Spine Condition Library

Atlantoaxial instability (AAI) refers to abnormal, excessive movement at the joint between the first and second cervical vertebrae (C1 atlas and C2 axis).

Cervical disc herniation occurs when the nucleus pulposus — the soft inner material of a cervical intervertebral disc — herniates through the outer annular ring and compresses one or more cervical nerve roots.

Cervical dystonia, also called spasmodic torticollis, is a painful neurological movement disorder in which the neck muscles contract involuntarily, forcing the head into abnormal postures.

Cervical myelopathy is a condition in which the spinal cord is compressed in the neck (cervical spine), disrupting nerve signals between the brain and the rest of the body.

A pinched nerve in the neck — medically known as cervical radiculopathy — occurs when a nerve root in the cervical spine becomes compressed or irritated.

A cervical rib is a supernumerary (extra) rib arising from the seventh cervical vertebra rather than the thoracic spine.

Cervical spinal stenosis is a narrowing of the spinal canal in the neck (cervical spine).

Cervical spinal stenosis is a narrowing of the spinal canal in the neck (cervical spine) that can compress the spinal cord and nerve roots.

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction in adults over 50.

Cervicogenic headache (CGH) is a form of secondary headache caused by pathology in the cervical spine — most commonly from the upper cervical joints (C2–C3) or muscles.

Klippel-Feil syndrome (KFS) is a congenital musculoskeletal disorder defined by the fusion of two or more cervical vertebrae.

Myelopathy — also called spinal cord compression — occurs when the spinal cord itself is squeezed by a narrowed spinal canal, a herniated disc, bone spurs, or other structural changes.

Neck pain — pain felt anywhere from the base of the skull to the top of the shoulders — is one of the most prevalent musculoskeletal conditions.

Os odontoideum is a condition in which the odontoid process (dens) of the second cervical vertebra (C2) exists as a separate rounded ossicle rather than being fused to the C2 body.

Whiplash — medically termed cervical acceleration-deceleration (CAD) injury — occurs when the head is thrown backward and then forward rapidly, straining cervical spine structures beyond their normal range.

Baastrup's disease, also called "kissing spine" syndrome, is a condition in which adjacent lumbar spinous processes make contact during lumbar extension, leading to friction, bursitis, and pain at the interspinous space.

Bertolotti syndrome is the clinical condition of low back pain arising specifically from the anomalous articulation formed between an enlarged transverse process of a lumbosacral transitional vertebra (LSTV) and the sacrum or iliac crest.

Cauda equina syndrome (CES) is a rare but surgical emergency caused by compression of the cauda equina — the bundle of nerve roots below the end of the spinal cord at L1.

Back pain is the leading cause of disability worldwide, affecting approximately 80% of people at some point in their lives.

Despite its name, degenerative disc disease is not a disease in the traditional sense — it is a natural process where intervertebral discs break down with age, losing height and hydration.

Degenerative spondylolisthesis (DS) is forward displacement of one vertebra over the one below resulting from age-related degeneration of the intervertebral disc and facet joints — without a pars interarticularis fracture.

A disc bulge (disc protrusion) occurs when the outer wall of an intervertebral disc weakens and extends beyond the normal disc margin — but unlike a herniation, the nucleus pulposus (inner gel) has not broken through the annulus fibrosus.

Failed back surgery syndrome (FBSS) — also called post-laminectomy syndrome — refers to chronic back or leg pain that persists or recurs after one or more spinal surgeries.

A far lateral disc herniation, also called an extraforaminal or foraminal disc herniation, is a herniation that occurs at or outside the lateral boundary of the intervertebral foramen rather than in the central or paracentral canal.

Neural foraminal stenosis occurs when the foramina — the small openings on either side of each vertebra through which spinal nerve roots exit the spinal canal — become narrowed.

A herniated disc — also called a slipped or ruptured disc — occurs when the soft inner gel of an intervertebral disc pushes through a crack in its tougher outer layer.

Isthmic spondylolisthesis is forward slippage of one vertebra over the one below, caused by a defect (fracture or elongation) of the pars interarticularis — the narrow bridge of bone connecting the superior and inferior articular processes.

Lateral recess stenosis is a specific subtype of spinal stenosis in which the lateral recess — the tunnel-shaped corridor through which the nerve root travels before exiting the intervertebral foramen — becomes narrowed.

Lumbar facet syndrome refers to pain originating from the small synovial joints (facet joints or zygapophyseal joints) that connect adjacent vertebrae in the lower back.

Lumbar radiculopathy occurs when a nerve root in the lower spine becomes compressed or irritated, sending pain, numbness, or tingling down the leg — a pattern commonly called sciatica.

Lumbar segmental instability occurs when one or more vertebral segments of the lumbar spine move beyond their normal physiological range under routine loads.

Lumbar spinal stenosis is a narrowing of the spinal canal in the lower back that puts pressure on the spinal cord and nerve roots.

Lumbar spondylolysis is a stress fracture or structural defect of the pars interarticularis — the narrow isthmus of bone in the posterior neural arch connecting the superior and inferior articular processes.

A lumbar synovial cyst is a fluid-filled sac that develops from the synovial lining of a degenerated facet joint in the lumbar spine.

A lumbosacral transitional vertebra (LSTV) is a congenital spinal variant in which the lowest lumbar vertebra takes on sacral characteristics (sacralization of L5) or the uppermost sacral segment retains lumbar characteristics (lumbarization of S1), creating a fourth or sixth lumbar-type vertebra.

Modic changes are characteristic MRI signal abnormalities in the vertebral body endplates adjacent to a degenerated intervertebral disc, first described and classified by Michael Modic in 1988.

Multilevel degenerative disc disease (DDD) is a condition in which two or more intervertebral discs undergo degeneration simultaneously, causing disc height loss, internal disc disruption, and often associated facet joint changes at each affected level.

Retrolisthesis is a backward (posterior) displacement of one vertebral body relative to the vertebra directly below it.

Sciatica is a symptom rather than a diagnosis — it refers to pain that radiates along the path of the sciatic nerve, from the lower back through the hip and down one leg.

Spondylolisthesis occurs when one vertebra slides forward (or less commonly backward) over the one below it.

A vertebral compression fracture (VCF) occurs when a vertebral body — one of the bony building blocks of the spine — collapses or cracks.