Spino-pelvic sagittal parameters in middle-aged and elderly Chinese: measurements and correlationship

English Keywords:Middle-aged and elderly  Sagittal alignment  Lumbar lordosis  Linear regression

English Abstract:

  【Abstract】 Objectives: To analyze the spino-pelvic sagittal parameters and their correlationship in middle-aged and elderly Chinese, and to establish a prediction between lumber lordosis and the other parameters. Methods: This study was a radiological analysis. Anteroposterior and lateral radiographs of the whole spine were taken in 106 Chinese volunteers, including 48 males and 58 females, aged from 55 to 76 years(average 62.4±5.2 years). Pelvic and spinal parameters including pelvic incidence(PI), pelvic tilt(PT), sacral slope(SS), lumbar lordosis(LL), thoracic kyphosis(TK), sagittal vertical axis(SVA), upper arc of total lumbar lordosis(UALL), lower arc of total lumbar lordosis(LALL) were measured by using picture archiving and communication systems. The correlations of all parameters were analyzed, and which were compared to the parameters in younger volunteers. A multifactor regression analysis was conducted by using the lumbar lordosis (dependent variable) and the other spino-pelvic parameters(independent variables) to determine the best sets of predictors. Results: Radiograhic measurements: PI, PT, SS, LL, UALL, LALL, TK, SVA were 46.5°±7.6°, 13.1°±6.6°, 32.3°±9.5°, 49.2°±9.1°, 15.9°±5.9°, 32.3°±9.5°, 34.0°±10.7° and -5.0±30mm respectively. LL was significantly correlated with PI, SS, TK and SVA (P<0.05), PT was significantly correlated with TK and SS. Compared with young people, PI, SS, LL and LALL had no significant difference(P>0.05), however, PT, TK, SVA and UALL had significant differences(P<0.01). Based on a multifactor regression analysis, LL predictive equation was LL=0.6PI+0.4TK+10°, R2=0.375. Conclusions: The spino-pelvic sagittal parameters have a clear correlation in middle-aged and elderly Chinese. There exists obvious difference in the spine and pelvis sagittal parameters such as TK, UALL, PT, SVA between the old and the young. By using the formula LL=0.6PI+0.4TK+10°, LL of the middle-aged and elderly can be ideally predicted.