How the Assessment of Pelvic Tilt, Pelvic Incidence/Lumbar Lordosis Mismatch and Sagittal Vertical Axis Predicts Disability in Adult Spinal Deformity: A Prospective Analysis

Keywords: scoliosis, spinal fusion, spine surgery, pain, thoracic spine

Interactive Manuscript

Ask Questions of this Manuscript:



     Spino-pelvic parameters provide a more complete assessment of sagittal spinal malalignment (SSM) than sagittal vertical axis (SVA) alone. Little data has correlated spino-pelvic parameters with disability.
     The purpose was to evaluate correlations between sagittal spino-pelvic parameters and health related quality of life (HRQOL) scores.
     Inclusion criteria: age<18 and ASD (scoliosis<20°, SVA<5cm, pelvic tilt PT<25°, or thoracic kyphosis<60°).492 consecutive ASD patients (mean age=51.9, SD 16.8) were enrolled. 
     Demographic, radiographic, and HRQOL data were obtained from patients consecutively enrolled into a multi-center, prospective study evaluating operative (OP) vs. nonoperative (NON) treatment for adult spinal deformity (ASD). HRQOL questionnaires: Oswestry Disability Index (ODI), Scoliosis Research Society Questionnaire (SRS-22r). Radiographic parameters demonstrating highest correlation with HRQOL values were evaluated to determine a disability threshold of ODI?40.
     Patients treated OP (n=178) were older (55 vs. 50.1, p<0.05), had greater SVA (5.5 vs. 1.7cm, p<0.05), greater PT (22° vs. 11°, p<0.05) and greater pelvic incidence/ lumbar lordosis mismatch (PI-LL; 12.2 vs. 4.3; p<0.05) than NON (n=314). OP demonstrated greater disability on all HRQOL measures compared to NON (ODI =41.4 vs. 23.9, p<0.05; SRS total=2.9 vs. 3.5, p<0.05). Pearson analysis demonstrated PT, SVA, and PI-LL correlated most strongly with disability for both OP and NON patients (p<0.001). Linear regression models demonstrated threshold radiographic spino-pelvic parameters for ODI?40 included: PT?22° (r=0.38), SVA ?46 mm (r=0.47), PI-LL?11 (r=0.45).
     This is a prospective study.
     Prospective analysis of ASD patients demonstrated PT and PI-LL, combined with SVA, predict patient disability and provide a guide for patient assessment.
     Threshold values for severe disability included: PT?22°, SVA ?46mm, and PI-LL?11°.


Project Roles: