O2094: Sublaminar Bands vs. Pedicle Screws for Posterior Spinal Instrumentation and Fusion. a Comparison of Preoperative SRS-22 Scores in Predicting Postoperative Achievement of MCID

Background: There is a growing body of literature assessing the role of preoperative patient-reported outcome measures in predicting postoperative achievement of the minimal clinically important difference (MCID). Sublaminar bands (SLB) and pedicle screws (PS) have been compared across a number of parameters for posterior spinal instrumentation and fusion in patients with adolescent idiopathic scoliosis. However, to the best of our knowledge, there are no studies assessing which surgical technique is better for predicting postoperative achievement of MCID. Our purpose is to determine if one surgical technique is superior to the other in this regard.

Methods: SRS-22 forms were provided to all patients scheduled to undergo posterior spinal instrumentation and fusion. MCID was calculated using distribution-based methods. Receiver operator characteristic (ROC) area under the curve (AUC) analysis was performed to assess the predictive probability of SRS-22 scores in predicting postoperative achievement of MCID across both surgical techniques.

Results: Of 98 patients with preoperative SRS-22 data, 82 (83.7%) completed SRS-22 surveys at 1 year postoperatively. Sixty-six (82.5%) patients were female, average age was 14.9 ± 1.9 years, and average preoperative Cobb angle was 60.0 ± 8.9 degrees. 48 patients were treated with PS and 34 were treated with SLB. Each surgery type had the follow AUCs:

Global PS: 0.74 (p=0.008)

Global SLB: 0.78 (p=0.01)

Function PS: 0.90 (p < 0.001)

Function SLB: 0.84 (p=0.002)

Pain PS: 0.82 (p < 0.001)

Pain SLB: 0.75 (p=0.050)

Mental Health PS: 0.91 (p < 0.001)

Mental Health SLB: 0.78 (p=0.008)

Satisfaction PS: 0.91 (p < 0.001)

Satisfaction SLB: 0.79 (p=0.01)

There were no significant differences in score change, preoperative Cobb angle, or preoperative score between groups.

Conclusion: Though preoperative SRS-22 scores can predict postoperative achievement of MCID for sublaminar bands and pedicle screws, preoperative scores in patients treated with pedicle screws appear to have superior predictive power with the function, mental health, and satisfaction domains having outstanding predictive ability. AUC analysis for pedicle screws revealed one SRS-22 domain with acceptable predictive ability, one with excellent predictive ability, and three with outstanding predictive ability. Among patients treated with sublaminar bands, four domains had acceptable predictive ability, and one had excellent predictive ability. Clinicians can use preoperative SRS-22 scores to predict postoperative achievement of MCID in patients treated with sublaminar bands or pedicle screws.