What is the medical term for a slipped disc?

Medical Term for Slipped Disc

The medical term for a slipped disc is "herniated disc" or more specifically "herniated nucleus pulposus" (HNP). 1

Definition and Pathophysiology

• A herniated disc refers to the displacement of the nucleus pulposus (inner portion of the intervertebral disc) through the annulus fibrosus (outer covering), which can result in compression of adjacent nerve roots or other structures. 2
• The most common cause of disc herniation is degeneration of the intervertebral disc, though factors such as genetics, weight, occupational risk factors, smoking, and sedentary professions can increase the risk. 3

Terminology Variations

• Other terms sometimes used to describe this condition include:
  • Herniated nucleus pulposus (HNP) - the most precise medical term 2
  • Lumbar disc herniation (when occurring in the lower back) 1
  • Intervertebral disc displacement 2

Clinical Presentation

• Pathognomonic symptoms of a herniated disc include sciatica, caused by compression of one or more spinal nerve roots. 3
• Clinical manifestations range from mild low back and buttock pain to severe, immobilizing cases of sciatica to cauda equina compression syndromes. 1
• When herniation occurs at specific levels, characteristic symptoms may appear:
  • L3-L4 herniation: Radicular pain radiating down the anterior and medial thigh to the knee; may show depression or absence of the patellar tendon reflex 4
  • L4-L5 herniation: Typically affects the L5 nerve root, causing weakness in foot dorsiflexion and great toe extension 4

Diagnosis

• Diagnosis is achieved through a thorough history and physical examination along with advanced imaging. 1
• MRI without contrast is the preferred imaging modality for confirming disc herniation. 4
• Plain radiography is not useful in diagnosing disc herniation. 5

Management Considerations

• Most patients (approximately 90-95%) with symptomatic disc herniations experience resolution of clinical manifestations with conservative therapy. 5
• Lumbar spinal fusion is not recommended as routine treatment following primary disc excision in patients with a herniated lumbar disc causing radiculopathy. 2, 6
• Lumbar fusion may be considered as a potential surgical adjunct in patients with:
  • Evidence of preoperative lumbar spinal deformity or instability 2, 6
  • Significant chronic axial low-back pain associated with radiculopathy due to a herniated disc 2, 6

Emergency Considerations

• Cauda equina syndrome occurs in 1-1.5% of cases and represents a true emergency requiring immediate surgical decompression. 3
• Signs of cauda equina syndrome include urinary retention or incontinence, bilateral motor weakness of the lower extremities, and saddle anesthesia. 2, 4
• Significant and rapidly deteriorating neurological deficits (within 24 hours) also require immediate attention and surgical intervention. 3