Scoliosis after pectus excavatum correction: does it improve or worsen?

OBJECTIVES: Scoliosis is associated with pectus excavatum. However, the change in the degree of scoliosis after pectus excavatum correction has not been clarified. This study examined how the correction of pectus excavatum influences the status of pre-existing scoliosis. METHODS: A total of 779 pectus excavatum patients operated between 2007 and 2011 using the pectus bar were retrospectively analysed. Preoperative severity and postoperative change of scoliosis in accordance with the severity of pectus excavatum were evaluated. Cobb angle, Haller index and sternal tilt degree were measured from pre- and postoperative whole-spine anteroposterior radiographs and chest computed tomography. RESULTS: Sixty-three (8%) patients had scoliosis (Cobb angle > 10A degrees). No significant correlation was noted between postoperative changes in Cobb angle, Haller index or sternal tilt angle. Preoperative severity of scoliosis showed a positive correlation with postoperative changes in Cobb angle (r = 0.527, P < 0.001). In analyses between groups with mild and moderate scoliosis (Cobb angle < 15A degrees and > 15A degrees, respectively), the mean postoperative Cobb angle was decreased in mild scoliosis (-2.88A degrees) but was increased in moderate scoliosis (3.86A degrees; P < 0.001). Regarding the 'improvement' and 'aggravation' of scoliosis after pectus correction, preoperative severity of scoliosis was the only significant factor in univariable and multivariable analysis. CONCLUSIONS: Pectus excavatum repair using a pectus bar may improve scoliosis, but when the preoperative Cobb angle exceeds 15A degrees, scoliosis may be aggravated. Therefore, pectus excavatum with concomitant moderate scoliosis requires extra caution during repair. This preliminary result suggests further investigation into the effect of chest cage remodelling on spine dynamics.