electrode percutaneous array(s), including fluoroscopy, when performed	-0.90799
27279	Sacroiliac joint stabilization for arthrodesis, percutaneous or minimally invasive (indirect visualization), with image guidance including bone graft when performed, and placement of transfixing device (short descriptor: Arthrodesis, sacroiliac joint)	0.0000*

^*Assigned for comparative purposes.