Purpose: The present study aimed to determine whether obtaining adequate lumbar (LL) or segmental (SL) lordosis during instrumented TLIF for one-level degenerative spondylolisthesis affects midterm clinical outcome.
Methods: The study was designed as a prospective one, including 57 patients who underwent single-level TLIF surgery for degenerative spondylolisthesis. Patients were analyzed globally with additional subgroup analysis according to pelvic incidence (PI). Radiographic analysis of spinopelvic sagittal parameters was conducted pre- and postoperatively. Clinical examination including ODI score was performed preoperatively, 1 and 5 years postoperatively.
Results: Significant improvement in ODI scores at 1 and 5 years postoperatively (p < 0.001) was demonstrated. There was a significant correlation between anterior shift of SVA and failure to improve SL (p = 0.046). Moreover, anterior SVA shift correlated with increased values of ODI score both 1 and 5 years postoperatively. In low-PI group, failure to correct LL correlated with high ODI scores 5 years postoperatively (r = - 0.499, p = 0.005).
Conclusions: Failure to correct segmental lordosis during surgery for one-level degenerative spondylolisthesis resulted in anterior displacement of the center of gravity, which in turn correlated with unfavorable clinical outcome 1 and 5 years postoperatively. In patients with low PI, failure to maintain lumbar lordosis correlated with unfavorable clinical outcome 5 years after surgery.
Level of evidence: II. These slides can be retrieved under Electronic Supplementary Material.
Keywords: Clinical outcomes; Degenerative spondylolisthesis; Sagittal balance; Segmental lordosis; TLIF.