Coronal and sagittal radiographic parameters in degenerative scoliosis

English Keywords:Degenerative scoliosis  Sagittal plane  Radiography

English Abstract:

  【Abstract】 Objectives: To analyze the radiographic characteristics in degenerative scoliosis(DS), and to explore the radiograghic parameters which correlated to sagittal balance. Methods: Medical records of 99 DS patients were reviewed. Demographic data included age and sex. Radiographic data including the coronal Cobb angle, location of apical vertebra/disc, convexity of curve, degree of apical vertebra rotation, curve segments, thoracic kyphosis(TK), lumbar lordosis(LL), thoracolumbar kyphosis(TL), sacral slope(SS), pelvic tilt(PT), pelvic incidence(PI), sagittal vertical axis(SVA) and PI minus LL(PI－LL) were reviewed. Furthermore, patients were divided into 2 groups according to whether the patients′ sagittal plane was balanced or not: imbalanced group(group A) with SVA>5 cm, and balanced group(group B) with SVA≤5 cm. Demographic and radiological parameters were compared between the 2 groups. Results: A total of 99 patients were included in this study, including 83 females and 16 males. The age ranged from 41 to 92 years, and the mean age was 67 years. The median of coronal Cobb angle and length of curve were 23°(range, 10°-75°) and 5 segments(range, 3-7), respectively. The most common location of apical vertebra was at L2 to L3(81%) and the mean degree of apical vertebra rotation was Ⅱ°(range, Ⅰ°-Ⅲ°). The study also showed significant correlations between coronal Cobb angle and curve segments(r=0.23, P<0.005), coronal Cobb angle and degree of apical vertebra rotation(r=0.53, P<0.005). With regard to the sagittal balance, there were significant differences in age, LL, PT, coronal Cobb angle, degree of apical vertebra rotation and PI－LL between group A(33 patients) and group B(66 patients)(P<0.05); however, no significant difference was observed in gender, TK, TL, SS or PI(P＞0.05). Conclusions: Coronal Cobb angle is significant correlated to curve segments and degree of apical vertebra rotation in DS patients. Furthermore, age, coronal Cobb angle, LL, PT and PILL between sagittal balance and imbalance are significantly different.