Relationship between sagittal radiographic parameters and disability in patients with spinal disease using 3D standing analysis.

PURPOSE

To clarify the relationship between whole body sagittal radiographic parameters and health related quality of life (HRQOL) in patients with spinal disease, and further analyse such relationship based on the pelvic incidence (PI) value.

METHODS

100 patients (mean age: 64.4 years, M/F=50/50) with lumbar degenerative disease or spinal deformity were prospectively investigated. Following oswestry disability index (ODI) and scoliosis research society score 22 (SRS-22) questionnaire, whole body sagittal x-ray parameters were measured using a slot-scanning 3D x-ray imager (EOS). Correlations between such radiographic parameters and ODI/SRS-22 scores were analysed. Then, patients were divided into three groups based on the PI value (PI≤45°, 45<PI≤60°, and 60<PI), and correlations between the significantly correlated parameters and ODI/SRS-22 scores were analysed for each PI group.

RESULTS

C2-7 lordosis, pelvic tilt (PT), pelvic incidence (PI), PI minus lumbar lordosis (PI-LL), sagittal vertical axis (SVA), full balance integrated index (FBI), and knee flexion angle (KneeFlex) had a significant correlation with ODI or SRS-22 scores. Among those parameters, PI and FBI showed a significant correlation with both ODI and SRS-22 scores. High PI (>60°) group showed a strong correlation (R>0.4) with both ODI and SRS-22 scores for PI-LL parameter.

CONCLUSIONS

PI and FBI showed a significant correlation with both ODI and SRS-22 scores. PI-LL mismatch was strongly correlated with disability in high PI patients. Our study results may indicate that it is important to pay attention to the PI value in addition to the spinopelvic relationship.

LEVEL OF EVIDENCE

II, prospective study.