23/01/2026
Discs Don’t “Slip”
Discs Don’t “Slip”
The phrase “slipped disc” is anatomically incorrect. Intervertebral discs are firmly bound to the vertebral bodies above and below via cartilaginous endplates and reinforced by the annulus fibrosus. They cannot move, slide, or slip out of position.
What actually occurs is a disc herniation. This describes a situation where disc material, usually the nucleus pulposus, displaces through a defect or tear in the annulus fibrosus. The disc remains in its normal anatomical location; only internal material migrates beyond its usual boundaries.
An intervertebral disc is composed of a central nucleus pulposus, a surrounding annulus fibrosus made of concentric collagen lamellae, and cartilaginous endplates that anchor the disc to the vertebral bodies. These structures develop together and are mechanically integrated, which is why the idea of a disc “slipping” between bones is not biologically plausible.
Disc herniation is a process influenced by age-related changes, mechanical loading, and biochemical factors within the disc. Over time, the annulus fibrosus can develop fissures. When internal pressure rises, nucleus material may protrude or extrude through these fissures. Symptoms arise not because the disc has moved out of place, but because displaced disc material can irritate or compress nearby neural structures and provoke an inflammatory response.
Pain associated with disc herniation is driven by two main mechanisms. One is mechanical compression of nerve roots or the spinal cord. The other is chemical irritation, as nucleus pulposus material is biologically active and can sensitise adjacent neural tissue even without significant compression.
In clinical practice, accurate terminology matters. Saying “slipped disc” reinforces the idea that something is out of place and needs to be put back, which is misleading and often increases fear. Terms such as disc herniation, herniated disc, pr*****ed disc, or herniated nucleus pulposus accurately describe the pathology and align with modern anatomical and clinical understanding.