Long-term pulmonary function outcomes in early onset scoliosis: A critical literature review.

Early-onset scoliosis (EOS) presents a unique clinical challenge due to its occurrence during critical phases of thoracic and pulmonary development. While growth-sparing strategies aim to preserve thoracic height and facilitate lung growth, their impact on long-term pulmonary function remains uncertain. This review synthesizes current evidence on long-term pulmonary outcomes in EOS, with emphasis on treatment modality, etiology, and prognostic factors. A structured narrative review was conducted using a systematic search of PubMed/MEDLINE, Scopus, and Embase, identifying 194 studies, of which 30 met inclusion criteria based on reporting objective pulmonary outcomes with a minimum two-year follow-up. Most included studies were retrospective and heterogeneous in design. Growth-sparing constructs consistently improved thoracic dimensions; however, these structural gains did not reliably translate into proportional improvements in pulmonary function, particularly when assessed using % predicted values. Delayed pulmonary improvement was observed in selected cohorts, especially with dual growing rod constructs, often manifesting beyond five years. Syndromic EOS, particularly Marfan syndrome, demonstrated persistent restrictive deficits despite intervention. Progressive airway obstruction emerged as an under recognized long-term complication, independent of restrictive physiology. Comparative studies suggest that pulmonary outcomes of growth-sparing surgery and definitive fusion may be comparable in older EOS patients; however, evidence remains limited. Overall, pulmonary outcomes in EOS are multifactorial and influenced by etiology, curve severity, age at intervention, and intrinsic lung development. Thoracic expansion alone does not guarantee functional pulmonary improvement, underscoring the importance of etiology-specific counseling and long-term respiratory monitoring.