O2076: Limited Fusion for Congenital Scoliosis: Is it Truly One and Done?

Background: Limited spinal fusion is a common surgical strategy in the treatment of congenital scoliosis. Due to the heterogeneity of deformity and treatment strategies, long term outcomes, including the need for additional surgery, are poorly understood. The purpose of the study was to understand the rate and risk factors for reoperation following limited fusion for congenital scoliosis. We hypothesized that larger preoperative curve magnitudes would be associated with the need for reoperation following limited fusion for congenital scoliosis.

Methods: Congenital scoliosis patients initially treated with a limited instrumented fusion at a tertiary pediatric medical center were reviewed for clinical and radiographic data. Curve progression, complications, and the surgical details were compared between patients who underwent additional surgery and patients who did not require additional surgery. Risk factors for reoperation were compared between groups.

Results: 35 patients underwent limited instrumented fusion at an average age of 4.9 years (SD: 2.5). The mean number of levels fused was 3.5 (SD: 1.3). Index surgery location included: thoracic (46%), thoracolumbar (31%), lumbar (17%), and lumbosacral (6%). Average follow-up was 7.6 years (range: 2.2-14.1, SD: 3.4). Average curve magnitude improved from 51° to 30°, with a mean improvement of 21° (range: 11° to 50°, SD: 15°, p=0.002). Eighteen patients (51%) required reoperation at a mean of 5.2 years, with a mean of 1.8 (SD: 3.0) additional surgeries. Preoperative curve magnitude was greater in patients who had reoperation compared to patients who did not require reoperation (66.7±20.3 vs 34.2±6.7, p< 0.001). Pre-operative curves ≥ 45° had a 94% (17/18) reoperation rate compared to only 6% (1/17) in curves < 45°, odds ratio of 272 (95% CI: [15.7,4724.2], p< 0.0001). Additionally, constructs that did not span the upper and lower end vertebrae were associated with greater need for additional surgery (58.8% vs 40.0%, p = 0.04). Age at index surgery, medical comorbidities, addressing all congenital anomalies during index procedure, number of levels fused, and location of surgery did not differ between groups (Table 1).

Conclusion: Limited fusion for congenital scoliosis resulted in a 51% reoperation rate at a mean of 5.2 years. The results suggest that limited fusion should be considered prior to the curve reaching 45º and instrumentation should span the entire deformity to minimize the need for reoperation.