Objective
To investigate stiffness-related disability (SRD) following surgical treatment in adolescent idiopathic scoliosis (AIS) patients particularly with respect to the lowest instrumented vertebra (LIV).
Summary of Background
Extensive spinal fusion inevitably results in loss of mobility which may induce SRD during activities of daily living. Few studies have examined SRD after surgical correction for AIS.
Methods
Patients who underwent surgical correction for AIS between 2014 and 2021 and were followed up for two years were included. The degree of SRD was evaluated using the Stiffness-Related Disability Index (SRDI) which consists of four categories, each containing three questions, giving a total of 12 components of the questionnaire.
The SRDI scores were compared according to the (LIV) levels. Correlation analysis was performed to examine the relationship between the SRDI and legacy health-related quality of life (HRQOL) measurements.
Results
This study included 174 patients (47 males, 127 females) with a mean age of 13.8 years. Among the 12 items of the SRDI, the scores of nine items showed a significant increase after surgery. The total sum of the SRDI scores also significantly increased after surgery. Pearson correlation analysis showed that the SRDI scores were significantly correlated with ODI (Oswestry disability index), nearly all domains, and the total sum of SRS-22 (Scoliosis Research Society-22 questionnaire), and SF-36 (Short Form 36 health questionnaire). No differences in the SRDI score were found among cases with the LIV between T12 and L3. However, The SRDI scores of patients with LIV at L4 were significantly higher than those of patients with other LIV levels. .
Conclusions
Various degree of SRD occurred after spinal fusion for AIS. The SRDI significantly correlated with the HRQOL measures. The SRDI score was highest in patients with the LIV at L4 compared to those with other LIV levels.
