Treated conditions

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Definition and Etiology

Symptoms

Diagnosis

Treatment

Treated conditions

Disc Herniation

Intervertebral discs are fibrocartilaginous cushions between vertebrae, containing a central nucleus pulposus (90% water) and a peripheral annulus fibrosus. Degeneration due to prolonged load, poor posture, and physical strain can weaken the annulus fibrosus, leading to herniation. Herniated nucleus pulposus compresses spinal cord and/or nerve roots, causing symptoms.

Classification

Based on location:

  • Intracanal herniation: nucleus pulposus projects into the spinal canal
  • Intraforaminal herniation: nucleus pulposus migrates into the neural foramen
  • Extraforaminal herniation: nucleus pulposus migrates laterally to the neural foramen

Based on nucleus pulposus protrusion:

  • Disc protrusion: annulus fibrosus deforms without rupture
  • Contained herniation: nucleus pulposus protrudes into the spinal canal but is contained by the posterior longitudinal ligament
  • Extruded herniation: nucleus pulposus ruptures through the annulus fibrosus and posterior longitudinal ligament

Causes

Excessive spinal load from physical labor, trauma, sports, sedentary lifestyle, obesity, genetic predisposition, and smoking.

Symptoms

Cervical Disc Herniation

  • Spinal cord compression: neck pain, upper/lower limb weakness, gait difficulty, urinary retention, constipation
  • Nerve root compression: neck to arm pain, arm/hand numbness, muscle weakness

Thoracic Disc Herniation

  • Spinal cord compression: back pain, lower limb weakness, gait difficulty, urinary retention, constipation, reduced sensitivity below compression
  • Nerve root compression: back pain, intercostal pain, intercostal numbness

Lumbar Disc Herniation

  • Nerve root compression: low back pain radiating to the leg, leg/foot numbness, muscle weakness

Diagnosis

MRI and CT scans confirm diagnosis, and electromyography (EMG) identifies affected nerve roots.

Treatment

Most herniations resolve with conservative treatment (medication, physical therapy). Surgery (5-10% cases) is needed for motor deficits, severe pain, or incontinence, involving removal of herniated disc material to resolve nerve/spinal cord compression. Procedures include:

Cervical Herniation Surgery:

Anterior approach with intervertebral disc removal and replacement with a titanium/PEEK prosthesis.

Thoracic Herniation Surgery:

Lateral/antero-lateral approach, possibly involving partial rib removal or trans-thoracic approach with thoracic surgeons.

Lumbar Herniation Surgery:

Posterior approach with small incision for herniated fragment removal.

Intervertebral disc anatomy. As the picture shows, in a normal condition the intervertebral disc doesn’t compress nerve roots or the spinal cord
Intracanal herniation. The nucleus pulposus spills into the spinal canal, compressing nerve roots and/or spinal cord.
Intraforaminal herniation. The nucleus pulposus spills into the intervertebral foramina, compressing the nerve root
Extraforaminal herniation. The nucleus pulposus spills laterally to the intervertebral foramina
Disc protrusion. The annulus fibrosus goes through a deformation (but remains intact) caused by the nucleus pulposus.
Contained Herniation. The nucleus pulposus spills in the vertebral canal through a tear in the annulus fibrosus, but is still contained by the posterior longitudinal ligament (represented pink in the picture)
Non-contained Herniation. The nucleus pulposus detaches and spills through the posterior longitudinal ligament, reaching the vertebral canal without maintaining any relation of continuity with the spinal disc. The herniation dislocates, in this way, the dural sac and/or the nerve root.
Classification of the disc herniations based on localization: cervical, thoracic, lumbar
Surgical treatment of the cervical disc herniation (1/3). In the picture the pathologic disc between the two cervical vertebrae is showed.
Surgical treatment of the cervical disc herniation (2/3). The intervertebral disc and the herniation are removed.
Surgical treatment of the cervical disc herniation (3/3). The intervertebral disc is replaced with a titanium or PEEK implant of the same size.
Surgical treatment of the lumbar disc herniation. In some cases, the discectomy is associated to vertebral stabilization. The picture shows the transpedicular screws and bars.