Background Data: Surgical management for high-grade spondylolisthesis is challenging and associated with high morbidity. There are many surgical techniques available for lumbosacral fixation and correction that differ in approaches and outcomes. The main concern during surgery is to decompress the neural element, correct focal kyphotic deformity, and restore or maintain global sagittal alignment.
Purpose: The purpose of this study was to present a case series of patients with high-grade spondylolisthesis who were treated with reduction and fixation and compare the results to in situ fusion technique.
Study Design: Retrospective observational study.
Patients and Methods: We retrospectively reviewed patients with L5/S1 high-grade spondylolisthesis who underwent surgery at our institute in the period between March 2013 and March 2017. Patient's demographic, preoperative, and postoperative data were collected. Taillard's technique and Meyerding's grade for spondylolisthesis were assessed for all cases. Additionally, we measured the pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) pre- and postoperatively. The Bridwell grading system was used to assess the degree of radiographic fusion. Preoperative and postoperative clinical outcomes were evaluated using Visual Analog Scale (VAS) and the Oswestry Disability Index (ODI). Complication rates were collected during the follow-up period.
Results: We included 16 cases in the current study. Patients were divided into two groups: reduction group includes nine patients, and in situ group includes seven. There was no significant difference in demographics or radiological data between groups. Moreover, operative data demonstrated comparable results between the two groups (P<0.05). Reduction group showed significant increase in L5 palsy compared to the in situ fusion group (0.037), although reduction showed more significant changes regarding correction of deformity (PT and SS). Both techniques were efficient in relieving pain and improving disability at 3-month and last follow-up visits (P<0.001).
Conclusion: The present study showed that both reduction and in situ fusion techniques are effective surgical tools in improving clinical outcomes for patients with L5/S1 high-grade spondylolisthesis. Attempt of complete reduction carries a high risk of L5 nerve root injury. Partial reduction under complete L5 nerve root decompression and visualization is crucial in reducing risk of injury. However, reduction technique demonstrated superior deformity correction at the index level of spondylolisthesis. (2019ESJ181)