Selective Lumbar Injections

1
Selective Lumbar Injections

• Joseph F. Galate, M.D.

2
Selective Lumbar Injections

• Selective injection in the spine is one of the
  most powerful diagnostic and therapeutic
  modalities available to the practitioner.
• Gives us information about the structures
  generating pain, less reliably obtained from PE,
  spinal imaging, or electrodiagnostic testing.
• 90 of spinal diagnosis depends on history and
  physical exam with testing to confirm the
  diagnosis.
• Most useful in those patients with residual pain
  and restricted ROM and function, despite 4-6
  weeks of aggressive rehabilitation.

3
Diagnostic Imaging

• Plain radiographs
• Bone Scans
• CT Scan
• MRI Scan
• CT Myelogram
• Many lesions may not be reliably identified on
  imaging studies (i.e., dynamic, irritative,
  chemical and immunologic).

4
Electrodiagnostic Testing

• Minimally invasive and very useful in identifying
  nerve root lesions
• Useful in evaluating radiculopathy

5
Diagnostic Selective Blocks

• Assess structural pain generators and quantify
  their relative contribution to a patients pain.
• Many lumbar pain syndromes are diagnosed solely
  by means of diagnostic blocks.
• Pain provocation through the stimulation of a
  structure by an anesthetic block, the similarity
  of the provoked pain to the patients normally
  perceived pain, and the relief of pain by local
  anesthetic are well-accepted medical diagnostic
  tools.
• The data obtained from a block must be congruent
  with other patients data.

6
Therapeutic Blocks

• The rationale for utilizing local anesthetic and
  corticosteroid injections for treatment of the
  lumbar spine was based on the efficacy of these
  injections to control inflammation.
• Corticosteroids (CS) relieve pain related to
  inflammation resulting from disk degeneration or
  injury due to chemical and immunological factors
• Seen in patients without a compressive lesion on
  radiological evaluation.
• Suppress ectopic discharges in the injured nerve-
  nociceptive axon activity
• Facilitate recovery from conduction block in
  nerve compression injury
• Prevent and suppress edema, production of
  chemical inflammatory mediators, fiber
  deposition, capillary dilatation, cellular
  migration and phagocytic activity
• Inhibits scarring and promotes lysis of adhesions

7
Chemical Irritants

• The nucleus of the disk contains high levels of
  phospholipase A2 (PLA2) which initiates the
  inflammatory cascade
• Other inflammatory mediators include
  prostaglandins, leukotrienes, histamine, and
  bradykinin, which act as inflammatory and immune
  mediators

8
Epidural Blockade

• Been around for 40 years.
• The epidural space is accessed throughout the
  caudal, transforaminal approach.

9
Caudal Epidural Blocks

• Simplest
• Low risk for thecal puncture. Dura ends at S2.
• Unreliable above the L4-5 levels.
• Requires higher volumes of medication (10-15cc to
  reach L4-L5 levels).
• Large area that is anesthetized limits the use of
  this block for diagnosis.
• Useful for paracentral disc protrusion at L4-L5,
  L5-S1 and subsequent radicular pain of both
  lower extremities.

10
Caudal Block
11
Caudal Block
12
Translaminar Epidural Blocks

• Intermediate difficulty.
• Close to the targeted pathology
• Lower volume/higher concentration delivered.
• Higher risk of puncture of dural sac.
• Spread of medication is usually unilateral -
  symptomatic side.

13
Translaminar Epidural Block
14
Translaminar Epidural Block
15
Transforaminal Epidural Block

• Most difficult.
• Very diagnostic as a selective nerve root block.
• Useful for large disk herniation, foraminal
  stenosis, lateral disk herniation.
• Can be used in conjunction with caudal orlumbar
  epidurals.

16
Transforaminal Epidural Block
17
Transforaminal Epidural Block
18
Facet Blocks

• Diagnosis - gold standard
• (PE) - pain with extension and rotations, side
  bending, return to standing from flex position
  with local tenderness to palpation over the facet
  joint.
• Radiographic - joint space narrowing,
  hypertrophy, sclerosis, trophism

19
Facet Blocks

• Fluoroscopic localization is a prerequisite for
  performing these blocks.
• Use of radiopaque dye confirms placement of the
  needle intra-articularly.
• Volume of joint 1.5cc
• Most common levels L4-L5, L5-S1.

20
Facet Blocks - Types
21
Facet Blocks - Types

• Medial Brand of the dorsal ramus (MBDR)
• anesthetize the entire capsule complex (see
  picture).

22
Sacral Iliac Joint Injection

• History usually follows a fall, or high velocity
  trauma (MVA)
• PE pain over SI joint, Patricks test, Gillets
  test
• Radiology not very useful unless there is
  sclerosis or partial fusion
• Diagnosis Gold Standard is flouroscopic guided
  injection of SI joint using dye and lidocaine
• Treatment SI joint injection with lidocaine and
  steroid and physical therapy

23
Sacral Iliac Joint Injection
24
Indwelling Epidural Catheters

• Placed for diagnostic and therapeutic purposes.
• Used mainly for central pain states,
  non-physiological pain syndromes, CRPS.

25
Diskography

• The only test that can assess pain for the disk.
• Nociceptive nerve fibers have been found in the
  outer annulus and granulation of tissue growing
  into disk fissures.

Figure 19-3 E. Normal L5-S1 nucleogram in the
lateral projection. F. L5-S1 nucleogram in
anteroposterior projection. There is a slight
lateral annular fissure (arrows), which was
asymptomatic, to the mid-annulus on the right.
26
Fluroscopy vs. Blind

• Confirm proper placement
• Up to 25 misplaced due to wrong location,venous
  uptake.
• Cost
• Safety Factor
• Non response

27
Efficacy of Epidural Blocks

• Poor patient selection.
• Questionable technique.
• Correct pain generator (see next slide)
• Modality vs. treatment
• White et al showed good short term pain relief
  82 at day one to 7 response after 6 months.
• The period of pain relief given by the ESI must
  be used in conjunction with an active
  rehabilitation program.

28
Pain Generators

• Common Sources of low back pain
• Structural Myofascial
• Neural Tissue
• Joints
• Intervertebraldiscs
• Skeletal boneabnormalities
• Emotional Factors
• Functional Changes

Muscles, Tendons, ligaments, fascia Nerve root
irritation, epidural inflammation, epidural
fibrosis, arachnoiditis Facet joints, sacro iliac
joints Disc degeneration/disruption, disc
herniation Osteoporosis, compression fractures,
spinal stenosis, spondylosis, spondylolysis,
spondylolisthesis, space occupying legions -
benign and malignant Stress, chronic pain,
personality changes, somatization, etc. Posture,
deconditioning, attitude/motivation
29
How Many Injections?

• Generally accepted that no further injections
  need to be performed in the same area if the
  first injection was not beneficial.
• If the initial response is favorable, but short
  lived, a second injection is reasonable.
• A maximum of 3 epidural injections per year is
  generally reported.
• Spacing - varies from days to weeks generally for
  a series of injections.

30
Complication to Epidural Injections

• Consent must be obtained.
• Infection - epidural abscess, meningitis.
• Bleeding - (No ASA) 7-10 days, NSAIDS 48-72 hrs.
• Thecal sac puncture 0.5-2.5 - spinal headache.
• Post-injection exacerbation of pain 1.
• Epidural hematoma
• Arachnoiditis with certain preparations of
  Depo-steroids
• Chemical meningitis (PEG)
• Suppression plasma cortisol levels up to 2 weeks.
• Increase in blood sugars
• Exacerbation of CHF due to reduction of fluids
• Vasovagal response.

31
Conclusion

• Complete history and physical
• Differential diagnosis
• Radiographic and/or electrophysiological
  conformation
• Locate the pain generator
• Selective Lumbar injections used for diagnosis
  and treatment
• The period of pain relief afforded by selective
  injections must be used in conjuction with an
  active rehabilitation program and is not an end
  in itself
• Selective injections are a valuable tool in
  rehabilitation and provides enormous cost savings
  in hospitalization, physical therapy, medication,
  and time lost from work.

32
Algorithm for Lumbar Spine Injection