Understanding spine-related medical terminology may help patients make more informed decisions about their care. The terms below cover common diagnostic concepts, structural anatomy, and treatment approaches used in pain management. Because spine conditions vary considerably from person to person, any specific diagnosis or treatment pathway should be discussed with a qualified clinician who can evaluate your individual case.

Annular Tear

An annular tear is a rip or fissure in the annulus fibrosus — the tough outer ring of a spinal disc. These tears are a frequent source of discogenic pain because they can allow inflammatory chemicals from the disc’s nucleus to leak out and irritate surrounding nerves. Unlike many other tissues, spinal discs have a limited blood supply, which often makes natural healing difficult. Identifying an annular tear — typically through advanced imaging or an annulargram — is an important step in understanding the root cause of chronic back pain and in determining appropriate treatment options, including regenerative approaches designed to repair this damage.

Expert Take

Annular tears are often missed on standard MRI because they may not produce obvious structural changes. A detailed clinical evaluation and, in some cases, a provocation discogram (annulargram) may be needed to confirm whether a tear is the pain generator — especially when conservative care has not provided adequate relief.

Degenerative Disc Disease (DDD)

Degenerative Disc Disease (DDD) describes the gradual breakdown of one or more spinal discs over time. Despite its name, it is not a true “disease” but rather an age-related process that can contribute to chronic pain in some individuals. Changes associated with DDD include loss of disc height, reduced hydration, and the development of tears in the disc’s outer layers. Many people with imaging evidence of DDD experience no symptoms at all, while others may notice back or neck pain, numbness, or weakness. Pain management strategies for DDD often focus on restoring disc health and function rather than simply masking symptoms. Learn more about spinal fusion alternatives for degenerative disc disease.

Herniated Disc

A herniated disc occurs when the nucleus pulposus — the gel-like center of a spinal disc — pushes through a tear in the outer annulus fibrosus and extends beyond the disc’s normal boundary. This displaced disc material can compress nearby spinal nerves, producing symptoms such as sharp pain, numbness, tingling, or weakness that radiates into the arms or legs (radiculopathy or sciatica). Treatment may focus on relieving nerve compression and, where appropriate, repairing the disc to reduce the likelihood of recurrence. Outcomes vary depending on the location, severity, and individual patient factors. See how herniated and bulging discs differ and what that means for treatment.

Bulging Disc

A bulging disc extends beyond its normal perimeter while the outer annulus fibrosus remains intact, containing the nucleus pulposus within. Unlike a herniated disc — where material has broken through the outer wall — a bulging disc represents an outward protrusion without full rupture. Although often asymptomatic, a bulging disc can cause pain by pressing on spinal nerves or the spinal cord, or by placing abnormal stress on surrounding structures. It is a common finding on MRI scans and a frequent contributor to localized back pain; however, imaging findings must always be correlated with a patient’s symptoms and clinical presentation.

Sciatica

Sciatica describes pain that radiates along the path of the sciatic nerve, which extends from the lower back through the hips and buttocks and down each leg. This pain pattern is typically felt on one side of the body and can range from a mild ache to a sharp, burning, or intense discomfort. Sciatica is not a stand-alone diagnosis but a symptom — most often caused by compression or irritation of lumbar nerve roots due to a herniated disc, bone spur, or spinal stenosis. Effective management requires identifying and addressing the underlying cause. Explore common myths about sciatica and non-surgical relief options.

Radiculopathy

Radiculopathy describes symptoms that arise when a spinal nerve root is compressed or irritated, including pain, numbness, tingling, or weakness that travels along that nerve’s pathway. Cervical radiculopathy affects the neck and arms; lumbar radiculopathy affects the lower back and legs. Common causes include herniated discs, bone spurs (osteophytes), spinal stenosis, and thickened ligaments. Pinpointing the specific nerve root involved — and its underlying cause — is essential for targeted treatment planning, which in some patients may include injections or regenerative therapies aimed at relieving pressure and supporting healing.

Expert Take

Radiculopathy and discogenic pain are sometimes confused because both can produce lower back or neck discomfort. The key distinction is the radiation pattern: radiculopathy follows a predictable nerve pathway, while discogenic pain typically stays closer to the spine. Accurate differentiation guides more effective, individualized treatment.

Discogenic Pain

Discogenic pain originates directly from a damaged or degenerated intervertebral disc, rather than from nerve compression or other spinal structures. This pain is typically felt deep within the back and may worsen with activities that increase intradiscal pressure, such as prolonged sitting, bending, or lifting. Unlike radicular pain, discogenic pain usually stays localized near the spine, although it can sometimes refer to the buttocks or thighs. A precise diagnosis — often confirmed with a provocation discogram (annulargram) — is considered important for guiding effective treatment. Read more about how damaged discs contribute to chronic back pain.

Spinal Stenosis

Spinal stenosis is a narrowing of the spinal canal — the bony channel that houses the spinal cord and nerve roots. This narrowing can develop in the cervical (neck), thoracic (mid-back), or lumbar (lower back) regions and is often linked to age-related changes such as bulging discs, bone spurs, thickened ligaments, or osteoarthritis. Reduced space within the canal can compress nerves, producing pain, numbness, tingling, or weakness — particularly when standing or walking (neurogenic claudication). Treatment strategies aim to alleviate nerve compression and improve functional mobility; approaches are selected based on each patient’s specific anatomy and symptom profile. See 10 common symptoms of spinal stenosis and non-surgical treatment options.

Failed Back Surgery Syndrome (FBSS)

Failed Back Surgery Syndrome (FBSS) is a term used when chronic pain persists or returns after one or more spine surgeries. Patients with FBSS may continue to experience significant discomfort — sometimes with new or worsened symptoms — despite having undergone an operation. Potential contributing factors include inadequate pre-surgical diagnosis, incomplete nerve decompression, scar tissue formation, or new problems developing at adjacent spinal segments. For patients in this situation, care teams often explore advanced non-surgical and regenerative options that may not have been previously evaluated. Learn how biologic disc repair may be considered after failed back surgery.

Annulus Fibrosus

The annulus fibrosus is the robust, multi-layered outer ring of each intervertebral disc. Composed of approximately 17 concentric layers of dense collagen fibers, it encases and protects the gel-like nucleus pulposus at the disc’s center. This structure is essential for absorbing spinal loads and allowing flexible movement. Tears in the annulus fibrosus — commonly called annular tears — are considered a primary source of chronic back pain, as they can allow inflammatory substances to escape and irritate nearby nerves. Evaluating the structural integrity of the annulus fibrosus is a key part of diagnosing and planning treatment for disc-related pain.

Intervertebral Disc

An intervertebral disc is a cushion-like structure located between adjacent vertebrae in the spinal column. These discs serve as shock absorbers, distributing pressure evenly across the spine and enabling flexible movement. Each disc has two main components: the tough, fibrous outer ring (annulus fibrosus) and the soft, gel-like inner core (nucleus pulposus). Disc degeneration or injury — such as tears or herniations — is one of the most common structural causes of chronic back and neck pain. Understanding how the disc works helps patients grasp why targeted, disc-focused therapies may be recommended in certain cases.

Annulargram (Discogram / Discography)

An annulargram — also called a discogram or discography — is a specialized diagnostic procedure used to identify annular tears and to determine whether a specific disc is the source of a patient’s pain. During the procedure, contrast dye is injected directly into the suspected disc under fluoroscopic (real-time X-ray) guidance. The dye fills any tears in the annulus fibrosus, making them visible. Crucially, if the injection reproduces the patient’s characteristic pain, it helps confirm that disc as the pain generator — a finding that can guide targeted, individualized treatment planning.

Expert Take

A well-performed annulargram, interpreted alongside a patient’s symptom history and imaging, can meaningfully change the treatment direction. In cases where standard MRI has not identified a clear pain source, this provocation study may reveal clinically significant annular disruption that would otherwise remain untreated.

Intradiscal Injection

An intradiscal injection refers to any procedure in which a substance is delivered directly into the nucleus pulposus or annulus fibrosus of an intervertebral disc. This approach allows highly targeted delivery of diagnostic agents or therapeutic compounds to the site of pathology. Some intradiscal injections are diagnostic in nature — such as an annulargram used to identify tears and confirm a pain source. Others are therapeutic, such as intra-annular fibrin injection, in which fibrin is introduced to seal annular tears and support the disc’s healing environment. The precise delivery method is central to both accurate diagnosis and effective regenerative care.

Epidural Steroid Injection

An epidural steroid injection is a common pain management procedure in which a corticosteroid — often combined with a local anesthetic — is delivered into the epidural space surrounding the spinal cord and nerve roots. This approach may provide temporary reduction in inflammation and pain, particularly in cases involving nerve compression from a herniated disc or spinal stenosis. However, epidural steroid injections do not address the underlying structural damage to the disc itself. They are frequently used as part of a broader pain management strategy while longer-term options are being evaluated. Read more about how epidural steroid injections compare with annular tear repair over the long term.

Fibrin

Fibrin is a naturally occurring protein involved in the body’s healing and clotting processes. When tissue is injured, fibrin forms a mesh-like scaffold that helps stop bleeding and provides a structural framework for new tissue growth. In the context of regenerative spine care, fibrin is used in biologic disc repair for annular tears because of its adhesive and reparative properties. When introduced into an annular tear, fibrin may act as a biologic seal and scaffold, supporting the disc’s own healing mechanisms. Individual responses to this treatment vary, and candidacy is evaluated on a case-by-case basis.

For a broader overview of spine-related terminology, we recommend exploring our companion resource: Glossary of Key Terms in Spine Anatomy and Disc Condition Terminology. For rehabilitation and recovery terminology, see our Glossary of Pain Management and Rehabilitation Terms.