Adult scoliosis: classification based on the L3-L5 segment - Abstract
1.1. Study Design: Retrospective review of a case series. 1.2. Objective: Define objective parameters to differentiate between Adults Degenerative Scoliosis (ADS), and Adult Idiopathic Scoliosis (AdIS). These are at the L3-L5 segment. 1.3. Methods: A series of 53 adult scoliosis (mean age 55 y.o., median 57 y.o. range: 20-84 y.o.), was studied. Variables: age, curve parameters (Cobb, end vertebra), coronal and sagittal balance, spinopelvic parameters, and L3-L5 parameters (distance from the center of the disc to CSVL, and endplate coronal tilt). Statistical study: R package software, some variables not normal distribution, non-parametric tests. Approved by the IRB. 1.4. Results: Distance of L3-L4 disc (18 mm; 2-52) showed a bimodal distribution that also correlated to spinopelvic parameters: if 15mm or less, then PT 22º±8º; if > 15 mm, then PT 32º±17º (p=0.04 U Mann-Whitney). L4 endplate tilt inversely correlates to SS (Pearson -0.3; p<0.01), and positively to PT (Pearson 0.4;p=0.002) L3-L5 segment helps differentiate ADS from AdIS. 1.5. Conclusions: Distance of the center of the disc L3-L4 to the central sacral line is an objective parameter to differentiate ADS from AdIS. It also correlates with compensatory mechanisms (PT), with statistical differences in PT between types of adult scoliosis.