DOES THE SRS-22 OUTCOME QUESTIONNAIRE CORRELATE WITH RADIOLOGICAL OUTCOME FOLLOWING ANTERIOR CORRECTION OF THORACOLUMBAR SCOLIOSIS?

Abstract

Introduction: Patient questionnaires permit a direct measure of the value of care as perceived by the recipient. The Scoliosis Research Society outcomes questionnaire (SRS-22) has been validated as a tool for self-assessment. We investigated the correlation between SRS-22 and a detailed radiological outcome two-years following anterior correction of ThoracoLumbar Adolescent Idiopathic Scoliosis (TL-AIS).

Methods: The SRS-22 questionnaire was completed by 30 patients two-years following anterior correction of TL-AIS. Pre-operative, post-operative and two-year follow-up radiographs of all 30 patients were assessed. The following parameters were measured at each time point: 1) Primary Cobb angle, 2) Secondary Cobb angle, 3) Coronal C7-midsacral plumb line, 4) Apical Vertebra Translation (AVT) of primary curve, 5) AVT of the secondary curve, 6) Upper instrumented vertebra (UIV) translation, 7) UIV tilt angle, 8) Lower instrumented vertebra (LIV), 8) LIV tilt angle 9) Apical Vertebra Rotation (AVR) of the primary curve, 10) Sagittal C7-posterior corner of sacrum plumb line 11) T5–T12 angle, 12) T12-S1 angle, 13) shoulder height difference. The percentage improvements for each were noted. Correlation was sought between Total SRS score, each of the five individual domains and various radiographic parameters listed above by quantifying Pearson’s Correlation Coefficient (r).

Results: Percentage improvement in primary Cobb angle (r = 0.052), secondary Cobb angle (r = 0.165) and AVT of the primary curve (r = −0.353) showed little or no correlation with the SRS-22 total score or any of its five domains. Significant inverse correlation was found between the UIV tilt angle at two years and the SRS-22 (r = −0.516). Lateral radiographs however showed little or no correlation between thoracic kyphosis (r = 0.043) and SRS-22.

Conclusion: The SRS-22 outcomes questionnaire does not correlate with most of the radiographic parameters commonly used by clinicians to assess patient outcome.