Posterior Lumbar Interbody Fusion Less Invasive Techniques

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Posterior Lumbar Interbody FusionLess Invasive
Techniques
www.spinalunit.org

• Manoj Krishna
• Spinal Surgeon
• University Hospital of North Tees.
• UK.

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Principles of PLIF surgery

• Removal of Pain Source- Disc
• Restoring Normal Load Transmission across disc
• Neural decompression
• Restoring Lordosis

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META-ANALYSIS OF FUSION. ESJ, 1997. BOOS AND
WEBB. n 5601
Good outcome
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META-ANALYSIS OF FUSION
BOOS and WEBB
Fusion
()
AIF
PLF
PLIF
PLFIF
PLFPF
PLIFPF
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META-ANALYSIS OF FUSION
BOOS and WEBB
AIF
PLF
PLIF
PLFIF
PLFPF
PLIFPF
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Meta-Analysis of Fusion
Turner, Deyo et al. JAMA. 1992.
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Posterolateral vs PLIF in lytic Spondylo-listhesis

• N40 posterolateral and 37 had PLIF added.
• 7.5 nonunion in PLF , none in PLIF
• 45 excellent results in PLF group
• 75 excellent results in PLIF group.
• 90 satisfied in both groups.

SUK et al, SPINE, 1997.
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Positioning in PLIF Surgery

• Tummy MUST be free
• Use Knee chest position if obese
• Jackson table ideal

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Minimising Blood Loss

• Positioning
• Hypotension-
• Reduce end-inspiratory pressure
• Sacral Epidural before surgery ?
• Flowseal topical coagulant.

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Exposure

• Keep midline intact
• do not expose transverse
• process
• Remove facet joint
• Decompress the lateral
• recess above the disc
• Re-suture fascia to
• Inter-spinous ligament

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Why total facetectomy?

• Decompress exiting nerve completely
• Provide space for cage
• Provide bone for grafting
• Remove possible pain source

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Why insert cage laterally?

• Thickest bone laterally
• No need to retract nerve root
• Better load transmission
• More bone graft between cages

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Getting the lateral disc out..
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Why Bilateral Cage Insertion?

• Degenerative disc pain source- inflamatory
  generators
• A lot of postero-lateral disc left on opposite
  side
• Can insert largest cages to re-tension the annulus

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Pedicle screw insertion
Burr just above pars. Just medial to mamillary
ridge No need to expose TP No muscle
stripping. Minimise exposure needed
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Restoring Disc Height

• Release rim of disc- lateral and anterior
• Sequential spreaders on alternate sides
• Aim for 10mm height
• Stop when spreaders in tension

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Restoring disc height
Tight lateral annulus
Disc
L5
S1
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Cage size

• Use largest cage possible- 10mm or more in 90.
• Remove posterior lip osteophyte to make room for
  cage insertion
• Protect both traversing and exiting nerves during
  cage insertion

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Making room for cage
Medio-lateral slope
Lip
AP view of disc
Lateral view of disc
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Disc Removal

• Key to success
• Shavers not good enough
• Use curettes on endplate

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Perforate Endplate

• Make small holes in endplate
• Better vascularity of graft
• Especially in smokers
• Chronic degeneration- thick endplates.

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Bone Graft

• Use morsellised local bone
• Mix with 10cc of Bone Marrow Aspirate
• Current Practise Do not take Iliac Crest Graft

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Prevent late Nerve Pain

• Remove small bone fragments from around the nerve
• Free exiting nerve in lateral recess above
• Complete facetectomy
• Avoid too much nerve retraction

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Current Practise

• Average time- 130 mins- single level
• Hospital stay- most stay 2 nights post-op
• Minimal exposure- 7cm incision
• Most report pre-operative pain is gone at
  discharge.

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Diagnosis

• Degenerative Disc Disease-- 61
• Spondylolysis/listhesis-- 22
• PostLaminectomy Syndrome--11
• Broad Based Disc Prolapse--7

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Duration of Pre-operative symptoms 4
months to 23 years mean 86months
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Hospital Stay 2 to 12 nights most often-2
nights
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Follow-up 12 months to 60 months
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Statistical Analysis(paired t-test)

• Low Back-pain VAS pre-op---7.68
• Low Back-pain VAS post-op---3.06
• 95 Confidence Interval 2.81-4.8
• P lt .0001

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Statistical Analysis (paired t-test)

• Leg Pain VAS pre-op6.48
• Leg Pain VAS post-op2.86
• 95 Confidence Interval 2.44 - 4.79
• P lt .0001

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Statistical Analysis (paired t-test)

• Oswestry Disability Index pre-op64.63
• Oswestry Disability Index post-op27.69
• 95 Confidence Interval 29.04 - 44.82
• P lt .0001

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Results

• 82/101 Totally Pain free/Much Better.
• 11/101 No Better (2- significant Bone Graft
  Pain).
• 2 worse off ( 1 with a sensory level at T10, 1
  with loss of bladder sensation)
• 5/101 Lost to follow-up/moved out of area.
• 1/101 Deceased, medical reasons.

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PLIF in Disc Prolapse ?

• Is disc going to fail ?
• 30-60 get intrusive LBP later.
• Which patients to select?

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Indications for PLIF in Disc Prolapse

• Central Disc prolapse
• Broad based posterolateral disc prolapse
• Underlying advanced degeneration
• Long history of LBP prior to sciatic symptoms
• Severe leg pain with no sign of neural
  compression

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RS. M. 07/60. Greengrocer.
Intermittent LBP several years. Then Rt sciatica
LBP settled. Scoliotic tilt and stooped
forwards 40 degrees. Rt SLR40 L5 decreased
sensation ? Discectomy or PLIF ?
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RS. M07/60. Greengrocer
June 2002- L4/5 PLIF Sept 2002 Back at work
doing heavy lifting. 100 pain relief. No leg
pain.