For a study, it was determined that the best treatment option for high-grade L5–S1 isthmic spondylolisthesis (HGS) was still up for debate. The impact of the decrease on clinical outcomes, the rate of pseudarthrosis, and postoperative foot drop were all important considerations. A study aimed to identify risk factors for foot drop and predict radiographic and clinical outcome factors after HGS surgery. The patients in this study were admitted for HGS, which was characterized as grade III or greater L5 translation according to the Meyerding (MD) classification. MD grade I or less was considered complete postoperative reduction, as was L5 slip of less than 20%. After two years of follow-up, 46 patients completed health-related quality-of-life questionnaires (Oswestry Disability Index, Physical Component Summary of SF-36, and visual analog scale) (average 105 months). In 61 patients, a 540° approach was employed by researchers, they used a 360° approach in 40, and an L5 corpectomy was used in 17. Measurements of global spinopelvic balance (e.g., pelvic incidence [PI], lumbar lordosis) as well as lumbosacral kyphosis angle (LSA), L4 slope (L4S), L5 slip (%), and postoperative rise in L5–S1 height were also included in the radiographic study.

The researchers looked at 101 patients who had been followed up clinically and radiographically for more than a year. The average age was 26. According to these parameters, the full reduction was achieved in 55 and 42 patients, respectively, with an average preoperative MD grade of 3.8 and an average L5 slip of 81 %. LSA was associated with all clinical outcomes during follow-up (r 0.4, P<0.05). A significant problem occurred in forty patients. Patients with more preoperative deformity (i.e., LSA) (P=0.04) and those who underwent L5 corpectomy (p<0.01) had a higher risk, which was connected with better deformity repair. The complete decrease was linked to a reduced risk of pseudarthrosis (P=0.08) and improved lumbar lordosis correction (P=0.03). About 30 patients experienced foot drop, which was associated with a higher MD grade and L5 slip (P<0.01), as well as a higher preoperative LSA (P<0.01). L5 corpectomy was more common in these patients with foot drop (P<0.01). Between patients with and without foot drop, there was a significant difference in preoperative L4S (P=0.02), LSA (P<0.01), and L5–S1 height (P=0.02). Foot drop was included as a dependent variable in a substantial risk model that included L4S change and PI as independent variables and foot drop as a dependent variable (82% negative predictive value and 71% positive predictive value, P<0.01). Degree of deformity (MD grade and L5 slip) and treatment of LSA were found to be significantly linked with foot drop, serious complications, and the need for revision surgery in a multivariable analysis. LSA correction was linked to a better functional outcome.