Radiographic analysis of the results of anterior internody arthrodesis on the sagittal lumbopelvic parameters/ Análise radiográfica dos resultados da artrodese intersomática anterior sobre os parâmetros lombopélvicos sagitais/ Análisis radiográfico de los resultados de la artrodesis intersomática anterior sobre los parámetros lumbopélvicos sagitales

ABSTRACT Objective The objective of this study is to analyze the radiographs of patients who underwent anterior lumbar interbody fusion (ALIF), to compare the values of the lumbopelvic measurements, and to quantify improvements in these parameters achieved through this technique. Methods The radiographs of 42 patients, all submitted to ALIF with a 12° interbody device, were evaluated from a database at a single center. The pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, segmental lordosis, and regional lordosis angles of each patient were measured in pre- and postoperative radiographs. Results We observed a discreet change in the pelvic parameters and a marked increase in regional lordosis with a mean increase of 5.8° (p>0.001). Segmental lordosis also showed a mean increase of 2.43°. The gain in segmental lordosis was even higher in patients with degenerative spondylolisthesis and when the operated level was L5-S1. Conclusions The ALIF technique in the lumbar spine is capable of significantly increase the lordosis of a segment, whether at one or two levels. Greater improvement in the lumbopelvic parameters was observed it the procedures performed in level L5-S1 and in cases that presented spondylolisthesis.