Standing in Schroth trained position significantly changes Cobb angle and leg length discrepancy: a pilot study.

Study Design: Retrospective.

Objective: The aim of this study is to evaluate if standing in a Schroth trained position influences the radiographic assessment of Cobb angle and other radiographic parameters compared to a normal standing position. Schroth method has been associated with improved Cobb angle. This study aims to evaluate if standing in the Schroth trained position influences radiographic assessment of Cobb angle compared to a normal standing position.

Methods: This is a retrospective review of patients with adolescent idiopathic scoliosis (AIS) who were participating in Schroth therapy at the time of radiographs. Ten pairs of radiographs were included in this study. Each pair consisted of two micro-dose biplanar PA thoracolumbar spine radiographs obtained on the same day, one with the patient standing in the Schroth trained position and one in their normal standing position. Each pair of radiographs was independently evaluated by three attending pediatric spine surgeons for Cobb angle, coronal balance, shoulder balance, and leg length discrepancy, for a total of 30 paired readings (3 readings for each of the 10 pairs of radiographs).

Results: Major Cobb angle was a mean of 6° less (p = 0.02) and the compensatory curve was 5° less (p = 0.03) in the Schroth trained position compared to their normal standing position. Neither coronal balance (p = 0.40) nor shoulder balance (p = 0.16) was significantly different. Mean leg length discrepancy was 6.8 mm greater in the Schroth trained versus normal position (p < 0.001).

Conclusion: Standing in a Schroth trained position for a PA spine radiograph was associated with a mean change in major Cobb angle of 6° compared to a normal standing position. If bracing was recommended for curves > 25° and surgery for curves > 45°, different treatment recommendations would have been made in 33% (10/30) of attendings' readings for the Schroth versus normally paired radiographs taken on the same day on the same patient. Studies evaluating the effect of Schroth therapy on Cobb angle must report if patients are standing in a normal or Schroth trained position during radiographs for conclusions to be valid, or differences may be due to a temporary, voluntary change in posture.

Level Of Evidence: III.