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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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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Oswestry Disability Index

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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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