Degenerative Spondylolisthesis: The Best Fixation is an Open Fusion with Hardware Options

1. Degenerative Spondylolisthesis:The Best Fixation is an Open Fusion with Hardware Options Colin B. Harris, MDAssistant Professor Department of Orthopaedics Rutgers – New Jersey Medical School Newark, NJ

2. Disclosures • Globus, Inc. – Consulting, teaching

3. Degenerative Spondylolisthesis • Common in older population

4. Degenerative Spondylolisthesis • Common in older population • “Source” of LBP

5. Degenerative Spondylolisthesis • Common in older population • “Source” of LBP • +/- Radiculopathy • +/- Neurogenic claudication

6. Degenerative Spondylolisthesis • Common in older population • “Source” of LBP • +/- Radiculopathy • +/- Neurogenic claudication • Usually L4-L5 > L3-L4 Conservative treatment 3-6 mo

8. Laminectomy + posterior fusion ALIF Laminectomy TLIF

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 Minimize cost and risk of complications

11. Why operate? • “Think Nerve”

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.

14. Decompression alone?

15. Decompression alone?

16. Decompression alone?

17. MIS TLIF? • Learning curve • Posterolateral fusion lacking • Long-term outcomes no better than open • Maybe: higher neurologic injury / CSF leak

18. “Trust me, I’m a doctor…”

19. “Trust me, I’m a doctor…”

20. “Trust me, I’m a doctor…”

21. “Trust me, I’m a doctor…”

22. ALIF / OLIF ? • High fusion rate • Large graft • Great operation

23. ALIF / OLIF ? • However… • Vascular injury 1-5% • Retrograde ejaculation • Revision difficult • Not easy at L4-L5

24. I’m a doctor too! Trust me…

25. I’m a doctor too! Trust me…

26. I’m a doctor too! Trust me…

27. I’m a doctor too! Trust me…

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

39. https://www2.aofoundation.org/wps/portal/

40. https://www2.aofoundation.org/wps/portal/

41. https://www2.aofoundation.org/wps/portal/

42. Pearls • Scrutinize axial cuts MRI/CT preop • Resect inferolateral corner suprajacent facet • Undertap by 1-2mm • Avoid burying screw head in facet

43. Cortical Screw Technique • More medial starting point • 30% greater pullout strength • Less soft tissue dissection • Ideal levels L3 – L4 – L5 (not for S1) Tortolani, Stroh JAAOS 24(11):755-61, 2016

44. Cortical Screw Technique

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

48. Thank you!