OR6.1 | Degenerative Spine Disorders — Glossary

The concentric fibrocartilaginous rings surrounding the nucleus pulposus; composed of type I and II collagen lamellae oriented at alternating angles. Radial tears in the annulus allow nuclear material to herniate in prolapsed disc disease.

A surgical procedure for cervical disc disease in which the disc and posterior osteophytes are removed through an anterior (pre-tracheal) approach, the nerve root or cord is decompressed, and the intervertebral space is fused with a bone graft or cage and anterior plate; the most commonly performed cervical spine procedure.

Enhancement of the SLR response: at the angle of pain, the examiner passively dorsiflexes the foot, which increases tension on the sciatic nerve and intensifies the radicular pain; a positive Bragard's sign increases specificity of the SLR for disc herniation.

A surgical emergency caused by compression of the cauda equina (L2-S5 nerve roots) in the lumbar canal, producing saddle anaesthesia, bladder/bowel dysfunction, and bilateral lower-limb deficits; requires emergency MRI and surgical decompression within 24-48 hours.

Dysfunction of the cervical spinal cord caused by central canal stenosis (from disc herniation, osteophytes, or OPLL), producing upper motor neurone signs below the level of compression, spastic gait, hand clumsiness, and bladder urgency; a surgical condition.

Dysfunction of a cervical nerve root caused by compression from a herniated disc or foraminal osteophyte, producing dermatomal arm pain, paraesthesiae, and myotomal weakness in the distribution of the affected root.

Age-related degenerative change in the cervical spine including intervertebral disc degeneration, disc space narrowing, osteophyte (spur) formation, and facet joint arthritis; a leading cause of neck pain, cervical radiculopathy, and cervical myelopathy in adults.

Injection of corticosteroid (e.g. methylprednisolone) into the epidural space via transforaminal or interlaminar route, targeting the inflamed nerve root; used as a bridge in acute radiculopathy to reduce pain and allow physiotherapy while awaiting natural disc resorption.

Inability to extend the great toe against resistance, the myotomal marker of L5 nerve root compromise; its presence alongside dorsiflexion weakness and lateral calf sensory loss localises lumbar disc herniation to the L4/L5 level compressing the L5 root.

An upper motor neurone sign in the upper limb: flicking the distal phalanx of the middle finger downward causes reflex flexion of the thumb and index finger, indicating hyperreflexia due to corticospinal tract dysfunction; associated with cervical myelopathy.

An electric-shock or tingling sensation that radiates down the spine and into the limbs on neck flexion; indicates cervical cord involvement (demyelination or mechanical compression) and is a clinical marker of cervical myelopathy.

Narrowing of the lumbar spinal canal or lateral recesses caused by hypertrophied ligamentum flavum, facet osteophytes, or disc bulge; produces neurogenic claudication in middle-aged and elderly patients; managed by decompressive laminectomy when conservative treatment fails.

Age-related degenerative disease of the lumbar spine producing disc space narrowing, osteophytes, facet hypertrophy, and ligamentum flavum hypertrophy; when canal stenosis results, the clinical syndrome of neurogenic claudication may develop.

Minimally invasive surgical removal of a herniated lumbar disc fragment via a small posterior or posterolateral approach under microscope magnification; the definitive treatment for lumbar PID with persistent radiculopathy failing conservative management, with an 85-90% success rate for sciatica relief.

Bilateral buttock and leg pain precipitated by walking or prolonged standing and relieved by sitting or lumbar flexion; caused by dynamic compression of the cauda equina or lumbar nerve roots in lumbar spinal stenosis, distinguished from vascular claudication by its postural relief.

The central gelatinous core of the intervertebral disc, composed of a proteoglycan-rich hydrated gel (approximately 80% water in youth) that distributes compressive loads across the disc. Degeneration leads to desiccation and progressive height loss.

Tuberculous infection of the spine — the most common form of skeletal tuberculosis — characterised by indolent onset, predilection for the lower thoracic/thoracolumbar junction, anterior vertebral body destruction, cold abscess formation, and kyphotic deformity (gibbus); distinguished from pyogenic discitis by its subacute/chronic tempo.

Herniation of degenerated nucleus pulposus through a tear in the annulus fibrosus, most commonly in a posterolateral direction compressing the adjacent descending nerve root; responsible for the clinical syndrome of acute lumbar or cervical radiculopathy.

Loss of sensation in the perineum, inner thighs, buttocks, and anus (the anatomical region corresponding to a saddle seat), reflecting compression of the S2-S4 sacral roots of the cauda equina; the most specific sign of cauda equina syndrome.

Radicular pain in the distribution of the sciatic nerve (L4-S1), classically described as sharp, shooting, or burning pain radiating from the back or buttock down the posterior or postero-lateral aspect of the leg to the foot; caused by lumbar nerve root compression.

Forward displacement (anterolisthesis) of one vertebra on the vertebra immediately below; most commonly at L4/L5 or L5/S1; a common cause of mechanical low back pain and, when significant, of lumbar canal stenosis and radiculopathy.

A clinical provocative test for lumbar radiculopathy: with the patient supine, passive elevation of the extended leg reproduces radicular leg pain below the knee at <70° of elevation; positive in L4-S1 root compression (high sensitivity, moderate specificity).