1. Degenerative Spondylolisthesis:
The Best Fixation is an Open Fusion
with Hardware Options
Colin B. Harris, MD
Assistant Professor
Department of Orthopaedics
Rutgers – New Jersey Medical School
Newark, NJ
6. Degenerative Spondylolisthesis
• Common in older population
• “Source” of LBP
• +/- Radiculopathy
• +/- Neurogenic claudication
• Usually L4-L5 > L3-L4
Conservative treatment 3-6 mo
9. To simplify: GOALS OF SURGERY
• Thorough decompression to address leg pain
and neurogenic claudication
• Stable fusion to prevent slip progression
• +/- improve lower back pain
10. To simplify: GOALS OF SURGERY
• Thorough decompression to address leg pain
and neurogenic claudication
• Stable fusion to prevent slip progression
• +/- improve lower back pain
12. Why operate?
• “Successful surgical management of isolated
lower back pain for degenerative conditions is
a gamble at best”
13. Laminectomy without fusion
• Reasonable for elderly / low
functioning, “stable” slip
– Not for young & active
– Risk recurrent back/leg pain
– Inferior outcomes vs
laminectomy and fusion
Herkowitz and Kurz 1991
Herkowitz H, Kurz L. JBJS Am 1991;73(6):802-8.
30. Open posterior
decompression and fusion
• Withstood test of time
• Significant benefits
– Allows thorough decompression
– Full exposure to posterolateral fusion bed
– Good long term outcomes
– Avoid morbidity of anterior / lateral approaches
31. • 76 patients non-instrumented vs instrumented single
level lami and fusion for DS
• 2 year follow up
• Instrumented group 82% fused (vs 45%)
• No significant difference in clinical outcomes
32. • Prospective, randomized study n=47
• Decompression + fusion with iliac crest autograft (no
instrumentation)
• Avg. F/U = 7 years, 8 months
• Excellent to good clinical outcome
– 86% with solid fusion vs. 56% pseudoarthrosis
• Conclusion: Patients with solid fusion do better
33. What do we know?
Patients with solid fusion do better
34. What do we know?
Patients with solid fusion do better
Instrumentation improves fusion rates
35. What do we know?
Patients with solid fusion do better
Instrumentation improves fusion rates
Addition of instrumentation BENEFICIAL despite
difficulty proving better outcomes in high
quality studies
36. What are our options
• Traditional pedicle screws
• Interspinous devices
• Cortical screw technique
37. Open pedicle screw technique
• Gold standard
• Safe
• Familiar to most surgeons
• Cons
– Need for larger soft tissue
dissection
– Risk of nerve injury / screw
malposition
– Add operative time and blood loss
38. Open pedicle screw technique
• Gold standard
• Safe
• Familiar to most surgeons
• Cons
–Need for larger soft tissue
dissection
– Risk of nerve injury / screw
malposition
– Suboptimal in osteopenic bone
45. Cortical Screw Technique
• Cons
– Learning curve
– Difficult to redirect after initial trajectory
– Difficult to perform posterolateral grafting
46. Interspinous Devices
• “Inter Spinous Fusion”
– Coflex-F
– Minuteman
• Minimally invasive
• Require preservation of
spinous processes
• Data limited to small case
series
47. Conclusions
• Open decompression and fusion remains gold
standard
• Role of newer techniques continues to evolve
• Key points
– Thorough decompression
– Meticulous graft bed preparation
– Choose best fixation technique in your hands
