A surgical treatment algorithm for restoring pelvic balance and health-related quality of life in high-grade lumbosacral spondylolisthesis

• Published in: Canadian Journal of Surgery Vol. 65; p. S147
• Main Authors: Mac-Thiong, Jean-Marc, Hresko, M Timothy, Alzakri, Abdulmajeed, Parent, Stefan, Sucato, Dan J, Lenke, Lawrence G, Marks, Michelle, Labelle, Hubert
• Format: Journal Article
• Language: English
• Published: Ottawa CMA Impact, Inc 01.12.2022
• Subjects: Algorithms; Pelvis; Quality of life; Surgery
• ISSN: 0008-428X; 1488-2310

Background: The purpose of this study is to propose an evidence-based surgical algorithm for achieving normal pelvic balance while optimizing health-related quality of life (HRQOL) in young patients with high-grade spondylolisthesis. Methods: This retrospective study assessed a multicentre cohort of 61 patients (aged 14.4 [standard deviation 2.7] yr) with high-grade L5-S1 spondylolisthesis followed for a minimum of 2 years after surgery. Classification and regression tree analysis was used to identify objective criteria associated with achieving a pelvic balance and HRQOL after surgery. Results: The most important predictor for achieving a balanced pelvis after surgery was a postoperative L5 incidence less than or equal to 63.5°. With a postoperative L5 incidence less than or equal 63.5°, preserving a residual slip percentage greater than 9%, and performing an L5-S1 posterior lumbar interbody fusion or transforaminal lumbar interbody fusion (PLIF/TLIF) increased the likelihood of achieving a balanced pelvis after surgery. When the L5 incidence was greater than 63.5°, a balanced pelvis was most likely observed with proximal extent of fusion limited to L5, residual slip percentage less than or equal to 40%, and residual lumbosacral angle greater than 98° between the L5 upper endplate and the posterior border of S1. Predictors of postoperative HRQOL scores were the preoperative HRQOL score, L5 incidence and slip percentage. Conclusion: A surgical algorithm is proposed to achieve normal pelvic balance, while optimizing HRQOL. The first step is to assess the L5 incidence, which integrates into a single parameter the lumbosacral kyphosis and abnormal pelvic morphology typically observed in high-grade spondylolisthesis. If L5 incidence is less than 65°, the next step will depend on preoperative pelvic balance. With a preoperative balanced pelvis, it is important not to reduce completely the slip percentage by leaving a residual slip percentage of 10% or greater. When the preoperative pelvis is unbalanced, performing a TLIF/PLIF at L5-S1 is strongly recommended because it will facilitate correcting the angular deformity at L5-S1. If L5 incidence is 65° or greater, a TLIF/PLIF at L5-S1 should also be carried out to correct the angular deformity at L5-S1, and fusion should ideally end at L5 proximally, in addition to performing gradual reduction of the slip percentage. If fusion up to L4 is required, achieving a lumbosacral angle of 100° or greater is key.