Philosophies and Surgical Techniques for High-Grade Spondylolisthesis Treatment with Literature Review.

Introduction:High-grade spondylolisthesis is defined as cases with more than 50% displacement and spondylolisthesis with Meyerding grade III and higher. The surgical management of high-grade spondylolisthesis is highly controversial. Many surgical methods have been reported such as posterior in situ fusion, instrumented posterior fusion with or without reduction, combined anterior and posterior procedures, spondylectomy with reduction of L4 to the sacrum (for spondyloptosis), and posterior interbody fusion with trans-sacral fixation. The literature has recently mentioned minimally invasive transforaminal lumbar interbody fusion for high-grade spondylolisthesis. This study aimed to review the recent literature that describes the surgical outcomes associated with various surgical techniques used for high-grade spondylolisthesis. Materials and Methods:Recent articles were searched on search engines such as PubMed and Google Scholar using keywords such as "high-grade spondylolisthesis," "surgical techniques," and "complications." Discussion:The surgical management of high-grade spondylolisthesis is an area of significant controversy. The literature is replete with regards to the need for reduction, decompression, levels of fusion, the nature of instrumentation, surgical approaches including open, minimally invasive, and "mini-open" procedures, and various techniques for reducing the slip and fusion strategy. The three basic options of high-grade spondylolisthesis include in-situ fusion, partial reduction and fusion, and complete reduction. Conclusion:Various techniques have been described for high-grade spondylolisthesis. Spine deformity study group classification gives guidelines about balanced and unbalanced pelvis and advises reduction and fusion in case of unbalanced pelvis for correction of biomechanical and global sagittal alignment. Each of the surgical techniques has its advantages and disadvantages. However, individual authors' experience, skill levels, and anatomic reduction with fusion techniques have yielded encouraging results.