Spine conditions involve complex anatomy and a wide range of treatment options — many patients find that understanding the terminology helps them ask sharper questions and evaluate whether a proposed treatment addresses structural causes or manages symptoms. Definitions below reflect how these terms are used clinically; individual evaluation is required before any treatment decision.

Intervertebral Disc

The intervertebral disc sits between adjacent vertebrae and functions as a shock absorber for the spine. Each disc has two main components: the annulus fibrosus, a tough outer ring of layered fibrocartilage, and the nucleus pulposus, a gel-like interior that distributes compressive load. With age or injury, discs may lose hydration, height, and structural integrity — a process called disc degeneration that can contribute to pain and reduced mobility in some patients.

Herniated Disc

A herniated disc occurs when the nucleus pulposus pushes outward through a tear or weakness in the annulus fibrosus. Depending on the location and direction of the herniation, the displaced material may press on nearby nerve roots, potentially producing symptoms such as sciatica or radiculopathy in some patients. The degree of nerve involvement varies by individual anatomy and disc position. Learn more about the structural connection in our overview of non-surgical approaches to annular tear repair.

Spinal Stenosis

Spinal stenosis refers to a narrowing of the spinal canal or the openings through which nerve roots exit the spine. This narrowing may compress the spinal cord or surrounding nerves, producing symptoms that can include pain, numbness, tingling, or weakness in the legs or arms, depending on where the stenosis occurs. Symptoms tend to develop gradually and vary in severity from patient to patient. Our clinical team has outlined eight non-surgical treatments for spinal stenosis that may be appropriate for evaluated candidates.

Sciatica

Sciatica is a symptom, not a diagnosis in itself. It describes pain that radiates along the path of the sciatic nerve — typically from the lower back through the hip and down one or both legs. Sciatica may result from a herniated disc, bone spur, or other structural issue compressing the nerve, though the underlying cause differs among patients. Addressing the root structure rather than the symptom alone tends to produce more durable relief in many cases. See our post on 10 common myths about sciatica and non-surgical relief.

Radiculopathy

Radiculopathy describes symptoms that arise from compression or irritation of a nerve root as it exits the spinal column. Cervical radiculopathy affects the neck and may cause pain, weakness, or numbness that radiates into the arms and hands. Lumbar radiculopathy affects the lower back and may produce similar symptoms down the legs. The specific pattern of symptoms depends on which nerve root is involved and how severely it is compressed; individual evaluation is required to determine the appropriate course of care.

Discectomy

A discectomy is a surgical procedure in which all or part of a damaged disc is removed to relieve pressure on a nerve. While a discectomy may reduce acute nerve compression in appropriate candidates, it does not repair the annular tear that allowed the herniation to occur. The disc may remain structurally vulnerable after the procedure, and some patients experience recurrent herniation or ongoing discogenic pain over time. Candidacy and expected outcomes vary by case.

Laminectomy

A laminectomy involves removing part or all of the lamina — the bony arch on the back of a vertebra — to create more space within the spinal canal and decompress affected nerves. The procedure may relieve nerve-related symptoms in some patients with spinal stenosis or other compressive conditions, but it does not address underlying disc degeneration. Stability of the operated segment and longer-term outcomes vary among individuals.

Spinal Fusion

Spinal fusion permanently joins two or more vertebrae, eliminating motion at that segment. The goal is to reduce pain associated with instability or degenerative disc disease at the fused level. Because fusion changes the biomechanics of the entire spine, it redistributes load to adjacent segments, which may accelerate wear over time in some patients. Patients who are offered spinal fusion are encouraged to understand both the intended benefits and the structural trade-offs before proceeding. Our clinical team has identified five signs that warrant a second opinion before spinal fusion.

Failed Back Surgery Syndrome (FBSS)

Failed back surgery syndrome (FBSS) is a term used when a patient continues to experience significant pain following spinal surgery — including after procedures that were technically successful. Causes vary and may include incomplete decompression, scar tissue formation, recurrent disc herniation, adjacent segment stress, or conditions that were not the true source of pain. FBSS is more common than many patients expect, and its management typically requires a thorough reassessment of the structural issues involved. We explore causes and alternatives in detail at Failed Back Surgery Syndrome: Causes and Alternatives.

Annular Tear

An annular tear is a fissure or crack in the annulus fibrosus — the tough outer wall of the intervertebral disc. Annular tears may develop from acute injury, repetitive stress, or gradual degeneration. Because the outer annulus has limited blood supply, these tears have restricted capacity for self-repair and may become a persistent source of pain. In evaluated candidates, biologic repair options that target the annular tear directly may support healing in ways that conventional treatments do not. Read more in Annular Tears: A Root Cause of Back Pain and the Role of Annular Tear Repair.

Discogenic Pain

Discogenic pain refers to pain that originates within the disc itself rather than from nerve root compression. It may result from annular tears, disc degeneration, or internal disc disruption, and it can be difficult to diagnose because standard imaging does not always reveal the degree of internal disc damage. Patients with discogenic pain may not respond predictably to treatments designed primarily to address nerve compression, making accurate diagnosis an important step in care planning.

Epidural Steroid Injection

An epidural steroid injection delivers anti-inflammatory medication into the epidural space surrounding the spinal cord and nerve roots. The goal is to reduce inflammation and provide temporary relief from nerve-related pain. For some patients, injections offer meaningful short-term symptom reduction; however, they do not repair disc structure or address underlying annular damage. Relief duration varies among individuals, and repeated injections may have diminishing returns over time. Our clinical team compared these approaches in Epidural Steroid Injections vs. Annular Tear Repair: A Long-Term Perspective.

Adjacent Segment Disease (ASD)

Adjacent segment disease describes accelerated degeneration of the spinal segments immediately above or below a previous fusion site. Because fusion eliminates motion at one level, neighboring segments absorb increased mechanical stress, which may hasten disc and joint wear over time in some patients. ASD may develop years after an otherwise successful fusion and can become a source of new or returning symptoms. We reviewed a relevant case example in our post on adjacent segment disease and fibrin treatment.

Intra-Annular Fibrin Injection

An intra-annular fibrin injection — also called the fibrin procedure or biologic disc repair — involves introducing a fibrin sealant directly into the damaged annulus fibrosus. Fibrin is a naturally occurring protein involved in the body’s wound-healing response; when delivered into the disc, it may act as a scaffold that supports tissue repair from within. Candidates are evaluated individually based on imaging findings, symptom profile, and prior treatment history. Outcomes vary by case, and not every candidate with an annular tear will qualify.

Regenerative Medicine

Regenerative medicine is a broad field focused on harnessing or augmenting the body’s natural healing mechanisms to repair or restore damaged tissue. In the context of spine care, regenerative approaches may aim to address structural disc damage rather than managing symptoms alone. This contrasts with many conventional surgical interventions, which alter or remove spinal structures. Patient selection and clinical evaluation remain essential — the appropriateness of any regenerative approach depends on an individual’s specific diagnosis and anatomy.

Expert Take

Understanding spine terminology gives patients a meaningful advantage during consultations. When a patient can distinguish between a procedure that removes tissue and one that attempts to repair it — or between symptom management and structural treatment — they are better equipped to ask whether a proposed intervention targets the root cause of their pain. The distinction between discogenic pain and nerve-compression pain, for example, has direct implications for which interventions are relevant to a given case. Terminology is not an end in itself, but it is a practical tool for navigating a field where treatment options vary widely in scope and intent. Our clinical team encourages patients to bring these questions into their initial evaluation.

For patients building their foundational knowledge of spine conditions, our glossary of key terms in spinal surgery and its alternatives covers additional vocabulary across surgical and non-surgical contexts. Our disc conditions glossary for patients provides a focused reference for understanding the range of disc-related diagnoses and how they differ. We also explore how biologic disc repair compares to traditional spine surgery for patients weighing their options.

"