Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

Featured on Channel NewsAsia

Thoracic Disc Herniation

Basics
Description
  • Thoracic disc herniation is a difficult condition to diagnose and treat given its vague symptoms, which are often similar to those of other conditions.
  • These difficulties are compounded by the fact that a high prevalence occurs of asymptomatic thoracic disc abnormalities and herniation.
Epidemiology
  • Symptomatic thoracic disc disease most commonly occurs in the 5th decade.
  • A slight male predominance is noted.
  • Up to 50% of patients report some traumatic event before the onset of symptoms .
Incidence
Symptomatic herniations occur in 1 per 1,00,000 patients per year.
Prevalence
  • Up to 73% of patients have some thoracic disc abnormalities on MRI.
  • 37% have asymptomatic disc herniations.
Risk Factors

Genetics
No known genetic link

Pathophysiology
  • Symptomatic disc herniations can lead to spinal cord or nerve root compression.
  • Spinal cord compression can lead to signs of myelopathy without upper extremity involvement.
Associated Conditions
Adolescents with Scheuermann disease often present with acute disc herniation.
Diagnosis
Signs and Symptoms
Patients may present with axial pain (localized from the middle to lower thoracic spine), radicular pain (T10 dermatomal is most common), or myelopathy (bowel and bladder dysfunction are seen in up to 20% of patients with symptomatic disc herniation) .
History
  • This disorder has a very extensive differential diagnosis given the vague signs and symptoms, depending on the level of disc herniation.
  • 2 separate clinical courses:
    • Young patients (usually <40 years old) with a soft disc herniation:
      • Usually present after a traumatic event
      • Usually have acute spinal cord compression
      • Respond well to nonoperative and operative treatment
    • Older patients (usually >40 years old) with long-standing symptoms and degenerative calcified discs:
      • Have no history of trauma
      • Have chronic cord or root compression
Physical Exam
  • Neurologic examination:
    • Signs of myelopathy
    • Asymmetric contraction of rectus abdominus during sit-up
    • Superficial cremasteric reflex
    • Sensory levels:
      • T4: Nipple line
      • T7: Xiphoid process
      • T10: Umbilicus
      • T12: Inguinal crease
  • Gait
  • ROM
Tests
  • Asymmetric contraction of rectus abdominus during sit-up
  • Superficial cremasteric reflex
Lab
Complete blood cell count, ESR, and C-reactive protein usually are used if infection or cancer is in the differential.
Imaging
  • Radiography:
    • AP and lateral radiographs of the spine show degenerative changes or spondylolisthesis and rule out fractures, infection, or tumor.
    • Radiographs should include the 1st rib, 12th rib, and sacrum to allow for appropriate localization of the level of abnormality.
  • MRI:
    • Shows compression of neural elements
    • The sagittal and axial T1- and T2-weighted images should be used to evaluate the disc herniation.
    • Special attention should be given to confirming the level of the disc herniation.
    • A sagittal localizer pulse sequence should be used to count down from C2 and count up from the sacrum.
    • Correlation should be made with the conventional radiographs.
  • CT-myelography is comparable to MRI in showing neural compression, but it is an invasive procedure (dye injection associated with subsequent headache).
Diagnostic Procedures/Surgery
Discography is controversial but often used to evaluate for axial back pain when multilevel disease or severe pain occurs in the presence of relatively normal imaging studies.
Differential Diagnosis
  • An extensive differential
  • Intrathoracic abnormality
  • Intra-abdominal abnormality
  • Infectious
  • Neoplastic
  • Degenerative
  • Metabolic
  • Deformity
  • Neurogenic
Treatment
General Measures
Acute thoracic disc herniations have a natural history similar to that of lumbar disc herniations and are managed similarly with nonoperative treatment in the absence of neurologic compromise.
Activity
As tolerated, as long as no other abnormality (e.g., fractures, gross instability, etc.) is present
Special Therapy
Physical Therapy
  • Acute phase:
    • Passive modalities:
      • Heat
      • Ice
      • Ultrasound
  • After overcoming the acute phase:
    • ROM
    • Flexibility
    • Strengthening exercises
    • Hyperextension exercises
Medication
No role for maintenance opiates
First Line
  • Anti-inflammatory medications (as long as no gastrointestinal side effects occur)
  • Enteric-coated aspirin (fewer gastrointestinal side effects)
  • Acetaminophen
Second Line
  • COX-2 inhibitors (be aware of changing side-effect profile)
  • Epidural or intercostals steroid injections
Surgery
  • Indicated when nonoperative treatment fails and the patient cannot attain a tolerable quality of life
  • Preoperative clearance by an internist, cardiologist, and/or anesthesiologist is necessary.
  • Correct level of surgical excision is ensured by use of intraoperative radiographs.
  • Anterior transthoracic approach is used most commonly.
  • Posterior pediculofacetectomy is the only recommended posterior approach.
  • Very high risk of neurologic injury with thoracic laminectomy (not recommended)
  • Lateral extracavitary and costotransversectomy are the 2 lateral approaches.
  • Video-assisted thoracoscopic surgery is a new, minimally invasive procedure.
  • Thoracic fusion is controversial because some contend that the rib cage gives the thoracic spine inherent stability, whereas other surgeons cite the possibility of deformity and instability.

Follow-up
Routine follow-up is at 6 weeks, 3 months, 6 months, 1 year, 2 years, and then every 2 years.
Disposition
Issues for Referral
Patients should be referred to appropriate specialists (thoracic or general surgeons, rheumatologists, etc.) if other conditions cannot be ruled out as part of the differential diagnosis.
Prognosis
Most patients who undergo disc excision have excellent or good long-term results .
Complications
  • The overall surgical complication rate after thoracic disc excision was 14.6% in a series of 82 patients .
  • The most serious complication is paralysis or paraparesis.
  • Myelopathy and/or neurologic compromise is also a potential complication of nonoperative treatment.
Patient Monitoring
Patients are monitored for resolution of symptoms, fusion (if arthrodesis was performed), and development of any complications.
Miscellaneous
Codes
ICD9-CM
  • 722.11 Thoracic intervertebral disc without myelopathy
  • 722.72 Intervertebral disc disorder with myelopathy, thoracic region
Patient Teaching
  • Patients should be educated about:
    • Being aware of progressive motor weakness and bladder/bowel dysfunction
    • The natural history of the condition
FAQ
Q: What is the most common surgical approach to perform a thoracic discectomy?
A: Anterior approach.

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