BACKGROUND: The differences in etiology, clinical manifestation, and whole body standing alignment between single-level LDS (sLDS) and double-level LDS (dLDS) have not been sufficiently clarified. We hypothesized that the etiology and manifestations of dLDS differ from those of sLDS. This study aimed to test this hypothesis. METHODS: A total of 112 cases with sLDS, 25 cases with dLDS, and 50 healthy volunteers as a normal control were enrolled in the study. Following the data collection on demographic and Health-related quality of life (HRQOL) by ODI and SRS-22, radiologic measurement by EOS system and MRI examination including lumbar spinal stenosis (LSS), facet angle, and segmental instability defined by facet opening were performed. All the parameters were compared among the groups. Correlations among radiologic parameters and HRQOL were analyzed. Risk factors for sLDS and dLDS were investigated respectively using multivariate logistic analysis. RESULTS: Age is the most important etiologic factor of sLDS; whereas high PI, age, and sagittally oriented facet joints are the important factors for dLDS. HRQOL significantly correlates with sagittal alignment. HRQOL does not, however, significantly differ between patients with sLDS and dLDS. Although the mean value of %slip was higher in the dLDS group than in the sLDS group, the difference was not statistically significant. %slip positively correlated with the PI. The number of spinal stenoses (LSS) per patient is significantly higher in patients with dLDS than in patients with sLDS. The HRQOL does not, however, correlate with the number of LSS. CONCLUSIONS: Age is the most important etiologic factor of sLDS; whereas high PI, age, and sagittally oriented facet joints are the important factors for dLDS. HRQOL does not significantly differ between patients with sLDS and dLDS. Number of LSS is significantly higher in dLDS than in sLDS without statistical difference in terms of HRQOL outcome.
BACKGROUND: The differences in etiology, clinical manifestation, and whole body standing alignment between single-level LDS (sLDS) and double-level LDS (dLDS) have not been sufficiently clarified. We hypothesized that the etiology and manifestations of dLDS differ from those of sLDS. This study aimed to test this hypothesis. METHODS: A total of 112 cases with sLDS, 25 cases with dLDS, and 50 healthy volunteers as a normal control were enrolled in the study. Following the data collection on demographic and Health-related quality of life (HRQOL) by ODI and SRS-22, radiologic measurement by EOS system and MRI examination including lumbar spinal stenosis (LSS), facet angle, and segmental instability defined by facet opening were performed. All the parameters were compared among the groups. Correlations among radiologic parameters and HRQOL were analyzed. Risk factors for sLDS and dLDS were investigated respectively using multivariate logistic analysis. RESULTS: Age is the most important etiologic factor of sLDS; whereas high PI, age, and sagittally oriented facet joints are the important factors for dLDS. HRQOL significantly correlates with sagittal alignment. HRQOL does not, however, significantly differ between patients with sLDS and dLDS. Although the mean value of %slip was higher in the dLDS group than in the sLDS group, the difference was not statistically significant. %slip positively correlated with the PI. The number of spinal stenoses (LSS) per patient is significantly higher in patients with dLDS than in patients with sLDS. The HRQOL does not, however, correlate with the number of LSS. CONCLUSIONS: Age is the most important etiologic factor of sLDS; whereas high PI, age, and sagittally oriented facet joints are the important factors for dLDS. HRQOL does not significantly differ between patients with sLDS and dLDS. Number of LSS is significantly higher in dLDS than in sLDS without statistical difference in terms of HRQOL outcome.