Morphometric analysis of iatrogenic breast asymmetry secondary to operative breast shape changes in thoracic adolescent idiopathic scoliosis

Abstract

Purpose: Spontaneous surgical alterations of the distorted surface shape of thoracic cage in adolescent idiopathic scoliosis (AIS) may relocate and remodel the bilateral breast mounds. The purpose of this study was to analyze the influence of scoliosis correction surgery on female breast morphology and to identify the risk factors for iatrogenic breast asymmetry secondary to operative breast shape changes in AIS. Methods: Thoracic AIS girls undergoing correction surgery were reviewed. Ten parameters concerning morphometric and CT evaluations of breast profile and symmetry were measured. The degree of asymmetry was determined and comparisons were made for evaluation of operative breast shape changes. The morphologically aggravated breast asymmetry would be considered if the concave and convex difference of either sternal notch-nipple length or sternal notch-nipple tilt angle increased post-operatively. Potential risk factors for iatrogenic breast asymmetry were identified. Results: Sixty-eight AIS girls were reviewed. The concave breasts showed significantly more linear and less angular changes in morphological parameters post-operatively (p < 0.05). The concave and convex difference was significantly increased in morphological parameters and yet decreased in radiographic parameters. Ratio of aggravated morphological breast asymmetry was 61.2 %, and this patient group trended to have a minor pre-operative breast asymmetry though the difference was not statistically significant (p > 0.05). Moreover, patients with apex located at or above T7 showed greater changes in both morphological and radiographic dimensions as compared with those with apex beneath T7 (p < 0.05). Conclusion: The incidence of aggravated post-operative breast asymmetry is notable. Those with higher thoracic apex level, combined with minor pre-operative breast asymmetry, were at relatively higher risk of iatrogenic breast asymmetry aggravation post-operatively. Moreover, discrepancy existed between the morphometric and radiographic parameters concerning the surgical influence on breast asymmetry.