fusion with open or minimally invasive techniques in degenerative listhesis
TRANSCRIPT
Degenerative listhesisFusion with open or MIS techniques
Mohamed Mohi EldinProfessor of Neurosurgery
Cairo University
SpondylodesisSpondylosyndesis
Spinal fusion
remains the gold standard in maintaining the stability
of unstable spinal segments
for multiple potential pathologies.
Listhesis Surgical Options(No clear consensus)
• Decompression without fusion
• Decompression with noninstrumented fusion
• Decompression with instrumented fusion
Special Considerations
Collapsed disc
No motion disc space
Osteoporotic vertebrae
Instrumentation
• Is recommended to improve fusion rates
• Not to improve clinical outcomes
Spinal Fusion Is It Worth It?
The other point of view says…Just because a 360 degree fusion is the popular option doesn’t
mean it’s the safest or most effective option. The spine is not meant to be a stationary structure, to maintain the natural
movement and curve of your spine.
Spinal Fusion is a Patient's Decision
Unlike many other types of surgery, only the patient can decide if the pain and inability to complete normal daily activities is
bad enough to warrant spinal fusion.
And the best way for a patient to make an informed decision is to fully understand the trade-offs between spinal fusion and
other non-surgical and surgical treatment options.
SPINAL fusion
used primarily to eliminate the pain caused by abnormal motion of the vertebrae.
Two main types of lumbar spinal fusion, which may be used in conjunction with each other;
posterolateral fusion
interbody fusion
Patients with “highly sensitive discs” as determined by discography achieved
significantly better long term outcomes with combined anterior/posterior fusion than with
inter- transverse fusion (ILIF) alone.
Interbody fusionInvolves radical disc removal and replacement with bone graft or popular interbody cages which are now
composed of a wide range of materials, such as titanium mesh, carbon fiber, polyetheretherketone
(PEEK)…etc.
Advantages of interbody fusion
• Most effective treatment of surgical discogenic back pain,
• Immediate anterior column load sharing,
• A large surface area for fusion,
• Bone graft subjected to compressive loads (better fusion),
• Ability to restore normal sagittal contour while indirectly decompressing the neural foramen.
The optimal interbody fusion technique for degenerative lumbar diseases
remains controversial
The currently recommended & more commonly implemented procedures
are
PLIF posterior lumbar interbody fusion
TLIF transforaminal lumbar interbody fusion
PLIF
First described by Cloward (1940)
TLIF
First described by Harms and Rolinger (1982)
PLIF
• Through the posterior approach,
• Enables a stable three-column fixation with 360° fusion and anterior support
PLIF Technique• Complete decompression laminectomy, medial facetectomy
• Discectomy, curettes and shavers
• Bone graft and cages (1 oblique or 2 better ?)
• Don't retract dura before foraminotomy or beyond midline
TLIF
• Involves the placement of pedicle screws and an interbody spacer via a single posterolateral route.
• Avoids retraction,
• Bilateral and multilevel exposure possible
TLIF Technique
• Facetectomy on the side of radiculopathy
• Identify exiting and traversing roots
• Total disc resection with angled curettes and shavers
• Bone graft and 1 cage (bean or rectangular)
TLIF Methods• By removing the entire facet joint, it minimizes retraction
• TLIF enables placement of graft within the anterior or middle of disc space to restore lumbar lordosis.
Final Assembly of rod-screw system
• Construct is compressed to establish optimal cage bone interface and to reestablish lordosis
• System tightened
• Perform ILIF if needed
Contraindications
• PLIF in L2,3 and more cranial segments, to avoid retraction on conus medullaris and cauda equina
• Both PLIF & TLIF in narrow disc space (ALIF)
• Both PLIF & TLIF in Kyphotic deformity (ALIF)
PLIF v TLIF
• The PLIF procedure required longer operative time due to broad and bilateral dissection and decompression
• No significant difference was found between the two procedures regarding blood loss
• However, significantly less blood loss occurred in the TLIF when two-level procedures were compared.
Operative time & Blood loss
Why PLIF longer than TLIF ?
Because in PLIF:
1. Discectomy steps
2. Bilateral disc opening
3. Two cages insertion
4. More incidental dural tears and their repair
On the other side TLIF technique is simpler and didn't require bilateral disc opening so, it saves
more time.
PLIF v TLIF
• PLIF results in a significantly higher complication rate than does TLIF
• Increased risk observed for PLIF compared with TLIF– durotomy,
– root injury,
– graft (pedicle screw, cage, and bone graft) malposition, and
– infection.
Complication rates
PLIF v TLIF
• TLIF technique is lateral to the vertebral foramen, there is – less retraction of the dura or
conus medullaris,
– greater protection of the spinous processes that can affect postoperative spinal stability.
– lower incidence of durotomy and root injury
PLIF v TLIF
• Because TLIF preserves the posterior compartment more effectively than PLIF does, transitional syndrome or screw fracture is less likely to occur.
PLIF v TLIF
• No significant difference was found between the two procedures regarding clinical satisfaction, or fusion rate.
Clinical results and fusion rates
PLIF v TLIF
• VAS was not significantly different among both groups preoperative and 48 hours postoperatively. Starting from 1 month postoperatively, VAS was significantly lower in TLIF group patients.
• the VAS improvement is related to the pre operative pathology.
Traditional Open TLIF & PLIFExtensive dissection of muscle /soft tissue
Wide retraction, prolonged pressure
Ischemia and denervation, muscle atrophy and pain
“Failed back syndrome”
“post laminectomy syndrome”
Modifications and refinements
• To achieve better outcomes
• Include
– minimization of retraction
– avoidance of broad dissection
– develop minimally invasive spine surgery to reduce complication rates, blood loss and postoperative hospitalization.
One of the main goals of MISS is to do an efficient “target surgery” with a minimum of
iatrogenic trauma.
Minimally invasive TLIF & PLIF
• Provides similar efficacy to conventional open technique,
• Intraoperative blood loss significantly lower than conventional open approaches.
• Proves superior in regards to patient satisfaction, length of hospital stay, time to mobilize and complication rates
• Became a prominent part of spinal fusion techniques
TLIF is a satisfactory minimally invasive choice
Mini-Open TLIF
Mini-TLIF
Open v MIS
pressure transducer with
minimally invasive retractor
(top) and standard open
retractor (bottom)
Reduced Intramuscular Pressure on the Paraspinal Muscles
IMP with MI retractor was transient in nature and significantly lower. This may be due to
the smaller footprint and more flexible walls compared with the standard open retractor.
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Time (sec)
IMP
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Pa
)
Open v MIS
• Coronal & axial T2w-images 6 mths post open L4-5 fusion, showing severe edema in multifidus.
• Coronal & axial T2w-images 5 mths post MIS L3-4 fusion, showing mild edema in multifidus.
Decreased Paraspinal Muscle Damage
Open v MISDecreased Paraspinal Muscle Damage
Single level posterolateral fusion & pedicle screw fixation
MRI scans performed ~6 months post surgery
Comparison of mean T2 relaxation times at level of fusion 90ms (+ 23.3)
p = 0.013
Open v MIS
Direct visualization of anatomic structures, use same bone
landmarks for placement of pedicle screws and access
of disc space as traditional approach.
Open v MIS
Postoperative pain was significantly lower following the MIS technique, but despite this, the amount of pain relief (change
in VAS score) provided by both procedures was not significantly different.
Statistically significant decrease in ODI & NRS
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% M
ean
OD
I
Oswestry Disability Index
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Mean
Pain
Sco
re
Numeric Rating Scale
Open v MIS• MIS, however, includes the use of imaging for
navigation during pedicle screw placement. The use of imaging prolongs operating times, while also increasing patient and surgeon exposure to ionising radiation.
• MIS techniques have steep learning curves, requiring a different set of cognitive, psychomotor and technical skills. It is recommended that surgeons have adequate experience with open procedures before attempting MIS methods.
Open v MIS
MIS approaches to spinal fusion have not yet been shown to be superior in effectiveness to
traditional open techniques.
Open v MIS
MIS approach provides greater patient satisfaction while being as effective, if not
more so, than the conventional open approach.
Clinical advantages
Reducing iatrogenic tissue injury theoretically reduce recovery time, and length of stay in
hospital.
MIS approaches with regard to recovery, which offset the costs of specialised and expensive equipment, ultimately making it a cheaper option than traditional open spinal fusion.
Conclusions
• MIS is safe and effective treatment for degenerative
listhesis
• Early outcome data compares favorably to retrospective open
case series
150 cc less blood
Fewer complications
Hospital stay decreased by 2 days
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