Neurology & Pain Management Coding Alert

Question: How do facet joint injections (64470-64476) differ from epidural blocks (62280-62282)? Maryland Subscriber Answer: Facet joint injections and epidural blocks differ in several respects, but the principal differences involve the type of substance injected and the duration of the injections' effects. Codes 64470-64476, as well as the term "facet joint injection," describe two distinct but related procedures. The first type of injection, sometimes referred to as an intra-articular block, involves the injection of anesthetic and/or steroid to denervate the paravertebral facet joint (the bony surface between vertebrae). In the second procedure, the physician targets the facet joint nerve, correctly called the median branch nerve. Such injections can be therapeutic but are usually diagnostic. As a diagnostic tool, the neurologist uses the injections to document or confirm diagnoses of posterior elemental biomechanical back pain caused by structural abnormalities. The physician uses the injection to block the pain. The patient then performs the same activities that usually aggravate his or her back pain, and the physician records any effects. The absence of lower back pain after the injections suggests that the facet joint(s) is the source of the problem. Therapeutic injections provide temporary pain relief that may facilitate other types of treatment, such as physical therapy. Epidural blocks as specified by 62280-62282 describe injection of neurolytic substances. These injections are primarily therapeutic and provide pain relief by permanently destroying damaged nerves. Generally, you can distinguish these procedures simply by noting the substance the physician injects. For steroids or anesthetics, 64470-64476, as appropriate to location (such as 64470, Injection, anesthetic agent and/or steroid, paravertebral facet joint or facet joint nerve; cervical or thoracic, single level), are correct. For neurolytic substances, such as alcohol, phenol or iced saline solutions, 62280-62282 again, as appropriate to location (for example, 62280*, Injection/infusion of neurolytic substance [e.g., alcohol, phenol, iced saline solutions], with or without other therapeutic substance; subarachnoid) are the more likely choice. Note that several other code groups, specifically 62310-62311, 62318-62319 and 64479-64484, describe various types of epidural blocks, not all of which involve permanent nerve destruction (for instance, 64479, Injection, anesthetic agent and/or steroid, transforaminal epidural; cervical or thoracic, single level). The descriptors for these codes, however, are more general than those for facet joint injections and do not specifically target the paravertebral space. Note: For more information on epidural blocks, see Neurology Coding Alert, January 2002.