Impact of the Preoperative Spinopelvic Parameters on the Segmental Lordosis Correction after One-level Lateral Lumbar Interbody Fusion

Objectives  The present study aimed to assess whether preoperative spinopelvic parameters can influence the gain of segmental lordosis after one level of lateral lumbar interbody fusion. Methods  The following radiological parameters were measured in the X-rays: pelvic incidence, lumbar lordosis, pelvic tilt, L4S1 lordosis, index level segmental lordosis, intraoperative index segmental lordosis, pelvic mismatch (IP-LL), distal lordosis proportion, delta segmental lordosis, Pelvic Titlt (PT) > 20, actual sacral slope, and ideal sacral slope, and the correlation of these variables with the gain of segmental lordosis was investigated. Afterwards, an exploratory cluster analysis was performed to identify common characteristics between patients and segmental lordosis gain. Results  The sample of the present study comprised 104 patients, of which 76% presented segmental lordosis gain. The most correlated parameters with the segmental lordosis gain were preoperative segmental lordosis (-0.50) and delta intraoperative lordosis (0.51). Moreover, patients in the high PI groups had a trend to gain more segmental lordosis ( p  < 0.05) and a reduced risk of losing segmental lordosis (Odds 6.08). Conclusion  Patients with low-medium PI profiles presented higher odds of loss of segmental lordosis. However, the preoperative spinopelvic parameters alone do not seem to play a significant role in the fate of segmental lordosis gain.