Which early onset scoliosis patients have improved pulmonary function 2 years after surgical intervention?

PURPOSE: To identify variables associated with good (improved or stable) outcomes in pulmonary function tests (PFT) at least 2 years after initial surgical intervention for early onset scoliosis (EOS).

METHODS

This was a multi-site retrospective review of EOS patients with PFTs preoperative and minimum 2 years postoperative. Clinical, radiographic, and PFT data were collected. Treatment types included definitive fusion (DF) and growth-friendly (GF). Forced vital capacity (FVC) ≥ 80% defined normal lung function. Penalized logistic regression analysis identified variables associated with a good outcome, defined as FVC ≥ 80% or if < 80%, then stable/improved > 10%. A poor outcome was defined as FVC < 80% or deterioration > 10%.

RESULTS

215 patients (191 GF, 24 DF) averaged 46 months follow-up. Etiology included (N) neuromuscular (29%), (I) idiopathic (27%), (C) congenital (24%), and (S) syndromic (20%). At index surgery, average age was 8.4 years, major curve 74°, and FVC 67%. Only 33% had initial FVC ≥ 80%, which decreased to 22% at 2-year follow-up (p < 0.001). Good PFT outcomes were found in 54% of patients. Good PFT outcomes were identified in I (32%) versus N (24%), C (23%) and S (21%) (p = 0.041), unrestricted vs. limited ambulation (81 vs. 19%, p = 0.015), and DF versus GF (92 vs. 60%, p = 0.003).

CONCLUSION

Half of the patients had improved or stable PFT postoperatively. Patients with an idiopathic etiology, lower baseline FVC%, unrestricted ambulation, and those who had definitive fusion at index surgery were more likely to have good outcomes.