Billing and Coding: Piriformis Injections

This article replaces all prior instructions for billing and performing a piriformis muscle injection. Piriformis syndrome may be a common cause of back, buttock and leg pain due to injury to the piriformis muscle. This clinical syndrome is due to compression of the sciatic nerve by the piriformis muscle and may be identical in clinical presentation to low back pain (LBP) with associated LS, S1 radiculopathy due to discogenic and/or lower lumbar facet arthropathy with foraminal narrowing. Patients may also demonstrate both of these clinical entities simultaneously. This diagnostic dilemma highlights the need for patients with LBP and associated radicular pain to undergo a complete history and physical examination. Noridian Healthcare Solutions (Noridian) has noted that CPT codes 72195-72197 (Magnetic resonance (e.g., proton) imaging, pelvis) are being used for mapping purposes prior to injection of the piriformis muscle and surrounding muscle groups (i.e., gemelli and obturator intemus muscles). However, there is no clear clinical evidence that doing an MRI, CT Scan or EMG for placement of the needle into the piriformis or to inject the sciatic nerve is of more benefit than using common land marks. Coding Clarification For these reasons, the MRI CPT Codes 72195-72197 will be denied when billed in conjunction with injection of the piriformis muscle or surrounding muscle groups. Noridian has also noted that providers have been using both CPT codes 64999 (unlisted procedure nervous system) and 64445 (Injection anesthetic agent; sciatic nerve, single) for the injection of the piriformis muscle and surrounding muscle groups. This is not the correct way to code. When the clinical notes reflect direct nerve block to the sciatic nerve, 64445 should be used. When the injection focus is in the piriformis muscle or surrounding muscle groups, 20552 should be used. Per CPT Assistant December 2011, Volume 21, Issue 12 page 8; There is a significant difference in the work and procedure, as well as intent, between an injection of the piriformis muscle and the perineural injection of the sciatic nerve. The sciatic nerve injection code (64445) should not be used to report a piriformis injection. Source: CPT Assistant December 2011, Volume 21, Issue 12 page 8.