Introduction: High-grade L5-S1 spondylolisthesis is challenging to treat, with no standard recommended operative technique. The authors performed a systematic review of the literature to evaluate efficacy and safety of modern transsacral instrumentation techniques for high-grade L5-S1 spondylolisthesis. An example from their institution is provided.

Methods: A systematic PubMED search adherent to PRISMA guidelines included relevant clinical studies (English, 1980-2015) reporting transsacral instrumentation for high-grade spondylolisthesis in adult humans. Available data on clinical and radiographic outcomes for individual patients were abstracted.

Results: Nine of 311 studies reported a total of 38 patients (mean 32.9 years; range 18-66) treated with transsacral instrumentation. Cages (6 articles, n=23), screws (2 articles, n=12) and rods (1 article, n=3) were used. Posterior (86.8%) and combined anterior-posterior approaches were used, both with (55.2%) and without decompression, partial reduction (23.7%), posterior pedicle screw fixation (94.7%) and adjacent level inter-body fusion (42.1%). Four patients (10.5%) had a total of 6 complications (vascular, neurologic, infectious, or thrombotic), one of whom required a second operation. Mean follow-up time was 30.1 months (range 2-58; n=37). All studies with outcomes reported at least some improvement in pain in all patients (n=32) and at least average function post-operatively (94.7%; n=33/35). All reported patients had adequate fusion on follow-up imaging (n=34) and no progression of slip (n=32). Case Illustration: A 31-year-old woman with Grade IV L5-S1 spondylolisthesis presented with back pain, L5 radiculopathy, saddle anesthesia and urinary retention. She underwent L5-S2 laminectomies, L4-L5-S1-iliac instrumented fusion and L5-S1 transsacral interbody cage placement without perioperative complications. Her numbness and radiculopathy improved. Adequate bony fusion without slip progression was achieved.

Conclusions: Operative techniques for managing high-grade L5-S1 spondylolisthesis are evolving. In this systematic review, modern transsacral instrumentation resulted in good clinical outcome and fusion rates, and acceptably high complication rates. Risks and benefits should be individualized for each patient.

Patient Care: This systematic review provides neurosurgeons with synthesized evidence from the primary literature regarding the safety and efficacy of transsacral instrumentation for patients with high-grade L5-S1 spondylolisthesis that has not previously been explored in detail.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe various operative techniques for treating high-grade L5-S1 spondylolisthesis using modern transsacral instrumentation 2) Evaluate the safety and efficacy of transsacral instrumentation in L5-S1 spondylolisthesis in the adult population.

References: Abdu WA, Wilber RG, Emery SE: Pedicular transvertebral screw fixation of the lumbosacral spine in spondylolisthesis. A new technique for stabilization. Spine 19:710-715, 1994. 2. Agabegi SS, Fischgrund JS: Contemporary management of isthmic spondylolisthesis: pediatric and adult. The spine journal : official journal of the North American Spine Society 10:530-543, 2010. 3. Ani N, Keppler L, Biscup RS, Steffee AD: Reduction of high-grade slips (grades III-V) with VSP instrumentation. Report of a series of 41 cases. Spine 16:S302-310, 1991. 4. Bartolozzi P, Sandri A, Cassini M, Ricci M: One-stage posterior decompression-stabilization and trans-sacral interbody fusion after partial reduction for severe L5-S1 spondylolisthesis. Spine 28:1135-1141, 2003. 5. Bohlman HH, Cook SS: One-stage decompression and posterolateral and interbody fusion for lumbosacral spondyloptosis through a posterior approach. Report of two cases. The Journal of bone and joint surgery American volume 64:415-418, 1982. 6. Boxall D, Bradford DS, Winter RB, Moe JH: Management of severe spondylolisthesis in children and adolescents. The Journal of bone and joint surgery American volume 61:479-495, 1979. 7. Bozkus H, Dickman CA: Transvertebral interbody cage and pedicle screw fixation for high-grade spondylolisthesis. Case report. Journal of neurosurgery 100:62-65, 2004. 8. Curylo LJ, Edwards C, DeWald RW: Radiographic markers in spondyloptosis: implications for spondylolisthesis progression. Spine 27:2021-2025, 2002. 9. DeWald CJ, Vartabedian JE, Rodts MF, Hammerberg KW: Evaluation and management of high-grade spondylolisthesis in adults. Spine 30:S49-59, 2005. 10. Hanson DS, Bridwell KH, Rhee JM, Lenke LG: Dowel fibular strut grafts for high-grade dysplastic isthmic spondylolisthesis. Spine 27:1982-1988, 2002. 11. Harris IE, Weinstein SL: Long-term follow-up of patients with grade-III and IV spondylolisthesis. Treatment with and without posterior fusion. The Journal of bone and joint surgery American volume 69:960-969, 1987. 12. Helenius I, Lamberg T, Osterman K, Schlenzka D, Yrjonen T, Tervahartiala P, Seitsalo S, Poussa M, Remes V: Posterolateral, anterior, or circumferential fusion in situ for high-grade spondylolisthesis in young patients: a long-term evaluation using the Scoliosis Research Society questionnaire. Spine 31:190-196, 2006. 13. Huang RP, Bohlman HH, Thompson GH, Poe-Kochert C: Predictive value of pelvic incidence in progression of spondylolisthesis. Spine 28:2381-2385; discussion 2385, 2003. 14. Kasliwal MK, Smith JS, Kanter A, Chen CJ, Mummaneni PV, Hart RA, Shaffrey CI: Management of high-grade spondylolisthesis. Neurosurgery clinics of North America 24:275-291, 2013. 15. Kasliwal MK, Smith JS, Shaffrey CI, Saulle D, Lenke LG, Polly DW, Jr., Ames CP, Perra JH: Short-term complications associated with surgery for high-grade spondylolisthesis in adults and pediatric patients: a report from the scoliosis research society morbidity and mortality database. Neurosurgery 71:109-116, 2012. 16. Labelle H, Roussouly P, Berthonnaud E, Transfeldt E, O'Brien M, Chopin D, Hresko T, Dimnet J: Spondylolisthesis, pelvic incidence, and spinopelvic balance: a correlation study. Spine 29:2049-2054, 2004. 17. Lakshmanan P, Ahuja S, Lewis M, Howes J, Davies PR: Transsacral screw fixation for high-grade spondylolisthesis. The spine journal : official journal of the North American Spine Society 9:1024-1029, 2009. 18. Lamberg T, Remes V, Helenius I, Schlenzka D, Seitsalo S, Poussa M: Uninstrumented in situ fusion for high-grade childhood and adolescent isthmic spondylolisthesis: long-term outcome. The Journal of bone and joint surgery American volume 89:512-518, 2007. 19. Lenke LG, Bridwell KH, Bullis D, Betz RR, Baldus C, Schoenecker PL: Results of in situ fusion for isthmic spondylolisthesis. Journal of spinal disorders 5:433-442, 1992. 20. Lonstein JE: Spondylolisthesis in children. Cause, natural history, and management. Spine 24:2640-2648, 1999. 21. Peek RD, Wiltse LL, Reynolds JB, Thomas JC, Guyer DW, Widell EH: In situ arthrodesis without decompression for Grade-III or IV isthmic spondylolisthesis in adults who have severe sciatica. The Journal of bone and joint surgery American volume 71:62-68, 1989. 22. Rodriguez-Olaverri JC, Zimick NC, Merola A, Vicente J, Rodriguez J, Tabuenca A, Loste A, Sunen E, Burgos J, Hevia E, Piza-Vallespir G: Comparing the clinical and radiological outcomes of pedicular transvertebral screw fixation of the lumbosacral spine in spondylolisthesis versus unilateral transforaminal lumbar interbody fusion (TLIF) with posterior fixation using anterior cages. Spine 33:1977-1981, 2008. 23. Sailhan F, Gollogly S, Roussouly P: The radiographic results and neurologic complications of instrumented reduction and fusion of high-grade spondylolisthesis without decompression of the neural elements: a retrospective review of 44 patients. Spine 31:161-169; discussion 170, 2006. 24. Shedid D, Weil AG, Lieberman I: A novel minimally invasive technique for the treatment of high-grade isthmic spondylolisthesis using a posterior transsacral rod. Journal of spinal disorders & techniques 27:E41-48, 2014. 25. Shufflebarger HL, Geck MJ: High-grade isthmic dysplastic spondylolisthesis: monosegmental surgical treatment. Spine 30:S42-48, 2005. 26. Smith JA, Deviren V, Berven S, Kleinstueck F, Bradford DS: Clinical outcome of trans-sacral interbody fusion after partial reduction for high-grade l5-s1 spondylolisthesis. Spine 26:2227-2234, 2001. 27. Smith JS, Saulle D, Chen CJ, Lenke LG, Polly DW, Jr., Kasliwal MK, Broadstone PA, Glassman SD, Vaccaro AR, Ames CP, Shaffrey CI: Rates and causes of mortality associated with spine surgery based on 108,419 procedures: a review of the Scoliosis Research Society Morbidity and Mortality Database. Spine 37:1975-1982, 2012. 28. Transfeldt EE, Mehbod AA: Evidence-based medicine analysis of isthmic spondylolisthesis treatment including reduction versus fusion in situ for high-grade slips. Spine 32:S126-129, 2007. 29. Weiss HR, Goodall D: Rate of complications in scoliosis surgery - a systematic review of the Pub Med literature. Scoliosis 3:9, 2008.