Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P33. The prevalence of L4-5 degenerative spondylolisthesis in females: role of spinal sagittal alignment and lumbopelvic morphology

Abstract

BACKGROUND CONTEXT L4/5 degenerative spondylolisthesis (L4DS) is a common radiographic finding and predisposing factors, such as increased lumbar lordosis (LL), pelvic incidence (PI), L5 vertebral slope, and sagittal orientation of the facet joint have been reported. Among female subjects aged >65years, prevalence of L4DS was reported to be 29%, which was 1.3- to 6.4-fold higher than male subjects. However, there are few studies investigating the factors associated with the gender difference of L4DS. PURPOSE The purpose of this study is to clarify radiographic factors of L4DS with a focus on gender-specific difference in spinal sagittal alignment and lumbopelvic morphology. STUDY DESIGN/SETTING This is a prospective study. PATIENT SAMPLE Consecutive 110 patients with symptomatic lumbar canal stenosis (LCS) who underwent upright whole spine X-ray imaging, myelography, CT and MRI between 2012 and 2017 were reviewed, and those with L4/5 LCS 5% anterior slip) were excluded. A final total of 86 subjects were included, and L4DS were found in 51; 30 females (L4DSF, 70.1±8.9 years) and 21 males (L4DSM, 69.7±10.4 years), and LCS was found in 35; 12 females (LCSF, 76.8±6.4 years) and 21 males (LCSM, 67.8±8.8 years). OUTCOME MEASURES Radiographic measurement included LL, PT, L5 slope, S1 slope (SS), sagittal vertical axis (SVA), pelvic incidence (PI), disc height (DH; average of anterior and posterior disc height), L4/5 facet orientation (FOR; the angle between bilateral facet by CT), L4/5 facet osteoarthritis (FOA; grade 1 normal to grade 4 severe OA by CT), and L4/5 disc degeneration (Pfirrmann grading by MRI). METHODS In these parameters, the significant differences between LCS and L4DS in female and male were evaluated. ANOVA was used for statistical analyses and significance level was set at p RESULTS Following parameters showed significant differences; PT between gender (female 21.2±9.3, male 17.2±7.5, p=.03) and between L4DS and LCS (L4DS 20.7±8.6, LCS 16.9±8.2, p=.040), LL between L4DSF and LCSF (L4DSF 42.7±11.7, LCSF 34.5±12.0, p=.048), L5 slope between L4DS and LCS༈L4DS 16.5±7.5, LCS 13.0±9.0, p=.049; L4DSF 16.9±9.1, LCSF 8.2±11.3, p=.002), L4/5 FOR between L4DS and LCS ༈L4DS 61.7±17.9, LCS 80.2±15.0, p CONCLUSIONS L4DS showed female predominance even among symptomatic LCS patients. L4/5 FOR and FOA were associated with L4DS regardless of gender, however, influence of sagittal alignment and lumbopelvic morphology were more prevalent among female patients than male counterpart, which might explain gender difference of DS incidence. Current study substantiated previous studies using multimodal evaluations, and further studies of muscle strength, joint laxity, and other clinical factors might be necessary for understanding gender-specific incidence of DS.