Investigating the long-term outcomes and efficacy of surgical intervention in patients with adolescent idiopathic scoliosis and Cobb angles ranging between 40 and 50 degrees.

Purpose: Patients with adolescent idiopathic scoliosis (AIS) are either managed with non-operative strategies or surgery depending on the severity of lateral curvature and impact on quality of life. However, supportive evidence for the appropriate treatment approach is lacking in AIS patients with Cobb angles between 40 and 50 degrees. Therefore, we investigated differences in long-term patient-centered outcomes in AIS patients with Cobb angles between 40 and 50 degrees who received either operative or non-operative management.

Methods: A total of 919 patients aged 10-21 years old with adolescent idiopathic scoliosis and 40-50 degree Cobb angles were identified from the HARMS Study Group (HSG) registry and dichotomized based on operative or non-operative management. Baseline and 2 year follow-up SRS-22 scores from these patients were analyzed for significant differences between the total score values, domain values, and the magnitude of score change over time using multiple comparisons analyses. Multivariable regressions adjusting for age, body mass index, location of spinal deformity, and management strategy were also performed.

Results: Operative versus non-operative strategy was significantly, independently associated with differences in SRS-22 total and domain scores over time (effect likelihood ratio test, p < 0.03 for all regressions). Operatively managed patients had significantly greater improvement in SRS-22 total and domain scores over the follow-up duration compared to non-operatively managed patients (p < 0.02 for all comparisons).

Conclusions: This preliminary analysis suggests that operatively managed patients may have had better long-term outcomes than non-operatively managed patients within this AIS subpopulation. These findings support the need for further prospective investigation to determine the optimal management strategy to improve evidence-based, patient-reported outcomes for AIS patients with Cobb angles between 40 and 50 degrees.

Level of evidence: Level III.