Multi-Center Study Analyzing the Relationship of Standardized Radiographic Scoring System of AIS and the SRS Outcomes Instrument

San Diego Children's Hospital, San Diego, CA, USA

PURPOSE: To evaluate the relationship between an objective radiographic scoring system and of patient quality of life measures as determined by the SRS Outcomes Instrument. Studies to date of operative scoliosis have been unable to demonstrate such a relationship.

METHODS: A standardized radiographic deformity scoring system and the SRS outcome tool were used in seven scoliosis centers to collect data on patients with AIS. Data points for 280 patients consisting of those with non-operative curves greater or equal to 10 degrees as well as those with surgically treated curves were analyzed. Correlation analysis was performed to identify significant relationships between any of the radiographic measures, total radiographic deformity scores and the seven SRS outcome domains (total pain, general self image, post-op self image, post-op function, general function, activity and satisfaction) as well as SRS outcome total scores. Radiographic measures that were identified as significantly correlated with SRS outcome scores were then entered into a stepwise regression analysis.

RESULTS: The coronal measures of thoracic curve and lumbar curve magnitudes were found to be significantly correlated with the total pain (p ‹ 0.0001), general self-image (p ‹ 0.0001), general function (p ‹ 0.002), and total SRS scores (p ‹ 0.0001). The "coronal" radiographic deformity sub-score as well as the "total" radiographic deformity score were also significantly correlated with these SRS domain and total scores. No radiographic measures taken post-operatively were significantly correlated with the post-op domains of the SRS outcomes instrument. Stepwise regression analysis of these radiographic measures as predictors of SRS scores resulted in R Square values of .031 to .073 (p ‹ 0.0001). While these results show that a significant association exists between radiographic measures and SRS outcomes scores, the relatively low R Square values indicate that other variables (psychosocial) must also be affecting these scores.

CONCLUSIONS: The Cobb angle measure of the major deformity has a statistically significant correlation with the reported total pain, general self-image, and general function as measured by the SRS outcomes instrument. Although none of the radiographic measures in this population correlated with post-op self-image, post-op function, or activity, the SRS outcomes tool may be useful in assessing individual patients before and after surgery.