Failed back surgery syndrome is a misnomer as it is actually a syndrome complex where the patient presents with persistent or new-onset back or leg pain followed by back surgery. Causes are
- Organic
- Psychological
Etiology of Failed back surgery syndrome
Inadequate Primary surgery
The wrong level of surgery
Inadequate or inappropriate surgery
Iatrogenic instability
Arachnoiditis, epidural fibrosis, infection, implant failure, etc
Unrelated to Primary Surgery
Recurrence of disc prolapsed
Adjacent level pathology (Spondylosis, Spondylolisthesis, Disc degeneration, Proximal junctional problems)
Epidural fibrosis
Ongoing degenerative pathology
Psychological
Depression
Chronic pain syndrome
Fibromyalgia
Classifications
- Post-operative (0-2 days to 6 weeks)
- Intermediate (6 weeks to 6 months)
- Late-onset ( > 6 months )
Physical tests
- Tenderness tests: Superficial and diffused tenderness
- Simulation test: Pain on axial loading and on simulated rotations
- Distraction test: Positive tests are rechecked when the patient’s attention is distracted. eg. SLR
- Regional disturbances: motor/sensory weakness
- Overreactions
Investigations
Diagnostic Blocks:
Selective nerve root blocks are helpful to confirm the exact locations of abnormalities and anesthetic responses.
Treatment options
Non-Operative treatment
- Physical therapy / Behavioral therapy
- Anticonvulsant: Neuropathic pain
- Antibiotics
- Selective nerve root blocks
- Spinal cord stimulations
- Epidural/Intrathecal analgesics
Operative
Revision fusion is challenging as it leaves scar and fibrosis from previous surgery and makes it difficult to identify anatomical landmarks.
Principle of Revision Spine Surgery
- Most of the cases can be approached from the back/ posterior approach entered by a midline approach/ Witse approach
- Wide exposure through unoperated normal anatomy
- Careful exposure of facet joint and lateral border of pars and approaching midline from lateral to medial
- Curette, small size Kerrison rongeur or Penfield dural retractoràused to identify the edge of laminectomy defects
- Good localization of the Dural sleeve should be done before mobilization of nerve roots
- Lumbar fusion surgery has been used as a salvage surgery in patients who had already done lumbar decompression procedures.
See also: Approaches of Spine
