Perioperative Vitamin D Repletion is Associated With Improvement in SRS-22r Function Scores in Pediatric Patients With Idiopathic Scoliosis Undergoing Posterior Spinal Fusion and Instrumentation

Background: The aims of this study were to assess the differences in preoperative Scoliosis Research Society 22r (SRS-22r) questionnaire scores, two-year postoperative SRS-22r scores, and the change in SRS-22r scores from preoperatively to two years postoperatively between patients with idiopathic scoliosis (IS) undergoing spinal fusion with instrumentation (PSFI) who were vitamin D sufficient and vitamin D deficient preoperatively. Methods: This was a retrospective review of patients with juvenile and adolescent IS aged 11 to 20 years who underwent PSFI from 2018 to 2022 with a minimum of 2-year follow-up. Patients with vitamin D levels <30 ng/mL were considered deficient and repleted with vitamin D3 800 to 2000 international units (IU) daily or 50,000 IU weekly. Variables were compared between vitamin D deficient and sufficient groups with Wilcoxon or two‑sample t tests. Linear regression was used to assess the relationship between preoperative major curve and vitamin D levels. Results: Forty-seven patients were included. Twenty-five patients (53%) were vitamin D deficient. The mean preoperative vitamin D levels were 21±6 ng/mL in the deficient group and 41±14 ng/mL in the sufficient group ( P <0.001). Pre-operatively, vitamin D deficient patients had lower SRS‑22r function scores than sufficient patients (4.4 vs. 4.6; P =0.020), while two-year postoperative scores were similar. When comparing preoperative to postoperative subdomains, function, management, pain and self-image scores all improved in the vitamin D deficient group, while management and self-image scores improved in the vitamin D sufficient group. Linear regression demonstrated a weak inverse relationship between vitamin D levels and preoperative major curve size (β=−0.178; r=−0.35; P =0.016). Conclusions: In patients undergoing PSFI for IS, vitamin D deficient patients had lower preoperative SRS-22r function scores compared with vitamin D sufficient patients. After perioperative repletion and PSFI, vitamin D deficient patients experienced improvement in their function score and achieved similar 2-year postoperative SRS-22r function scores compared with sufficient patients. Our findings strongly support preoperative vitamin D screening and perioperative vitamin D repletion in IS patients undergoing PSFI. Level of Evidence: Level III—retrospective case control study.