Bone and Spine

Orthopedic health, conditions and treatment

Failed Back Surgery Syndrome – Causes, Diagnosis and Treatment

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Last Updated on September 16, 2023

Failed back surgery syndrome refers to persistent or recurrent back pain after one or more surgical procedures on the spine, such as a discectomy, laminectomy, and lumbosacral fusion.

A spine surgery in the lumbar region  is mainly done for

  • To decompress a nerve root
  • To stabilize a painful joint.

Back pain, radicular pain and functional impairment are hallmarks of this condition.

The procedures frequently associated with failed back surgery syndrome are

Failed back surgery is also called failed back surgery syndrome and post-laminectomy syndrome. However, a failed back surgery does not mean that the procedure has failed. Because there are many factors that cannot be controlled and may result in failed back surgery syndrome.

The term failed back is also used vaguely for this condition but in a broader sense implies functional failure of the back, as opposed to the failure of treatment or surgery.failed back surgery syndrome

Ten to 40% of the patients undergoing back surgery have been reported to have FBSS.

The risk of failed back surgery increases as the complexity of the surgery performed increases. For example, decompression and pedicle screw stabilization and fusion are more at risk of developing failed back than simple discectomy.

Repeat surgeries are more commonly associated with failed back than the first surgery.

The symptoms of failed back syndrome may appear immediately after surgery or develop after a period.

Risk Factors

Certain factors, habits and choices of the patient may cause increased risk. Similarly, certain choices and decisions by physicians may put the likelihood of failure back at an increased risk. Once the procedure is initiated, certain things that are not under control may play an important role.

Presurgical factors

  • Anxiety and depression  -Highest risk
  • Smoking
  • Obesity
  • Prior to multiple back surgeries
  • Immunodeficiency – increases the likelihood of infection after surgery
  • Certain diagnoses
    • Spinal stenosis
    • Disc herniation
  • Poor candidate selection
    • No specific attributable cause of pain)
  • Wrong level selection for surgery
    • Often due to a specific level not being established as a part of diagnosis-making

Surgical Risk Factors

  • Multiple level surgery
  • Inappropriate surgical technique
  • Neural Injury during the procedure
  • Inadequate decompression
    • inadequate disc removal
    • more than one level of decompression needed, only one done

Post-surgical risk factors

  • Adjacent segment degeneration
  • Increased stress in adjoining segments leads to degeneration and back pain
  • A failed spinal fusion (pseudoarthrosis)
  • Implant failure
  • Non-compliance to activity restriction
  • Inappropriate patient selection
  • Postoperative Infection
  • Epidural Scar
  • Arachnoiditis [meningeal inflammation]

Clinical Presentation

The patient may present with symptoms of back pain and/or leg pain after surgery has been done. This could occur in the immediate postoperative period [the patient is not relieved from the pain for which surgery was done] or after a certain period where the patient is asymptomatic.

There could be a history of more than one surgery.

Common symptoms associated with failed back surgery syndrome include

  • Diffuse, dull and aching pain involving the back and/or legs
  • Sharp pain in legs
  • Abnormal sensations
    • Burning
    • Pins and needles
    • Decreased sensations of touch
    • Increased sensations touch
  • Muscle spasms

The patient should be evaluated in detail for

  • Musculoskeletal examination
  • Neurologic signs.
  • Any psychological issues

It is essential to detect physical findings predictive of poor outcomes, of a repeat surgical procedure.

Abnormalities such as weakness or sensory loss that appear and disappear at various times, change location, are suggestive of secondary gain or psychological problems and argue against repeat surgery.

Investigations

There are no specific lab tests for failed back surgery syndrome. Routine tests for general well-being and factors like diabetes and other co-morbidities may be done.

  • Imaging
    • Gadolinium-enhanced MRI is the imaging of choice
    • Bony anatomy is better visualized by plain X-Ray and CT.
  • Electromyography
    • To find nerve damage/diseases
  • Psychological Evaluation
  • Diagnostic Blocks
    • To find multilevel involvement
    • To locate the level of the pain
    • Limited predictive value
  • Provocative Discography
    • To ascertain if a particular disc level reproduces pain on loading that disc during the procedure
    • A negative result implies that the particular disc level is not responsible

Treatment of Failed Back Surgery Syndrome

Treatment of failed back surgery syndrome can be difficult and frustrating syndrome to treat.

Nonoperative Treatment

Because of the complexity of the problem, not everything works in all patients so a combination of treatments may need to be devised differently for different individuals

The various treatment options are

  • Physical therapy
  • Nerve blocks
  • Transcutaneous electrical nerve stimulation (TENS)
  • Behavioural therapy
  • Medication
    • Non-steroidal anti-inflammatory (NSAID) drugs for pain
    • Opioid pain relief drugs
      • Intrathecal morphine pump
      • Opioids are known for the development of tolerance
    • Membrane-stabilizing drugs like pregabalin
    • Antidepressants
  • Epidural steroid injections
  • Spinal cord stimulation
    • an implanted device that sends low levels of electricity directly into the spinal cord to relieve pain.

Contributing factors like obesity, depression or smoking should be addressed as well.

Facet  Joint Block

The facet joints form an articulation between the inferior articular process of the vertebra above and the superior articular process of the vertebra below. The joint pathologies can be responsible for back pain and radiating pain to legs or buttocks.

The facet block can be used to relieve the pain of facet joint arthropathy.

Epidural Steroids in Failed Back Surgery Syndrome

Following epidural steroids, pain relief occurs for  3-9 months.

Surgery

The following are considered indications for surgery in failed back surgery syndrome –

  • Failure conservative therapy.
  • Imaging confirmed nerve root or cauda equina compression
  • Segmental instability
  • Radicular pain with corresponding segmental
    • sensory/motor loss
    • Abnormal deep tendon reflexes

The reported success rate of surgeries is 12-100% in different studies.

Ablative Procedures

Ablative procedures have had a relatively poor outcome.

Removal of the entire dorsal root ganglion may thus be more effective than rhizotomy.

Spinal cord stimulation

Low-voltage electrical stimulation is applied by an implanted device to the spinal cord to create a current field that activates neurons in the dorsal column leading to paresthesia, which interferes with or blocks pain signals to the brain.

Intrathecal Drug Infusion

This uses implanted pumps for subarachnoid infusion to deliver opiates intrathecally. This avoids the systemic complications of opioids.

References

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