Spinal Fusion in Prader-Willi Syndrome: Early Radiographic Outcomes and Complications With a Subset Analysis of Two-year Follow-up in a Multicenter Cohort.

BACKGROUND: Prader-Willi syndrome (PWS) is a rare genetic disorder characterized by hypotonia, obesity, and endocrine dysfunction. Scoliosis affects over 70% of patients and frequently requires surgical treatment. Despite recognition of PWS as a high-risk syndromic population, contemporary multicenter data describing radiographic outcomes, complications, and unplanned return to the operating room (UPROR) after spinal fusion remain limited. METHODS: Prospectively collected multicenter registry data were retrospectively reviewed for patients with PWS who underwent spinal fusion. Variables included demographics, body mass index (BMI), age at surgery, prior treatments, growth hormone therapy, radiographic parameters, EOSQ-24 outcomes, perioperative complications, and UPROR. Analyses were primarily descriptive, with paired statistical comparisons limited to complete data pairs. Associations between BMI and complications or reoperations were assessed with negative binomial regression. RESULTS: Twenty-three patients were included, with a mean age at surgery of 11.9±2.5 years and a mean follow-up of 1.5±1.8 years. A subset of 10 patients with >2 years follow-up (mean 3.0±1.4 y) was analyzed for durability. Among 21 patients, 76.2% had prior treatment (bracing, halo, casting), and 61.9% used growth hormone therapy. Mean major Cobb angle improved from 76.8±21.1 degrees preoperatively to 35.4±16.3 degrees postoperatively (55.8% improvement, P<0.001), with maintenance at final follow-up. Mean kyphosis improved from 69.5±27.6 degrees to 48.4±17.9 degrees postoperatively (22.7% improvement, P=0.001) and remained stable. Nine complications occurred in 5 patients (21.7%), with 6 UPROR in 4 patients (17.4%), at a median of 41 days postoperatively (IQR 0 to 484). Higher BMI was associated with more complications (P=0.03). EOSQ-24 data (n=10) demonstrated the greatest improvements in satisfaction and pulmonary function. CONCLUSION: Spinal fusion in patients with PWS provides durable deformity correction with early functional improvement, but carries a higher risk of perioperative complications and early UPROR. The combined impact of sagittal deformity and obesity highlights the need for risk-focused counseling and careful perioperative planning in this population. LEVEL OF EVIDENCE: Level IV-case series.