MIS Treatment of Spondylolisthesis

This surgeon is a consultant of Medtronic, but received no compensation for this case discussion.

History

The patient is a 61-year-old male with a 3-year history of progressive severe low back pain and pain in both legs. His back pain is mechanical in nature; 60% back and 40% leg pain. He has a 6-month history of right lower extremity weakness.

Previously, he was treated with angioplasty and stents for cardiac disease.

Prior Treatment

Before referral to my practice, the patient had tried several organized programs of physical therapy, multiple epidural steroid injections (caudal and transforaminal), nonsteroidal anti-inflammatory drugs (NSAIDs), and chiropractic care.

Examination

There is limited range of motion in the patient's lumbar spine. Pain is worse during flexion and extension; although, slightly worse in flexion.

He has 2/5 motor responses in his left tibialis anterior and gluteus medius. Both lower extremities are hypesthesic and hypalgesic (L4-distal). The patient's gait is antalgic and he walks with cane assistance.

Pre-treatment Images

Radiographs in standing (Fig. 1), flexion (Fig. 2A), and extension (Fig. 2B).

Figure 1. Standing

Figure 2A. Flexion

Figure 2B. Extension

Sagittal magnetic resonance imaging (MRI) (Figures 3A-3C)

Figure 3A

Figure 3B

Figure 3C

Axial MRI L3-L4 (Figs. 4A, 4B), L5 (Fig. 4C)

Figure 4A

Figure 4B

Figure 4C

Diagnosis

• Lumbar spinal stenosis
• Grade I spondylolisthesis
• Small left L3-L4 synovial cyst
• Degenerative disc disease

Selected Treatment

• DLIF at L3-L4 and L4-L5
• MIS hemilaminectomy at L3
• Resect the synovial cyst
• Interbody spacer
• Percutaneous pedicle screw fixation at L3-L5

Treatment was selected to address the patient's spinal stenosis, synovial cyst, Grade 1 spondylolisthesis, and degenerative disc disease at L4-L5 with foraminal stenosis.

The minimally invasive approach was desirable considering his past medical history, specifically the cardiac stents. The MIS approach shortened operative time, reduced blood loss, and decreased time hospitalized.

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Post-operative Images
Post-operative posteroanterior and lateral standing radiographs (Figs. 5A-5B).

Figure 5A. Posteroanterior, standing

Figure 5B. Lateral, standing

Figure 6A. Axial CT, L3-L4

Figure 6B

Figure 6C. Left sagittal

The estimated blood loss was 150-cc.

Immediately after surgery, the patient reported a reduction in his bilateral lower extremity pain and slight improvement in strength. He was discharged home on the first post-operative day.

Outcome

Eight months after surgery, the patient's back pain and bilateral lower extremity pain is resolved. Sensation is improved, although there is residual bilateral numbness in his feet.

His gait is improved and he walks unassisted (without a cane). Motor function is improved although there is a trace amount of weakness in the tibialis anterior. However, the patient notes he continues to improve.

Note to patients: As you read this, please keep in mind that all treatment and outcome results are specific to the individual patient. Results may vary. Complications, such as infection, blood loss, bowel or bladder problems, are some of the potential adverse risks. Please consult with your physician for a complete list of indications, warnings, precautions, adverse events, clinical results, and other important medical information.

This therapy is not for everyone. Please consult your physician. A prescription is required. For further information, please call MEDTRONIC at (800) 876-3133.

Case Discussion

Reginald Q. Knight, MD, MHA

Director

Bassett Spine Care Institute

This surgeon is a consultant of Medtronic, but received no compensation for this case discussion.

Doctor Barry's case suggests a combination of mechanical low back pain, radiculopathy, and spinal stenosis. Decision making with respect to these symptoms is often difficult.

The patient's long-standing complaints represent chronic nerve root compression and may negatively impact the final outcome regarding neurologic recovery. Plain radiographs illustrate a grade one spondylolisthesis at L3-L4 with degenerative changes at L4-L5. Dynamic motion at L3-L4, with associated spondylosis at L4-L5, may be a source of mechanical back pain.

Although the patient has tried a series of non-operative modalities, the response has not produced sufficient functional improvement. As noted, the patient's mechanical low back pain is less well-documented when compared to his 2/5 motor testing in the L4 distribution, which can readily be attributed to the dynamic stenosis at L3-L4 and foraminal stenosis at L4-L5.

MRI findings clearly demonstrate elements of neural compression at both L3-L4 and L4-L5. However, the MRI may provide misleading information regarding the integrity of L3-L4 disc. The slices provided show well-maintained disc height and absences of Modic endplate changes. The MRI obtained in a supine position serves to minimize anterior translation suggested by the bending films.

Emphasis has been placed on evidence-based medicine. Unfortunately, in this clinical situation, there is limited evidence to support one operative treatment modality over another. Recent enthusiasm regarding minimally invasive procedures is couched in the surgeon's desire to create less patient morbidity via soft tissue disruption. It is our hope that reducing soft tissue disruption will improve patient recovery and limit iatrogenic instability. Minimally invasive direct lateral transposas lumbar interbody fusion and transforaminal lumbar interbody fusion are key components in the armamentarium of spine surgeons today. These procedures can be utilized separately or in combination.

Based on the information provided, I probably would offer a direct lateral procedure at L3-L4 with MIS TLIF at L4-L5. Due to my preference for indirect decompression, a formal laminotomy at L3-L4 would be held in abeyance. Anterior column support provided by the above procedures would be further stabilized via percutaneous posterior instrumentation.

Dr. Barry's decision to approach L4-L5 via DLIF demonstrates his comfort with the procedure. On plain radiographs, the L4-L5 disc space is below the iliac crest on both lateral and anteroposterior projections. Low riding L4-L5 discs can present difficulty for surgeons who chose the transpsoas approach. The benefits of an appropriate surgical procedure are clearly demonstrated by the patient's functional improvement in low back pain and neurologic symptoms.

Author's Response to Case Discussion

Christopher J. Barry, MD

Neurosurgeon

Neurological Services PLLC

Dr. Knight's comments are appreciated. A lateral approach can at times be difficult at L4-L5, particularly in males, usually due to a high riding iliac crest. As such, a TLIF at this level is certainly a good option.

*The NIM-ECLIPSE® System is manufactured by Axon, Inc. and distributed by Medtronic.

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