Work

Risk factors for insufficient segmental lordosis at the fused level following posterior lumbar interbody fusion: Effect of change in segmental lordosis in the intraoperative prone position

Year: 2026

Type: article

Abstract: Background A decrease in segmental lordosis (SL) at the fused level (ΔSL < 0) following posterior lumbar interbody fusion (PLIF) has been identified as a contributing factor to early-onset adjacent segment disease. However, achieving sufficient SL can be challenging despite technical strategies such as optimized cage placement. This study aimed to identify risk factors for ΔSL < 0 following PLIF, with a particular focus on intraoperative prone SL. Methods A total of 105 patients who underwent primary single-level PLIF at L4-5 for degenerative lumbar spondylolisthesis between 2017 and 2022 were included. Radiological evaluations included measurements of preoperative, intraoperative (prone position), and 1-week postoperative radiographs, as well as preoperative CT images. ΔSL-P was defined as the change in SL between preoperative standing and intraoperative prone positions. Patients were categorized into the ΔSL ≥ 0 and the ΔSL < 0 group. Patient demographics, preoperative radiological parameters, intraoperative SL, ΔSL-P, cage configuration, and the cage height–disc height ratio were compared between the 2 groups. Results The ΔSL ≥ 0 group comprised 48 patients, while the ΔSL < 0 group included 57. Multivariate analysis identified preoperative standing SL (OR 1.15, 95% CI 1.01–1.31, p=.033) and ΔSL-P (OR 0.66, 95% CI 0.53–0.82, p < .001) as significant risk factors for ΔSL < 0. Preoperative standing SL showed a significant negative correlation with ΔSL ( r = −0.591, p < .001), while ΔSL-P demonstrated a significant positive correlation with ΔSL ( r = 0.661, p < .001). Receiver operating characteristic curve analysis identified a ΔSL-P cutoff value of −1° for predicting ΔSL < 0 (AUC 0.84), sensitivity of 91% and specificity of 58%. Conclusions ΔSL-P was identified as the most significant risk factor for ΔSL < 0. A decrease in prone SL relative to the preoperative standing value may warrant careful attention.

Source: North American Spine Society Journal (NASSJ)

DOI: 10.1016/j.xnsj.2026.100850

Authors: Hiroyuki Ishiguro, Shota Takenaka, Masanori Kaneko, Hiroyuki Aono

Institutions: Osaka National Hospital, Osaka Hospital, Japan Community Healthcare Organization

Language: English

Topic: Spine and Intervertebral Disc Pathology

Subfield: Pathology and Forensic Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $1,950